__init__.py 95.9 KB
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# SPDX-License-Identifier: Apache-2.0
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# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
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import contextlib
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import datetime
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import enum
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import gc
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import getpass
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import hashlib
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import importlib
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import importlib.metadata
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import importlib.util
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import inspect
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import ipaddress
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import json
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import multiprocessing
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import os
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import pickle
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import signal
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import socket
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import subprocess
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import sys
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import tempfile
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import textwrap
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import threading
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import time
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import traceback
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import types
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import uuid
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import warnings
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import weakref
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from argparse import (
    Action,
    ArgumentDefaultsHelpFormatter,
    ArgumentParser,
    ArgumentTypeError,
    RawDescriptionHelpFormatter,
    _ArgumentGroup,
)
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from collections import UserDict, defaultdict
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from collections.abc import (
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    Callable,
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    Collection,
    Generator,
    Hashable,
    Iterable,
    Iterator,
    Mapping,
    Sequence,
)
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from concurrent.futures.process import ProcessPoolExecutor
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from dataclasses import dataclass, field
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from functools import cache, lru_cache, partial, wraps
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from pathlib import Path
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from typing import (
    TYPE_CHECKING,
    Any,
    Generic,
    Literal,
    TextIO,
    TypeVar,
)
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from urllib.parse import urlparse
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from uuid import uuid4
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import cbor2
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import cloudpickle
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import numpy as np
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import numpy.typing as npt
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import psutil
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import regex as re
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import setproctitle
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import torch
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import torch.types
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import yaml
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import zmq
import zmq.asyncio
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from packaging import version
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from packaging.version import Version
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from torch.library import Library
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from typing_extensions import Never, TypeIs, assert_never
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import vllm.envs as envs
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from vllm.logger import enable_trace_function_call, init_logger
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from vllm.ray.lazy_utils import is_in_ray_actor
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if TYPE_CHECKING:
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    from argparse import Namespace

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    from vllm.config import ModelConfig, VllmConfig
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    from vllm.sequence import IntermediateTensors
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else:
    Namespace = object

    ModelConfig = object
    VllmConfig = object
    IntermediateTensors = object
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logger = init_logger(__name__)

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# This value is chosen to have a balance between ITL and TTFT. Note it is
# not optimized for throughput.
DEFAULT_MAX_NUM_BATCHED_TOKENS = 2048
POOLING_MODEL_MAX_NUM_BATCHED_TOKENS = 32768
MULTIMODAL_MODEL_MAX_NUM_BATCHED_TOKENS = 5120

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# Constants related to forcing the attention backend selection

# String name of register which may be set in order to
# force auto-selection of attention backend by Attention
# wrapper
STR_BACKEND_ENV_VAR: str = "VLLM_ATTENTION_BACKEND"

# Possible string values of STR_BACKEND_ENV_VAR
# register, corresponding to possible backends
STR_FLASHINFER_ATTN_VAL: str = "FLASHINFER"
STR_TORCH_SDPA_ATTN_VAL: str = "TORCH_SDPA"
STR_XFORMERS_ATTN_VAL: str = "XFORMERS"
STR_FLASH_ATTN_VAL: str = "FLASH_ATTN"
STR_INVALID_VAL: str = "INVALID"

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MB_bytes = 1_000_000
"""The number of bytes in one megabyte (MB)."""

MiB_bytes = 1 << 20
"""The number of bytes in one mebibyte (MiB)."""

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GB_bytes = 1_000_000_000
"""The number of bytes in one gigabyte (GB)."""

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GiB_bytes = 1 << 30
"""The number of bytes in one gibibyte (GiB)."""

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# ANSI color codes
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CYAN = "\033[1;36m"
RESET = "\033[0;0m"
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STR_DTYPE_TO_TORCH_DTYPE = {
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    "float32": torch.float32,
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    "half": torch.half,
    "bfloat16": torch.bfloat16,
    "float": torch.float,
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    "fp8": torch.uint8,
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    "fp8_e4m3": torch.uint8,
    "fp8_e5m2": torch.uint8,
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    "int8": torch.int8,
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    "fp8_inc": torch.float8_e4m3fn,
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    "fp8_ds_mla": torch.uint8,
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}
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TORCH_DTYPE_TO_NUMPY_DTYPE = {
    torch.float16: np.float16,
    torch.float32: np.float32,
    torch.float64: np.float64,
    torch.uint8: np.uint8,
    torch.int32: np.int32,
    torch.int64: np.int64,
}

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@contextlib.contextmanager
def set_default_torch_num_threads(num_threads: int):
    """Sets the default number of threads for PyTorch to the given value."""
    old_num_threads = torch.get_num_threads()
    torch.set_num_threads(num_threads)
    yield
    torch.set_num_threads(old_num_threads)


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T = TypeVar("T")
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U = TypeVar("U")
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_K = TypeVar("_K", bound=Hashable)
_V = TypeVar("_V")
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class Device(enum.Enum):
    GPU = enum.auto()
    CPU = enum.auto()


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class LayerBlockType(enum.Enum):
    attention = "attention"
    mamba = "mamba"


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class Counter:
    def __init__(self, start: int = 0) -> None:
        self.counter = start

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    def __next__(self) -> int:
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        i = self.counter
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        self.counter += 1
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        return i
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    def reset(self) -> None:
        self.counter = 0
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@cache
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def get_max_shared_memory_bytes(gpu: int = 0) -> int:
    """Returns the maximum shared memory per thread block in bytes."""
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    from vllm import _custom_ops as ops
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    max_shared_mem = ops.get_max_shared_memory_per_block_device_attribute(gpu)
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    # value 0 will cause MAX_SEQ_LEN become negative and test_attention.py
    # will fail
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    assert max_shared_mem > 0, "max_shared_mem can not be zero"
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    return int(max_shared_mem)


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def get_cpu_memory() -> int:
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    """Returns the total CPU memory of the node in bytes."""
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    return psutil.virtual_memory().total
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def random_uuid() -> str:
    return str(uuid.uuid4().hex)
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def close_sockets(sockets: Sequence[zmq.Socket | zmq.asyncio.Socket]):
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    for sock in sockets:
        if sock is not None:
            sock.close(linger=0)


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def get_ip() -> str:
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    host_ip = envs.VLLM_HOST_IP
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    if "HOST_IP" in os.environ and "VLLM_HOST_IP" not in os.environ:
        logger.warning(
            "The environment variable HOST_IP is deprecated and ignored, as"
            " it is often used by Docker and other software to"
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            " interact with the container's network stack. Please "
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            "use VLLM_HOST_IP instead to set the IP address for vLLM processes"
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            " to communicate with each other."
        )
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    if host_ip:
        return host_ip

    # IP is not set, try to get it from the network interface

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    # try ipv4
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    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
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    try:
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        s.connect(("8.8.8.8", 80))  # Doesn't need to be reachable
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        return s.getsockname()[0]
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    except Exception:
        pass

    # try ipv6
    try:
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        s = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM)
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        # Google's public DNS server, see
        # https://developers.google.com/speed/public-dns/docs/using#addresses
        s.connect(("2001:4860:4860::8888", 80))  # Doesn't need to be reachable
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        return s.getsockname()[0]
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    except Exception:
        pass

    warnings.warn(
        "Failed to get the IP address, using 0.0.0.0 by default."
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        "The value can be set by the environment variable"
        " VLLM_HOST_IP or HOST_IP.",
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        stacklevel=2,
    )
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    return "0.0.0.0"
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def test_loopback_bind(address, family):
    try:
        s = socket.socket(family, socket.SOCK_DGRAM)
        s.bind((address, 0))  # Port 0 = auto assign
        s.close()
        return True
    except OSError:
        return False


def get_loopback_ip() -> str:
    loopback_ip = envs.VLLM_LOOPBACK_IP
    if loopback_ip:
        return loopback_ip

    # VLLM_LOOPBACK_IP is not set, try to get it based on network interface

    if test_loopback_bind("127.0.0.1", socket.AF_INET):
        return "127.0.0.1"
    elif test_loopback_bind("::1", socket.AF_INET6):
        return "::1"
    else:
        raise RuntimeError(
            "Neither 127.0.0.1 nor ::1 are bound to a local interface. "
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            "Set the VLLM_LOOPBACK_IP environment variable explicitly."
        )
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def is_valid_ipv6_address(address: str) -> bool:
    try:
        ipaddress.IPv6Address(address)
        return True
    except ValueError:
        return False


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def split_host_port(host_port: str) -> tuple[str, int]:
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    # ipv6
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    if host_port.startswith("["):
        host, port = host_port.rsplit("]", 1)
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        host = host[1:]
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        port = port.split(":")[1]
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        return host, int(port)
    else:
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        host, port = host_port.split(":")
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        return host, int(port)


def join_host_port(host: str, port: int) -> str:
    if is_valid_ipv6_address(host):
        return f"[{host}]:{port}"
    else:
        return f"{host}:{port}"


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def get_distributed_init_method(ip: str, port: int) -> str:
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    return get_tcp_uri(ip, port)


def get_tcp_uri(ip: str, port: int) -> str:
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    if is_valid_ipv6_address(ip):
        return f"tcp://[{ip}]:{port}"
    else:
        return f"tcp://{ip}:{port}"
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def get_open_zmq_ipc_path() -> str:
    base_rpc_path = envs.VLLM_RPC_BASE_PATH
    return f"ipc://{base_rpc_path}/{uuid4()}"


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def get_open_zmq_inproc_path() -> str:
    return f"inproc://{uuid4()}"


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def get_open_port() -> int:
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    """
    Get an open port for the vLLM process to listen on.
    An edge case to handle, is when we run data parallel,
    we need to avoid ports that are potentially used by
    the data parallel master process.
    Right now we reserve 10 ports for the data parallel master
    process. Currently it uses 2 ports.
    """
    if "VLLM_DP_MASTER_PORT" in os.environ:
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        dp_master_port = envs.VLLM_DP_MASTER_PORT
        reserved_port_range = range(dp_master_port, dp_master_port + 10)
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        while True:
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            candidate_port = _get_open_port()
            if candidate_port not in reserved_port_range:
                return candidate_port
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    return _get_open_port()

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def get_open_ports_list(count: int = 5) -> list[int]:
    """Get a list of open ports."""
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    ports = set[int]()
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    while len(ports) < count:
        ports.add(get_open_port())
    return list(ports)


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def _get_open_port() -> int:
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    port = envs.VLLM_PORT
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    if port is not None:
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        while True:
            try:
                with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
                    s.bind(("", port))
                    return port
            except OSError:
                port += 1  # Increment port number if already in use
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                logger.info("Port %d is already in use, trying port %d", port - 1, port)
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    # try ipv4
    try:
        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
            s.bind(("", 0))
            return s.getsockname()[1]
    except OSError:
        # try ipv6
        with socket.socket(socket.AF_INET6, socket.SOCK_STREAM) as s:
            s.bind(("", 0))
            return s.getsockname()[1]
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def find_process_using_port(port: int) -> psutil.Process | None:
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    # TODO: We can not check for running processes with network
    # port on macOS. Therefore, we can not have a full graceful shutdown
    # of vLLM. For now, let's not look for processes in this case.
    # Ref: https://www.florianreinhard.de/accessdenied-in-psutil/
    if sys.platform.startswith("darwin"):
        return None

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    our_pid = os.getpid()
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    for conn in psutil.net_connections():
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        if conn.laddr.port == port and (conn.pid is not None and conn.pid != our_pid):
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            try:
                return psutil.Process(conn.pid)
            except psutil.NoSuchProcess:
                return None
    return None


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def update_environment_variables(envs: dict[str, str]):
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    for k, v in envs.items():
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        if k in os.environ and os.environ[k] != v:
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            logger.warning(
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                "Overwriting environment variable %s from '%s' to '%s'",
                k,
                os.environ[k],
                v,
            )
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        os.environ[k] = v
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def chunk_list(lst: list[T], chunk_size: int):
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    """Yield successive chunk_size chunks from lst."""
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    for i in range(0, len(lst), chunk_size):
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        yield lst[i : i + chunk_size]
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def cdiv(a: int, b: int) -> int:
    """Ceiling division."""
    return -(a // -b)


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def next_power_of_2(n) -> int:
    """The next power of 2 (inclusive)"""
    if n < 1:
        return 1
    return 1 << (n - 1).bit_length()


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def prev_power_of_2(n: int) -> int:
    """The previous power of 2 (inclusive)"""
    if n <= 0:
        return 0
    return 1 << (n.bit_length() - 1)


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def round_up(x: int, y: int) -> int:
    return ((x + y - 1) // y) * y


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def round_down(x: int, y: int) -> int:
    return (x // y) * y


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def _generate_random_fp8(
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    tensor: torch.Tensor,
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    low: float,
    high: float,
) -> None:
    # NOTE(zhaoyang): Due to NaN and Inf representation for fp8 data type,
    # it may occur Inf or NaN if we directly use torch.randint
    # to generate random data for fp8 data.
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    # For example, s.11111.00 in fp8e5m2 format represents Inf.
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    #     | E4M3        | E5M2
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    # -----|-------------|-------------------
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    # Inf | N/A         | s.11111.00
    # NaN | s.1111.111  | s.11111.{01,10,11}
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    from vllm import _custom_ops as ops
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    tensor_tmp = torch.empty_like(tensor, dtype=torch.float16)
    tensor_tmp.uniform_(low, high)
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    ops.convert_fp8(tensor, tensor_tmp)
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    del tensor_tmp


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def get_kv_cache_torch_dtype(
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    cache_dtype: str | torch.dtype | None,
    model_dtype: str | torch.dtype | None = None,
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) -> torch.dtype:
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    if isinstance(cache_dtype, str):
        if cache_dtype == "auto":
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            if isinstance(model_dtype, str) and model_dtype in STR_DTYPE_TO_TORCH_DTYPE:
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                torch_dtype = STR_DTYPE_TO_TORCH_DTYPE[model_dtype]
            elif isinstance(model_dtype, torch.dtype):
                torch_dtype = model_dtype
            else:
                raise ValueError(f"Invalid model dtype: {model_dtype}")
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        elif cache_dtype in STR_DTYPE_TO_TORCH_DTYPE:
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            torch_dtype = STR_DTYPE_TO_TORCH_DTYPE[cache_dtype]
        else:
            raise ValueError(f"Invalid kv cache dtype: {cache_dtype}")
    elif isinstance(cache_dtype, torch.dtype):
        torch_dtype = cache_dtype
    else:
        raise ValueError(f"Invalid kv cache dtype: {cache_dtype}")
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    return torch_dtype


def create_kv_caches_with_random_flash(
    num_blocks: int,
    block_size: int,
    num_layers: int,
    num_heads: int,
    head_size: int,
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    cache_dtype: str | torch.dtype | None,
    model_dtype: str | torch.dtype | None = None,
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    seed: int | None = None,
    device: str | None = "cuda",
    cache_layout: str | None = "NHD",
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) -> tuple[list[torch.Tensor], list[torch.Tensor]]:
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    from vllm.platforms import current_platform
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    current_platform.seed_everything(seed)
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    dtype = get_kv_cache_torch_dtype(cache_dtype, model_dtype)
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    generic_kv_cache_shape = (num_blocks, 2, block_size, num_heads, head_size)
    assert cache_layout in ("NHD", "HND")
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    stride_order = (0, 1, 2, 3, 4) if cache_layout == "NHD" else (0, 1, 3, 2, 4)
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    kv_cache_allocation_shape = tuple(generic_kv_cache_shape[i] for i in stride_order)
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    scale = head_size**-0.5
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    key_caches: list[torch.Tensor] = []
    value_caches: list[torch.Tensor] = []
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    for _ in range(num_layers):
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        key_value_cache = torch.empty(
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            size=kv_cache_allocation_shape, dtype=dtype, device=device
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        ).permute(*stride_order)
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        if cache_dtype in ["auto", "half", "bfloat16", "float"]:
            key_value_cache.uniform_(-scale, scale)
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        elif cache_dtype == "fp8":
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            _generate_random_fp8(key_value_cache, -scale, scale)
        else:
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            raise ValueError(f"Does not support key cache of type {cache_dtype}")
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        key_caches.append(key_value_cache[:, 0])
        value_caches.append(key_value_cache[:, 1])
    return key_caches, value_caches


def create_kv_caches_with_random(
    num_blocks: int,
    block_size: int,
    num_layers: int,
    num_heads: int,
    head_size: int,
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    cache_dtype: str | torch.dtype | None,
    model_dtype: str | torch.dtype | None = None,
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    seed: int | None = None,
    device: str | None = "cuda",
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) -> tuple[list[torch.Tensor], list[torch.Tensor]]:
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    if cache_dtype == "fp8" and head_size % 16:
        raise ValueError(
            f"Does not support key cache of type fp8 with head_size {head_size}"
        )
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    from vllm.platforms import current_platform
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    current_platform.seed_everything(seed)
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    dtype = get_kv_cache_torch_dtype(cache_dtype, model_dtype)
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    scale = head_size**-0.5
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    x = 16 // torch.tensor([], dtype=dtype).element_size()
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    key_cache_shape = (num_blocks, num_heads, head_size // x, block_size, x)
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    key_caches: list[torch.Tensor] = []
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    for _ in range(num_layers):
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        key_cache = torch.empty(size=key_cache_shape, dtype=dtype, device=device)
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        if cache_dtype in ["auto", "half", "bfloat16", "float"]:
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            key_cache.uniform_(-scale, scale)
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        elif cache_dtype == "fp8":
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            _generate_random_fp8(key_cache, -scale, scale)
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        else:
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            raise ValueError(f"Does not support key cache of type {cache_dtype}")
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        key_caches.append(key_cache)

    value_cache_shape = (num_blocks, num_heads, head_size, block_size)
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    value_caches: list[torch.Tensor] = []
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    for _ in range(num_layers):
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        value_cache = torch.empty(size=value_cache_shape, dtype=dtype, device=device)
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        if cache_dtype in ["auto", "half", "bfloat16", "float"]:
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            value_cache.uniform_(-scale, scale)
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        elif cache_dtype == "fp8":
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            _generate_random_fp8(value_cache, -scale, scale)
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        else:
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            raise ValueError(f"Does not support value cache of type {cache_dtype}")
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        value_caches.append(value_cache)
    return key_caches, value_caches
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@cache
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def is_pin_memory_available() -> bool:
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    from vllm.platforms import current_platform
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    return current_platform.is_pin_memory_available()
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@cache
def is_uva_available() -> bool:
    """Check if Unified Virtual Addressing (UVA) is available."""
    # UVA requires pinned memory.
    # TODO: Add more requirements for UVA if needed.
    return is_pin_memory_available()


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class DeviceMemoryProfiler:
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    def __init__(self, device: torch.types.Device | None = None):
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        self.device = device

    def current_memory_usage(self) -> float:
        # Return the memory usage in bytes.
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        from vllm.platforms import current_platform
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        gc.collect()
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        return current_platform.get_current_memory_usage(self.device)
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    def __enter__(self):
        self.initial_memory = self.current_memory_usage()
        # This allows us to call methods of the context manager if needed
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.final_memory = self.current_memory_usage()
        self.consumed_memory = self.final_memory - self.initial_memory

        # Force garbage collection
        gc.collect()
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def make_ndarray_with_pad(
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    x: list[list[T]],
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    pad: T,
    dtype: npt.DTypeLike,
    *,
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    max_len: int | None = None,
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) -> npt.NDArray:
    """
    Make a padded array from 2D inputs.
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    The padding is applied to the end of each inner list until it reaches
    `max_len`.
    """
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    if max_len is None:
        # Unlike for most functions, map is faster than a genexpr over `len`
        max_len = max(map(len, x), default=0)

    padded_x = np.full((len(x), max_len), pad, dtype=dtype)
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    for ind, blocktb in enumerate(x):
        assert len(blocktb) <= max_len
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        padded_x[ind, : len(blocktb)] = blocktb
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    return padded_x


def make_tensor_with_pad(
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    x: list[list[T]],
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    pad: T,
    dtype: torch.dtype,
    *,
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    max_len: int | None = None,
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    device: str | torch.device | None = None,
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    pin_memory: bool = False,
) -> torch.Tensor:
    """
    Make a padded tensor from 2D inputs.

    The padding is applied to the end of each inner list until it reaches
    `max_len`.
    """
    np_dtype = TORCH_DTYPE_TO_NUMPY_DTYPE[dtype]
    padded_x = make_ndarray_with_pad(x, pad, np_dtype, max_len=max_len)

    tensor = torch.from_numpy(padded_x).to(device)
    if pin_memory:
        tensor = tensor.pin_memory()

    return tensor
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def async_tensor_h2d(
    data: list,
    dtype: torch.dtype,
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    target_device: str | torch.device,
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    pin_memory: bool,
) -> torch.Tensor:
    """Asynchronously create a tensor and copy it from host to device."""
    t = torch.tensor(data, dtype=dtype, pin_memory=pin_memory, device="cpu")
    return t.to(device=target_device, non_blocking=True)


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def get_dtype_size(dtype: torch.dtype) -> int:
    """Get the size of the data type in bytes."""
    return torch.tensor([], dtype=dtype).element_size()


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# bool = 0, int = 1, float = 2, complex = 3
def _get_precision_level(dtype: torch.dtype) -> int:
    # NOTE: Complex dtypes return `is_floating_point=False`
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    return (dtype != torch.bool) + dtype.is_floating_point + dtype.is_complex * 2
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def is_lossless_cast(src_dtype: torch.dtype, tgt_dtype: torch.dtype):
    """
    Test whether it is lossless to cast a tensor from
    `src_dtype` to `tgt_dtype`.
    """
    if src_dtype == tgt_dtype:
        return True

    src_level = _get_precision_level(src_dtype)
    tgt_level = _get_precision_level(tgt_dtype)

    if src_level < tgt_level:
        return True
    if src_level > tgt_level:
        return False

    # Compare integral types
    if not src_dtype.is_floating_point and not src_dtype.is_complex:
        src_info = torch.iinfo(src_dtype)
        tgt_info = torch.iinfo(tgt_dtype)
        return src_info.min >= tgt_info.min and src_info.max <= tgt_info.max

    # Compare floating-point types
    src_info = torch.finfo(src_dtype)
    tgt_info = torch.finfo(tgt_dtype)
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    return (
        src_info.min >= tgt_info.min
        and src_info.max <= tgt_info.max
        and src_info.resolution >= tgt_info.resolution
    )
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def common_broadcastable_dtype(dtypes: Collection[torch.dtype]):
    """
    Get the common `dtype` where all of the other `dtypes` can be
    cast to it without losing any information.
    """
    return max(
        dtypes,
        key=lambda dtype: sum(is_lossless_cast(dt, dtype) for dt in dtypes),
    )


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def as_list(maybe_list: Iterable[T]) -> list[T]:
    """Convert iterable to list, unless it's already a list."""
    return maybe_list if isinstance(maybe_list, list) else list(maybe_list)


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def as_iter(obj: T | Iterable[T]) -> Iterable[T]:
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    if isinstance(obj, str) or not isinstance(obj, Iterable):
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        return [obj]  # type: ignore[list-item]
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    return obj


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# `collections` helpers
def is_list_of(
    value: object,
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    typ: type[T] | tuple[type[T], ...],
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    *,
    check: Literal["first", "all"] = "first",
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) -> TypeIs[list[T]]:
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    if not isinstance(value, list):
        return False

    if check == "first":
        return len(value) == 0 or isinstance(value[0], typ)
    elif check == "all":
        return all(isinstance(v, typ) for v in value)

    assert_never(check)


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def flatten_2d_lists(lists: Iterable[Iterable[T]]) -> list[T]:
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    """Flatten a list of lists to a single list."""
    return [item for sublist in lists for item in sublist]


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def full_groupby(values: Iterable[_V], *, key: Callable[[_V], _K]):
    """
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    Unlike [`itertools.groupby`][], groups are not broken by
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    non-contiguous data.
    """
    groups = defaultdict[_K, list[_V]](list)

    for value in values:
        groups[key(value)].append(value)

    return groups.items()


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# TODO: This function can be removed if transformer_modules classes are
# serialized by value when communicating between processes
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def init_cached_hf_modules() -> None:
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    """
    Lazy initialization of the Hugging Face modules.
    """
    from transformers.dynamic_module_utils import init_hf_modules
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    init_hf_modules()
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@cache
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def find_library(lib_name: str) -> str:
    """
    Find the library file in the system.
    `lib_name` is full filename, with both prefix and suffix.
    This function resolves `lib_name` to the full path of the library.
    """
    # Adapted from https://github.com/openai/triton/blob/main/third_party/nvidia/backend/driver.py#L19 # noqa
    # According to https://en.wikipedia.org/wiki/Filesystem_Hierarchy_Standard
    # `/sbin/ldconfig` should exist in all Linux systems.
    # `/sbin/ldconfig` searches the library in the system
    libs = subprocess.check_output(["/sbin/ldconfig", "-p"]).decode()
    # each line looks like the following:
    # libcuda.so.1 (libc6,x86-64) => /lib/x86_64-linux-gnu/libcuda.so.1
    locs = [line.split()[-1] for line in libs.splitlines() if lib_name in line]
    # `LD_LIBRARY_PATH` searches the library in the user-defined paths
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    env_ld_library_path = envs.LD_LIBRARY_PATH
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    if not locs and env_ld_library_path:
        locs = [
            os.path.join(dir, lib_name)
            for dir in env_ld_library_path.split(":")
            if os.path.exists(os.path.join(dir, lib_name))
        ]
    if not locs:
        raise ValueError(f"Cannot find {lib_name} in the system.")
    return locs[0]


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def find_nccl_library() -> str:
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    """
    We either use the library file specified by the `VLLM_NCCL_SO_PATH`
    environment variable, or we find the library file brought by PyTorch.
    After importing `torch`, `libnccl.so.2` or `librccl.so.1` can be
    found by `ctypes` automatically.
    """
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    so_file = envs.VLLM_NCCL_SO_PATH
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    # manually load the nccl library
    if so_file:
        logger.info(
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            "Found nccl from environment variable VLLM_NCCL_SO_PATH=%s", so_file
        )
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    else:
        if torch.version.cuda is not None:
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            so_file = "libnccl.so.2"
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        elif torch.version.hip is not None:
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            so_file = "librccl.so.1"
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        else:
            raise ValueError("NCCL only supports CUDA and ROCm backends.")
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        logger.debug_once("Found nccl from library %s", so_file)
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    return so_file
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def find_nccl_include_paths() -> list[str] | None:
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    """
    We either use the nccl.h specified by the `VLLM_NCCL_INCLUDE_PATH`
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    environment variable, or we find the library file brought by
    nvidia-nccl-cuXX. load_inline by default uses
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    torch.utils.cpp_extension.include_paths
    """
    paths: list[str] = []
    inc = envs.VLLM_NCCL_INCLUDE_PATH
    if inc and os.path.isdir(inc):
        paths.append(inc)

    try:
        import importlib.util
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        spec = importlib.util.find_spec("nvidia.nccl")
        if spec and getattr(spec, "submodule_search_locations", None):
            for loc in spec.submodule_search_locations:
                inc_dir = os.path.join(loc, "include")
                if os.path.exists(os.path.join(inc_dir, "nccl.h")):
                    paths.append(inc_dir)
    except Exception:
        pass

    seen = set()
    out: list[str] = []
    for p in paths:
        if p and p not in seen:
            out.append(p)
            seen.add(p)
    return out or None


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prev_set_stream = torch.cuda.set_stream

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_current_stream_tls = threading.local()
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def _patched_set_stream(stream: torch.cuda.Stream) -> None:
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    _current_stream_tls.value = stream
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    prev_set_stream(stream)


torch.cuda.set_stream = _patched_set_stream


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class _StreamPlaceholder:
    def __init__(self):
        self.synchronize = lambda: None


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def current_stream() -> torch.cuda.Stream:
    """
    replace `torch.cuda.current_stream()` with `vllm.utils.current_stream()`.
    it turns out that `torch.cuda.current_stream()` is quite expensive,
    as it will construct a new stream object at each call.
    here we patch `torch.cuda.set_stream` to keep track of the current stream
    directly, so that we can avoid calling `torch.cuda.current_stream()`.

    the underlying hypothesis is that we do not call `torch._C._cuda_setStream`
    from C/C++ code.
    """
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    from vllm.platforms import current_platform
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    if not hasattr(_current_stream_tls, "value") or _current_stream_tls.value is None:
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        # when this function is called before any stream is set,
        # we return the default stream.
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        # On ROCm using the default 0 stream in combination with RCCL
        # is hurting performance. Therefore creating a dedicated stream
        # per process
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        if current_platform.is_rocm():
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            # torch.cuda.set_stream here is the alias of _pathed_set_stream
            torch.cuda.set_stream(torch.cuda.Stream())
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        elif current_platform.is_cpu():
            _current_stream_tls.value = _StreamPlaceholder()
        else:
            current_stream = current_platform.current_stream
            if current_stream is not None:
                _current_stream_tls.value = current_stream()
            else:
                raise ValueError(
                    "Fail to set current stream, current platform "
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                    "may not support current_stream with torch API"
                )
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    return _current_stream_tls.value
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def enable_trace_function_call_for_thread(vllm_config: VllmConfig) -> None:
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    """Set up function tracing for the current thread,
    if enabled via the VLLM_TRACE_FUNCTION environment variable
    """

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    if envs.VLLM_TRACE_FUNCTION:
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        tmp_dir = tempfile.gettempdir()
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        # add username to tmp_dir to avoid permission issues
        tmp_dir = os.path.join(tmp_dir, getpass.getuser())
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        filename = (
            f"VLLM_TRACE_FUNCTION_for_process_{os.getpid()}"
            f"_thread_{threading.get_ident()}_"
            f"at_{datetime.datetime.now()}.log"
        ).replace(" ", "_")
        log_path = os.path.join(
            tmp_dir, "vllm", f"vllm-instance-{vllm_config.instance_id}", filename
        )
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        os.makedirs(os.path.dirname(log_path), exist_ok=True)
        enable_trace_function_call(log_path)
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@lru_cache(maxsize=8)
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def _cuda_device_count_stateless(cuda_visible_devices: str | None = None) -> int:
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    # Note: cuda_visible_devices is not used, but we keep it as an argument for
    # LRU Cache purposes.

    # Code below is based on
    # https://github.com/pytorch/pytorch/blob/
    # c1cd946818442aca8c7f812b16d187ce1586c3bc/
    # torch/cuda/__init__.py#L831C1-L831C17
    import torch.cuda
    import torch.version

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    from vllm.platforms import current_platform
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    if not torch.cuda._is_compiled():
        return 0
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    if current_platform.is_rocm():
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        # ROCm uses amdsmi instead of nvml for stateless device count
        # This requires a sufficiently modern version of Torch 2.4.0
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        raw_count = (
            torch.cuda._device_count_amdsmi()
            if (hasattr(torch.cuda, "_device_count_amdsmi"))
            else -1
        )
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    else:
        raw_count = torch.cuda._device_count_nvml()
    r = torch._C._cuda_getDeviceCount() if raw_count < 0 else raw_count
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    return r


def cuda_device_count_stateless() -> int:
    """Get number of CUDA devices, caching based on the value of
    CUDA_VISIBLE_DEVICES at the time of call.
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    This should be used instead of torch.cuda.device_count()
    unless CUDA_VISIBLE_DEVICES has already been set to the desired
    value."""

    # This can be removed and simply replaced with torch.cuda.get_device_count
    # after https://github.com/pytorch/pytorch/pull/122815 is released.
    return _cuda_device_count_stateless(envs.CUDA_VISIBLE_DEVICES)
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def cuda_is_initialized() -> bool:
    """Check if CUDA is initialized."""
    if not torch.cuda._is_compiled():
        return False
    return torch.cuda.is_initialized()


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def xpu_is_initialized() -> bool:
    """Check if XPU is initialized."""
    if not torch.xpu._is_compiled():
        return False
    return torch.xpu.is_initialized()


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def cuda_get_device_properties(
    device, names: Sequence[str], init_cuda=False
) -> tuple[Any, ...]:
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    """Get specified CUDA device property values without initializing CUDA in
    the current process."""
    if init_cuda or cuda_is_initialized():
        props = torch.cuda.get_device_properties(device)
        return tuple(getattr(props, name) for name in names)

    # Run in subprocess to avoid initializing CUDA as a side effect.
    mp_ctx = multiprocessing.get_context("fork")
    with ProcessPoolExecutor(max_workers=1, mp_context=mp_ctx) as executor:
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        return executor.submit(cuda_get_device_properties, device, names, True).result()
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def weak_bind(
    bound_method: Callable[..., Any],
) -> Callable[..., None]:
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    """Make an instance method that weakly references
    its associated instance and no-ops once that
    instance is collected."""
    ref = weakref.ref(bound_method.__self__)  # type: ignore[attr-defined]
    unbound = bound_method.__func__  # type: ignore[attr-defined]

    def weak_bound(*args, **kwargs) -> None:
        if inst := ref():
            unbound(inst, *args, **kwargs)

    return weak_bound


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class StoreBoolean(Action):
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    def __call__(self, parser, namespace, values, option_string=None):
        if values.lower() == "true":
            setattr(namespace, self.dest, True)
        elif values.lower() == "false":
            setattr(namespace, self.dest, False)
        else:
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            raise ValueError(
                f"Invalid boolean value: {values}. Expected 'true' or 'false'."
            )
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class SortedHelpFormatter(ArgumentDefaultsHelpFormatter, RawDescriptionHelpFormatter):
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    """SortedHelpFormatter that sorts arguments by their option strings."""

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    def _split_lines(self, text, width):
        """
        1. Sentences split across lines have their single newlines removed.
        2. Paragraphs and explicit newlines are split into separate lines.
        3. Each line is wrapped to the specified width (width of terminal).
        """
        # The patterns also include whitespace after the newline
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        single_newline = re.compile(r"(?<!\n)\n(?!\n)\s*")
        multiple_newlines = re.compile(r"\n{2,}\s*")
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        text = single_newline.sub(" ", text)
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        lines = re.split(multiple_newlines, text)
        return sum([textwrap.wrap(line, width) for line in lines], [])

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    def add_arguments(self, actions):
        actions = sorted(actions, key=lambda x: x.option_strings)
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        super().add_arguments(actions)
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class FlexibleArgumentParser(ArgumentParser):
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    """ArgumentParser that allows both underscore and dash in names."""

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    _deprecated: set[Action] = set()
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    _json_tip: str = (
        "When passing JSON CLI arguments, the following sets of arguments "
        "are equivalent:\n"
        '   --json-arg \'{"key1": "value1", "key2": {"key3": "value2"}}\'\n'
        "   --json-arg.key1 value1 --json-arg.key2.key3 value2\n\n"
        "Additionally, list elements can be passed individually using +:\n"
        '   --json-arg \'{"key4": ["value3", "value4", "value5"]}\'\n'
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        "   --json-arg.key4+ value3 --json-arg.key4+='value4,value5'\n\n"
    )
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    _search_keyword: str | None = None
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    def __init__(self, *args, **kwargs):
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        # Set the default "formatter_class" to SortedHelpFormatter
        if "formatter_class" not in kwargs:
            kwargs["formatter_class"] = SortedHelpFormatter
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        # Pop kwarg "add_json_tip" to control whether to add the JSON tip
        self.add_json_tip = kwargs.pop("add_json_tip", True)
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        super().__init__(*args, **kwargs)

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    if sys.version_info < (3, 13):
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        # Enable the deprecated kwarg for Python 3.12 and below
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        def parse_known_args(self, args=None, namespace=None):
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            if args is not None and "--disable-log-requests" in args:
                # Special case warning because the warning below won't trigger
                # if –-disable-log-requests because its value is default.
                logger.warning_once(
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                    "argument '--disable-log-requests' is deprecated and "
                    "replaced with '--enable-log-requests'. This will be "
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                    "removed in v0.12.0."
                )
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            namespace, args = super().parse_known_args(args, namespace)
            for action in FlexibleArgumentParser._deprecated:
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                if (
                    hasattr(namespace, dest := action.dest)
                    and getattr(namespace, dest) != action.default
                ):
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                    logger.warning_once("argument '%s' is deprecated", dest)
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            return namespace, args

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        def add_argument(self, *args, **kwargs):
            deprecated = kwargs.pop("deprecated", False)
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            action = super().add_argument(*args, **kwargs)
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            if deprecated:
                FlexibleArgumentParser._deprecated.add(action)
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            return action

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        class _FlexibleArgumentGroup(_ArgumentGroup):
            def add_argument(self, *args, **kwargs):
                deprecated = kwargs.pop("deprecated", False)
                action = super().add_argument(*args, **kwargs)
                if deprecated:
                    FlexibleArgumentParser._deprecated.add(action)
                return action

        def add_argument_group(self, *args, **kwargs):
            group = self._FlexibleArgumentGroup(self, *args, **kwargs)
            self._action_groups.append(group)
            return group
1149

1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
    def format_help(self):
        # Only use custom help formatting for bottom level parsers
        if self._subparsers is not None:
            return super().format_help()

        formatter = self._get_formatter()

        # Handle keyword search of the args
        if (search_keyword := self._search_keyword) is not None:
            # Normalise the search keyword
            search_keyword = search_keyword.lower().replace("_", "-")
            # Return full help if searching for 'all'
1162
            if search_keyword == "all":
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
                self.epilog = self._json_tip
                return super().format_help()

            # Return group help if searching for a group title
            for group in self._action_groups:
                if group.title and group.title.lower() == search_keyword:
                    formatter.start_section(group.title)
                    formatter.add_text(group.description)
                    formatter.add_arguments(group._group_actions)
                    formatter.end_section()
                    formatter.add_text(self._json_tip)
                    return formatter.format_help()

            # Return matched args if searching for an arg name
            matched_actions = []
            for group in self._action_groups:
                for action in group._group_actions:
                    # search option name
1181
1182
1183
                    if any(
                        search_keyword in opt.lower() for opt in action.option_strings
                    ):
1184
1185
                        matched_actions.append(action)
            if matched_actions:
1186
                formatter.start_section(f"Arguments matching '{search_keyword}'")
1187
1188
1189
1190
1191
1192
1193
1194
1195
                formatter.add_arguments(matched_actions)
                formatter.end_section()
                formatter.add_text(self._json_tip)
                return formatter.format_help()

            # No match found
            formatter.add_text(
                f"No group or arguments matching '{search_keyword}'.\n"
                "Use '--help' to see available groups or "
1196
1197
                "'--help=all' to see all available parameters."
            )
1198
1199
1200
            return formatter.format_help()

        # usage
1201
        formatter.add_usage(self.usage, self._actions, self._mutually_exclusive_groups)
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222

        # description
        formatter.add_text(self.description)

        # positionals, optionals and user-defined groups
        formatter.start_section("Config Groups")
        config_groups = ""
        for group in self._action_groups:
            if not group._group_actions:
                continue
            title = group.title
            description = group.description or ""
            config_groups += f"{title: <24}{description}\n"
        formatter.add_text(config_groups)
        formatter.end_section()

        # epilog
        formatter.add_text(self.epilog)

        # determine help from format above
        return formatter.format_help()
1223

1224
1225
1226
1227
1228
    def parse_args(  # type: ignore[override]
        self,
        args: list[str] | None = None,
        namespace: Namespace | None = None,
    ):
1229
1230
1231
        if args is None:
            args = sys.argv[1:]

1232
1233
        # Check for --model in command line arguments first
        if args and args[0] == "serve":
1234
1235
            try:
                model_idx = next(
1236
1237
1238
1239
                    i
                    for i, arg in enumerate(args)
                    if arg == "--model" or arg.startswith("--model=")
                )
1240
                logger.warning(
1241
1242
                    "With `vllm serve`, you should provide the model as a "
                    "positional argument or in a config file instead of via "
1243
                    "the `--model` option. "
1244
1245
                    "The `--model` option will be removed in v0.13."
                )
1246
1247
1248
1249
1250
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1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267

                if args[model_idx] == "--model":
                    model_tag = args[model_idx + 1]
                    rest_start_idx = model_idx + 2
                else:
                    model_tag = args[model_idx].removeprefix("--model=")
                    rest_start_idx = model_idx + 1

                # Move <model> to the front, e,g:
                # [Before]
                # vllm serve -tp 2 --model <model> --enforce-eager --port 8001
                # [After]
                # vllm serve <model> -tp 2 --enforce-eager --port 8001
                args = [
                    "serve",
                    model_tag,
                    *args[1:model_idx],
                    *args[rest_start_idx:],
                ]
                print("args", args)
            except StopIteration:
                pass
1268

1269
        if "--config" in args:
1270
            args = self._pull_args_from_config(args)
1271

1272
1273
1274
1275
1276
1277
1278
        def repl(match: re.Match) -> str:
            """Replaces underscores with dashes in the matched string."""
            return match.group(0).replace("_", "-")

        # Everything between the first -- and the first .
        pattern = re.compile(r"(?<=--)[^\.]*")

1279
        # Convert underscores to dashes and vice versa in argument names
1280
        processed_args = list[str]()
1281
        for i, arg in enumerate(args):
1282
            if arg.startswith("--help="):
1283
                FlexibleArgumentParser._search_keyword = arg.split("=", 1)[-1].lower()
1284
                processed_args.append("--help")
1285
1286
1287
            elif arg.startswith("--"):
                if "=" in arg:
                    key, value = arg.split("=", 1)
1288
                    key = pattern.sub(repl, key, count=1)
1289
                    processed_args.append(f"{key}={value}")
1290
                else:
1291
1292
                    key = pattern.sub(repl, arg, count=1)
                    processed_args.append(key)
1293
            elif arg.startswith("-O") and arg != "-O" and arg[2] != ".":
1294
1295
                # allow -O flag to be used without space, e.g. -O3 or -Odecode
                # -O.<...> handled later
1296
1297
1298
                # also handle -O=<mode> here
                mode = arg[3:] if arg[2] == "=" else arg[2:]
                processed_args.append(f"-O.mode={mode}")
1299
1300
1301
1302
1303
            elif (
                arg == "-O"
                and i + 1 < len(args)
                and args[i + 1] in {"0", "1", "2", "3"}
            ):
1304
1305
                # Convert -O <n> to -O.mode <n>
                processed_args.append("-O.mode")
1306
1307
1308
            else:
                processed_args.append(arg)

1309
        def create_nested_dict(keys: list[str], value: str) -> dict[str, Any]:
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
            """Creates a nested dictionary from a list of keys and a value.

            For example, `keys = ["a", "b", "c"]` and `value = 1` will create:
            `{"a": {"b": {"c": 1}}}`
            """
            nested_dict: Any = value
            for key in reversed(keys):
                nested_dict = {key: nested_dict}
            return nested_dict

1320
1321
1322
        def recursive_dict_update(
            original: dict[str, Any],
            update: dict[str, Any],
1323
1324
1325
1326
1327
        ) -> set[str]:
            """Recursively updates a dictionary with another dictionary.
            Returns a set of duplicate keys that were overwritten.
            """
            duplicates = set[str]()
1328
1329
            for k, v in update.items():
                if isinstance(v, dict) and isinstance(original.get(k), dict):
1330
1331
1332
1333
                    nested_duplicates = recursive_dict_update(original[k], v)
                    duplicates |= {f"{k}.{d}" for d in nested_duplicates}
                elif isinstance(v, list) and isinstance(original.get(k), list):
                    original[k] += v
1334
                else:
1335
1336
                    if k in original:
                        duplicates.add(k)
1337
                    original[k] = v
1338
            return duplicates
1339

1340
1341
        delete = set[int]()
        dict_args = defaultdict[str, dict[str, Any]](dict)
1342
        duplicates = set[str]()
1343
        for i, processed_arg in enumerate(processed_args):
1344
1345
1346
1347
            if i in delete:  # skip if value from previous arg
                continue

            if processed_arg.startswith("-") and "." in processed_arg:
1348
                if "=" in processed_arg:
1349
                    processed_arg, value_str = processed_arg.split("=", 1)
1350
                    if "." not in processed_arg:
1351
                        # False positive, '.' was only in the value
1352
1353
                        continue
                else:
1354
                    value_str = processed_args[i + 1]
1355
                    delete.add(i + 1)
1356

1357
1358
1359
1360
                if processed_arg.endswith("+"):
                    processed_arg = processed_arg[:-1]
                    value_str = json.dumps(list(value_str.split(",")))

1361
                key, *keys = processed_arg.split(".")
1362
1363
1364
1365
1366
                try:
                    value = json.loads(value_str)
                except json.decoder.JSONDecodeError:
                    value = value_str

1367
1368
                # Merge all values with the same key into a single dict
                arg_dict = create_nested_dict(keys, value)
1369
1370
                arg_duplicates = recursive_dict_update(dict_args[key], arg_dict)
                duplicates |= {f"{key}.{d}" for d in arg_duplicates}
1371
1372
                delete.add(i)
        # Filter out the dict args we set to None
1373
        processed_args = [a for i, a in enumerate(processed_args) if i not in delete]
1374
1375
1376
        if duplicates:
            logger.warning("Found duplicate keys %s", ", ".join(duplicates))

1377
1378
1379
1380
1381
        # Add the dict args back as if they were originally passed as JSON
        for dict_arg, dict_value in dict_args.items():
            processed_args.append(dict_arg)
            processed_args.append(json.dumps(dict_value))

1382
        return super().parse_args(processed_args, namespace)
1383

1384
1385
1386
1387
    def check_port(self, value):
        try:
            value = int(value)
        except ValueError:
1388
            msg = "Port must be an integer"
1389
            raise ArgumentTypeError(msg) from None
1390
1391

        if not (1024 <= value <= 65535):
1392
            raise ArgumentTypeError("Port must be between 1024 and 65535")
1393
1394
1395

        return value

1396
    def _pull_args_from_config(self, args: list[str]) -> list[str]:
1397
1398
        """Method to pull arguments specified in the config file
        into the command-line args variable.
1399
1400

        The arguments in config file will be inserted between
1401
        the argument list.
1402

1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
        example:
        ```yaml
            port: 12323
            tensor-parallel-size: 4
        ```
        ```python
        $: vllm {serve,chat,complete} "facebook/opt-12B" \
            --config config.yaml -tp 2
        $: args = [
            "serve,chat,complete",
1413
1414
            "facebook/opt-12B",
            '--config', 'config.yaml',
1415
1416
1417
1418
            '-tp', '2'
        ]
        $: args = [
            "serve,chat,complete",
1419
1420
1421
            "facebook/opt-12B",
            '--port', '12323',
            '--tensor-parallel-size', '4',
1422
1423
1424
1425
1426
            '-tp', '2'
            ]
        ```

        Please note how the config args are inserted after the sub command.
1427
        this way the order of priorities is maintained when these are args
1428
1429
        parsed by super().
        """
1430
        assert args.count("--config") <= 1, "More than one config file specified!"
1431

1432
        index = args.index("--config")
1433
        if index == len(args) - 1:
1434
1435
1436
1437
            raise ValueError(
                "No config file specified! \
                             Please check your command-line arguments."
            )
1438
1439
1440

        file_path = args[index + 1]

1441
        config_args = self.load_config_file(file_path)
1442

1443
        # 0th index might be the sub command {serve,chat,complete,...}
1444
        # optionally followed by model_tag (only for serve)
1445
1446
1447
1448
        # followed by config args
        # followed by rest of cli args.
        # maintaining this order will enforce the precedence
        # of cli > config > defaults
1449
        if args[0].startswith("-"):
1450
            # No sub command (e.g., api_server entry point)
1451
            args = config_args + args[0:index] + args[index + 2 :]
1452
        elif args[0] == "serve":
1453
1454
            model_in_cli = len(args) > 1 and not args[1].startswith("-")
            model_in_config = any(arg == "--model" for arg in config_args)
1455
1456

            if not model_in_cli and not model_in_config:
1457
                raise ValueError(
1458
                    "No model specified! Please specify model either "
1459
1460
                    "as a positional argument or in a config file."
                )
1461
1462
1463

            if model_in_cli:
                # Model specified as positional arg, keep CLI version
1464
1465
1466
1467
1468
1469
1470
                args = (
                    [args[0]]
                    + [args[1]]
                    + config_args
                    + args[2:index]
                    + args[index + 2 :]
                )
1471
1472
            else:
                # No model in CLI, use config if available
1473
                args = [args[0]] + config_args + args[1:index] + args[index + 2 :]
1474
        else:
1475
            args = [args[0]] + config_args + args[1:index] + args[index + 2 :]
1476
1477
1478

        return args

1479
    def load_config_file(self, file_path: str) -> list[str]:
1480
        """Loads a yaml file and returns the key value pairs as a
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
        flattened list with argparse like pattern
        ```yaml
            port: 12323
            tensor-parallel-size: 4
        ```
        returns:
            processed_args: list[str] = [
                '--port': '12323',
                '--tensor-parallel-size': '4'
            ]
        """
1492
1493
        extension: str = file_path.split(".")[-1]
        if extension not in ("yaml", "yml"):
1494
1495
            raise ValueError(
                "Config file must be of a yaml/yml type.\
1496
1497
1498
                              %s supplied",
                extension,
            )
1499
1500

        # only expecting a flat dictionary of atomic types
1501
        processed_args: list[str] = []
1502

1503
        config: dict[str, int | str] = {}
1504
        try:
1505
            with open(file_path) as config_file:
1506
1507
1508
1509
                config = yaml.safe_load(config_file)
        except Exception as ex:
            logger.error(
                "Unable to read the config file at %s. \
1510
1511
1512
                Make sure path is correct",
                file_path,
            )
1513
1514
            raise ex

1515
        store_boolean_arguments = [
1516
            action.dest for action in self._actions if isinstance(action, StoreBoolean)
1517
1518
        ]

1519
        for key, value in config.items():
1520
1521
            if isinstance(value, bool) and key not in store_boolean_arguments:
                if value:
1522
                    processed_args.append("--" + key)
1523
1524
            elif isinstance(value, list):
                if value:
1525
                    processed_args.append("--" + key)
1526
1527
                    for item in value:
                        processed_args.append(str(item))
1528
            else:
1529
                processed_args.append("--" + key)
1530
                processed_args.append(str(value))
1531
1532
1533

        return processed_args

1534

1535
1536
1537
1538
1539
1540
# Using dynamo with vLLM doesn't really work well with PyTorch versions < 2.4.0.
# In particular, the FakeScalarType is not supported for earlier versions of
# PyTorch which breaks dynamo for any ops registered using ScalarType.
def supports_dynamo() -> bool:
    base_torch_version = Version(Version(torch.__version__).base_version)
    return base_torch_version >= Version("2.4.0")
1541
1542


1543
# Supports xccl with PyTorch versions >= 2.8.0.dev for XPU platform
1544
def supports_xccl() -> bool:
1545
1546
1547
    return (
        is_torch_equal_or_newer("2.8.0.dev") and torch.distributed.is_xccl_available()
    )
1548
1549


1550
1551
1552
1553
1554
1555
# Some backends use pytorch version < 2.4.0 which doesn't
# support `torch.library.custom_op`.
def supports_custom_op() -> bool:
    return hasattr(torch.library, "custom_op")


1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
class AtomicCounter:
    """An atomic, thread-safe counter"""

    def __init__(self, initial=0):
        """Initialize a new atomic counter to given initial value"""
        self._value = initial
        self._lock = threading.Lock()

    def inc(self, num=1):
        """Atomically increment the counter by num and return the new value"""
        with self._lock:
            self._value += num
            return self._value

    def dec(self, num=1):
        """Atomically decrement the counter by num and return the new value"""
        with self._lock:
            self._value -= num
            return self._value

    @property
    def value(self):
        return self._value
1579
1580
1581


# Adapted from: https://stackoverflow.com/a/47212782/5082708
1582
class LazyDict(Mapping[str, T], Generic[T]):
1583
    def __init__(self, factory: dict[str, Callable[[], T]]):
1584
        self._factory = factory
1585
        self._dict: dict[str, T] = {}
1586

1587
    def __getitem__(self, key: str) -> T:
1588
1589
1590
1591
1592
1593
        if key not in self._dict:
            if key not in self._factory:
                raise KeyError(key)
            self._dict[key] = self._factory[key]()
        return self._dict[key]

1594
1595
1596
    def __setitem__(self, key: str, value: Callable[[], T]):
        self._factory[key] = value

1597
1598
1599
1600
1601
    def __iter__(self):
        return iter(self._factory)

    def __len__(self):
        return len(self._factory)
1602
1603


1604
1605
class ClassRegistry(UserDict[type[T], _V]):
    def __getitem__(self, key: type[T]) -> _V:
1606
1607
1608
1609
1610
1611
1612
        for cls in key.mro():
            if cls in self.data:
                return self.data[cls]

        raise KeyError(key)

    def __contains__(self, key: object) -> bool:
1613
1614
1615
        return self.contains(key)

    def contains(self, key: object, *, strict: bool = False) -> bool:
1616
1617
1618
        if not isinstance(key, type):
            return False

1619
1620
1621
        if strict:
            return key in self.data

1622
1623
1624
        return any(cls in self.data for cls in key.mro())


1625
def weak_ref_tensor(tensor: Any) -> Any:
1626
1627
1628
1629
1630
    """
    Create a weak reference to a tensor.
    The new tensor will share the same data as the original tensor,
    but will not keep the original tensor alive.
    """
1631
1632
1633
1634
    if isinstance(tensor, torch.Tensor):
        return torch.ops._C.weak_ref_tensor(tensor)
    else:
        return tensor
1635
1636
1637


def weak_ref_tensors(
1638
1639
1640
1641
1642
    tensors: torch.Tensor
    | list[torch.Tensor]
    | tuple[torch.Tensor]
    | IntermediateTensors,
) -> torch.Tensor | list[Any] | tuple[Any] | Any:
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
    """
    Convenience function to create weak references to tensors,
    for single tensor, list of tensors or tuple of tensors.
    """
    if isinstance(tensors, torch.Tensor):
        return weak_ref_tensor(tensors)
    if isinstance(tensors, list):
        return [weak_ref_tensor(t) for t in tensors]
    if isinstance(tensors, tuple):
        return tuple(weak_ref_tensor(t) for t in tensors)
1653
1654
1655

    # For IntermediateTensors used in pipeline parallelism
    from vllm.sequence import IntermediateTensors
1656

1657
    if isinstance(tensors, IntermediateTensors):
1658
1659
1660
        ret = IntermediateTensors(
            {key: weak_ref_tensor(val) for key, val in tensors.tensors.items()}
        )
1661
        return ret
1662
    raise ValueError("Invalid type for tensors")
1663
1664


1665
1666
1667
1668
1669
1670
1671
1672
def get_cuda_view_from_cpu_tensor(cpu_tensor: torch.Tensor) -> torch.Tensor:
    """
    Get a CUDA view of a CPU tensor using Unified Virtual Addressing (UVA).
    """
    assert cpu_tensor.is_pinned(), "CPU tensor must be pinned"
    return torch.ops._C.get_cuda_view_from_cpu_tensor(cpu_tensor)


1673
def import_from_path(module_name: str, file_path: str | os.PathLike):
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
    """
    Import a Python file according to its file path.

    Based on the official recipe:
    https://docs.python.org/3/library/importlib.html#importing-a-source-file-directly
    """
    spec = importlib.util.spec_from_file_location(module_name, file_path)
    if spec is None:
        raise ModuleNotFoundError(f"No module named '{module_name}'")

    assert spec.loader is not None

    module = importlib.util.module_from_spec(spec)
    sys.modules[module_name] = module
    spec.loader.exec_module(module)
    return module


1692
@cache
1693
1694
1695
1696
1697
1698
1699
def get_vllm_optional_dependencies():
    metadata = importlib.metadata.metadata("vllm")
    requirements = metadata.get_all("Requires-Dist", [])
    extras = metadata.get_all("Provides-Extra", [])

    return {
        extra: [
1700
1701
            re.split(r";|>=|<=|==", req)[0]
            for req in requirements
1702
1703
1704
1705
1706
1707
            if req.endswith(f'extra == "{extra}"')
        ]
        for extra in extras
    }


1708
1709
1710
1711
1712
class _PlaceholderBase:
    """
    Disallows downstream usage of placeholder modules.

    We need to explicitly override each dunder method because
1713
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    [`__getattr__`][vllm.utils._PlaceholderBase.__getattr__]
    is not called when they are accessed.
1715

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    Info:
        [Special method lookup](https://docs.python.org/3/reference/datamodel.html#special-lookup)
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    """

    def __getattr__(self, key: str) -> Never:
        """
        The main class should implement this to throw an error
        for attribute accesses representing downstream usage.
        """
        raise NotImplementedError

    # [Basic customization]

    def __lt__(self, other: object):
        return self.__getattr__("__lt__")

    def __le__(self, other: object):
        return self.__getattr__("__le__")

    def __eq__(self, other: object):
        return self.__getattr__("__eq__")

    def __ne__(self, other: object):
        return self.__getattr__("__ne__")

    def __gt__(self, other: object):
        return self.__getattr__("__gt__")

    def __ge__(self, other: object):
        return self.__getattr__("__ge__")

    def __hash__(self):
        return self.__getattr__("__hash__")

    def __bool__(self):
        return self.__getattr__("__bool__")

    # [Callable objects]

    def __call__(self, *args: object, **kwargs: object):
        return self.__getattr__("__call__")

    # [Container types]

    def __len__(self):
        return self.__getattr__("__len__")

    def __getitem__(self, key: object):
        return self.__getattr__("__getitem__")

    def __setitem__(self, key: object, value: object):
        return self.__getattr__("__setitem__")

    def __delitem__(self, key: object):
        return self.__getattr__("__delitem__")

    # __missing__ is optional according to __getitem__ specification,
    # so it is skipped

    # __iter__ and __reversed__ have a default implementation
    # based on __len__ and __getitem__, so they are skipped.

    # [Numeric Types]

    def __add__(self, other: object):
        return self.__getattr__("__add__")

    def __sub__(self, other: object):
        return self.__getattr__("__sub__")

    def __mul__(self, other: object):
        return self.__getattr__("__mul__")

    def __matmul__(self, other: object):
        return self.__getattr__("__matmul__")

    def __truediv__(self, other: object):
        return self.__getattr__("__truediv__")

    def __floordiv__(self, other: object):
        return self.__getattr__("__floordiv__")

    def __mod__(self, other: object):
        return self.__getattr__("__mod__")

    def __divmod__(self, other: object):
        return self.__getattr__("__divmod__")

    def __pow__(self, other: object, modulo: object = ...):
        return self.__getattr__("__pow__")

    def __lshift__(self, other: object):
        return self.__getattr__("__lshift__")

    def __rshift__(self, other: object):
        return self.__getattr__("__rshift__")

    def __and__(self, other: object):
        return self.__getattr__("__and__")

    def __xor__(self, other: object):
        return self.__getattr__("__xor__")

    def __or__(self, other: object):
        return self.__getattr__("__or__")

    # r* and i* methods have lower priority than
    # the methods for left operand so they are skipped

    def __neg__(self):
        return self.__getattr__("__neg__")

    def __pos__(self):
        return self.__getattr__("__pos__")

    def __abs__(self):
        return self.__getattr__("__abs__")

    def __invert__(self):
        return self.__getattr__("__invert__")

    # __complex__, __int__ and __float__ have a default implementation
    # based on __index__, so they are skipped.

    def __index__(self):
        return self.__getattr__("__index__")

    def __round__(self, ndigits: object = ...):
        return self.__getattr__("__round__")

    def __trunc__(self):
        return self.__getattr__("__trunc__")

    def __floor__(self):
        return self.__getattr__("__floor__")

    def __ceil__(self):
        return self.__getattr__("__ceil__")

    # [Context managers]

    def __enter__(self):
        return self.__getattr__("__enter__")

    def __exit__(self, *args: object, **kwargs: object):
        return self.__getattr__("__exit__")


class PlaceholderModule(_PlaceholderBase):
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    """
    A placeholder object to use when a module does not exist.

    This enables more informative errors when trying to access attributes
1869
    of a module that does not exist.
1870
    """
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    def __init__(self, name: str) -> None:
        super().__init__()

        # Apply name mangling to avoid conflicting with module attributes
        self.__name = name
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    def placeholder_attr(self, attr_path: str):
        return _PlaceholderModuleAttr(self, attr_path)

    def __getattr__(self, key: str):
1882
        name = self.__name
1883
1884

        try:
1885
            importlib.import_module(name)
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        except ImportError as exc:
            for extra, names in get_vllm_optional_dependencies().items():
                if name in names:
                    msg = f"Please install vllm[{extra}] for {extra} support"
                    raise ImportError(msg) from exc

            raise exc

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        raise AssertionError(
            "PlaceholderModule should not be used "
            "when the original module can be imported"
        )
1898
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1900
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class _PlaceholderModuleAttr(_PlaceholderBase):
    def __init__(self, module: PlaceholderModule, attr_path: str) -> None:
        super().__init__()

        # Apply name mangling to avoid conflicting with module attributes
        self.__module = module
        self.__attr_path = attr_path
1907
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    def placeholder_attr(self, attr_path: str):
1909
        return _PlaceholderModuleAttr(self.__module, f"{self.__attr_path}.{attr_path}")
1910
1911

    def __getattr__(self, key: str):
1912
        getattr(self.__module, f"{self.__attr_path}.{key}")
1913

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        raise AssertionError(
            "PlaceholderModule should not be used "
            "when the original module can be imported"
        )
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1919


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1924
# create a library to hold the custom op
vllm_lib = Library("vllm", "FRAGMENT")  # noqa


def direct_register_custom_op(
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    op_name: str,
    op_func: Callable,
1927
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1929
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    mutates_args: list[str] | None = None,
    fake_impl: Callable | None = None,
    target_lib: Library | None = None,
    dispatch_key: str | None = None,
1931
    tags: tuple[torch.Tag, ...] = (),
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):
    """
    `torch.library.custom_op` can have significant overhead because it
    needs to consider complicated dispatching logic. This function
    directly registers a custom op and dispatches it to the CUDA backend.
    See https://gist.github.com/youkaichao/ecbea9ec9fc79a45d2adce1784d7a9a5
    for more details.

    By default, the custom op is registered to the vLLM library. If you
    want to register it to a different library, you can pass the library
    object to the `target_lib` argument.

    IMPORTANT: the lifetime of the operator is tied to the lifetime of the
    library object. If you want to bind the operator to a different library,
    make sure the library object is alive when the operator is used.
    """
1948
    if not supports_custom_op():
1949
        from vllm.platforms import current_platform
1950

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        assert not current_platform.is_cuda_alike(), (
            "cuda platform needs torch>=2.4 to support custom op, "
            "chances are you are using an old version of pytorch "
            "or a custom build of pytorch. It is recommended to "
            "use vLLM in a fresh new environment and let it install "
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            "the required dependencies."
        )
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        return

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    if mutates_args is None:
        mutates_args = []

    if dispatch_key is None:
        from vllm.platforms import current_platform
1965

1966
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        dispatch_key = current_platform.dispatch_key

1968
    import torch.library
1969

1970
    if hasattr(torch.library, "infer_schema"):
1971
        schema_str = torch.library.infer_schema(op_func, mutates_args=mutates_args)
1972
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1974
    else:
        # for pytorch 2.4
        import torch._custom_op.impl
1975

1976
        schema_str = torch._custom_op.impl.infer_schema(op_func, mutates_args)
1977
    my_lib = target_lib or vllm_lib
1978
    my_lib.define(op_name + schema_str, tags=tags)
1979
    my_lib.impl(op_name, op_func, dispatch_key=dispatch_key)
1980
1981
    if fake_impl is not None:
        my_lib._register_fake(op_name, fake_impl)
1982
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1984
1985


def resolve_obj_by_qualname(qualname: str) -> Any:
    """
1986
    Resolve an object by its fully-qualified class name.
1987
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1989
1990
    """
    module_name, obj_name = qualname.rsplit(".", 1)
    module = importlib.import_module(module_name)
    return getattr(module, obj_name)
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def kill_process_tree(pid: int):
    """
    Kills all descendant processes of the given pid by sending SIGKILL.

    Args:
        pid (int): Process ID of the parent process
    """
    try:
        parent = psutil.Process(pid)
    except psutil.NoSuchProcess:
        return

    # Get all children recursively
    children = parent.children(recursive=True)

    # Send SIGKILL to all children first
    for child in children:
        with contextlib.suppress(ProcessLookupError):
            os.kill(child.pid, signal.SIGKILL)

    # Finally kill the parent
    with contextlib.suppress(ProcessLookupError):
        os.kill(pid, signal.SIGKILL)
2016
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@dataclass
class MemorySnapshot:
    """Memory snapshot."""
2021

2022
    torch_peak: int = 0
2023
2024
    free_memory: int = 0
    total_memory: int = 0
2025
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2027
    cuda_memory: int = 0
    torch_memory: int = 0
    non_torch_memory: int = 0
2028
    timestamp: float = 0.0
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    auto_measure: bool = True

    def __post_init__(self):
        if self.auto_measure:
            self.measure()
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2035

    def measure(self):
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2037
        from vllm.platforms import current_platform

2038
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2042
        # we measure the torch peak memory usage via allocated_bytes,
        # rather than `torch.cuda.memory_reserved()` .
        # After `torch.cuda.reset_peak_memory_stats()`,
        # `torch.cuda.memory_reserved()` will keep growing, and only shrink
        # when we call `torch.cuda.empty_cache()` or OOM happens.
2043
        self.torch_peak = torch.cuda.memory_stats().get("allocated_bytes.all.peak", 0)
2044

2045
        self.free_memory, self.total_memory = torch.cuda.mem_get_info()
2046
2047
2048
2049
2050
        shared_sysmem_device_mem_sms = ((8, 7), (11, 0), (12, 1))  # Orin, Thor, Spark
        if (
            current_platform.is_cuda()
            and current_platform.get_device_capability() in shared_sysmem_device_mem_sms
        ):
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            # On UMA (Orin, Thor and Spark) platform,
            # where both CPU and GPU rely on system memory,
            # the cudaMemGetInfo function shows the amount of free system memory
            # rather than what’s actually available.
            # In the case,
            # torch.cuda.mem_get_info() only reports "free" memory,
            # which can be lower than what is actually
            # available due to not including cache memory.
            # There’s also a comprehensive reference page
            # that explains how you can compute the proper value yourself.
            # https://docs.nvidia.com/cuda/cuda-for-tegra-appnote/#estimating-total-allocatable-device-memory-on-an-integrated-gpu-device
            self.free_memory = psutil.virtual_memory().available

2064
        self.cuda_memory = self.total_memory - self.free_memory
2065

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        # torch.cuda.memory_reserved() is how many bytes
        # PyTorch gets from cuda (by calling cudaMalloc, etc.)
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2071
        # this is used to measure the non-torch memory usage
        self.torch_memory = torch.cuda.memory_reserved()

        self.non_torch_memory = self.cuda_memory - self.torch_memory
2072
2073
        self.timestamp = time.time()

2074
    def __sub__(self, other: "MemorySnapshot") -> "MemorySnapshot":
2075
        return MemorySnapshot(
2076
            torch_peak=self.torch_peak - other.torch_peak,
2077
2078
            free_memory=self.free_memory - other.free_memory,
            total_memory=self.total_memory - other.total_memory,
2079
2080
2081
2082
2083
2084
            cuda_memory=self.cuda_memory - other.cuda_memory,
            torch_memory=self.torch_memory - other.torch_memory,
            non_torch_memory=self.non_torch_memory - other.non_torch_memory,
            timestamp=self.timestamp - other.timestamp,
            auto_measure=False,
        )
2085
2086
2087
2088


@dataclass
class MemoryProfilingResult:
2089
2090
    """Memory profiling result. All numbers are in bytes."""

2091
2092
2093
2094
2095
    non_kv_cache_memory: int = 0
    torch_peak_increase: int = 0
    non_torch_increase: int = 0
    weights_memory: float = 0
    before_create: MemorySnapshot = field(default_factory=MemorySnapshot)
2096
2097
2098
2099
    before_profile: MemorySnapshot = field(default_factory=MemorySnapshot)
    after_profile: MemorySnapshot = field(default_factory=MemorySnapshot)
    profile_time: float = 0.0

2100
    def __repr__(self) -> str:
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
        return (
            f"Memory profiling takes {self.profile_time:.2f} seconds. "
            f"Total non KV cache memory: "
            f"{(self.non_kv_cache_memory / GiB_bytes):.2f}GiB; "
            f"torch peak memory increase: "
            f"{(self.torch_peak_increase / GiB_bytes):.2f}GiB; "
            f"non-torch forward increase memory: "
            f"{(self.non_torch_increase / GiB_bytes):.2f}GiB; "
            f"weights memory: {(self.weights_memory / GiB_bytes):.2f}GiB."
        )
2111

2112
2113
2114

@contextlib.contextmanager
def memory_profiling(
2115
2116
    baseline_snapshot: MemorySnapshot, weights_memory: int
) -> Generator[MemoryProfilingResult, None, None]:
2117
    """Memory profiling context manager.
2118
2119
    baseline_snapshot: the memory snapshot before the current vLLM instance.
    weights_memory: memory used by PyTorch when loading the model weights.
2120
2121
        Note that, before loading the model weights, we also initialize the device
        and distributed environment, which may consume some memory. This part is not
2122
        included in the weights_memory because PyTorch does not control it.
2123
2124
2125
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2128
2129
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2135
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2141
2142
2143
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2145
2146
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2148
2149
2150
2151
2152
2153
2154
2155
2156

    The memory in one GPU can be classified into 3 categories:
    1. memory used by anything other than the current vLLM instance.
    2. memory used by torch in the current vLLM instance.
    3. memory used in the current vLLM instance, but not by torch.

    A quantitive example:

    Before creating the current vLLM instance:
        category 1: 1 GiB
        category 2: 0 GiB
        category 3: 0 GiB

    After creating the current vLLM instance and loading the model,
    (i.e. before profiling):
        category 1: 1 GiB
        category 2: 2 GiB (model weights take 2 GiB)
        category 3: 0.5 GiB (memory used by NCCL)

    During profiling (peak):
        category 1: 1 GiB
        category 2: 4 GiB (peak activation tensors take 2 GiB)
        category 3: 1 GiB (memory used by NCCL + buffers for some attention backends)

    After profiling:
        category 1: 1 GiB
        category 2: 3 GiB (after garbage-collecting activation tensors)
        category 3: 1 GiB (memory used by NCCL + buffers for some attention backends)

    In this case, non-kv cache takes 5 GiB in total, including:
    a. 2 GiB used by the model weights (category 2)
    b. 2 GiB reserved for the peak activation tensors (category 2)
    c. 1 GiB used by non-torch components (category 3)

2157
    The memory used for loading weights (a.) is directly given from the argument `weights_memory`.
2158

2159
    The increase of `torch.cuda.memory_stats()["allocated_bytes.all.peak"]` during profiling gives (b.).
2160

2161
    The increase of `non_torch_memory` from creating the current vLLM instance until after profiling to get (c.).
2162
    """  # noqa
2163
2164
    gc.collect()
    torch.cuda.empty_cache()
2165
2166
2167
2168
    torch.cuda.reset_peak_memory_stats()

    result = MemoryProfilingResult()

2169
    result.before_create = baseline_snapshot
2170
    # the part of memory used for holding the model weights
2171
    result.weights_memory = weights_memory
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181

    result.before_profile.measure()

    yield result

    gc.collect()
    torch.cuda.empty_cache()

    result.after_profile.measure()

2182
2183
2184
2185
2186
    diff_profile = result.after_profile - result.before_profile
    diff_from_create = result.after_profile - result.before_create
    result.torch_peak_increase = diff_profile.torch_peak
    result.non_torch_increase = diff_from_create.non_torch_memory
    result.profile_time = diff_profile.timestamp
2187
2188
2189

    non_torch_memory = result.non_torch_increase
    peak_activation_memory = result.torch_peak_increase
2190
2191
2192
    result.non_kv_cache_memory = (
        non_torch_memory + peak_activation_memory + result.weights_memory
    )  # noqa
2193
2194


2195
# Adapted from: https://github.com/sgl-project/sglang/blob/v0.4.1/python/sglang/srt/utils.py#L630 # noqa: E501
2196
def set_ulimit(target_soft_limit=65535):
2197
    if sys.platform.startswith("win"):
2198
2199
2200
2201
        logger.info("Windows detected, skipping ulimit adjustment.")
        return

    import resource
2202

2203
2204
2205
2206
2207
    resource_type = resource.RLIMIT_NOFILE
    current_soft, current_hard = resource.getrlimit(resource_type)

    if current_soft < target_soft_limit:
        try:
2208
            resource.setrlimit(resource_type, (target_soft_limit, current_hard))
2209
2210
        except ValueError as e:
            logger.warning(
2211
2212
                "Found ulimit of %s and failed to automatically increase "
                "with error %s. This can cause fd limit errors like "
2213
                "`OSError: [Errno 24] Too many open files`. Consider "
2214
2215
2216
2217
                "increasing with ulimit -n",
                current_soft,
                e,
            )
2218
2219
2220
2221
2222
2223
2224
2225
2226


# Adapted from: https://github.com/sgl-project/sglang/blob/v0.4.1/python/sglang/utils.py#L28 # noqa: E501
def get_exception_traceback():
    etype, value, tb = sys.exc_info()
    err_str = "".join(traceback.format_exception(etype, value, tb))
    return err_str


2227
def split_zmq_path(path: str) -> tuple[str, str, str]:
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
    """Split a zmq path into its parts."""
    parsed = urlparse(path)
    if not parsed.scheme:
        raise ValueError(f"Invalid zmq path: {path}")

    scheme = parsed.scheme
    host = parsed.hostname or ""
    port = str(parsed.port or "")

    if scheme == "tcp" and not all((host, port)):
        # The host and port fields are required for tcp
        raise ValueError(f"Invalid zmq path: {path}")

    if scheme != "tcp" and port:
        # port only makes sense with tcp
        raise ValueError(f"Invalid zmq path: {path}")

    return scheme, host, port


2248
def make_zmq_path(scheme: str, host: str, port: int | None = None) -> str:
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
    """Make a ZMQ path from its parts.

    Args:
        scheme: The ZMQ transport scheme (e.g. tcp, ipc, inproc).
        host: The host - can be an IPv4 address, IPv6 address, or hostname.
        port: Optional port number, only used for TCP sockets.

    Returns:
        A properly formatted ZMQ path string.
    """
2259
    if port is None:
2260
2261
2262
2263
2264
2265
        return f"{scheme}://{host}"
    if is_valid_ipv6_address(host):
        return f"{scheme}://[{host}]:{port}"
    return f"{scheme}://{host}:{port}"


2266
2267
# Adapted from: https://github.com/sgl-project/sglang/blob/v0.4.1/python/sglang/srt/utils.py#L783 # noqa: E501
def make_zmq_socket(
2268
    ctx: zmq.asyncio.Context | zmq.Context,  # type: ignore[name-defined]
2269
    path: str,
2270
    socket_type: Any,
2271
2272
2273
    bind: bool | None = None,
    identity: bytes | None = None,
    linger: int | None = None,
2274
) -> zmq.Socket | zmq.asyncio.Socket:  # type: ignore[name-defined]
2275
2276
2277
    """Make a ZMQ socket with the proper bind/connect semantics."""

    mem = psutil.virtual_memory()
2278
    socket = ctx.socket(socket_type)
2279
2280
2281
2282
2283
2284
2285
2286

    # Calculate buffer size based on system memory
    total_mem = mem.total / 1024**3
    available_mem = mem.available / 1024**3
    # For systems with substantial memory (>32GB total, >16GB available):
    # - Set a large 0.5GB buffer to improve throughput
    # For systems with less memory:
    # - Use system default (-1) to avoid excessive memory consumption
2287
    buf_size = int(0.5 * 1024**3) if total_mem > 32 and available_mem > 16 else -1
2288

2289
    if bind is None:
2290
        bind = socket_type not in (zmq.PUSH, zmq.SUB, zmq.XSUB)
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302

    if socket_type in (zmq.PULL, zmq.DEALER, zmq.ROUTER):
        socket.setsockopt(zmq.RCVHWM, 0)
        socket.setsockopt(zmq.RCVBUF, buf_size)

    if socket_type in (zmq.PUSH, zmq.DEALER, zmq.ROUTER):
        socket.setsockopt(zmq.SNDHWM, 0)
        socket.setsockopt(zmq.SNDBUF, buf_size)

    if identity is not None:
        socket.setsockopt(zmq.IDENTITY, identity)

2303
2304
2305
    if linger is not None:
        socket.setsockopt(zmq.LINGER, linger)

2306
2307
2308
    if socket_type == zmq.XPUB:
        socket.setsockopt(zmq.XPUB_VERBOSE, True)

2309
2310
2311
2312
2313
2314
    # Determine if the path is a TCP socket with an IPv6 address.
    # Enable IPv6 on the zmq socket if so.
    scheme, host, _ = split_zmq_path(path)
    if scheme == "tcp" and is_valid_ipv6_address(host):
        socket.setsockopt(zmq.IPV6, 1)

2315
    if bind:
2316
        socket.bind(path)
2317
    else:
2318
        socket.connect(path)
2319
2320
2321
2322
2323

    return socket


@contextlib.contextmanager
2324
2325
2326
def zmq_socket_ctx(
    path: str,
    socket_type: Any,
2327
    bind: bool | None = None,
2328
    linger: int = 0,
2329
    identity: bytes | None = None,
2330
) -> Iterator[zmq.Socket]:
2331
2332
    """Context manager for a ZMQ socket"""

2333
    ctx = zmq.Context()  # type: ignore[attr-defined]
2334
    try:
2335
        yield make_zmq_socket(ctx, path, socket_type, bind=bind, identity=identity)
2336
2337
2338
2339
    except KeyboardInterrupt:
        logger.debug("Got Keyboard Interrupt.")

    finally:
2340
        ctx.destroy(linger=linger)
2341
2342


2343
2344
2345
2346
2347
2348
2349
def _maybe_force_spawn():
    """Check if we need to force the use of the `spawn` multiprocessing start
    method.
    """
    if os.environ.get("VLLM_WORKER_MULTIPROC_METHOD") == "spawn":
        return

2350
2351
    reasons = []
    if is_in_ray_actor():
2352
2353
2354
2355
        # even if we choose to spawn, we need to pass the ray address
        # to the subprocess so that it knows how to connect to the ray cluster.
        # env vars are inherited by subprocesses, even if we use spawn.
        import ray
2356

2357
        os.environ["RAY_ADDRESS"] = ray.get_runtime_context().gcs_address
2358
2359
2360
2361
2362
2363
        reasons.append("In a Ray actor and can only be spawned")

    if cuda_is_initialized():
        reasons.append("CUDA is initialized")
    elif xpu_is_initialized():
        reasons.append("XPU is initialized")
2364

2365
    if reasons:
2366
2367
2368
        logger.warning(
            "We must use the `spawn` multiprocessing start method. "
            "Overriding VLLM_WORKER_MULTIPROC_METHOD to 'spawn'. "
2369
            "See https://docs.vllm.ai/en/latest/usage/"
2370
            "troubleshooting.html#python-multiprocessing "
2371
2372
2373
            "for more information. Reasons: %s",
            "; ".join(reasons),
        )
2374
2375
2376
2377
        os.environ["VLLM_WORKER_MULTIPROC_METHOD"] = "spawn"


def get_mp_context():
2378
2379
2380
2381
2382
2383
2384
    """Get a multiprocessing context with a particular method (spawn or fork).
    By default we follow the value of the VLLM_WORKER_MULTIPROC_METHOD to
    determine the multiprocessing method (default is fork). However, under
    certain conditions, we may enforce spawn and override the value of
    VLLM_WORKER_MULTIPROC_METHOD.
    """
    _maybe_force_spawn()
2385
2386
    mp_method = envs.VLLM_WORKER_MULTIPROC_METHOD
    return multiprocessing.get_context(mp_method)
2387
2388
2389


def bind_kv_cache(
2390
2391
    ctx: dict[str, Any],
    kv_cache: list[list[torch.Tensor]],  # [virtual_engine][layer_index]
2392
    shared_kv_cache_layers: dict[str, str] | None = None,
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
) -> None:
    # Bind the kv_cache tensor to Attention modules, similar to
    # ctx[layer_name].kv_cache[ve]=kv_cache[ve][extract_layer_index(layer_name)]
    # Special things handled here:
    # 1. Some models have non-attention layers, e.g., Jamba
    # 2. Pipeline parallelism, each rank only has a subset of layers
    # 3. Encoder attention has no kv cache
    # 4. Encoder-decoder models, encoder-decoder attention and decoder-only
    #    attention of the same layer (e.g., bart's decoder.layers.1.self_attn
    #    and decoder.layers.1.encoder_attn) is mapped to the same kv cache
    #    tensor
2404
2405
2406
2407
    # 5. Some models have attention layers that share kv cache with previous
    #    layers, this is specified through shared_kv_cache_layers
    if shared_kv_cache_layers is None:
        shared_kv_cache_layers = {}
2408
2409
    from vllm.attention import AttentionType
    from vllm.model_executor.models.utils import extract_layer_index
2410

2411
    layer_need_kv_cache = [
2412
2413
2414
2415
2416
2417
2418
2419
        layer_name
        for layer_name in ctx
        if (
            hasattr(ctx[layer_name], "attn_type")
            and ctx[layer_name].attn_type
            in (AttentionType.DECODER, AttentionType.ENCODER_DECODER)
        )
        and ctx[layer_name].kv_sharing_target_layer_name is None
2420
2421
    ]
    layer_index_sorted = sorted(
2422
2423
        set(extract_layer_index(layer_name) for layer_name in layer_need_kv_cache)
    )
2424
    for layer_name in layer_need_kv_cache:
2425
        kv_cache_idx = layer_index_sorted.index(extract_layer_index(layer_name))
2426
2427
2428
2429
        forward_ctx = ctx[layer_name]
        assert len(forward_ctx.kv_cache) == len(kv_cache)
        for ve, ve_kv_cache in enumerate(kv_cache):
            forward_ctx.kv_cache[ve] = ve_kv_cache[kv_cache_idx]
2430
2431
    if shared_kv_cache_layers is not None:
        for layer_name, target_layer_name in shared_kv_cache_layers.items():
2432
2433
2434
            assert extract_layer_index(target_layer_name) < extract_layer_index(
                layer_name
            ), "v0 doesn't support interleaving kv sharing"
2435
            ctx[layer_name].kv_cache = ctx[target_layer_name].kv_cache
2436
2437


2438
2439
def run_method(
    obj: Any,
2440
    method: str | bytes | Callable,
2441
2442
2443
    args: tuple[Any],
    kwargs: dict[str, Any],
) -> Any:
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
    """
    Run a method of an object with the given arguments and keyword arguments.
    If the method is string, it will be converted to a method using getattr.
    If the method is serialized bytes and will be deserialized using
    cloudpickle.
    If the method is a callable, it will be called directly.
    """
    if isinstance(method, bytes):
        func = partial(cloudpickle.loads(method), obj)
    elif isinstance(method, str):
        try:
            func = getattr(obj, method)
        except AttributeError:
2457
2458
2459
            raise NotImplementedError(
                f"Method {method!r} is not implemented."
            ) from None
2460
2461
2462
    else:
        func = partial(method, obj)  # type: ignore
    return func(*args, **kwargs)
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483


def import_pynvml():
    """
    Historical comments:

    libnvml.so is the library behind nvidia-smi, and
    pynvml is a Python wrapper around it. We use it to get GPU
    status without initializing CUDA context in the current process.
    Historically, there are two packages that provide pynvml:
    - `nvidia-ml-py` (https://pypi.org/project/nvidia-ml-py/): The official
        wrapper. It is a dependency of vLLM, and is installed when users
        install vLLM. It provides a Python module named `pynvml`.
    - `pynvml` (https://pypi.org/project/pynvml/): An unofficial wrapper.
        Prior to version 12.0, it also provides a Python module `pynvml`,
        and therefore conflicts with the official one. What's worse,
        the module is a Python package, and has higher priority than
        the official one which is a standalone Python file.
        This causes errors when both of them are installed.
        Starting from version 12.0, it migrates to a new module
        named `pynvml_utils` to avoid the conflict.
2484
2485
2486
2487
2488
2489
2490
    It is so confusing that many packages in the community use the
    unofficial one by mistake, and we have to handle this case.
    For example, `nvcr.io/nvidia/pytorch:24.12-py3` uses the unofficial
    one, and it will cause errors, see the issue
    https://github.com/vllm-project/vllm/issues/12847 for example.
    After all the troubles, we decide to copy the official `pynvml`
    module to our codebase, and use it directly.
2491
    """
2492
    import vllm.third_party.pynvml as pynvml
2493

2494
    return pynvml
2495
2496


2497
def warn_for_unimplemented_methods(cls: type[T]) -> type[T]:
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
    """
    A replacement for `abc.ABC`.
    When we use `abc.ABC`, subclasses will fail to instantiate
    if they do not implement all abstract methods.
    Here, we only require `raise NotImplementedError` in the
    base class, and log a warning if the method is not implemented
    in the subclass.
    """

    original_init = cls.__init__

    def find_unimplemented_methods(self: object):
        unimplemented_methods = []
        for attr_name in dir(self):
            # bypass inner method
2513
            if attr_name.startswith("_"):
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
                continue

            try:
                attr = getattr(self, attr_name)
                # get the func of callable method
                if callable(attr):
                    attr_func = attr.__func__
            except AttributeError:
                continue
            src = inspect.getsource(attr_func)
            if "NotImplementedError" in src:
                unimplemented_methods.append(attr_name)
        if unimplemented_methods:
2527
2528
            method_names = ",".join(unimplemented_methods)
            msg = f"Methods {method_names} not implemented in {self}"
2529
            logger.debug(msg)
2530
2531
2532
2533
2534
2535

    @wraps(original_init)
    def wrapped_init(self, *args, **kwargs) -> None:
        original_init(self, *args, **kwargs)
        find_unimplemented_methods(self)

2536
    type.__setattr__(cls, "__init__", wrapped_init)
2537
    return cls
2538
2539
2540
2541
2542
2543


class LazyLoader(types.ModuleType):
    """
    LazyLoader module borrowed from Tensorflow
    https://github.com/tensorflow/tensorflow/blob/main/tensorflow/python/util/lazy_loader.py
2544
    with an addition of "module caching".
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588

    Lazily import a module, mainly to avoid pulling in large dependencies.
    Modules such as `xgrammar` might do additional side effects, so we
    only want to use this when it is needed, delaying all eager effects
    """

    def __init__(
        self,
        local_name: str,
        parent_module_globals: dict[str, Any],
        name: str,
    ):
        self._local_name = local_name
        self._parent_module_globals = parent_module_globals
        self._module: types.ModuleType | None = None

        super().__init__(str(name))

    def _load(self) -> types.ModuleType:
        # Import the target module and insert it into the parent's namespace
        try:
            module = importlib.import_module(self.__name__)
            self._parent_module_globals[self._local_name] = module
            # The additional add to sys.modules
            # ensures library is actually loaded.
            sys.modules[self._local_name] = module
        except ModuleNotFoundError as err:
            raise err from None

        # Update this object's dict so that if someone keeps a
        # reference to the LazyLoader, lookups are efficient
        # (__getattr__ is only called on lookups that fail).
        self.__dict__.update(module.__dict__)
        return module

    def __getattr__(self, item: Any) -> Any:
        if self._module is None:
            self._module = self._load()
        return getattr(self._module, item)

    def __dir__(self) -> list[str]:
        if self._module is None:
            self._module = self._load()
        return dir(self._module)
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604


def swap_dict_values(obj: dict[_K, _V], key1: _K, key2: _K) -> None:
    """
    Helper function to swap values for two keys
    """
    v1 = obj.get(key1)
    v2 = obj.get(key2)
    if v1 is not None:
        obj[key2] = v1
    else:
        obj.pop(key2, None)
    if v2 is not None:
        obj[key1] = v2
    else:
        obj.pop(key1, None)
2605
2606
2607


@contextlib.contextmanager
2608
def cprofile_context(save_file: str | None = None):
2609
2610
2611
2612
    """Run a cprofile

    Args:
        save_file: path to save the profile result. "1" or
2613
            None will result in printing to stdout.
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
    """
    import cProfile

    prof = cProfile.Profile()
    prof.enable()

    try:
        yield
    finally:
        prof.disable()
        if save_file and save_file != "1":
            prof.dump_stats(save_file)
        else:
            prof.print_stats(sort="cumtime")


2630
def cprofile(save_file: str | None = None, enabled: bool = True):
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
    """Decorator to profile a Python method using cProfile.

    Args:
        save_file: Path to save the profile result.
            If "1", None, or "", results will be printed to stdout.
        enabled: Set to false to turn this into a no-op
    """

    def decorator(func: Callable):
        @wraps(func)
        def wrapper(*args, **kwargs):
            if not enabled:
                # If profiling is disabled, just call the function directly.
                return func(*args, **kwargs)

            with cprofile_context(save_file):
                return func(*args, **kwargs)

        return wrapper

    return decorator
2652
2653


2654
2655
# Only relevant for models using ALiBi (e.g, MPT)
def check_use_alibi(model_config: ModelConfig) -> bool:
2656
    cfg = model_config.hf_text_config
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
    return (
        getattr(cfg, "alibi", False)  # Falcon
        or (
            "BloomForCausalLM" in getattr(model_config.hf_config, "architectures", [])
        )  # Bloom
        or getattr(cfg, "position_encoding_type", "") == "alibi"  # codellm_1b_alibi
        or (
            hasattr(cfg, "attn_config")  # MPT
            and (
                (
                    isinstance(cfg.attn_config, dict)
                    and cfg.attn_config.get("alibi", False)
                )
                or (
                    not isinstance(cfg.attn_config, dict)
                    and getattr(cfg.attn_config, "alibi", False)
                )
            )
        )
    )
2677
2678


2679
def sha256(input: Any) -> bytes:
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
    """Hash any picklable Python object using SHA-256.

    The input is serialized using pickle before hashing, which allows
    arbitrary Python objects to be used. Note that this function does
    not use a hash seed—if you need one, prepend it explicitly to the input.

    Args:
        input: Any picklable Python object.

    Returns:
2690
        Bytes representing the SHA-256 hash of the serialized input.
2691
2692
    """
    input_bytes = pickle.dumps(input, protocol=pickle.HIGHEST_PROTOCOL)
2693
    return hashlib.sha256(input_bytes).digest()
2694
2695


2696
def sha256_cbor(input: Any) -> bytes:
2697
    """
2698
    Hash objects using CBOR serialization and SHA-256.
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708

    This option is useful for non-Python-dependent serialization and hashing.

    Args:
        input: Object to be serialized and hashed. Supported types include
            basic Python types and complex structures like lists, tuples, and
            dictionaries.
            Custom classes must implement CBOR serialization methods.

    Returns:
2709
        Bytes representing the SHA-256 hash of the CBOR serialized input.
2710
2711
    """
    input_bytes = cbor2.dumps(input, canonical=True)
2712
    return hashlib.sha256(input_bytes).digest()
2713
2714


2715
def get_hash_fn_by_name(hash_fn_name: str) -> Callable[[Any], bytes]:
2716
2717
2718
2719
2720
2721
2722
2723
2724
    """Get a hash function by name, or raise an error if
    the function is not found.
    Args:
        hash_fn_name: Name of the hash function.
    Returns:
        A hash function.
    """
    if hash_fn_name == "sha256":
        return sha256
2725
2726
    if hash_fn_name == "sha256_cbor":
        return sha256_cbor
2727
2728
2729
2730

    raise ValueError(f"Unsupported hash function: {hash_fn_name}")


2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
def is_torch_equal_or_newer(target: str) -> bool:
    """Check if the installed torch version is >= the target version.

    Args:
        target: a version string, like "2.6.0".

    Returns:
        Whether the condition meets.
    """
    try:
2741
        return _is_torch_equal_or_newer(str(torch.__version__), target)
2742
2743
    except Exception:
        # Fallback to PKG-INFO to load the package info, needed by the doc gen.
2744
        return Version(importlib.metadata.version("torch")) >= Version(target)
2745
2746
2747
2748
2749
2750


# Helper function used in testing.
def _is_torch_equal_or_newer(torch_version: str, target: str) -> bool:
    torch_version = version.parse(torch_version)
    return torch_version >= version.parse(target)
2751
2752


2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
def _is_torch_equal(target: str) -> bool:
    assert target.count(".") == 2
    torch_version = str(torch.__version__)
    torch_version = version.parse(torch_version)
    # torch version is like "2.6.0.dev20240101" or "2.6.0.dev20240101+cpu"
    # or "2.6.0+cu128" but never "2.6.0.1"
    return (
        torch_version >= version.parse(target)
        and version.parse(target + ".1") > torch_version
    )


def is_torch_equal(target: str) -> bool:
    """Check if the installed torch version is == the target version.

    Args:
        target: a version string, like "2.6.0".

    Returns:
        Whether the condition meets.
    """
    try:
        return _is_torch_equal(target)
    except Exception:
        return Version(importlib.metadata.version("torch")) == Version(target)


2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
@cache
def _has_module(module_name: str) -> bool:
    """Return True if *module_name* can be found in the current environment.

    The result is cached so that subsequent queries for the same module incur
    no additional overhead.
    """
    return importlib.util.find_spec(module_name) is not None


def has_pplx() -> bool:
    """Whether the optional `pplx_kernels` package is available."""

    return _has_module("pplx_kernels")


def has_deep_ep() -> bool:
    """Whether the optional `deep_ep` package is available."""

    return _has_module("deep_ep")


def has_deep_gemm() -> bool:
    """Whether the optional `deep_gemm` package is available."""

2805
    return _has_module("deep_gemm")
2806
2807


2808
2809
2810
2811
2812
2813
def has_triton_kernels() -> bool:
    """Whether the optional `triton_kernels` package is available."""

    return _has_module("triton_kernels")


2814
2815
2816
2817
2818
2819
def has_tilelang() -> bool:
    """Whether the optional `tilelang` package is available."""

    return _has_module("tilelang")


2820
2821
2822
def set_process_title(
    name: str, suffix: str = "", prefix: str = envs.VLLM_PROCESS_NAME_PREFIX
) -> None:
2823
2824
2825
    """
    Set the current process title to a specific name with an
    optional suffix.
2826
2827

    Args:
2828
        name: The title to assign to the current process.
2829
        suffix: An optional suffix to append to the base name.
2830
        prefix: A prefix to prepend to the front separated by `::`.
2831
2832
2833
    """
    if suffix:
        name = f"{name}_{suffix}"
2834
    setproctitle.setproctitle(f"{prefix}::{name}")
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def _add_prefix(file: TextIO, worker_name: str, pid: int) -> None:
    """Prepend each output line with process-specific prefix"""

    prefix = f"{CYAN}({worker_name} pid={pid}){RESET} "
    file_write = file.write

    def write_with_prefix(s: str):
        if not s:
            return
        if file.start_new_line:  # type: ignore[attr-defined]
            file_write(prefix)
        idx = 0
2849
        while (next_idx := s.find("\n", idx)) != -1:
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            next_idx += 1
            file_write(s[idx:next_idx])
            if next_idx == len(s):
                file.start_new_line = True  # type: ignore[attr-defined]
                return
            file_write(prefix)
            idx = next_idx
        file_write(s[idx:])
        file.start_new_line = False  # type: ignore[attr-defined]

    file.start_new_line = True  # type: ignore[attr-defined]
    file.write = write_with_prefix  # type: ignore[method-assign]


2864
def decorate_logs(process_name: str | None = None) -> None:
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2883
    """
    Adds a process-specific prefix to each line of output written to stdout and
    stderr.

    This function is intended to be called before initializing the api_server,
    engine_core, or worker classes, so that all subsequent output from the
    process is prefixed with the process name and PID. This helps distinguish
    log output from different processes in multi-process environments.

    Args:
        process_name: Optional; the name of the process to use in the prefix.
            If not provided, the current process name from the multiprocessing
            context is used.
    """
    if process_name is None:
        process_name = get_mp_context().current_process().name
    pid = os.getpid()
    _add_prefix(sys.stdout, process_name, pid)
    _add_prefix(sys.stderr, process_name, pid)
2884
2885
2886


def length_from_prompt_token_ids_or_embeds(
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2888
    prompt_token_ids: list[int] | None,
    prompt_embeds: torch.Tensor | None,
2889
) -> int:
2890
    """Calculate the request length (in number of tokens) give either
2891
2892
    prompt_token_ids or prompt_embeds.
    """
2893
2894
    prompt_token_len = None if prompt_token_ids is None else len(prompt_token_ids)
    prompt_embeds_len = None if prompt_embeds is None else len(prompt_embeds)
2895
2896
2897

    if prompt_token_len is None:
        if prompt_embeds_len is None:
2898
            raise ValueError("Neither prompt_token_ids nor prompt_embeds were defined.")
2899
2900
        return prompt_embeds_len
    else:
2901
        if prompt_embeds_len is not None and prompt_embeds_len != prompt_token_len:
2902
2903
2904
            raise ValueError(
                "Prompt token ids and prompt embeds had different lengths"
                f" prompt_token_ids={prompt_token_len}"
2905
2906
                f" prompt_embeds={prompt_embeds_len}"
            )
2907
        return prompt_token_len
2908
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2913
2914
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2916
2917
2918
2919
2920


@contextlib.contextmanager
def set_env_var(key, value):
    old = os.environ.get(key)
    os.environ[key] = value
    try:
        yield
    finally:
        if old is None:
            del os.environ[key]
        else:
            os.environ[key] = old
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2934
2935
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2938
2939
2940


def unique_filepath(fn: Callable[[int], Path]) -> Path:
    """
    unique_filepath returns a unique path by trying
    to include an integer in increasing order.

    fn should be a callable that returns a path that
    includes the passed int at a fixed location.

    Note: This function has a TOCTOU race condition.
    Caller should use atomic operations (e.g., open with 'x' mode)
    when creating the file to ensure thread safety.
    """
    i = 0
    while True:
        p = fn(i)
        if not p.exists():
            return p
        i += 1