Fix constrained decoding (#1634)

python/sglang/srt/managers/schedule_batch.py

@@ -810,6 +810,8 @@ class ScheduleBatch:
             self.sampling_info.regex_fsm_states = [
                 req.regex_fsm_state for req in self.reqs
             ]
+        else:
+            self.sampling_info.regex_fsms = None
 
         return ModelWorkerBatch(
             forward_mode=self.forward_mode,

test/srt/test_json_constrained.py

 import json
 import unittest
+from concurrent.futures import ThreadPoolExecutor
 
 import openai
 import requests
@@ -27,13 +28,18 @@ class TestJSONConstrained(unittest.TestCase):
                 "required": ["name", "population"],
             }
         )
-        cls.process = popen_launch_server(cls.model, cls.base_url, timeout=300)
+        cls.process = popen_launch_server(
+            cls.model,
+            cls.base_url,
+            timeout=300,
+            other_args=["--max-running-requests", "10"],
+        )
 
     @classmethod
     def tearDownClass(cls):
         kill_child_process(cls.process.pid)
 
-    def run_decode(self, return_logprob=False, top_logprobs_num=0, n=1):
+    def run_decode(self, json_schema, return_logprob=False, top_logprobs_num=0, n=1):
         response = requests.post(
             self.base_url + "/generate",
             json={
@@ -43,7 +49,7 @@ class TestJSONConstrained(unittest.TestCase):
                     "max_new_tokens": 128,
                     "n": n,
                     "stop_token_ids": [119690],
-                    "json_schema": self.json_schema,
+                    "json_schema": json_schema,
                 },
                 "stream": False,
                 "return_logprob": return_logprob,
@@ -53,6 +59,10 @@ class TestJSONConstrained(unittest.TestCase):
         )
         print(json.dumps(response.json()))
         print("=" * 100)
+
+        if not json_schema:
+            return
+
         try:
             js_obj = json.loads(response.json()["text"])
         except (TypeError, json.decoder.JSONDecodeError):
@@ -61,7 +71,7 @@ class TestJSONConstrained(unittest.TestCase):
         assert isinstance(js_obj["population"], int)
 
     def test_json_generate(self):
-        self.run_decode()
+        self.run_decode(json_schema=self.json_schema)
 
     def test_json_openai(self):
         client = openai.Client(api_key="EMPTY", base_url=f"{self.base_url}/v1")
@@ -89,6 +99,12 @@ class TestJSONConstrained(unittest.TestCase):
         assert isinstance(js_obj["name"], str)
         assert isinstance(js_obj["population"], int)
 
+    def test_mix_json_and_other(self):
+        json_schemas = [None, None, self.json_schema, self.json_schema] * 10
+
+        with ThreadPoolExecutor(len(json_schemas)) as executor:
+            list(executor.map(self.run_decode, json_schemas))
+
 
 if __name__ == "__main__":
     unittest.main()