Add a /free route to unload models or free all memory.

A POST request to /free with: {"unload_models":true}
will unload models from vram.

A POST request to /free with: {"free_memory":true}
will unload models and free all cached data from the last run workflow.

execution.py

@@ -268,11 +268,14 @@ def recursive_output_delete_if_changed(prompt, old_prompt, outputs, current_item
 
 class PromptExecutor:
     def __init__(self, server):
+        self.server = server
+        self.reset()
+
+    def reset(self):
         self.outputs = {}
         self.object_storage = {}
         self.outputs_ui = {}
         self.old_prompt = {}
-        self.server = server
 
     def handle_execution_error(self, prompt_id, prompt, current_outputs, executed, error, ex):
         node_id = error["node_id"]
@@ -706,6 +709,7 @@ class PromptQueue:
         self.queue = []
         self.currently_running = {}
         self.history = {}
+        self.flags = {}
         server.prompt_queue = self
 
     def put(self, item):
@@ -792,3 +796,17 @@ class PromptQueue:
     def delete_history_item(self, id_to_delete):
         with self.mutex:
             self.history.pop(id_to_delete, None)
+
+    def set_flag(self, name, data):
+        with self.mutex:
+            self.flags[name] = data
+            self.not_empty.notify()
+
+    def get_flags(self, reset=True):
+        with self.mutex:
+            if reset:
+                ret = self.flags
+                self.flags = {}
+                return ret
+            else:
+                return self.flags.copy()

main.py

@@ -97,7 +97,7 @@ def prompt_worker(q, server):
     gc_collect_interval = 10.0
 
     while True:
-        timeout = None
+        timeout = 1000.0
         if need_gc:
             timeout = max(gc_collect_interval - (current_time - last_gc_collect), 0.0)
 
@@ -118,6 +118,19 @@ def prompt_worker(q, server):
             execution_time = current_time - execution_start_time
             print("Prompt executed in {:.2f} seconds".format(execution_time))
 
+        flags = q.get_flags()
+        free_memory = flags.get("free_memory", False)
+
+        if flags.get("unload_models", free_memory):
+            comfy.model_management.unload_all_models()
+            need_gc = True
+            last_gc_collect = 0
+
+        if free_memory:
+            e.reset()
+            need_gc = True
+            last_gc_collect = 0
+
         if need_gc:
             current_time = time.perf_counter()
             if (current_time - last_gc_collect) > gc_collect_interval:

server.py

@@ -507,6 +507,17 @@ class PromptServer():
             nodes.interrupt_processing()
             return web.Response(status=200)
 
+        @routes.post("/free")
+        async def post_interrupt(request):
+            json_data = await request.json()
+            unload_models = json_data.get("unload_models", False)
+            free_memory = json_data.get("free_memory", False)
+            if unload_models:
+                self.prompt_queue.set_flag("unload_models", unload_models)
+            if free_memory:
+                self.prompt_queue.set_flag("free_memory", free_memory)
+            return web.Response(status=200)
+
         @routes.post("/history")
         async def post_history(request):
             json_data =  await request.json()