feat(shared_storage): prevent event loop blocking in multiprocess mode

Add auxiliary async locks in multiprocess mode to prevent event loop blocking

lightrag/kg/shared_storage.py

@@ -41,6 +41,9 @@ _pipeline_status_lock: Optional[LockType] = None
 _graph_db_lock: Optional[LockType] = None
 _data_init_lock: Optional[LockType] = None
 
+# async locks for coroutine synchronization in multiprocess mode
+_async_locks: Optional[Dict[str, asyncio.Lock]] = None
+
 
 class UnifiedLock(Generic[T]):
     """Provide a unified lock interface type for asyncio.Lock and multiprocessing.Lock"""
@@ -51,12 +54,14 @@ class UnifiedLock(Generic[T]):
         is_async: bool,
         name: str = "unnamed",
         enable_logging: bool = True,
+        async_lock: Optional[asyncio.Lock] = None,
     ):
         self._lock = lock
         self._is_async = is_async
         self._pid = os.getpid()  # for debug only
         self._name = name  # for debug only
         self._enable_logging = enable_logging  # for debug only
+        self._async_lock = async_lock  # auxiliary lock for coroutine synchronization
 
     async def __aenter__(self) -> "UnifiedLock[T]":
         try:
@@ -64,16 +69,35 @@ class UnifiedLock(Generic[T]):
                 f"== Lock == Process {self._pid}: Acquiring lock '{self._name}' (async={self._is_async})",
                 enable_output=self._enable_logging,
             )
+            
+            # If in multiprocess mode and async lock exists, acquire it first
+            if not self._is_async and self._async_lock is not None:
+                direct_log(
+                    f"== Lock == Process {self._pid}: Acquiring async lock for '{self._name}'",
+                    enable_output=self._enable_logging,
+                )
+                await self._async_lock.acquire()
+                direct_log(
+                    f"== Lock == Process {self._pid}: Async lock for '{self._name}' acquired",
+                    enable_output=self._enable_logging,
+                )
+            
+            # Then acquire the main lock
             if self._is_async:
                 await self._lock.acquire()
             else:
                 self._lock.acquire()
+                
             direct_log(
                 f"== Lock == Process {self._pid}: Lock '{self._name}' acquired (async={self._is_async})",
                 enable_output=self._enable_logging,
             )
             return self
         except Exception as e:
+            # If main lock acquisition fails, release the async lock if it was acquired
+            if not self._is_async and self._async_lock is not None and self._async_lock.locked():
+                self._async_lock.release()
+                
             direct_log(
                 f"== Lock == Process {self._pid}: Failed to acquire lock '{self._name}': {e}",
                 level="ERROR",
@@ -82,15 +106,29 @@ class UnifiedLock(Generic[T]):
             raise
 
     async def __aexit__(self, exc_type, exc_val, exc_tb):
+        main_lock_released = False
         try:
             direct_log(
                 f"== Lock == Process {self._pid}: Releasing lock '{self._name}' (async={self._is_async})",
                 enable_output=self._enable_logging,
             )
+            
+            # Release main lock first
             if self._is_async:
                 self._lock.release()
             else:
                 self._lock.release()
+            
+            main_lock_released = True
+                
+            # Then release async lock if in multiprocess mode
+            if not self._is_async and self._async_lock is not None:
+                direct_log(
+                    f"== Lock == Process {self._pid}: Releasing async lock for '{self._name}'",
+                    enable_output=self._enable_logging,
+                )
+                self._async_lock.release()
+                
             direct_log(
                 f"== Lock == Process {self._pid}: Lock '{self._name}' released (async={self._is_async})",
                 enable_output=self._enable_logging,
@@ -101,6 +139,27 @@ class UnifiedLock(Generic[T]):
                 level="ERROR",
                 enable_output=self._enable_logging,
             )
+            
+            # If main lock release failed but async lock hasn't been released, try to release it
+            if not main_lock_released and not self._is_async and self._async_lock is not None:
+                try:
+                    direct_log(
+                        f"== Lock == Process {self._pid}: Attempting to release async lock after main lock failure",
+                        level="WARNING",
+                        enable_output=self._enable_logging,
+                    )
+                    self._async_lock.release()
+                    direct_log(
+                        f"== Lock == Process {self._pid}: Successfully released async lock after main lock failure",
+                        enable_output=self._enable_logging,
+                    )
+                except Exception as inner_e:
+                    direct_log(
+                        f"== Lock == Process {self._pid}: Failed to release async lock after main lock failure: {inner_e}",
+                        level="ERROR",
+                        enable_output=self._enable_logging,
+                    )
+            
             raise
 
     def __enter__(self) -> "UnifiedLock[T]":
@@ -151,51 +210,61 @@ class UnifiedLock(Generic[T]):
 
 def get_internal_lock(enable_logging: bool = False) -> UnifiedLock:
     """return unified storage lock for data consistency"""
+    async_lock = _async_locks.get("internal_lock") if is_multiprocess else None
     return UnifiedLock(
         lock=_internal_lock,
         is_async=not is_multiprocess,
         name="internal_lock",
         enable_logging=enable_logging,
+        async_lock=async_lock,
     )
 
 
 def get_storage_lock(enable_logging: bool = False) -> UnifiedLock:
     """return unified storage lock for data consistency"""
+    async_lock = _async_locks.get("storage_lock") if is_multiprocess else None
     return UnifiedLock(
         lock=_storage_lock,
         is_async=not is_multiprocess,
         name="storage_lock",
         enable_logging=enable_logging,
+        async_lock=async_lock,
     )
 
 
 def get_pipeline_status_lock(enable_logging: bool = False) -> UnifiedLock:
     """return unified storage lock for data consistency"""
+    async_lock = _async_locks.get("pipeline_status_lock") if is_multiprocess else None
     return UnifiedLock(
         lock=_pipeline_status_lock,
         is_async=not is_multiprocess,
         name="pipeline_status_lock",
         enable_logging=enable_logging,
+        async_lock=async_lock,
     )
 
 
 def get_graph_db_lock(enable_logging: bool = False) -> UnifiedLock:
     """return unified graph database lock for ensuring atomic operations"""
+    async_lock = _async_locks.get("graph_db_lock") if is_multiprocess else None
     return UnifiedLock(
         lock=_graph_db_lock,
         is_async=not is_multiprocess,
         name="graph_db_lock",
         enable_logging=enable_logging,
+        async_lock=async_lock,
     )
 
 
 def get_data_init_lock(enable_logging: bool = False) -> UnifiedLock:
     """return unified data initialization lock for ensuring atomic data initialization"""
+    async_lock = _async_locks.get("data_init_lock") if is_multiprocess else None
     return UnifiedLock(
         lock=_data_init_lock,
         is_async=not is_multiprocess,
         name="data_init_lock",
         enable_logging=enable_logging,
+        async_lock=async_lock,
     )
 
 
@@ -229,7 +298,8 @@ def initialize_share_data(workers: int = 1):
         _shared_dicts, \
         _init_flags, \
         _initialized, \
-        _update_flags
+        _update_flags, \
+        _async_locks
 
     # Check if already initialized
     if _initialized:
@@ -251,6 +321,16 @@ def initialize_share_data(workers: int = 1):
         _shared_dicts = _manager.dict()
         _init_flags = _manager.dict()
         _update_flags = _manager.dict()
+        
+        # Initialize async locks for multiprocess mode
+        _async_locks = {
+            "internal_lock": asyncio.Lock(),
+            "storage_lock": asyncio.Lock(),
+            "pipeline_status_lock": asyncio.Lock(),
+            "graph_db_lock": asyncio.Lock(),
+            "data_init_lock": asyncio.Lock(),
+        }
+        
         direct_log(
             f"Process {os.getpid()} Shared-Data created for Multiple Process (workers={workers})"
         )
@@ -264,6 +344,7 @@ def initialize_share_data(workers: int = 1):
         _shared_dicts = {}
         _init_flags = {}
         _update_flags = {}
+        _async_locks = None  # No need for async locks in single process mode
         direct_log(f"Process {os.getpid()} Shared-Data created for Single Process")
 
     # Mark as initialized
@@ -458,7 +539,8 @@ def finalize_share_data():
         _shared_dicts, \
         _init_flags, \
         _initialized, \
-        _update_flags
+        _update_flags, \
+        _async_locks
 
     # Check if already initialized
     if not _initialized:
@@ -523,5 +605,6 @@ def finalize_share_data():
     _graph_db_lock = None
     _data_init_lock = None
     _update_flags = None
+    _async_locks = None
 
     direct_log(f"Process {os.getpid()} storage data finalization complete")