/*++ Copyright (c) 1995 Microsoft Corporation Module Name: common\trace\worker.c Abstract: Worker threads for the router process Revision History: Gurdeep Singh Pall 7/28/95 Created 12-10-97: lokeshs: removed blocking of InitializeWorkerThread() on initialization of the first AlertableThread() created --*/ #include #include #include #include #include #include #include #include //#define STRSAFE_LIB #include #include "trace.h" #include "workerinc.h" // Time that thread has to be idle before exiting LARGE_INTEGER ThreadIdleTO = { (ULONG)(THREAD_IDLE_TIMEOUT*(-10000000)), 0xFFFFFFFF}; // Time that the worker queue is not served before starting new thread CONST LARGE_INTEGER WorkQueueTO = { (ULONG)(WORK_QUEUE_TIMEOUT*(-10000000)), 0xFFFFFFFF}; // Total number of threads LONG ThreadCount; // Number of threads waiting on the completion port LONG ThreadsWaiting; // Min allowed number of threads LONG MinThreads; // Completion port for threads to wait on HANDLE WorkQueuePort; // Timer to intiate creation of new thread if worker queue is not // server within a timeout HANDLE WorkQueueTimer; // Queue for alertable work items LIST_ENTRY AlertableWorkQueue ; // Lock for the alertable work item queue CRITICAL_SECTION AlertableWorkQueueLock ; // Heap for alertable work items HANDLE AlertableWorkerHeap ; // Worker Semaphore used for releasing alertable worker threads HANDLE AlertableThreadSemaphore; // Number of alertable threads LONG AlertableThreadCount; volatile LONG WorkersInitialized=WORKERS_NOT_INITIALIZED; //* WorkerThread() // // Function: Thread to execute work items in. // // Returns: Nothing // //* DWORD APIENTRY WorkerThread ( LPVOID param ) { // It'll be waiting InterlockedIncrement (&ThreadsWaiting); do { LPOVERLAPPED_COMPLETION_ROUTINE completionRoutine; NTSTATUS status; PVOID context; IO_STATUS_BLOCK ioStatus; status = NtRemoveIoCompletion ( WorkQueuePort, (PVOID *)&completionRoutine, &context, &ioStatus, &ThreadIdleTO); if (NT_SUCCESS (status)) { switch (status) { // We did dequeue a work item case STATUS_SUCCESS: if (InterlockedExchangeAdd (&ThreadsWaiting, -1)==1) { // Last thread to wait, start the timer // to create a new thread SetWaitableTimer (WorkQueueTimer, &WorkQueueTO, 0, NULL, NULL, FALSE); } // Execute work item/completion routine completionRoutine ( // Quick check for success that all work items // and most of IRP complete with (ioStatus.Status==STATUS_SUCCESS) ? NO_ERROR : RtlNtStatusToDosError (ioStatus.Status), (DWORD)ioStatus.Information, (LPOVERLAPPED)context); if (InterlockedExchangeAdd (&ThreadsWaiting, 1)==0) { // Cancel time if this is the first thread // to return CancelWaitableTimer (WorkQueueTimer); } break; // Thread was not used for ThreadIdle timeout, see // if we need to quit case STATUS_TIMEOUT: while (1) { // Make a local copy of the count and // attempt to atomically check and update // it if necessary LONG count = ThreadCount; // Quick check for min thread condition if (count<=MinThreads) break; else { // Attempt to decrease the count // use another local variable // because of MIPS optimizer bug LONG newCount = count-1; if (InterlockedCompareExchange (&ThreadCount, newCount, count)==count) { // Succeded, exit the thread goto ExitThread; } // else try again } } break; default: ASSERTMSG ("Unexpected status code returned ", FALSE); break; } } // Execute while we are initialized } while (WorkersInitialized==WORKERS_INITIALIZED); ExitThread: InterlockedDecrement (&ThreadsWaiting); return 0; } //* AlertableWorkerThread() // // Function: Alertable work item thread // // Returns: Nothing // //* DWORD APIENTRY AlertableWorkerThread ( LPVOID param ) { HANDLE WaitArray [] = { #define ALERTABLE_THREAD_SEMAPHORE WAIT_OBJECT_0 AlertableThreadSemaphore, #define WORK_QUEUE_TIMER (WAIT_OBJECT_0+1) WorkQueueTimer }; do { WorkItem *workitem; DWORD rc; // Wait for signal to run // rc = WaitForMultipleObjectsEx ( sizeof (WaitArray)/sizeof (WaitArray[0]), WaitArray, FALSE, INFINITE, TRUE); switch (rc) { case ALERTABLE_THREAD_SEMAPHORE: // Pick up and execute the worker EnterCriticalSection (&AlertableWorkQueueLock); ASSERT (!IsListEmpty (&AlertableWorkQueue)); workitem = (WorkItem *) RemoveHeadList (&AlertableWorkQueue) ; LeaveCriticalSection (&AlertableWorkQueueLock); (workitem->WI_Function) (workitem->WI_Context); HeapFree (AlertableWorkerHeap, 0, workitem); break; case WORK_QUEUE_TIMER: // Work queue has not been served wothin specified // timeout while (1) { // Make a local copy of the count LONG count = ThreadCount; // Make sure we havn't exceded the limit if (count>=MAX_WORKER_THREADS) break; else { // Try to increment the value // use another local variable // because of MIPS optimizer bug LONG newCount = count+1; if (InterlockedCompareExchange (&ThreadCount, newCount, count)==count) { HANDLE hThread; DWORD tid; // Create new thread if increment succeded hThread = CreateThread (NULL, 0, WorkerThread, NULL, 0, &tid); if (hThread!=NULL) { CloseHandle (hThread); } else // Restore the value if thread creation // failed InterlockedDecrement (&ThreadCount); break; } // else repeat the loop if ThreadCount was modified // while we were checking } } break; case WAIT_IO_COMPLETION: // Handle IO completion break; case 0xFFFFFFFF: // Error, we must have closed the semaphore handle break; default: ASSERTMSG ("Unexpected rc from WaitForObject ", FALSE); } } while (WorkersInitialized==WORKERS_INITIALIZED); return 0 ; } //* WorkerCompletionRoutine // // Function: Worker function wrapper for non-io work items // VOID WINAPI WorkerCompletionRoutine ( DWORD dwErrorCode, PVOID ActualContext, LPOVERLAPPED ActualCompletionRoutine ) { UNREFERENCED_PARAMETER (dwErrorCode); ((WORKERFUNCTION)ActualCompletionRoutine)(ActualContext); } //* InitializeWorkerThread() // // Function: Called by the first work item // // Returns: WORKERS_INITIALIZED if successful. // WORKERS_NOT_INITIALIZED not. //* LONG InitializeWorkerThread ( LONG initFlag ) { DWORD dwErr; #if 0 if (initFlag==WORKERS_INITIALIZING) { #if DBG DbgPrint ("RTUTILS: %lx - waiting for worker initialization.\n", GetCurrentThreadId ()); #endif while (WorkersInitialized==WORKERS_INITIALIZING) Sleep (100); #if DBG DbgPrint ("RTUTILS: %lx - wait for worker initialization done.\n", GetCurrentThreadId ()); #endif } if (WorkersInitialized==WORKERS_INITIALIZED) { return WORKERS_INITIALIZED; } else { INT i; DWORD tid; HANDLE threadhandle; SYSTEM_INFO systeminfo; // Get number of processors // GetSystemInfo (&systeminfo) ; MinThreads = systeminfo.dwNumberOfProcessors; ThreadsWaiting = 0; // Init critical section // InitializeCriticalSection (&AlertableWorkQueueLock); // Initialize work queue // InitializeListHead (&AlertableWorkQueue) ; // Allocate private heap // AlertableWorkerHeap = HeapCreate (0, // no flags systeminfo.dwPageSize,// initial heap size 0); // no maximum size if (AlertableWorkerHeap != NULL) { // Create counting semaphore for releasing alertable threads AlertableThreadSemaphore = CreateSemaphore(NULL, // No security 0, // Initial value MAXLONG, // Max items to queue NULL); // No name if (AlertableThreadSemaphore!=NULL) { // Create completion port for work items WorkQueuePort = CreateIoCompletionPort ( INVALID_HANDLE_VALUE, // Just create a port, no file yet NULL, // New port 0, // Key is ignored MAX_WORKER_THREADS); // Number of active threads if (WorkQueuePort!=NULL) { // Create timer to trigger creation of // new threads if work queue is not served // for the specified timeout WorkQueueTimer = CreateWaitableTimer ( NULL, // No security FALSE, // auto-reset NULL); // No name if (WorkQueueTimer!=NULL) { // Start Alertable threads // // // initialize the global structure for wait threads // dwErr = InitializeWaitGlobal(); if (dwErr!=NO_ERROR) { DeInitializeWaitGlobal(); goto ThreadCreationError; } /*WTG.g_InitializedEvent = CreateEvent(NULL, FALSE, FALSE, NULL); if (WTG.g_InitializedEvent==NULL) goto ThreadCreationError; */ // // create one alertable thread and wait for it to get initialized // This makes sure that at least one server thread is initialized // before the others attemp to use it. // i =0; threadhandle = CreateThread ( NULL, // No security 0, // Default stack AlertableWaitWorkerThread,// Start routine (PVOID)(LONG_PTR)i, // Thread param 0, // No flags &tid); if (threadhandle!=NULL) CloseHandle (threadhandle); else goto ThreadCreationError; /* WaitForSingleObject(WTG.g_InitializedEvent, INFINITE); CloseHandle(WTG.g_InitializedEvent); */ /* // // create the other alertable threads but dont wait on them to // get initialization // for (i=1; i < NUM_ALERTABLE_THREADS; i++) { threadhandle = CreateThread ( NULL, // No security 0, // Default stack AlertableWaitWorkerThread,// Start routine (PVOID)(LONG_PTR)i, // Thread id 0, // No flags &tid); if (threadhandle!=NULL) CloseHandle (threadhandle); else goto ThreadCreationError; } */ // Start the rest of worker threads // for (i=0; i < MinThreads; i++) { threadhandle = CreateThread ( NULL, // No security 0, // Default stack WorkerThread,// Start routine NULL, // No parameter 0, // No flags &tid) ; if (threadhandle!=NULL) CloseHandle (threadhandle); else goto ThreadCreationError; } ThreadCount = i; WorkersInitialized = WORKERS_INITIALIZED; return WORKERS_INITIALIZED; ThreadCreationError: // Cleanup in case of failure // Threads will exit by themselves when objects are // deleted CloseHandle (WorkQueueTimer); } CloseHandle (WorkQueuePort); } CloseHandle (AlertableThreadSemaphore); } HeapDestroy (AlertableWorkerHeap); } DeleteCriticalSection (&AlertableWorkQueueLock); #if DBG DbgPrint ("RTUTILS: %lx - worker initialization failed (%ld).\n", GetCurrentThreadId (), GetLastError ()); #endif return WORKERS_NOT_INITIALIZED; } #endif return WORKERS_NOT_INITIALIZED; } //* StopWorkers() // // Function: Cleanup worker thread when dll is unloaded // //* VOID StopWorkers ( VOID ) { // Make sure we were initialized if (WorkersInitialized==WORKERS_INITIALIZED) { // All work items should have been completed // already (no other components should be using // our routines or we shouldn't have been unloaded) // Set the flag telling all threads to quit WorkersInitialized = WORKERS_NOT_INITIALIZED; // Close all syncronization objects (this should // terminate the wait) if (WorkQueueTimer) CloseHandle (WorkQueueTimer); if (WorkQueuePort) CloseHandle (WorkQueuePort); if (AlertableThreadSemaphore) CloseHandle (AlertableThreadSemaphore); // Let threads complete Sleep (1000); // Destroy the rest if (AlertableWorkerHeap) HeapDestroy (AlertableWorkerHeap); DeleteCriticalSection (&AlertableWorkQueueLock); } } //* QueueWorkItem() // // Function: Queues the supplied work item in the work queue. // // Returns: 0 (success) // Win32 error codes for cases like out of memory // //* DWORD APIENTRY QueueWorkItem (WORKERFUNCTION functionptr, PVOID context, BOOL serviceinalertablethread) { DWORD retcode ; LONG initFlag; if (functionptr == NULL) return ERROR_INVALID_PARAMETER; // if uninitialized, attempt to initialize worker threads // if (!ENTER_WORKER_API) { retcode = GetLastError(); return (retcode == NO_ERROR ? ERROR_CAN_NOT_COMPLETE : retcode); } // based on this flag insert in either the alertablequeue or the workerqueue // if (!serviceinalertablethread) { NTSTATUS status; // Use completion port to execute the item status = NtSetIoCompletion ( WorkQueuePort, // Port (PVOID)WorkerCompletionRoutine, // Completion routine functionptr, // Apc context STATUS_SUCCESS, // Status (ULONG_PTR)context); // Information () if (status==STATUS_SUCCESS) retcode = NO_ERROR; else retcode = RtlNtStatusToDosError (status); } else { // Create and queue work item WorkItem *workitem ; workitem = (WorkItem *) HeapAlloc ( AlertableWorkerHeap, 0, // No flags sizeof (WorkItem)); if (workitem != NULL) { workitem->WI_Function = functionptr ; workitem->WI_Context = context ; EnterCriticalSection (&AlertableWorkQueueLock) ; InsertTailList (&AlertableWorkQueue, &workitem->WI_List) ; LeaveCriticalSection (&AlertableWorkQueueLock) ; // let a worker thread run if waiting // ReleaseSemaphore (AlertableThreadSemaphore, 1, NULL) ; retcode = 0 ; } else retcode = ERROR_NOT_ENOUGH_MEMORY ; } return retcode ; } // Function: Associates file handle with the completion port (all // asynchronous io on this handle will be queued to the // completion port) // // FileHandle: file handle to be associated with completion port // CompletionProc: procedure to be called when io associated with // the file handle completes. This function will be // executed in the context of non-alertable worker thread DWORD APIENTRY SetIoCompletionProc ( IN HANDLE FileHandle, IN LPOVERLAPPED_COMPLETION_ROUTINE CompletionProc ) { HANDLE hdl; LONG initFlag; DWORD retcode; if (!CompletionProc) return ERROR_INVALID_PARAMETER; if (FileHandle==NULL || FileHandle==INVALID_HANDLE_VALUE) return ERROR_INVALID_PARAMETER; // if uninitialized, attempt to initialize worker threads // if (!ENTER_WORKER_API) { retcode = GetLastError(); return (retcode == NO_ERROR ? ERROR_CAN_NOT_COMPLETE : retcode); } hdl = CreateIoCompletionPort (FileHandle, WorkQueuePort, (UINT_PTR)CompletionProc, 0); if (hdl!=NULL) return NO_ERROR; else return GetLastError (); }