diff options
Diffstat (limited to 'unix/tclUnixNotfy.c')
| -rw-r--r-- | unix/tclUnixNotfy.c | 355 |
1 files changed, 226 insertions, 129 deletions
diff --git a/unix/tclUnixNotfy.c b/unix/tclUnixNotfy.c index b234667..2b648ca 100644 --- a/unix/tclUnixNotfy.c +++ b/unix/tclUnixNotfy.c @@ -1,3 +1,5 @@ +#define AT_FORK_INIT_VALUE 0 +#define RESET_ATFORK_MUTEX 1 /* * tclUnixNotify.c -- * @@ -97,10 +99,11 @@ typedef struct ThreadSpecificData { * by sending this event. */ void *hwnd; /* Messaging window. */ #else /* !__CYGWIN__ */ - Tcl_Condition waitCV; /* Any other thread alerts a notifier that an + pthread_cond_t waitCV; /* Any other thread alerts a notifier that an * event is ready to be processed by signaling * this condition variable. */ #endif /* __CYGWIN__ */ + int waitCVinitialized; /* Variable to flag initialization of the structure */ int eventReady; /* True if an event is ready to be processed. * Used as condition flag together with waitCV * above. */ @@ -120,15 +123,6 @@ static Tcl_ThreadDataKey dataKey; static int notifierCount = 0; /* - * The following static stores the process ID of the initialized notifier - * thread. If it changes, we have passed a fork and we should start a new - * notifier thread. - * - * You must hold the notifierMutex lock before accessing this variable. - */ -static pid_t processIDInitialized = 0; - -/* * The following variable points to the head of a doubly-linked list of * ThreadSpecificData structures for all threads that are currently waiting on * an event. @@ -158,7 +152,15 @@ static int triggerPipe = -1; * The notifierMutex locks access to all of the global notifier state. */ -TCL_DECLARE_MUTEX(notifierMutex) +pthread_mutex_t notifierInitMutex = PTHREAD_MUTEX_INITIALIZER; +pthread_mutex_t notifierMutex = PTHREAD_MUTEX_INITIALIZER; +/* + * The following static indicates if the notifier thread is running. + * + * You must hold the notifierInitMutex before accessing this variable. + */ + +static int notifierThreadRunning = 0; /* * The notifier thread signals the notifierCV when it has finished @@ -166,7 +168,7 @@ TCL_DECLARE_MUTEX(notifierMutex) * terminates. */ -static Tcl_Condition notifierCV; +static pthread_cond_t notifierCV = PTHREAD_COND_INITIALIZER; /* * The pollState bits @@ -194,15 +196,15 @@ static Tcl_ThreadId notifierThread; #ifdef TCL_THREADS static void NotifierThreadProc(ClientData clientData); -#if defined(HAVE_PTHREAD_ATFORK) && !defined(__APPLE__) && !defined(__hpux) -static int atForkInit = 0; +#if defined(HAVE_PTHREAD_ATFORK) +static int atForkInit = AT_FORK_INIT_VALUE; static void AtForkPrepare(void); static void AtForkParent(void); static void AtForkChild(void); #endif /* HAVE_PTHREAD_ATFORK */ #endif /* TCL_THREADS */ static int FileHandlerEventProc(Tcl_Event *evPtr, int flags); - + /* * Import of Windows API when building threaded with Cygwin. */ @@ -251,13 +253,58 @@ extern unsigned char __stdcall ResetEvent(void *); extern unsigned char __stdcall TranslateMessage(const MSG *); /* - * Threaded-cygwin specific functions in this file: + * Threaded-cygwin specific constants and functions in this file: */ +static const WCHAR NotfyClassName[] = L"TclNotifier"; static DWORD __stdcall NotifierProc(void *hwnd, unsigned int message, void *wParam, void *lParam); #endif /* TCL_THREADS && __CYGWIN__ */ +#if TCL_THREADS +/* + *---------------------------------------------------------------------- + * + * StartNotifierThread -- + * + * Start a notfier thread and wait for the notifier pipe to be created. + * + * Results: + * None. + * + * Side effects: + * Running Thread. + * + *---------------------------------------------------------------------- + */ +static void +StartNotifierThread(const char *proc) +{ + if (!notifierThreadRunning) { + pthread_mutex_lock(¬ifierInitMutex); + if (!notifierThreadRunning) { + if (TclpThreadCreate(¬ifierThread, NotifierThreadProc, NULL, + TCL_THREAD_STACK_DEFAULT, TCL_THREAD_JOINABLE) != TCL_OK) { + Tcl_Panic("%s: unable to start notifier thread", proc); + } + + pthread_mutex_lock(¬ifierMutex); + /* + * Wait for the notifier pipe to be created. + */ + + while (triggerPipe < 0) { + pthread_cond_wait(¬ifierCV, ¬ifierMutex); + } + pthread_mutex_unlock(¬ifierMutex); + + notifierThreadRunning = 1; + } + pthread_mutex_unlock(¬ifierInitMutex); + } +} +#endif /* TCL_THREADS */ + /* *---------------------------------------------------------------------- * @@ -286,13 +333,39 @@ Tcl_InitNotifier(void) tsdPtr->eventReady = 0; /* - * Start the Notifier thread if necessary. + * Initialize thread specific condition variable for this thread. */ + if (tsdPtr->waitCVinitialized == 0) { +#ifdef __CYGWIN__ + WNDCLASS class; + + class.style = 0; + class.cbClsExtra = 0; + class.cbWndExtra = 0; + class.hInstance = TclWinGetTclInstance(); + class.hbrBackground = NULL; + class.lpszMenuName = NULL; + class.lpszClassName = NotfyClassName; + class.lpfnWndProc = NotifierProc; + class.hIcon = NULL; + class.hCursor = NULL; + + RegisterClassW(&class); + tsdPtr->hwnd = CreateWindowExW(NULL, class.lpszClassName, + class.lpszClassName, 0, 0, 0, 0, 0, NULL, NULL, + TclWinGetTclInstance(), NULL); + tsdPtr->event = CreateEventW(NULL, 1 /* manual */, + 0 /* !signaled */, NULL); +#else + pthread_cond_init(&tsdPtr->waitCV, NULL); +#endif /* __CYGWIN__ */ + tsdPtr->waitCVinitialized = 1; + } - Tcl_MutexLock(¬ifierMutex); -#if defined(HAVE_PTHREAD_ATFORK) && !defined(__APPLE__) && !defined(__hpux) + pthread_mutex_lock(¬ifierInitMutex); +#if defined(HAVE_PTHREAD_ATFORK) /* - * Install pthread_atfork handlers to reinitialize the notifier in the + * Install pthread_atfork handlers to clean up the notifier in the * child of a fork. */ @@ -305,35 +378,11 @@ Tcl_InitNotifier(void) atForkInit = 1; } #endif /* HAVE_PTHREAD_ATFORK */ - /* - * Check if my process id changed, e.g. I was forked - * In this case, restart the notifier thread and close the - * pipe to the original notifier thread - */ - if (notifierCount > 0 && processIDInitialized != getpid()) { - notifierCount = 0; - processIDInitialized = 0; - close(triggerPipe); - triggerPipe = -1; - } - if (notifierCount == 0) { - if (TclpThreadCreate(¬ifierThread, NotifierThreadProc, NULL, - TCL_THREAD_STACK_DEFAULT, TCL_THREAD_JOINABLE) != TCL_OK) { - Tcl_Panic("Tcl_InitNotifier: unable to start notifier thread"); - } - processIDInitialized = getpid(); - } - notifierCount++; - /* - * Wait for the notifier pipe to be created. - */ + notifierCount++; - while (triggerPipe < 0) { - Tcl_ConditionWait(¬ifierCV, ¬ifierMutex, NULL); - } + pthread_mutex_unlock(¬ifierInitMutex); - Tcl_MutexUnlock(¬ifierMutex); #endif /* TCL_THREADS */ return tsdPtr; } @@ -368,7 +417,7 @@ Tcl_FinalizeNotifier( #ifdef TCL_THREADS ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); - Tcl_MutexLock(¬ifierMutex); + pthread_mutex_lock(¬ifierInitMutex); notifierCount--; /* @@ -377,37 +426,25 @@ Tcl_FinalizeNotifier( */ if (notifierCount == 0) { - int result; - - if (triggerPipe < 0) { - Tcl_Panic("Tcl_FinalizeNotifier: %s", - "notifier pipe not initialized"); - } - /* - * Send "q" message to the notifier thread so that it will - * terminate. The notifier will return from its call to select() - * and notice that a "q" message has arrived, it will then close - * its side of the pipe and terminate its thread. Note the we can - * not just close the pipe and check for EOF in the notifier thread - * because if a background child process was created with exec, - * select() would not register the EOF on the pipe until the child - * processes had terminated. [Bug: 4139] [Bug: 1222872] - */ - - if (write(triggerPipe, "q", 1) != 1) { - Tcl_Panic("Tcl_FinalizeNotifier: %s", - "unable to write q to triggerPipe"); - } - close(triggerPipe); - while(triggerPipe >= 0) { - Tcl_ConditionWait(¬ifierCV, ¬ifierMutex, NULL); - } + if (triggerPipe != -1) { + if (write(triggerPipe, "q", 1) != 1) { + Tcl_Panic("Tcl_FinalizeNotifier: %s", + "unable to write q to triggerPipe"); + } + close(triggerPipe); + while(triggerPipe != -1) { + pthread_cond_wait(¬ifierCV, ¬ifierMutex); + } + if (notifierThreadRunning) { + int result = pthread_join((pthread_t) notifierThread, NULL); - result = Tcl_JoinThread(notifierThread, NULL); - if (result) { - Tcl_Panic("Tcl_FinalizeNotifier: %s", - "unable to join notifier thread"); + if (result) { + Tcl_Panic("Tcl_FinalizeNotifier: unable to join notifier " + "thread"); + } + notifierThreadRunning = 0; + } } } @@ -416,12 +453,14 @@ Tcl_FinalizeNotifier( */ #ifdef __CYGWIN__ + DestroyWindow(tsdPtr->hwnd); CloseHandle(tsdPtr->event); #else /* __CYGWIN__ */ - Tcl_ConditionFinalize(&(tsdPtr->waitCV)); + pthread_cond_destroy(&tsdPtr->waitCV); #endif /* __CYGWIN__ */ + tsdPtr->waitCVinitialized = 0; - Tcl_MutexUnlock(¬ifierMutex); + pthread_mutex_unlock(¬ifierInitMutex); #endif /* TCL_THREADS */ } } @@ -456,14 +495,15 @@ Tcl_AlertNotifier( #ifdef TCL_THREADS ThreadSpecificData *tsdPtr = clientData; - Tcl_MutexLock(¬ifierMutex); + pthread_mutex_lock(¬ifierMutex); tsdPtr->eventReady = 1; + # ifdef __CYGWIN__ PostMessageW(tsdPtr->hwnd, 1024, 0, 0); # else - Tcl_ConditionNotify(&tsdPtr->waitCV); + pthread_cond_broadcast(&tsdPtr->waitCV); # endif /* __CYGWIN__ */ - Tcl_MutexUnlock(¬ifierMutex); + pthread_mutex_unlock(¬ifierMutex); #endif /* TCL_THREADS */ } } @@ -526,8 +566,10 @@ Tcl_ServiceModeHook( if (tclNotifierHooks.serviceModeHookProc) { tclNotifierHooks.serviceModeHookProc(mode); return; - } else { - /* Does nothing in this implementation. */ + } else if (mode == TCL_SERVICE_ALL) { +#if TCL_THREADS + StartNotifierThread("Tcl_ServiceModeHook"); +#endif } } @@ -740,6 +782,7 @@ FileHandlerEventProc( */ tsdPtr = TCL_TSD_INIT(&dataKey); + for (filePtr = tsdPtr->firstFileHandlerPtr; filePtr != NULL; filePtr = filePtr->nextPtr) { if (filePtr->fd != fileEvPtr->fd) { @@ -877,35 +920,13 @@ Tcl_WaitForEvent( #ifdef TCL_THREADS /* - * Place this thread on the list of interested threads, signal the - * notifier thread, and wait for a response or a timeout. + * Start notifier thread and place this thread on the list of + * interested threads, signal the notifier thread, and wait for a + * response or a timeout. */ + StartNotifierThread("Tcl_WaitForEvent"); -#ifdef __CYGWIN__ - if (!tsdPtr->hwnd) { - WNDCLASS class; - - class.style = 0; - class.cbClsExtra = 0; - class.cbWndExtra = 0; - class.hInstance = TclWinGetTclInstance(); - class.hbrBackground = NULL; - class.lpszMenuName = NULL; - class.lpszClassName = L"TclNotifier"; - class.lpfnWndProc = NotifierProc; - class.hIcon = NULL; - class.hCursor = NULL; - - RegisterClassW(&class); - tsdPtr->hwnd = CreateWindowExW(NULL, class.lpszClassName, - class.lpszClassName, 0, 0, 0, 0, 0, NULL, NULL, - TclWinGetTclInstance(), NULL); - tsdPtr->event = CreateEventW(NULL, 1 /* manual */, - 0 /* !signaled */, NULL); - } -#endif /* __CYGWIN */ - - Tcl_MutexLock(¬ifierMutex); + pthread_mutex_lock(¬ifierMutex); if (timePtr != NULL && timePtr->sec == 0 && (timePtr->usec == 0 #if defined(__APPLE__) && defined(__LP64__) @@ -970,12 +991,23 @@ Tcl_WaitForEvent( } else { timeout = 0xFFFFFFFF; } - Tcl_MutexUnlock(¬ifierMutex); + pthread_mutex_unlock(¬ifierMutex); MsgWaitForMultipleObjects(1, &tsdPtr->event, 0, timeout, 1279); - Tcl_MutexLock(¬ifierMutex); + pthread_mutex_lock(¬ifierMutex); } #else - Tcl_ConditionWait(&tsdPtr->waitCV, ¬ifierMutex, timePtr); + if (timePtr != NULL) { + Tcl_Time now; + struct timespec ptime; + + Tcl_GetTime(&now); + ptime.tv_sec = timePtr->sec + now.sec + (timePtr->usec + now.usec) / 1000000; + ptime.tv_nsec = 1000 * ((timePtr->usec + now.usec) % 1000000); + + pthread_cond_timedwait(&tsdPtr->waitCV, ¬ifierMutex, &ptime); + } else { + pthread_cond_wait(&tsdPtr->waitCV, ¬ifierMutex); + } #endif /* __CYGWIN__ */ } tsdPtr->eventReady = 0; @@ -1078,7 +1110,7 @@ Tcl_WaitForEvent( filePtr->readyMask = mask; } #ifdef TCL_THREADS - Tcl_MutexUnlock(¬ifierMutex); + pthread_mutex_unlock(¬ifierMutex); #endif /* TCL_THREADS */ return 0; } @@ -1150,15 +1182,15 @@ NotifierThreadProc( * Install the write end of the pipe into the global variable. */ - Tcl_MutexLock(¬ifierMutex); + pthread_mutex_lock(¬ifierMutex); triggerPipe = fds[1]; /* * Signal any threads that are waiting. */ - Tcl_ConditionNotify(¬ifierCV); - Tcl_MutexUnlock(¬ifierMutex); + pthread_cond_broadcast(¬ifierCV); + pthread_mutex_unlock(¬ifierMutex); /* * Look for file events and report them to interested threads. @@ -1174,7 +1206,7 @@ NotifierThreadProc( * notifiers. */ - Tcl_MutexLock(¬ifierMutex); + pthread_mutex_lock(¬ifierMutex); timePtr = NULL; for (tsdPtr = waitingListPtr; tsdPtr; tsdPtr = tsdPtr->nextPtr) { for (i = tsdPtr->numFdBits-1; i >= 0; --i) { @@ -1201,7 +1233,7 @@ NotifierThreadProc( timePtr = &poll; } } - Tcl_MutexUnlock(¬ifierMutex); + pthread_mutex_unlock(¬ifierMutex); /* * Set up the select mask to include the receive pipe. @@ -1225,7 +1257,7 @@ NotifierThreadProc( * Alert any threads that are waiting on a ready file descriptor. */ - Tcl_MutexLock(¬ifierMutex); + pthread_mutex_lock(¬ifierMutex); for (tsdPtr = waitingListPtr; tsdPtr; tsdPtr = tsdPtr->nextPtr) { found = 0; @@ -1271,12 +1303,12 @@ NotifierThreadProc( } #ifdef __CYGWIN__ PostMessageW(tsdPtr->hwnd, 1024, 0, 0); -#else - Tcl_ConditionNotify(&tsdPtr->waitCV); +#else /* __CYGWIN__ */ + pthread_cond_broadcast(&tsdPtr->waitCV); #endif /* __CYGWIN__ */ } } - Tcl_MutexUnlock(¬ifierMutex); + pthread_mutex_unlock(¬ifierMutex); /* * Consume the next byte from the notifier pipe if the pipe was @@ -1305,15 +1337,15 @@ NotifierThreadProc( */ close(receivePipe); - Tcl_MutexLock(¬ifierMutex); + pthread_mutex_lock(¬ifierMutex); triggerPipe = -1; - Tcl_ConditionNotify(¬ifierCV); - Tcl_MutexUnlock(¬ifierMutex); + pthread_cond_broadcast(¬ifierCV); + pthread_mutex_unlock(¬ifierMutex); TclpThreadExit(0); } -#if defined(HAVE_PTHREAD_ATFORK) && !defined(__APPLE__) && !defined(__hpux) +#if defined(HAVE_PTHREAD_ATFORK) /* *---------------------------------------------------------------------- * @@ -1333,6 +1365,9 @@ NotifierThreadProc( static void AtForkPrepare(void) { +#if RESET_ATFORK_MUTEX == 0 + pthread_mutex_lock(¬ifierInitMutex); +#endif } /* @@ -1354,6 +1389,9 @@ AtForkPrepare(void) static void AtForkParent(void) { +#if RESET_ATFORK_MUTEX == 0 + pthread_mutex_unlock(¬ifierInitMutex); +#endif } /* @@ -1375,8 +1413,67 @@ AtForkParent(void) static void AtForkChild(void) { - notifierMutex = NULL; - notifierCV = NULL; + if (notifierThreadRunning == 1) { + pthread_cond_destroy(¬ifierCV); + } +#if RESET_ATFORK_MUTEX == 0 + pthread_mutex_unlock(¬ifierInitMutex); +#else + pthread_mutex_init(¬ifierInitMutex, NULL); + pthread_mutex_init(¬ifierMutex, NULL); +#endif + pthread_cond_init(¬ifierCV, NULL); + + /* + * notifierThreadRunning == 1: thread is running, (there might be data in notifier lists) + * atForkInit == 0: InitNotifier was never called + * notifierCount != 0: unbalanced InitNotifier() / FinalizeNotifier calls + * waitingListPtr != 0: there are threads currently waiting for events. + */ + + if (atForkInit == 1) { + + notifierCount = 0; + if (notifierThreadRunning == 1) { + ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); + notifierThreadRunning = 0; + + close(triggerPipe); + triggerPipe = -1; + /* + * The waitingListPtr might contain event info from multiple + * threads, which are invalid here, so setting it to NULL is not + * unreasonable. + */ + waitingListPtr = NULL; + + /* + * The tsdPtr from before the fork is copied as well. But since + * we are paranoic, we don't trust its condvar and reset it. + */ +#ifdef __CYGWIN__ + DestroyWindow(tsdPtr->hwnd); + tsdPtr->hwnd = CreateWindowExW(NULL, NotfyClassName, + NotfyClassName, 0, 0, 0, 0, 0, NULL, NULL, + TclWinGetTclInstance(), NULL); + ResetEvent(tsdPtr->event); +#else + pthread_cond_destroy(&tsdPtr->waitCV); + pthread_cond_init(&tsdPtr->waitCV, NULL); +#endif + /* + * In case, we had multiple threads running before the fork, + * make sure, we don't try to reach out to their thread local data. + */ + tsdPtr->nextPtr = tsdPtr->prevPtr = NULL; + + /* + * The list of registered event handlers at fork time is in + * tsdPtr->firstFileHandlerPtr; + */ + } + } + Tcl_InitNotifier(); } #endif /* HAVE_PTHREAD_ATFORK */ |