diff options
Diffstat (limited to 'unix/tclUnixNotfy.c')
| -rw-r--r-- | unix/tclUnixNotfy.c | 119 |
1 files changed, 115 insertions, 4 deletions
diff --git a/unix/tclUnixNotfy.c b/unix/tclUnixNotfy.c index 6e90807..043735a 100644 --- a/unix/tclUnixNotfy.c +++ b/unix/tclUnixNotfy.c @@ -96,7 +96,7 @@ typedef struct ThreadSpecificData { * that an event is ready to be processed * by sending this event. */ void *hwnd; /* Messaging window. */ -#else +#else /* !__CYGWIN__ */ Tcl_Condition waitCV; /* Any other thread alerts a notifier that an * event is ready to be processed by signaling * this condition variable. */ @@ -120,6 +120,15 @@ 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. @@ -184,9 +193,15 @@ static Tcl_ThreadId notifierThread; */ #ifdef TCL_THREADS -static void NotifierThreadProc(ClientData clientData); -#endif -static int FileHandlerEventProc(Tcl_Event *evPtr, int flags); +static void NotifierThreadProc(ClientData clientData); +#if defined(HAVE_PTHREAD_ATFORK) && !defined(__APPLE__) && !defined(__hpux) +static int atForkInit = 0; +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. @@ -275,11 +290,38 @@ Tcl_InitNotifier(void) */ Tcl_MutexLock(¬ifierMutex); +#if defined(HAVE_PTHREAD_ATFORK) && !defined(__APPLE__) && !defined(__hpux) + /* + * Install pthread_atfork handlers to reinitialize the notifier in the + * child of a fork. + */ + + if (!atForkInit) { + int result = pthread_atfork(AtForkPrepare, AtForkParent, AtForkChild); + + if (result) { + Tcl_Panic("Tcl_InitNotifier: pthread_atfork failed"); + } + 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++; @@ -1270,6 +1312,75 @@ NotifierThreadProc( TclpThreadExit(0); } + +#if defined(HAVE_PTHREAD_ATFORK) && !defined(__APPLE__) && !defined(__hpux) +/* + *---------------------------------------------------------------------- + * + * AtForkPrepare -- + * + * Lock the notifier in preparation for a fork. + * + * Results: + * None. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +static void +AtForkPrepare(void) +{ +} + +/* + *---------------------------------------------------------------------- + * + * AtForkParent -- + * + * Unlock the notifier in the parent after a fork. + * + * Results: + * None. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +static void +AtForkParent(void) +{ +} + +/* + *---------------------------------------------------------------------- + * + * AtForkChild -- + * + * Unlock and reinstall the notifier in the child after a fork. + * + * Results: + * None. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +static void +AtForkChild(void) +{ + notifierMutex = NULL; + notifierCV = NULL; + Tcl_InitNotifier(); +} +#endif /* HAVE_PTHREAD_ATFORK */ + #endif /* TCL_THREADS */ #endif /* !HAVE_COREFOUNDATION */ |