/* * tclMacOSXNotify.c -- * * This file contains the implementation of a merged CFRunLoop/select() * based notifier, which is the lowest-level part of the Tcl event loop. * This file works together with generic/tclNotify.c. * * Copyright © 1995-1997 Sun Microsystems, Inc. * Copyright © 2001-2009, Apple Inc. * Copyright © 2005-2009 Daniel A. Steffen * * See the file "license.terms" for information on usage and redistribution of * this file, and for a DISCLAIMER OF ALL WARRANTIES. */ #include "tclInt.h" /* * In macOS 10.12 the os_unfair_lock was introduced as a replacement for the * OSSpinLock, and the OSSpinLock was deprecated. */ #if MAC_OS_X_VERSION_MIN_REQUIRED >= 101200 #define USE_OS_UNFAIR_LOCK #include #undef TCL_MAC_DEBUG_NOTIFIER #endif #ifdef HAVE_COREFOUNDATION /* Traditional unix select-based notifier is * in tclUnixNotfy.c */ #include #include /* #define TCL_MAC_DEBUG_NOTIFIER 1 */ #if !defined(USE_OS_UNFAIR_LOCK) /* * We use the Darwin-native spinlock API rather than pthread mutexes for * notifier locking: this radically simplifies the implementation and lowers * overhead. Note that these are not pure spinlocks, they employ various * strategies to back off and relinquish the processor, making them immune to * most priority-inversion livelocks (c.f. 'man 3 OSSpinLockLock' and Darwin * sources: xnu/osfmk/{ppc,i386}/commpage/spinlocks.s). */ #if defined(HAVE_LIBKERN_OSATOMIC_H) && defined(HAVE_OSSPINLOCKLOCK) #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wdeprecated-declarations" #pragma GCC diagnostic ignored "-Wunused-function" /* * Use OSSpinLock API where available (Tiger or later). */ #include #if defined(HAVE_WEAK_IMPORT) && MAC_OS_X_VERSION_MIN_REQUIRED < 1040 /* * Support for weakly importing spinlock API. */ #define WEAK_IMPORT_SPINLOCKLOCK #if MAC_OS_X_VERSION_MAX_ALLOWED >= 1050 #define VOLATILE volatile #else #define VOLATILE #endif /* MAC_OS_X_VERSION_MAX_ALLOWED >= 1050 */ #ifndef bool #define bool int #endif extern void OSSpinLockLock(VOLATILE OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE; extern void OSSpinLockUnlock(VOLATILE OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE; extern bool OSSpinLockTry(VOLATILE OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE; extern void _spin_lock(VOLATILE OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE; extern void _spin_unlock(VOLATILE OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE; extern bool _spin_lock_try(VOLATILE OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE; static void (* lockLock)(VOLATILE OSSpinLock *lock) = NULL; static void (* lockUnlock)(VOLATILE OSSpinLock *lock) = NULL; static bool (* lockTry)(VOLATILE OSSpinLock *lock) = NULL; #undef VOLATILE static pthread_once_t spinLockLockInitControl = PTHREAD_ONCE_INIT; static void SpinLockLockInit(void) { lockLock = OSSpinLockLock != NULL ? OSSpinLockLock : _spin_lock; lockUnlock = OSSpinLockUnlock != NULL ? OSSpinLockUnlock : _spin_unlock; lockTry = OSSpinLockTry != NULL ? OSSpinLockTry : _spin_lock_try; if (lockLock == NULL || lockUnlock == NULL) { Tcl_Panic("SpinLockLockInit: no spinlock API available"); } } /* * Wrappers so that we get warnings in just one small part of this file. */ static inline void SpinLockLock( VOLATILE OSSpinLock *lock) { lockLock(lock); } static inline void SpinLockUnlock( VOLATILE OSSpinLock *lock) { lockUnlock(lock); } static inline bool SpinLockTry( VOLATILE OSSpinLock *lock) { return lockTry(lock); } #else /* !HAVE_WEAK_IMPORT */ /* * Wrappers so that we get warnings in just one small part of this file. */ static inline void SpinLockLock( OSSpinLock *lock) { OSSpinLockLock(lock); } static inline void SpinLockUnlock( OSSpinLock *lock) { OSSpinLockUnlock(lock); } static inline bool SpinLockTry( OSSpinLock *lock) { return OSSpinLockTry(lock); } #endif /* HAVE_WEAK_IMPORT */ #define SPINLOCK_INIT OS_SPINLOCK_INIT #else /* * Otherwise, use commpage spinlock SPI directly. */ typedef uint32_t OSSpinLock; static inline void SpinLockLock( OSSpinLock *lock) { extern void _spin_lock(OSSpinLock *lock); _spin_lock(lock); } static inline void SpinLockUnlock( OSSpinLock *lock) { extern void _spin_unlock(OSSpinLock *lock); _spin_unlock(lock); } static inline int SpinLockTry( OSSpinLock *lock) { extern int _spin_lock_try(OSSpinLock *lock); return _spin_lock_try(lock); } #define SPINLOCK_INIT 0 #pragma GCC diagnostic pop #endif /* HAVE_LIBKERN_OSATOMIC_H && HAVE_OSSPINLOCKLOCK */ #endif /* not using os_unfair_lock */ /* * These locks control access to the global notifier state. */ #if defined(USE_OS_UNFAIR_LOCK) static os_unfair_lock notifierInitLock = OS_UNFAIR_LOCK_INIT; static os_unfair_lock notifierLock = OS_UNFAIR_LOCK_INIT; #else static OSSpinLock notifierInitLock = SPINLOCK_INIT; static OSSpinLock notifierLock = SPINLOCK_INIT; #endif /* * Macros that abstract notifier locking/unlocking */ #if defined(USE_OS_UNFAIR_LOCK) #define LOCK_NOTIFIER_INIT os_unfair_lock_lock(¬ifierInitLock) #define UNLOCK_NOTIFIER_INIT os_unfair_lock_unlock(¬ifierInitLock) #define LOCK_NOTIFIER os_unfair_lock_lock(¬ifierLock) #define UNLOCK_NOTIFIER os_unfair_lock_unlock(¬ifierLock) #define LOCK_NOTIFIER_TSD os_unfair_lock_lock(&tsdPtr->tsdLock) #define UNLOCK_NOTIFIER_TSD os_unfair_lock_unlock(&tsdPtr->tsdLock) #else #define LOCK_NOTIFIER_INIT SpinLockLock(¬ifierInitLock) #define UNLOCK_NOTIFIER_INIT SpinLockUnlock(¬ifierInitLock) #define LOCK_NOTIFIER SpinLockLock(¬ifierLock) #define UNLOCK_NOTIFIER SpinLockUnlock(¬ifierLock) #define LOCK_NOTIFIER_TSD SpinLockLock(&tsdPtr->tsdLock) #define UNLOCK_NOTIFIER_TSD SpinLockUnlock(&tsdPtr->tsdLock) #endif /* * The debug version of the Notifier only works if using OSSpinLock. */ #if defined(TCL_MAC_DEBUG_NOTIFIER) && !defined(USE_OS_UNFAIR_LOCK) #define TclMacOSXNotifierDbgMsg(m, ...) \ do { \ fprintf(notifierLog?notifierLog:stderr, "tclMacOSXNotify.c:%d: " \ "%s() pid %5d thread %10p: " m "\n", __LINE__, __func__, \ getpid(), pthread_self(), ##__VA_ARGS__); \ fflush(notifierLog?notifierLog:stderr); \ } while (0) /* * Debug version of SpinLockLock that logs the time spent waiting for the lock */ #define SpinLockLockDbg(p) \ if (!SpinLockTry(p)) { \ long long s = TclpGetWideClicks(), e; \ \ SpinLockLock(p); \ e = TclpGetWideClicks(); \ TclMacOSXNotifierDbgMsg("waited on %s for %8.0f ns", \ #p, TclpWideClicksToNanoseconds(e-s)); \ } #undef LOCK_NOTIFIER_INIT #define LOCK_NOTIFIER_INIT SpinLockLockDbg(¬ifierInitLock) #undef LOCK_NOTIFIER #define LOCK_NOTIFIER SpinLockLockDbg(¬ifierLock) #undef LOCK_NOTIFIER_TSD #define LOCK_NOTIFIER_TSD SpinLockLockDbg(tsdPtr->tsdLock) #include static FILE *notifierLog = NULL; #ifndef NOTIFIER_LOG #define NOTIFIER_LOG "/tmp/tclMacOSXNotify.log" #endif #define OPEN_NOTIFIER_LOG \ if (!notifierLog) { \ notifierLog = fopen(NOTIFIER_LOG, "a"); \ /*TclMacOSXNotifierDbgMsg("open log"); \ *asl_set_filter(NULL, \ * ASL_FILTER_MASK_UPTO(ASL_LEVEL_DEBUG)); \ *asl_add_log_file(NULL, fileno(notifierLog));*/ \ } #define CLOSE_NOTIFIER_LOG \ if (notifierLog) { \ /*asl_remove_log_file(NULL, fileno(notifierLog)); \ *TclMacOSXNotifierDbgMsg("close log");*/ \ fclose(notifierLog); \ notifierLog = NULL; \ } #define ENABLE_ASL \ if (notifierLog) { \ /*tsdPtr->asl = asl_open(NULL, "com.apple.console", \ * ASL_OPT_NO_REMOTE); \ *asl_set_filter(tsdPtr->asl, \ * ASL_FILTER_MASK_UPTO(ASL_LEVEL_DEBUG)); \ *asl_add_log_file(tsdPtr->asl, fileno(notifierLog));*/ \ } #define DISABLE_ASL \ /*if (tsdPtr->asl) { \ * if (notifierLog) { \ * asl_remove_log_file(tsdPtr->asl, fileno(notifierLog)); \ * } \ * asl_close(tsdPtr->asl); \ *}*/ #define ASLCLIENT_DECL /*aslclient asl*/ #else #define TclMacOSXNotifierDbgMsg(m, ...) #define OPEN_NOTIFIER_LOG #define CLOSE_NOTIFIER_LOG #define ENABLE_ASL #define DISABLE_ASL #define ASLCLIENT_DECL #endif /* TCL_MAC_DEBUG_NOTIFIER */ /* * This structure is used to keep track of the notifier info for a registered * file. */ typedef struct FileHandler { int fd; int mask; /* Mask of desired events: TCL_READABLE, * etc. */ int readyMask; /* Mask of events that have been seen since * the last time file handlers were invoked * for this file. */ Tcl_FileProc *proc; /* Function to call, in the style of * Tcl_CreateFileHandler. */ ClientData clientData; /* Argument to pass to proc. */ struct FileHandler *nextPtr;/* Next in list of all files we care about. */ } FileHandler; /* * The following structure is what is added to the Tcl event queue when file * handlers are ready to fire. */ typedef struct { Tcl_Event header; /* Information that is standard for all * events. */ int fd; /* File descriptor that is ready. Used to find * the FileHandler structure for the file * (can't point directly to the FileHandler * structure because it could go away while * the event is queued). */ } FileHandlerEvent; /* * The following structure contains a set of select() masks to track readable, * writable, and exceptional conditions. */ typedef struct { fd_set readable; fd_set writable; fd_set exceptional; } SelectMasks; /* * The following static structure contains the state information for the * select based implementation of the Tcl notifier. One of these structures is * created for each thread that is using the notifier. */ typedef struct ThreadSpecificData { FileHandler *firstFileHandlerPtr; /* Pointer to head of file handler list. */ int polled; /* True if the notifier thread has polled for * this thread. */ int sleeping; /* True if runloop is inside Tcl_Sleep. */ int runLoopSourcePerformed; /* True after the runLoopSource callack was * performed. */ int runLoopRunning; /* True if this thread's Tcl runLoop is * running. */ int runLoopNestingLevel; /* Level of nested runLoop invocations. */ /* Must hold the notifierLock before accessing the following fields: */ /* Start notifierLock section */ int onList; /* True if this thread is on the * waitingList */ struct ThreadSpecificData *nextPtr, *prevPtr; /* All threads that are currently waiting on * an event have their ThreadSpecificData * structure on a doubly-linked listed formed * from these pointers. */ /* End notifierLock section */ #if defined(USE_OS_UNFAIR_LOCK) os_unfair_lock tsdLock; #else OSSpinLock tsdLock; /* Must hold this lock before acessing the * following fields from more than one * thread. */ #endif /* Start tsdLock section */ SelectMasks checkMasks; /* This structure is used to build up the * masks to be used in the next call to * select. Bits are set in response to calls * to Tcl_CreateFileHandler. */ SelectMasks readyMasks; /* This array reflects the readable/writable * conditions that were found to exist by the * last call to select. */ int numFdBits; /* Number of valid bits in checkMasks (one * more than highest fd for which * Tcl_WatchFile has been called). */ int polling; /* True if this thread is polling for * events. */ CFRunLoopRef runLoop; /* This thread's CFRunLoop, needs to be woken * up whenever the runLoopSource is * signaled. */ CFRunLoopSourceRef runLoopSource; /* Any other thread alerts a notifier that an * event is ready to be processed by signaling * this CFRunLoopSource. */ CFRunLoopObserverRef runLoopObserver, runLoopObserverTcl; /* Adds/removes this thread from waitingList * when the CFRunLoop starts/stops. */ CFRunLoopTimerRef runLoopTimer; /* Wakes up CFRunLoop after given timeout when * running embedded. */ /* End tsdLock section */ CFTimeInterval waitTime; /* runLoopTimer wait time when running * embedded. */ ASLCLIENT_DECL; } ThreadSpecificData; static Tcl_ThreadDataKey dataKey; /* * The following static indicates the number of threads that have initialized * notifiers. * * You must hold the notifierInitLock before accessing this variable. */ static int notifierCount = 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. * * You must hold the notifierLock before accessing this list. */ static ThreadSpecificData *waitingListPtr = NULL; /* * The notifier thread spends all its time in select() waiting for a file * descriptor associated with one of the threads on the waitingListPtr list to * do something interesting. But if the contents of the waitingListPtr list * ever changes, we need to wake up and restart the select() system call. You * can wake up the notifier thread by writing a single byte to the file * descriptor defined below. This file descriptor is the input-end of a pipe * and the notifier thread is listening for data on the output-end of the same * pipe. Hence writing to this file descriptor will cause the select() system * call to return and wake up the notifier thread. * * You must hold the notifierLock lock before writing to the pipe. */ static int triggerPipe = -1; static int receivePipe = -1; /* Output end of triggerPipe */ /* * The following static indicates if the notifier thread is running. * * You must hold the notifierInitLock before accessing this variable. */ static int notifierThreadRunning; /* * This is the thread ID of the notifier thread that does select. Only valid * when notifierThreadRunning is non-zero. * * You must hold the notifierInitLock before accessing this variable. */ static pthread_t notifierThread; /* * Custom runloop mode for running with only the runloop source for the * notifier thread. */ #ifndef TCL_EVENTS_ONLY_RUN_LOOP_MODE #define TCL_EVENTS_ONLY_RUN_LOOP_MODE "com.tcltk.tclEventsOnlyRunLoopMode" #endif #ifdef __CONSTANT_CFSTRINGS__ #define tclEventsOnlyRunLoopMode CFSTR(TCL_EVENTS_ONLY_RUN_LOOP_MODE) #else static CFStringRef tclEventsOnlyRunLoopMode = NULL; #endif /* * CFTimeInterval to wait forever. */ #define CF_TIMEINTERVAL_FOREVER 5.05e8 /* * Static routines defined in this file. */ static void StartNotifierThread(void); static TCL_NORETURN void NotifierThreadProc(ClientData clientData); static int FileHandlerEventProc(Tcl_Event *evPtr, int flags); static void TimerWakeUp(CFRunLoopTimerRef timer, void *info); static void QueueFileEvents(void *info); static void UpdateWaitingListAndServiceEvents( CFRunLoopObserverRef observer, CFRunLoopActivity activity, void *info); static int OnOffWaitingList(ThreadSpecificData *tsdPtr, int onList, int signalNotifier); #ifdef HAVE_PTHREAD_ATFORK static int atForkInit = 0; static void AtForkPrepare(void); static void AtForkParent(void); static void AtForkChild(void); #if defined(HAVE_WEAK_IMPORT) && MAC_OS_X_VERSION_MIN_REQUIRED < 1040 /* Support for weakly importing pthread_atfork. */ #define WEAK_IMPORT_PTHREAD_ATFORK extern int pthread_atfork(void (*prepare)(void), void (*parent)(void), void (*child)(void)) WEAK_IMPORT_ATTRIBUTE; #define MayUsePthreadAtfork() (pthread_atfork != NULL) #else #define MayUsePthreadAtfork() (1) #endif /* HAVE_WEAK_IMPORT */ /* * On Darwin 9 and later, it is not possible to call CoreFoundation after * a fork. */ #if !defined(MAC_OS_X_VERSION_MIN_REQUIRED) || \ MAC_OS_X_VERSION_MIN_REQUIRED < 1050 MODULE_SCOPE long tclMacOSXDarwinRelease; #define noCFafterFork (tclMacOSXDarwinRelease >= 9) #else /* MAC_OS_X_VERSION_MIN_REQUIRED */ #define noCFafterFork 1 #endif /* MAC_OS_X_VERSION_MIN_REQUIRED */ #endif /* HAVE_PTHREAD_ATFORK */ /* *---------------------------------------------------------------------- * * Tcl_InitNotifier -- * * Initializes the platform specific notifier state. * * Results: * Returns a handle to the notifier state for this thread. * * Side effects: * None. * *---------------------------------------------------------------------- */ ClientData Tcl_InitNotifier(void) { ThreadSpecificData *tsdPtr; if (tclNotifierHooks.initNotifierProc) { return tclNotifierHooks.initNotifierProc(); } tsdPtr = TCL_TSD_INIT(&dataKey); #ifdef WEAK_IMPORT_SPINLOCKLOCK /* * Initialize support for weakly imported spinlock API. */ if (pthread_once(&spinLockLockInitControl, SpinLockLockInit)) { Tcl_Panic("Tcl_InitNotifier: pthread_once failed"); } #endif #ifndef __CONSTANT_CFSTRINGS__ if (!tclEventsOnlyRunLoopMode) { tclEventsOnlyRunLoopMode = CFSTR(TCL_EVENTS_ONLY_RUN_LOOP_MODE); } #endif /* * Initialize CFRunLoopSource and add it to CFRunLoop of this thread. */ if (!tsdPtr->runLoop) { CFRunLoopRef runLoop = CFRunLoopGetCurrent(); CFRunLoopSourceRef runLoopSource; CFRunLoopSourceContext runLoopSourceContext; CFRunLoopObserverContext runLoopObserverContext; CFRunLoopObserverRef runLoopObserver, runLoopObserverTcl; bzero(&runLoopSourceContext, sizeof(CFRunLoopSourceContext)); runLoopSourceContext.info = tsdPtr; runLoopSourceContext.perform = QueueFileEvents; runLoopSource = CFRunLoopSourceCreate(NULL, LONG_MIN, &runLoopSourceContext); if (!runLoopSource) { Tcl_Panic("Tcl_InitNotifier: could not create CFRunLoopSource"); } CFRunLoopAddSource(runLoop, runLoopSource, kCFRunLoopCommonModes); CFRunLoopAddSource(runLoop, runLoopSource, tclEventsOnlyRunLoopMode); bzero(&runLoopObserverContext, sizeof(CFRunLoopObserverContext)); runLoopObserverContext.info = tsdPtr; runLoopObserver = CFRunLoopObserverCreate(NULL, kCFRunLoopEntry|kCFRunLoopExit, TRUE, LONG_MIN, UpdateWaitingListAndServiceEvents, &runLoopObserverContext); if (!runLoopObserver) { Tcl_Panic("Tcl_InitNotifier: could not create " "CFRunLoopObserver"); } CFRunLoopAddObserver(runLoop, runLoopObserver, kCFRunLoopCommonModes); /* * Create a second CFRunLoopObserver with the same callback as above * for the tclEventsOnlyRunLoopMode to ensure that the callback can be * re-entered via Tcl_ServiceAll() in the kCFRunLoopBeforeWaiting case * (CFRunLoop prevents observer callback re-entry of a given observer * instance). */ runLoopObserverTcl = CFRunLoopObserverCreate(NULL, kCFRunLoopEntry|kCFRunLoopExit, TRUE, LONG_MIN, UpdateWaitingListAndServiceEvents, &runLoopObserverContext); if (!runLoopObserverTcl) { Tcl_Panic("Tcl_InitNotifier: could not create " "CFRunLoopObserver"); } CFRunLoopAddObserver(runLoop, runLoopObserverTcl, tclEventsOnlyRunLoopMode); tsdPtr->runLoop = runLoop; tsdPtr->runLoopSource = runLoopSource; tsdPtr->runLoopObserver = runLoopObserver; tsdPtr->runLoopObserverTcl = runLoopObserverTcl; tsdPtr->runLoopTimer = NULL; tsdPtr->waitTime = CF_TIMEINTERVAL_FOREVER; #if defined(USE_OS_UNFAIR_LOCK) tsdPtr->tsdLock = OS_UNFAIR_LOCK_INIT; #else tsdPtr->tsdLock = SPINLOCK_INIT; #endif } LOCK_NOTIFIER_INIT; #ifdef HAVE_PTHREAD_ATFORK /* * Install pthread_atfork handlers to reinitialize the notifier in the * child of a fork. */ if (MayUsePthreadAtfork() && !atForkInit) { int result = pthread_atfork(AtForkPrepare, AtForkParent, AtForkChild); if (result) { Tcl_Panic("Tcl_InitNotifier: pthread_atfork failed"); } atForkInit = 1; } #endif /* HAVE_PTHREAD_ATFORK */ if (notifierCount == 0) { int fds[2], status; /* * Initialize trigger pipe. */ if (pipe(fds) != 0) { Tcl_Panic("Tcl_InitNotifier: could not create trigger pipe"); } status = fcntl(fds[0], F_GETFL); status |= O_NONBLOCK; if (fcntl(fds[0], F_SETFL, status) < 0) { Tcl_Panic("Tcl_InitNotifier: could not make receive pipe non " "blocking"); } status = fcntl(fds[1], F_GETFL); status |= O_NONBLOCK; if (fcntl(fds[1], F_SETFL, status) < 0) { Tcl_Panic("Tcl_InitNotifier: could not make trigger pipe non " "blocking"); } receivePipe = fds[0]; triggerPipe = fds[1]; /* * Create notifier thread lazily in Tcl_WaitForEvent() to avoid * interfering with fork() followed immediately by execve() (we cannot * execve() when more than one thread is present). */ notifierThreadRunning = 0; OPEN_NOTIFIER_LOG; } ENABLE_ASL; notifierCount++; UNLOCK_NOTIFIER_INIT; return tsdPtr; } /* *---------------------------------------------------------------------- * * Tcl_MacOSXNotifierAddRunLoopMode -- * * Add the tcl notifier RunLoop source, observer and timer (if any) * to the given RunLoop mode. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------- */ void Tcl_MacOSXNotifierAddRunLoopMode( const void *runLoopMode) { ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); CFStringRef mode = (CFStringRef) runLoopMode; if (tsdPtr->runLoop) { CFRunLoopAddSource(tsdPtr->runLoop, tsdPtr->runLoopSource, mode); CFRunLoopAddObserver(tsdPtr->runLoop, tsdPtr->runLoopObserver, mode); if (tsdPtr->runLoopTimer) { CFRunLoopAddTimer(tsdPtr->runLoop, tsdPtr->runLoopTimer, mode); } } } /* *---------------------------------------------------------------------- * * StartNotifierThread -- * * Start notifier thread if necessary. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------- */ static void StartNotifierThread(void) { LOCK_NOTIFIER_INIT; if (!notifierCount) { Tcl_Panic("StartNotifierThread: notifier not initialized"); } if (!notifierThreadRunning) { int result; pthread_attr_t attr; pthread_attr_init(&attr); pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM); pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE); pthread_attr_setstacksize(&attr, 60 * 1024); result = pthread_create(¬ifierThread, &attr, (void * (*)(void *))NotifierThreadProc, NULL); pthread_attr_destroy(&attr); if (result) { Tcl_Panic("StartNotifierThread: unable to start notifier thread"); } notifierThreadRunning = 1; } UNLOCK_NOTIFIER_INIT; } /* *---------------------------------------------------------------------- * * Tcl_FinalizeNotifier -- * * This function is called to cleanup the notifier state before a thread * is terminated. * * Results: * None. * * Side effects: * May terminate the background notifier thread if this is the last * notifier instance. * *---------------------------------------------------------------------- */ void Tcl_FinalizeNotifier( ClientData clientData) { ThreadSpecificData *tsdPtr; if (tclNotifierHooks.finalizeNotifierProc) { tclNotifierHooks.finalizeNotifierProc(clientData); return; } tsdPtr = TCL_TSD_INIT(&dataKey); LOCK_NOTIFIER_INIT; notifierCount--; DISABLE_ASL; /* * If this is the last thread to use the notifier, close the notifier pipe * and wait for the background thread to terminate. */ if (notifierCount == 0) { if (triggerPipe != -1) { /* * 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] */ write(triggerPipe, "q", 1); close(triggerPipe); if (notifierThreadRunning) { int result = pthread_join(notifierThread, NULL); if (result) { Tcl_Panic("Tcl_FinalizeNotifier: unable to join notifier " "thread"); } notifierThreadRunning = 0; } close(receivePipe); triggerPipe = -1; } CLOSE_NOTIFIER_LOG; } UNLOCK_NOTIFIER_INIT; LOCK_NOTIFIER_TSD; /* For concurrency with Tcl_AlertNotifier */ if (tsdPtr->runLoop) { tsdPtr->runLoop = NULL; /* * Remove runLoopSource, runLoopObserver and runLoopTimer from all * CFRunLoops. */ CFRunLoopSourceInvalidate(tsdPtr->runLoopSource); CFRelease(tsdPtr->runLoopSource); tsdPtr->runLoopSource = NULL; CFRunLoopObserverInvalidate(tsdPtr->runLoopObserver); CFRelease(tsdPtr->runLoopObserver); tsdPtr->runLoopObserver = NULL; CFRunLoopObserverInvalidate(tsdPtr->runLoopObserverTcl); CFRelease(tsdPtr->runLoopObserverTcl); tsdPtr->runLoopObserverTcl = NULL; if (tsdPtr->runLoopTimer) { CFRunLoopTimerInvalidate(tsdPtr->runLoopTimer); CFRelease(tsdPtr->runLoopTimer); tsdPtr->runLoopTimer = NULL; } } UNLOCK_NOTIFIER_TSD; } /* *---------------------------------------------------------------------- * * Tcl_AlertNotifier -- * * Wake up the specified notifier from any thread. This routine is called * by the platform independent notifier code whenever the Tcl_ThreadAlert * routine is called. This routine is guaranteed not to be called on a * given notifier after Tcl_FinalizeNotifier is called for that notifier. * * Results: * None. * * Side effects: * Signals the notifier condition variable for the specified notifier. * *---------------------------------------------------------------------- */ void Tcl_AlertNotifier( ClientData clientData) { ThreadSpecificData *tsdPtr = (ThreadSpecificData *)clientData; if (tclNotifierHooks.alertNotifierProc) { tclNotifierHooks.alertNotifierProc(clientData); return; } LOCK_NOTIFIER_TSD; if (tsdPtr->runLoop) { CFRunLoopSourceSignal(tsdPtr->runLoopSource); CFRunLoopWakeUp(tsdPtr->runLoop); } UNLOCK_NOTIFIER_TSD; } /* *---------------------------------------------------------------------- * * Tcl_SetTimer -- * * This function sets the current notifier timer value. * * Results: * None. * * Side effects: * Replaces any previous timer. * *---------------------------------------------------------------------- */ void Tcl_SetTimer( const Tcl_Time *timePtr) /* Timeout value, may be NULL. */ { ThreadSpecificData *tsdPtr; CFRunLoopTimerRef runLoopTimer; CFTimeInterval waitTime; if (tclNotifierHooks.setTimerProc) { tclNotifierHooks.setTimerProc(timePtr); return; } tsdPtr = TCL_TSD_INIT(&dataKey); runLoopTimer = tsdPtr->runLoopTimer; if (!runLoopTimer) { return; } if (timePtr) { Tcl_Time vTime = *timePtr; if (vTime.sec != 0 || vTime.usec != 0) { tclScaleTimeProcPtr(&vTime, tclTimeClientData); waitTime = vTime.sec + 1.0e-6 * vTime.usec; } else { waitTime = 0; } } else { waitTime = CF_TIMEINTERVAL_FOREVER; } tsdPtr->waitTime = waitTime; CFRunLoopTimerSetNextFireDate(runLoopTimer, CFAbsoluteTimeGetCurrent() + waitTime); } /* *---------------------------------------------------------------------- * * TimerWakeUp -- * * CFRunLoopTimer callback. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------- */ static void TimerWakeUp( TCL_UNUSED(CFRunLoopTimerRef), TCL_UNUSED(ClientData)) { } /* *---------------------------------------------------------------------- * * Tcl_ServiceModeHook -- * * This function is invoked whenever the service mode changes. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------- */ void Tcl_ServiceModeHook( int mode) /* Either TCL_SERVICE_ALL, or * TCL_SERVICE_NONE. */ { ThreadSpecificData *tsdPtr; if (tclNotifierHooks.serviceModeHookProc) { tclNotifierHooks.serviceModeHookProc(mode); return; } tsdPtr = TCL_TSD_INIT(&dataKey); if (mode == TCL_SERVICE_ALL && !tsdPtr->runLoopTimer) { if (!tsdPtr->runLoop) { Tcl_Panic("Tcl_ServiceModeHook: Notifier not initialized"); } tsdPtr->runLoopTimer = CFRunLoopTimerCreate(NULL, CFAbsoluteTimeGetCurrent() + CF_TIMEINTERVAL_FOREVER, CF_TIMEINTERVAL_FOREVER, 0, 0, TimerWakeUp, NULL); if (tsdPtr->runLoopTimer) { CFRunLoopAddTimer(tsdPtr->runLoop, tsdPtr->runLoopTimer, kCFRunLoopCommonModes); StartNotifierThread(); } } } /* *---------------------------------------------------------------------- * * Tcl_CreateFileHandler -- * * This function registers a file handler with the select notifier. * * Results: * None. * * Side effects: * Creates a new file handler structure. * *---------------------------------------------------------------------- */ void Tcl_CreateFileHandler( int fd, /* Handle of stream to watch. */ int mask, /* OR'ed combination of TCL_READABLE, * TCL_WRITABLE, and TCL_EXCEPTION: indicates * conditions under which proc should be * called. */ Tcl_FileProc *proc, /* Function to call for each selected * event. */ ClientData clientData) /* Arbitrary data to pass to proc. */ { ThreadSpecificData *tsdPtr; FileHandler *filePtr; if (tclNotifierHooks.createFileHandlerProc) { tclNotifierHooks.createFileHandlerProc(fd, mask, proc, clientData); return; } tsdPtr = TCL_TSD_INIT(&dataKey); for (filePtr = tsdPtr->firstFileHandlerPtr; filePtr != NULL; filePtr = filePtr->nextPtr) { if (filePtr->fd == fd) { break; } } if (filePtr == NULL) { filePtr = (FileHandler *)ckalloc(sizeof(FileHandler)); filePtr->fd = fd; filePtr->readyMask = 0; filePtr->nextPtr = tsdPtr->firstFileHandlerPtr; tsdPtr->firstFileHandlerPtr = filePtr; } filePtr->proc = proc; filePtr->clientData = clientData; filePtr->mask = mask; /* * Update the check masks for this file. */ LOCK_NOTIFIER_TSD; if (mask & TCL_READABLE) { FD_SET(fd, &tsdPtr->checkMasks.readable); } else { FD_CLR(fd, &tsdPtr->checkMasks.readable); } if (mask & TCL_WRITABLE) { FD_SET(fd, &tsdPtr->checkMasks.writable); } else { FD_CLR(fd, &tsdPtr->checkMasks.writable); } if (mask & TCL_EXCEPTION) { FD_SET(fd, &tsdPtr->checkMasks.exceptional); } else { FD_CLR(fd, &tsdPtr->checkMasks.exceptional); } if (tsdPtr->numFdBits <= fd) { tsdPtr->numFdBits = fd+1; } UNLOCK_NOTIFIER_TSD; } /* *---------------------------------------------------------------------- * * Tcl_DeleteFileHandler -- * * Cancel a previously-arranged callback arrangement for a file. * * Results: * None. * * Side effects: * If a callback was previously registered on file, remove it. * *---------------------------------------------------------------------- */ void Tcl_DeleteFileHandler( int fd) /* Stream id for which to remove callback * function. */ { FileHandler *filePtr, *prevPtr; int i, numFdBits; ThreadSpecificData *tsdPtr; if (tclNotifierHooks.deleteFileHandlerProc) { tclNotifierHooks.deleteFileHandlerProc(fd); return; } tsdPtr = TCL_TSD_INIT(&dataKey); numFdBits = -1; /* * Find the entry for the given file (and return if there isn't one). */ for (prevPtr = NULL, filePtr = tsdPtr->firstFileHandlerPtr; ; prevPtr = filePtr, filePtr = filePtr->nextPtr) { if (filePtr == NULL) { return; } if (filePtr->fd == fd) { break; } } /* * Find current max fd. */ if (fd+1 == tsdPtr->numFdBits) { numFdBits = 0; for (i = fd-1; i >= 0; i--) { if (FD_ISSET(i, &tsdPtr->checkMasks.readable) || FD_ISSET(i, &tsdPtr->checkMasks.writable) || FD_ISSET(i, &tsdPtr->checkMasks.exceptional)) { numFdBits = i+1; break; } } } LOCK_NOTIFIER_TSD; if (numFdBits != -1) { tsdPtr->numFdBits = numFdBits; } /* * Update the check masks for this file. */ if (filePtr->mask & TCL_READABLE) { FD_CLR(fd, &tsdPtr->checkMasks.readable); } if (filePtr->mask & TCL_WRITABLE) { FD_CLR(fd, &tsdPtr->checkMasks.writable); } if (filePtr->mask & TCL_EXCEPTION) { FD_CLR(fd, &tsdPtr->checkMasks.exceptional); } UNLOCK_NOTIFIER_TSD; /* * Clean up information in the callback record. */ if (prevPtr == NULL) { tsdPtr->firstFileHandlerPtr = filePtr->nextPtr; } else { prevPtr->nextPtr = filePtr->nextPtr; } ckfree(filePtr); } /* *---------------------------------------------------------------------- * * FileHandlerEventProc -- * * This function is called by Tcl_ServiceEvent when a file event reaches * the front of the event queue. This function is responsible for * actually handling the event by invoking the callback for the file * handler. * * Results: * Returns 1 if the event was handled, meaning it should be removed from * the queue. Returns 0 if the event was not handled, meaning it should * stay on the queue. The only time the event isn't handled is if the * TCL_FILE_EVENTS flag bit isn't set. * * Side effects: * Whatever the file handler's callback function does. * *---------------------------------------------------------------------- */ static int FileHandlerEventProc( Tcl_Event *evPtr, /* Event to service. */ int flags) /* Flags that indicate what events to handle, * such as TCL_FILE_EVENTS. */ { int mask; FileHandler *filePtr; FileHandlerEvent *fileEvPtr = (FileHandlerEvent *) evPtr; ThreadSpecificData *tsdPtr; if (!(flags & TCL_FILE_EVENTS)) { return 0; } /* * Search through the file handlers to find the one whose handle matches * the event. We do this rather than keeping a pointer to the file handler * directly in the event, so that the handler can be deleted while the * event is queued without leaving a dangling pointer. */ tsdPtr = TCL_TSD_INIT(&dataKey); for (filePtr = tsdPtr->firstFileHandlerPtr; filePtr != NULL; filePtr = filePtr->nextPtr) { if (filePtr->fd != fileEvPtr->fd) { continue; } /* * The code is tricky for two reasons: * 1. The file handler's desired events could have changed since the * time when the event was queued, so AND the ready mask with the * desired mask. * 2. The file could have been closed and re-opened since the time * when the event was queued. This is why the ready mask is stored * in the file handler rather than the queued event: it will be * zeroed when a new file handler is created for the newly opened * file. */ mask = filePtr->readyMask & filePtr->mask; filePtr->readyMask = 0; if (mask != 0) { LOCK_NOTIFIER_TSD; if (mask & TCL_READABLE) { FD_CLR(filePtr->fd, &tsdPtr->readyMasks.readable); } if (mask & TCL_WRITABLE) { FD_CLR(filePtr->fd, &tsdPtr->readyMasks.writable); } if (mask & TCL_EXCEPTION) { FD_CLR(filePtr->fd, &tsdPtr->readyMasks.exceptional); } UNLOCK_NOTIFIER_TSD; filePtr->proc(filePtr->clientData, mask); } break; } return 1; } /* *---------------------------------------------------------------------- * * Tcl_WaitForEvent -- * * This function is called by Tcl_DoOneEvent to wait for new events on * the message queue. If the block time is 0, then Tcl_WaitForEvent just * polls without blocking. * * Results: * Returns 0 if a tcl event or timeout ocurred and 1 if a non-tcl * CFRunLoop source was processed. * * Side effects: * None. * *---------------------------------------------------------------------- */ int Tcl_WaitForEvent( const Tcl_Time *timePtr) /* Maximum block time, or NULL. */ { int result, polling, runLoopRunning; CFTimeInterval waitTime; SInt32 runLoopStatus; ThreadSpecificData *tsdPtr; if (tclNotifierHooks.waitForEventProc) { return tclNotifierHooks.waitForEventProc(timePtr); } result = -1; polling = 0; waitTime = CF_TIMEINTERVAL_FOREVER; tsdPtr = TCL_TSD_INIT(&dataKey); if (!tsdPtr->runLoop) { Tcl_Panic("Tcl_WaitForEvent: Notifier not initialized"); } /* * A NULL timePtr means wait forever. */ if (timePtr) { Tcl_Time vTime = *timePtr; /* * TIP #233 (Virtualized Time). Is virtual time in effect? And do we * actually have something to scale? If yes to both then we call the * handler to do this scaling. */ if (vTime.sec != 0 || vTime.usec != 0) { tclScaleTimeProcPtr(&vTime, tclTimeClientData); waitTime = vTime.sec + 1.0e-6 * vTime.usec; } else { /* * The max block time was set to 0. * * If we set the waitTime to 0, then the call to CFRunLoopInMode * may return without processing all of its sources. The Apple * documentation says that if the waitTime is 0 "only one pass is * made through the run loop before returning; if multiple sources * or timers are ready to fire immediately, only one (possibly two * if one is a version 0 source) will be fired, regardless of the * value of returnAfterSourceHandled." This can cause some chanio * tests to fail. So we use a small positive waitTime unless there * is another RunLoop running. */ polling = 1; waitTime = tsdPtr->runLoopRunning ? 0 : 0.0001; } } StartNotifierThread(); LOCK_NOTIFIER_TSD; tsdPtr->polling = polling; UNLOCK_NOTIFIER_TSD; tsdPtr->runLoopSourcePerformed = 0; /* * If the Tcl runloop is already running (e.g. if Tcl_WaitForEvent was * called recursively) start a new runloop in a custom runloop mode * containing only the source for the notifier thread. Otherwise wakeups * from other sources added to the common runloop mode might get lost or * 3rd party event handlers might get called when they do not expect to * be. */ runLoopRunning = tsdPtr->runLoopRunning; tsdPtr->runLoopRunning = 1; runLoopStatus = CFRunLoopRunInMode( runLoopRunning ? tclEventsOnlyRunLoopMode : kCFRunLoopDefaultMode, waitTime, TRUE); tsdPtr->runLoopRunning = runLoopRunning; LOCK_NOTIFIER_TSD; tsdPtr->polling = 0; UNLOCK_NOTIFIER_TSD; switch (runLoopStatus) { case kCFRunLoopRunFinished: Tcl_Panic("Tcl_WaitForEvent: CFRunLoop finished"); break; case kCFRunLoopRunTimedOut: QueueFileEvents(tsdPtr); result = 0; break; case kCFRunLoopRunStopped: case kCFRunLoopRunHandledSource: result = tsdPtr->runLoopSourcePerformed ? 0 : 1; break; } return result; } /* *---------------------------------------------------------------------- * * QueueFileEvents -- * * CFRunLoopSource callback for queueing file events. * * Results: * None. * * Side effects: * Queues file events that are detected by the select. * *---------------------------------------------------------------------- */ static void QueueFileEvents( void *info) { SelectMasks readyMasks; FileHandler *filePtr; ThreadSpecificData *tsdPtr = (ThreadSpecificData *)info; /* * Queue all detected file events. */ LOCK_NOTIFIER_TSD; FD_COPY(&tsdPtr->readyMasks.readable, &readyMasks.readable); FD_COPY(&tsdPtr->readyMasks.writable, &readyMasks.writable); FD_COPY(&tsdPtr->readyMasks.exceptional, &readyMasks.exceptional); FD_ZERO(&tsdPtr->readyMasks.readable); FD_ZERO(&tsdPtr->readyMasks.writable); FD_ZERO(&tsdPtr->readyMasks.exceptional); UNLOCK_NOTIFIER_TSD; tsdPtr->runLoopSourcePerformed = 1; for (filePtr = tsdPtr->firstFileHandlerPtr; (filePtr != NULL); filePtr = filePtr->nextPtr) { int mask = 0; if (FD_ISSET(filePtr->fd, &readyMasks.readable)) { mask |= TCL_READABLE; } if (FD_ISSET(filePtr->fd, &readyMasks.writable)) { mask |= TCL_WRITABLE; } if (FD_ISSET(filePtr->fd, &readyMasks.exceptional)) { mask |= TCL_EXCEPTION; } if (!mask) { continue; } /* * Don't bother to queue an event if the mask was previously non-zero * since an event must still be on the queue. */ if (filePtr->readyMask == 0) { FileHandlerEvent *fileEvPtr = (FileHandlerEvent *)ckalloc(sizeof(FileHandlerEvent)); fileEvPtr->header.proc = FileHandlerEventProc; fileEvPtr->fd = filePtr->fd; Tcl_QueueEvent((Tcl_Event *) fileEvPtr, TCL_QUEUE_TAIL); } filePtr->readyMask = mask; } } /* *---------------------------------------------------------------------- * * UpdateWaitingListAndServiceEvents -- * * CFRunLoopObserver callback for updating waitingList and * servicing Tcl events. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------- */ static void UpdateWaitingListAndServiceEvents( TCL_UNUSED(CFRunLoopObserverRef), CFRunLoopActivity activity, void *info) { ThreadSpecificData *tsdPtr = (ThreadSpecificData *)info; if (tsdPtr->sleeping) { return; } switch (activity) { case kCFRunLoopEntry: tsdPtr->runLoopNestingLevel++; if (tsdPtr->numFdBits > 0 || tsdPtr->polling) { LOCK_NOTIFIER; if (!OnOffWaitingList(tsdPtr, 1, 1) && tsdPtr->polling) { write(triggerPipe, "", 1); } UNLOCK_NOTIFIER; } break; case kCFRunLoopExit: if (tsdPtr->runLoopNestingLevel == 1) { LOCK_NOTIFIER; OnOffWaitingList(tsdPtr, 0, 1); UNLOCK_NOTIFIER; } tsdPtr->runLoopNestingLevel--; break; default: break; } } /* *---------------------------------------------------------------------- * * OnOffWaitingList -- * * Add/remove the specified thread to/from the global waitingList and * optionally signal the notifier. * * !!! Requires notifierLock to be held !!! * * Results: * Boolean indicating whether the waitingList was changed. * * Side effects: * None. * *---------------------------------------------------------------------- */ static int OnOffWaitingList( ThreadSpecificData *tsdPtr, int onList, int signalNotifier) { int changeWaitingList; #if defined(TCL_MAC_DEBUG_NOTIFIER) && !defined(USE_OS_UNFAIR_LOCK) if (SpinLockTry(¬ifierLock)) { Tcl_Panic("OnOffWaitingList: notifierLock unlocked"); } #endif changeWaitingList = (!onList ^ !tsdPtr->onList); if (changeWaitingList) { if (onList) { tsdPtr->nextPtr = waitingListPtr; if (waitingListPtr) { waitingListPtr->prevPtr = tsdPtr; } tsdPtr->prevPtr = NULL; waitingListPtr = tsdPtr; tsdPtr->onList = 1; } else { if (tsdPtr->prevPtr) { tsdPtr->prevPtr->nextPtr = tsdPtr->nextPtr; } else { waitingListPtr = tsdPtr->nextPtr; } if (tsdPtr->nextPtr) { tsdPtr->nextPtr->prevPtr = tsdPtr->prevPtr; } tsdPtr->nextPtr = tsdPtr->prevPtr = NULL; tsdPtr->onList = 0; } if (signalNotifier) { write(triggerPipe, "", 1); } } return changeWaitingList; } /* *---------------------------------------------------------------------- * * Tcl_Sleep -- * * Delay execution for the specified number of milliseconds. * * Results: * None. * * Side effects: * Time passes. * *---------------------------------------------------------------------- */ void Tcl_Sleep( int ms) /* Number of milliseconds to sleep. */ { Tcl_Time vdelay; ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); if (ms <= 0) { return; } /* * TIP #233: Scale from virtual time to real-time. */ vdelay.sec = ms / 1000; vdelay.usec = (ms % 1000) * 1000; tclScaleTimeProcPtr(&vdelay, tclTimeClientData); if (tsdPtr->runLoop) { CFTimeInterval waitTime; CFRunLoopTimerRef runLoopTimer = tsdPtr->runLoopTimer; CFAbsoluteTime nextTimerFire = 0, waitEnd, now; SInt32 runLoopStatus; waitTime = vdelay.sec + 1.0e-6 * vdelay.usec; now = CFAbsoluteTimeGetCurrent(); waitEnd = now + waitTime; if (runLoopTimer) { nextTimerFire = CFRunLoopTimerGetNextFireDate(runLoopTimer); if (nextTimerFire < waitEnd) { CFRunLoopTimerSetNextFireDate(runLoopTimer, now + CF_TIMEINTERVAL_FOREVER); } else { runLoopTimer = NULL; } } tsdPtr->sleeping = 1; do { runLoopStatus = CFRunLoopRunInMode(kCFRunLoopDefaultMode, waitTime, FALSE); switch (runLoopStatus) { case kCFRunLoopRunFinished: Tcl_Panic("Tcl_Sleep: CFRunLoop finished"); break; case kCFRunLoopRunStopped: TclMacOSXNotifierDbgMsg("CFRunLoop stopped"); waitTime = waitEnd - CFAbsoluteTimeGetCurrent(); break; case kCFRunLoopRunTimedOut: waitTime = 0; break; } } while (waitTime > 0); tsdPtr->sleeping = 0; if (runLoopTimer) { CFRunLoopTimerSetNextFireDate(runLoopTimer, nextTimerFire); } } else { struct timespec waitTime; waitTime.tv_sec = vdelay.sec; waitTime.tv_nsec = vdelay.usec * 1000; while (nanosleep(&waitTime, &waitTime)); } } /* *---------------------------------------------------------------------- * * TclUnixWaitForFile -- * * This function waits synchronously for a file to become readable or * writable, with an optional timeout. * * Results: * The return value is an OR'ed combination of TCL_READABLE, * TCL_WRITABLE, and TCL_EXCEPTION, indicating the conditions that are * present on file at the time of the return. This function will not * return until either "timeout" milliseconds have elapsed or at least * one of the conditions given by mask has occurred for file (a return * value of 0 means that a timeout occurred). No normal events will be * serviced during the execution of this function. * * Side effects: * Time passes. * *---------------------------------------------------------------------- */ int TclUnixWaitForFile( int fd, /* Handle for file on which to wait. */ int mask, /* What to wait for: OR'ed combination of * TCL_READABLE, TCL_WRITABLE, and * TCL_EXCEPTION. */ int timeout) /* Maximum amount of time to wait for one of * the conditions in mask to occur, in * milliseconds. A value of 0 means don't wait * at all, and a value of -1 means wait * forever. */ { Tcl_Time abortTime = {0, 0}, now; /* silence gcc 4 warning */ struct timeval blockTime, *timeoutPtr; int numFound, result = 0; fd_set readableMask; fd_set writableMask; fd_set exceptionalMask; #define SET_BITS(var, bits) ((var) |= (bits)) #define CLEAR_BITS(var, bits) ((var) &= ~(bits)) #ifndef _DARWIN_C_SOURCE /* * Sanity check fd. */ if (fd >= FD_SETSIZE) { Tcl_Panic("TclUnixWaitForFile can't handle file id %d", fd); /* must never get here, or select masks overrun will occur below */ } #endif /* * If there is a non-zero finite timeout, compute the time when we give * up. */ if (timeout > 0) { Tcl_GetTime(&now); abortTime.sec = now.sec + timeout/1000; abortTime.usec = now.usec + (timeout%1000)*1000; if (abortTime.usec >= 1000000) { abortTime.usec -= 1000000; abortTime.sec += 1; } timeoutPtr = &blockTime; } else if (timeout == 0) { timeoutPtr = &blockTime; blockTime.tv_sec = 0; blockTime.tv_usec = 0; } else { timeoutPtr = NULL; } /* * Initialize the select masks. */ FD_ZERO(&readableMask); FD_ZERO(&writableMask); FD_ZERO(&exceptionalMask); /* * Loop in a mini-event loop of our own, waiting for either the file to * become ready or a timeout to occur. */ while (1) { if (timeout > 0) { blockTime.tv_sec = abortTime.sec - now.sec; blockTime.tv_usec = abortTime.usec - now.usec; if (blockTime.tv_usec < 0) { blockTime.tv_sec -= 1; blockTime.tv_usec += 1000000; } if (blockTime.tv_sec < 0) { blockTime.tv_sec = 0; blockTime.tv_usec = 0; } } /* * Setup the select masks for the fd. */ if (mask & TCL_READABLE) { FD_SET(fd, &readableMask); } if (mask & TCL_WRITABLE) { FD_SET(fd, &writableMask); } if (mask & TCL_EXCEPTION) { FD_SET(fd, &exceptionalMask); } /* * Wait for the event or a timeout. */ numFound = select(fd + 1, &readableMask, &writableMask, &exceptionalMask, timeoutPtr); if (numFound == 1) { if (FD_ISSET(fd, &readableMask)) { SET_BITS(result, TCL_READABLE); } if (FD_ISSET(fd, &writableMask)) { SET_BITS(result, TCL_WRITABLE); } if (FD_ISSET(fd, &exceptionalMask)) { SET_BITS(result, TCL_EXCEPTION); } result &= mask; if (result) { break; } } if (timeout == 0) { break; } if (timeout < 0) { continue; } /* * The select returned early, so we need to recompute the timeout. */ Tcl_GetTime(&now); if ((abortTime.sec < now.sec) || (abortTime.sec==now.sec && abortTime.usec<=now.usec)) { break; } } return result; } /* *---------------------------------------------------------------------- * * NotifierThreadProc -- * * This routine is the initial (and only) function executed by the * special notifier thread. Its job is to wait for file descriptors to * become readable or writable or to have an exception condition and then * to notify other threads who are interested in this information by * signalling a condition variable. Other threads can signal this * notifier thread of a change in their interests by writing a single * byte to a special pipe that the notifier thread is monitoring. * * Result: * None. Once started, this routine never exits. It dies with the overall * process. * * Side effects: * The trigger pipe used to signal the notifier thread is created when * the notifier thread first starts. * *---------------------------------------------------------------------- */ static TCL_NORETURN void NotifierThreadProc( TCL_UNUSED(ClientData)) { ThreadSpecificData *tsdPtr; fd_set readableMask, writableMask, exceptionalMask; int i, numFdBits = 0, polling; struct timeval poll = {0., 0.}, *timePtr; char buf[2]; /* * Look for file events and report them to interested threads. */ while (1) { FD_ZERO(&readableMask); FD_ZERO(&writableMask); FD_ZERO(&exceptionalMask); /* * Compute the logical OR of the select masks from all the waiting * notifiers. */ timePtr = NULL; LOCK_NOTIFIER; for (tsdPtr = waitingListPtr; tsdPtr; tsdPtr = tsdPtr->nextPtr) { LOCK_NOTIFIER_TSD; for (i = tsdPtr->numFdBits-1; i >= 0; --i) { if (FD_ISSET(i, &tsdPtr->checkMasks.readable)) { FD_SET(i, &readableMask); } if (FD_ISSET(i, &tsdPtr->checkMasks.writable)) { FD_SET(i, &writableMask); } if (FD_ISSET(i, &tsdPtr->checkMasks.exceptional)) { FD_SET(i, &exceptionalMask); } } if (tsdPtr->numFdBits > numFdBits) { numFdBits = tsdPtr->numFdBits; } polling = tsdPtr->polling; UNLOCK_NOTIFIER_TSD; if ((tsdPtr->polled = polling)) { timePtr = &poll; } } UNLOCK_NOTIFIER; /* * Set up the select mask to include the receive pipe. */ if (receivePipe >= numFdBits) { numFdBits = receivePipe + 1; } FD_SET(receivePipe, &readableMask); if (select(numFdBits, &readableMask, &writableMask, &exceptionalMask, timePtr) == -1) { /* * Try again immediately on an error. */ continue; } /* * Alert any threads that are waiting on a ready file descriptor. */ LOCK_NOTIFIER; for (tsdPtr = waitingListPtr; tsdPtr; tsdPtr = tsdPtr->nextPtr) { int found = 0; SelectMasks readyMasks, checkMasks; LOCK_NOTIFIER_TSD; FD_COPY(&tsdPtr->checkMasks.readable, &checkMasks.readable); FD_COPY(&tsdPtr->checkMasks.writable, &checkMasks.writable); FD_COPY(&tsdPtr->checkMasks.exceptional, &checkMasks.exceptional); UNLOCK_NOTIFIER_TSD; found = tsdPtr->polled; FD_ZERO(&readyMasks.readable); FD_ZERO(&readyMasks.writable); FD_ZERO(&readyMasks.exceptional); for (i = tsdPtr->numFdBits-1; i >= 0; --i) { if (FD_ISSET(i, &checkMasks.readable) && FD_ISSET(i, &readableMask)) { FD_SET(i, &readyMasks.readable); found = 1; } if (FD_ISSET(i, &checkMasks.writable) && FD_ISSET(i, &writableMask)) { FD_SET(i, &readyMasks.writable); found = 1; } if (FD_ISSET(i, &checkMasks.exceptional) && FD_ISSET(i, &exceptionalMask)) { FD_SET(i, &readyMasks.exceptional); found = 1; } } if (found) { /* * Remove the ThreadSpecificData structure of this thread from * the waiting list. This prevents us from spinning * continuously on select until the other threads runs and * services the file event. */ OnOffWaitingList(tsdPtr, 0, 0); LOCK_NOTIFIER_TSD; FD_COPY(&readyMasks.readable, &tsdPtr->readyMasks.readable); FD_COPY(&readyMasks.writable, &tsdPtr->readyMasks.writable); FD_COPY(&readyMasks.exceptional, &tsdPtr->readyMasks.exceptional); UNLOCK_NOTIFIER_TSD; tsdPtr->polled = 0; if (tsdPtr->runLoop) { CFRunLoopSourceSignal(tsdPtr->runLoopSource); CFRunLoopWakeUp(tsdPtr->runLoop); } } } UNLOCK_NOTIFIER; /* * Consume the next byte from the notifier pipe if the pipe was * readable. Note that there may be multiple bytes pending, but to * avoid a race condition we only read one at a time. */ if (FD_ISSET(receivePipe, &readableMask)) { i = read(receivePipe, buf, 1); if ((i == 0) || ((i == 1) && (buf[0] == 'q'))) { /* * Someone closed the write end of the pipe or sent us a Quit * message [Bug: 4139] and then closed the write end of the * pipe so we need to shut down the notifier thread. */ break; } } } pthread_exit(0); } #ifdef HAVE_PTHREAD_ATFORK /* *---------------------------------------------------------------------- * * AtForkPrepare -- * * Lock the notifier in preparation for a fork. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------- */ static void AtForkPrepare(void) { ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); LOCK_NOTIFIER_INIT; LOCK_NOTIFIER; LOCK_NOTIFIER_TSD; } /* *---------------------------------------------------------------------- * * AtForkParent -- * * Unlock the notifier in the parent after a fork. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------- */ static void AtForkParent(void) { ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); UNLOCK_NOTIFIER_TSD; UNLOCK_NOTIFIER; UNLOCK_NOTIFIER_INIT; } /* *---------------------------------------------------------------------- * * AtForkChild -- * * Unlock and reinstall the notifier in the child after a fork. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------- */ static void AtForkChild(void) { ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); /* * If a child process unlocks an os_unfair_lock that was created in its parent * the child will exit with an illegal instruction error. So we reinitialize * the lock in the child rather than attempt to unlock it. */ #if defined(USE_OS_UNFAIR_LOCK) tsdPtr->tsdLock = OS_UNFAIR_LOCK_INIT; #else UNLOCK_NOTIFIER_TSD; UNLOCK_NOTIFIER; UNLOCK_NOTIFIER_INIT; #endif if (tsdPtr->runLoop) { tsdPtr->runLoop = NULL; if (!noCFafterFork) { CFRunLoopSourceInvalidate(tsdPtr->runLoopSource); CFRelease(tsdPtr->runLoopSource); if (tsdPtr->runLoopTimer) { CFRunLoopTimerInvalidate(tsdPtr->runLoopTimer); CFRelease(tsdPtr->runLoopTimer); } } tsdPtr->runLoopSource = NULL; tsdPtr->runLoopTimer = NULL; } if (notifierCount > 0) { notifierCount = 1; notifierThreadRunning = 0; /* * Assume that the return value of Tcl_InitNotifier in the child will * be identical to the one stored as clientData in tclNotify.c's * ThreadSpecificData by the parent's TclInitNotifier, so discard the * return value here. This assumption may require the fork() to be * executed in the main thread of the parent, otherwise * Tcl_AlertNotifier may break in the child. */ if (!noCFafterFork) { Tcl_InitNotifier(); } } } #endif /* HAVE_PTHREAD_ATFORK */ #else /* HAVE_COREFOUNDATION */ void Tcl_MacOSXNotifierAddRunLoopMode( const void *runLoopMode) { Tcl_Panic("Tcl_MacOSXNotifierAddRunLoopMode: " "Tcl not built with CoreFoundation support"); } #endif /* HAVE_COREFOUNDATION */ /* * Local Variables: * mode: c * c-basic-offset: 4 * fill-column: 78 * End: */