diff options
Diffstat (limited to 'macosx/tclMacOSXNotify.c')
| -rw-r--r-- | macosx/tclMacOSXNotify.c | 528 |
1 files changed, 274 insertions, 254 deletions
diff --git a/macosx/tclMacOSXNotify.c b/macosx/tclMacOSXNotify.c index 95cc46f..6c46562 100644 --- a/macosx/tclMacOSXNotify.c +++ b/macosx/tclMacOSXNotify.c @@ -1,23 +1,22 @@ /* * 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. + * 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 (c) 1995-1997 Sun Microsystems, Inc. * Copyright 2001, Apple Computer, Inc. * Copyright 2005, Tcl Core Team. * - * See the file "license.terms" for information on usage and redistribution - * of this file, and for a DISCLAIMER OF ALL WARRANTIES. + * See the file "license.terms" for information on usage and redistribution of + * this file, and for a DISCLAIMER OF ALL WARRANTIES. * - * RCS: @(#) $Id: tclMacOSXNotify.c,v 1.3 2005/05/20 02:50:17 das Exp $ + * RCS: @(#) $Id: tclMacOSXNotify.c,v 1.4 2005/07/25 20:48:34 dkf Exp $ */ -#ifdef HAVE_COREFOUNDATION /* Traditional unix select-based notifier - * is in tclUnixNotfy.c */ +#ifdef HAVE_COREFOUNDATION /* Traditional unix select-based notifier is + * in tclUnixNotfy.c */ #include "tclInt.h" #include <CoreFoundation/CoreFoundation.h> #include <pthread.h> @@ -26,42 +25,41 @@ extern TclStubs tclStubs; extern Tcl_NotifierProcs tclOriginalNotifier; /* - * This structure is used to keep track of the notifier info for a - * a registered file. + * 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; /* Procedure to call, in the style of + 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. + * The following structure is what is added to the Tcl event queue when file + * handlers are ready to fire. */ typedef struct FileHandlerEvent { - 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). */ + 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. + * The following structure contains a set of select() masks to track readable, + * writable, and exceptional conditions. */ typedef struct SelectMasks { @@ -72,49 +70,50 @@ typedef struct 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. + * 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. */ - - 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 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 + int numFdBits; /* Number of valid bits in checkMasks (one + * more than highest fd for which * Tcl_WatchFile has been called). */ int onList; /* True if it is in this list */ - unsigned int pollState; /* pollState is used to implement a polling + unsigned int pollState; /* pollState is used to implement a polling * handshake between each thread and the * notifier thread. Bits defined below. */ struct ThreadSpecificData *nextPtr, *prevPtr; - /* All threads that are currently waiting on + /* All threads that are currently waiting on * an event have their ThreadSpecificData * structure on a doubly-linked listed formed - * from these pointers. You must hold the + * from these pointers. You must hold the * notifierLock before accessing these * fields. */ CFRunLoopSourceRef runLoopSource; - /* Any other thread alerts a notifier - * that an event is ready to be processed - * by signaling this CFRunLoopSource. */ - CFRunLoopRef runLoop; /* This thread's CFRunLoop, needs to be woken - * up whenever the runLoopSource is signaled. */ - int eventReady; /* True if an event is ready to be processed. */ + /* Any other thread alerts a notifier that an + * event is ready to be processed by signaling + * this CFRunLoopSource. */ + CFRunLoopRef runLoop; /* This thread's CFRunLoop, needs to be woken + * up whenever the runLoopSource is + * signaled. */ + int eventReady; /* True if an event is ready to be + * processed. */ } ThreadSpecificData; static Tcl_ThreadDataKey dataKey; /* - * The following static indicates the number of threads that have - * initialized notifiers. + * The following static indicates the number of threads that have initialized + * notifiers. * * You must hold the notifierInitLock before accessing this variable. */ @@ -122,9 +121,9 @@ static Tcl_ThreadDataKey dataKey; static int notifierCount = 0; /* - * The following variable points to the head of a doubly-linked list of - * of ThreadSpecificData structures for all threads that are currently - * waiting on an event. + * 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. */ @@ -132,16 +131,15 @@ static int notifierCount = 0; 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. + * 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. */ @@ -151,55 +149,64 @@ static int receivePipe = -1; /* Output end of triggerPipe */ /* * We use Darwin-native spinlocks instead of 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, making them immune to most priority-inversion - * livelocks (c.f. man 3 OSSpinLockLock). + * locking: this radically simplifies the implementation and lowers overhead. + * Note that these are not pure spinlocks, they employ various strategies to + * back off, making them immune to most priority-inversion livelocks (c.f. man + * 3 OSSpinLockLock). */ #if defined(HAVE_LIBKERN_OSATOMIC_H) && defined(HAVE_OSSPINLOCKLOCK) -/* Use OSSpinLock API where available (Tiger or later) */ +/* + * Use OSSpinLock API where available (Tiger or later). + */ + #include <libkern/OSAtomic.h> + #else -/* Otherwise, use commpage spinlock SPI directly */ +/* + * Otherwise, use commpage spinlock SPI directly. + */ + typedef uint32_t OSSpinLock; -extern void _spin_lock(OSSpinLock *lock); -extern void _spin_unlock(OSSpinLock *lock); -#define OSSpinLockLock(p) _spin_lock(p) -#define OSSpinLockUnlock(p) _spin_unlock(p) -#endif +extern void _spin_lock(OSSpinLock *lock); +extern void _spin_unlock(OSSpinLock *lock); +#define OSSpinLockLock(p) _spin_lock(p) +#define OSSpinLockUnlock(p) _spin_unlock(p) + +#endif /* HAVE_LIBKERN_OSATOMIC_H && HAVE_OSSPINLOCKLOCK */ /* - * These spinlocks lock access to the global notifier state. + * These spinlocks lock access to the global notifier state. */ static OSSpinLock notifierInitLock = 0; static OSSpinLock notifierLock = 0; -/* +/* * Macros abstracting notifier locking/unlocking */ -#define LOCK_NOTIFIER_INIT OSSpinLockLock(¬ifierInitLock) -#define UNLOCK_NOTIFIER_INIT OSSpinLockUnlock(¬ifierInitLock) -#define LOCK_NOTIFIER OSSpinLockLock(¬ifierLock) -#define UNLOCK_NOTIFIER OSSpinLockUnlock(¬ifierLock) +#define LOCK_NOTIFIER_INIT OSSpinLockLock(¬ifierInitLock) +#define UNLOCK_NOTIFIER_INIT OSSpinLockUnlock(¬ifierInitLock) +#define LOCK_NOTIFIER OSSpinLockLock(¬ifierLock) +#define UNLOCK_NOTIFIER OSSpinLockUnlock(¬ifierLock) /* * The pollState bits * POLL_WANT is set by each thread before it waits on its condition - * variable. It is checked by the notifier before it does - * select. - * POLL_DONE is set by the notifier if it goes into select after - * seeing POLL_WANT. The idea is to ensure it tries a select - * with the same bits the initial thread had set. + * variable. It is checked by the notifier before it does select. + * POLL_DONE is set by the notifier if it goes into select after seeing + * POLL_WANT. The idea is to ensure it tries a select with the + * same bits the initial thread had set. */ + #define POLL_WANT 0x1 #define POLL_DONE 0x2 /* * This is the thread ID of the notifier thread that does select. */ + static pthread_t notifierThread; /* @@ -231,25 +238,25 @@ Tcl_InitNotifier() ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); tsdPtr->eventReady = 0; - - /* + + /* * Initialize CFRunLoopSource and add it to CFRunLoop of this thread */ - + if (!tsdPtr->runLoop) { - CFRunLoopRef runLoop = CFRunLoopGetCurrent(); - CFRunLoopSourceRef runLoopSource; - CFRunLoopSourceContext runLoopSourceContext; - - bzero(&runLoopSourceContext, sizeof(CFRunLoopSourceContext)); - runLoopSourceContext.info = tsdPtr; - runLoopSource = CFRunLoopSourceCreate(NULL, 0, &runLoopSourceContext); - if (!runLoopSource) { - Tcl_Panic("Tcl_InitNotifier: could not create CFRunLoopSource."); - } - CFRunLoopAddSource(runLoop, runLoopSource, kCFRunLoopCommonModes); - tsdPtr->runLoopSource = runLoopSource; - tsdPtr->runLoop = runLoop; + CFRunLoopRef runLoop = CFRunLoopGetCurrent(); + CFRunLoopSourceRef runLoopSource; + CFRunLoopSourceContext runLoopSourceContext; + + bzero(&runLoopSourceContext, sizeof(CFRunLoopSourceContext)); + runLoopSourceContext.info = tsdPtr; + runLoopSource = CFRunLoopSourceCreate(NULL, 0, &runLoopSourceContext); + if (!runLoopSource) { + Tcl_Panic("Tcl_InitNotifier: could not create CFRunLoopSource."); + } + CFRunLoopAddSource(runLoop, runLoopSource, kCFRunLoopCommonModes); + tsdPtr->runLoopSource = runLoopSource; + tsdPtr->runLoop = runLoop; } /* @@ -258,40 +265,41 @@ Tcl_InitNotifier() LOCK_NOTIFIER_INIT; if (notifierCount == 0) { - int fds[2], status, result; - pthread_attr_t attr; - - 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]; - - 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); + int fds[2], status, result; + pthread_attr_t attr; + + 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]; + + 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("Tcl_InitNotifier: unable to start notifier thread."); } } notifierCount++; UNLOCK_NOTIFIER_INIT; - + return (ClientData) tsdPtr; } @@ -300,15 +308,15 @@ Tcl_InitNotifier() * * Tcl_FinalizeNotifier -- * - * This function is called to cleanup the notifier state before - * a thread is terminated. + * 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. + * May terminate the background notifier thread if this is the last + * notifier instance. * *---------------------------------------------------------------------- */ @@ -323,47 +331,52 @@ Tcl_FinalizeNotifier(clientData) notifierCount--; /* - * If this is the last thread to use the notifier, close the notifier - * pipe and wait for the background thread to terminate. + * 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) { - int result; - + int result; + if (triggerPipe < 0) { Tcl_Panic("Tcl_FinalizeNotifier: 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] + * 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] */ + write(triggerPipe, "q", 1); close(triggerPipe); - result = pthread_join(notifierThread, NULL); + result = pthread_join(notifierThread, NULL); if (result) { Tcl_Panic("Tcl_FinalizeNotifier: unable to join notifier thread."); } - + close(receivePipe); - triggerPipe = -1; + triggerPipe = -1; } UNLOCK_NOTIFIER_INIT; - - LOCK_NOTIFIER; /* for concurrency with Tcl_AlertNotifier */ + + LOCK_NOTIFIER; /* for concurrency with Tcl_AlertNotifier */ if (tsdPtr->runLoop) { - tsdPtr->runLoop = NULL; - /* Remove runLoopSource from all CFRunLoops and release it */ - CFRunLoopSourceInvalidate(tsdPtr->runLoopSource); - CFRelease(tsdPtr->runLoopSource); - tsdPtr->runLoopSource = NULL; + tsdPtr->runLoop = NULL; + + /* + * Remove runLoopSource from all CFRunLoops and release it. + */ + + CFRunLoopSourceInvalidate(tsdPtr->runLoopSource); + CFRelease(tsdPtr->runLoopSource); + tsdPtr->runLoopSource = NULL; } UNLOCK_NOTIFIER; } @@ -373,18 +386,16 @@ Tcl_FinalizeNotifier(clientData) * * 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. + * 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. + * Signals the notifier condition variable for the specified notifier. * *---------------------------------------------------------------------- */ @@ -394,11 +405,12 @@ Tcl_AlertNotifier(clientData) ClientData clientData; { ThreadSpecificData *tsdPtr = (ThreadSpecificData *) clientData; + LOCK_NOTIFIER; if (tsdPtr->runLoop) { - tsdPtr->eventReady = 1; - CFRunLoopSourceSignal(tsdPtr->runLoopSource); - CFRunLoopWakeUp(tsdPtr->runLoop); + tsdPtr->eventReady = 1; + CFRunLoopSourceSignal(tsdPtr->runLoopSource); + CFRunLoopWakeUp(tsdPtr->runLoop); } UNLOCK_NOTIFIER; } @@ -408,9 +420,9 @@ Tcl_AlertNotifier(clientData) * * Tcl_SetTimer -- * - * This procedure sets the current notifier timer value. This - * interface is not implemented in this notifier because we are - * always running inside of Tcl_DoOneEvent. + * This function sets the current notifier timer value. This interface is + * not implemented in this notifier because we are always running inside + * of Tcl_DoOneEvent. * * Results: * None. @@ -426,9 +438,9 @@ Tcl_SetTimer(timePtr) Tcl_Time *timePtr; /* Timeout value, may be NULL. */ { /* - * The interval timer doesn't do anything in this implementation, - * because the only event loop is via Tcl_DoOneEvent, which passes - * timeout values to Tcl_WaitForEvent. + * The interval timer doesn't do anything in this implementation, because + * the only event loop is via Tcl_DoOneEvent, which passes timeout values + * to Tcl_WaitForEvent. */ if (tclStubs.tcl_SetTimer != tclOriginalNotifier.setTimerProc) { @@ -464,7 +476,7 @@ Tcl_ServiceModeHook(mode) * * Tcl_CreateFileHandler -- * - * This procedure registers a file handler with the select notifier. + * This function registers a file handler with the select notifier. * * Results: * None. @@ -479,17 +491,18 @@ void Tcl_CreateFileHandler(fd, mask, proc, clientData) 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; /* Procedure to call for each + * 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 = TCL_TSD_INIT(&dataKey); FileHandler *filePtr; - if (tclStubs.tcl_CreateFileHandler != tclOriginalNotifier.createFileHandlerProc) { + if (tclStubs.tcl_CreateFileHandler != + tclOriginalNotifier.createFileHandlerProc) { tclStubs.tcl_CreateFileHandler(fd, mask, proc, clientData); return; } @@ -540,8 +553,7 @@ Tcl_CreateFileHandler(fd, mask, proc, clientData) * * Tcl_DeleteFileHandler -- * - * Cancel a previously-arranged callback arrangement for - * a file. + * Cancel a previously-arranged callback arrangement for a file. * * Results: * None. @@ -554,13 +566,15 @@ Tcl_CreateFileHandler(fd, mask, proc, clientData) void Tcl_DeleteFileHandler(fd) - int fd; /* Stream id for which to remove callback procedure. */ + int fd; /* Stream id for which to remove callback + * function. */ { FileHandler *filePtr, *prevPtr; int i; ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); - if (tclStubs.tcl_DeleteFileHandler != tclOriginalNotifier.deleteFileHandlerProc) { + if (tclStubs.tcl_DeleteFileHandler != + tclOriginalNotifier.deleteFileHandlerProc) { tclStubs.tcl_DeleteFileHandler(fd); return; } @@ -626,19 +640,19 @@ Tcl_DeleteFileHandler(fd) * * FileHandlerEventProc -- * - * This procedure is called by Tcl_ServiceEvent when a file event - * reaches the front of the event queue. This procedure is - * responsible for actually handling the event by invoking the - * callback for the file handler. + * 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. + * 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 procedure does. + * Whatever the file handler's callback function does. * *---------------------------------------------------------------------- */ @@ -646,8 +660,8 @@ Tcl_DeleteFileHandler(fd) static int FileHandlerEventProc(evPtr, flags) Tcl_Event *evPtr; /* Event to service. */ - int flags; /* Flags that indicate what events to - * handle, such as TCL_FILE_EVENTS. */ + int flags; /* Flags that indicate what events to handle, + * such as TCL_FILE_EVENTS. */ { int mask; FileHandler *filePtr; @@ -660,9 +674,9 @@ FileHandlerEventProc(evPtr, flags) /* * 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. + * 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); @@ -674,14 +688,14 @@ FileHandlerEventProc(evPtr, flags) /* * 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. + * 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; @@ -699,13 +713,12 @@ FileHandlerEventProc(evPtr, flags) * * 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. + * 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 -1 if the select would block forever, otherwise - * returns 0. + * Returns -1 if the select would block forever, otherwise returns 0. * * Side effects: * Queues file events that are detected by the select. @@ -730,9 +743,11 @@ Tcl_WaitForEvent(timePtr) } if (timePtr != NULL) { - /* 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 */ + /* + * 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. + */ myTime.sec = timePtr->sec; myTime.usec = timePtr->usec; @@ -757,10 +772,10 @@ Tcl_WaitForEvent(timePtr) if (myTimePtr != NULL && myTimePtr->sec == 0 && myTimePtr->usec == 0) { /* * Cannot emulate a polling select with a polling condition variable. - * Instead, pretend to wait for files and tell the notifier - * thread what we are doing. The notifier thread makes sure - * it goes through select with its select mask in the same state - * as ours currently is. We block until that happens. + * Instead, pretend to wait for files and tell the notifier thread + * what we are doing. The notifier thread makes sure it goes through + * select with its select mask in the same state as ours currently is. + * We block until that happens. */ waitForFiles = 1; @@ -772,9 +787,9 @@ Tcl_WaitForEvent(timePtr) if (waitForFiles) { /* - * Add the ThreadSpecificData structure of this thread to the list - * of ThreadSpecificData structures of all threads that are waiting - * on file events. + * Add the ThreadSpecificData structure of this thread to the list of + * ThreadSpecificData structures of all threads that are waiting on + * file events. */ tsdPtr->nextPtr = waitingListPtr; @@ -793,23 +808,23 @@ Tcl_WaitForEvent(timePtr) FD_ZERO(&(tsdPtr->readyMasks.exceptional)); if (!tsdPtr->eventReady) { - CFTimeInterval waitTime; - - if (myTimePtr == NULL) { - waitTime = 1.0e10; /* Wait forever, as per CFRunLoop.c */ - } else { - waitTime = myTimePtr->sec + 1.0e-6 * myTimePtr->usec; - } - UNLOCK_NOTIFIER; - CFRunLoopRunInMode(kCFRunLoopDefaultMode, waitTime, TRUE); - LOCK_NOTIFIER; + CFTimeInterval waitTime; + + if (myTimePtr == NULL) { + waitTime = 1.0e10; /* Wait forever, as per CFRunLoop.c */ + } else { + waitTime = myTimePtr->sec + 1.0e-6 * myTimePtr->usec; + } + UNLOCK_NOTIFIER; + CFRunLoopRunInMode(kCFRunLoopDefaultMode, waitTime, TRUE); + LOCK_NOTIFIER; } tsdPtr->eventReady = 0; if (waitForFiles && tsdPtr->onList) { /* * Remove the ThreadSpecificData structure of this thread from the - * waiting list. Alert the notifier thread to recompute its select + * waiting list. Alert the notifier thread to recompute its select * masks - skipping this caused a hang when trying to close a pipe * which the notifier thread was still doing a select on. */ @@ -827,7 +842,6 @@ Tcl_WaitForEvent(timePtr) write(triggerPipe, "", 1); } - /* * Queue all detected file events before returning. */ @@ -851,8 +865,8 @@ Tcl_WaitForEvent(timePtr) } /* - * Don't bother to queue an event if the mask was previously - * non-zero since an event must still be on the queue. + * 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) { @@ -873,21 +887,20 @@ Tcl_WaitForEvent(timePtr) * 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. + * 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. + * 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. + * The trigger pipe used to signal the notifier thread is created when + * the notifier thread first starts. * *---------------------------------------------------------------------- */ @@ -915,8 +928,8 @@ NotifierThreadProc(clientData) FD_ZERO(&exceptionalMask); /* - * Compute the logical OR of the select masks from all the - * waiting notifiers. + * Compute the logical OR of the select masks from all the waiting + * notifiers. */ LOCK_NOTIFIER; @@ -938,8 +951,8 @@ NotifierThreadProc(clientData) } if (tsdPtr->pollState & POLL_WANT) { /* - * Here we make sure we go through select() with the same - * mask bits that were present when the thread tried to poll. + * Here we make sure we go through select() with the same mask + * bits that were present when the thread tried to poll. */ tsdPtr->pollState |= POLL_DONE; @@ -996,10 +1009,10 @@ NotifierThreadProc(clientData) tsdPtr->eventReady = 1; if (tsdPtr->onList) { /* - * Remove the ThreadSpecificData structure of this - * thread from the waiting list. This prevents us from - * continuously spining on select until the other - * threads runs and services the file event. + * Remove the ThreadSpecificData structure of this thread + * from the waiting list. This prevents us from + * continuously spining on select until the other threads + * runs and services the file event. */ if (tsdPtr->prevPtr) { @@ -1024,8 +1037,8 @@ NotifierThreadProc(clientData) /* * 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. + * 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)) { @@ -1033,9 +1046,9 @@ NotifierThreadProc(clientData) 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. + * 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; @@ -1044,5 +1057,12 @@ NotifierThreadProc(clientData) } pthread_exit (0); } - #endif /* HAVE_COREFOUNDATION */ + +/* + * Local Variables: + * mode: c + * c-basic-offset: 4 + * fill-column: 78 + * End: + */ |