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Diffstat (limited to 'macosx/tkMacOSXNotify.c')
| -rw-r--r-- | macosx/tkMacOSXNotify.c | 1145 |
1 files changed, 1145 insertions, 0 deletions
diff --git a/macosx/tkMacOSXNotify.c b/macosx/tkMacOSXNotify.c new file mode 100644 index 0000000..c8c5af9 --- /dev/null +++ b/macosx/tkMacOSXNotify.c @@ -0,0 +1,1145 @@ +/* + * tclMacOSXNotify.c -- + * + * This file contains the implementation of a merged + * Carbon/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. + * + * See the file "license.terms" for information on usage and redistribution + * of this file, and for a DISCLAIMER OF ALL WARRANTIES. + * + * RCS: @(#) $Id: tkMacOSXNotify.c,v 1.2 2002/08/31 06:12:30 das Exp $ + */ + +#include "tclInt.h" +#include "tclPort.h" + +/* FIXME - Why do I need these here? */ + +#undef environ +#include "tkMacOSX.h" +#include "tkMacOSXEvent.h" +#include <signal.h> + +extern TclStubs tclStubs; + +/* + * This structure is used to keep track of the notifier info for a + * 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 + * 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 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). */ +} FileHandlerEvent; + +/* + * 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. */ + fd_mask checkMasks[3*MASK_SIZE]; + /* This array 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. */ + fd_mask readyMasks[3*MASK_SIZE]; + /* 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 isMainLoop; /* Is this the main Carbon Loop (in which case + * we will call RNE in the actual wait... */ +#ifdef TCL_THREADS + int onList; /* True if it is in this list */ + 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 + * an event have their ThreadSpecificData + * structure on a doubly-linked listed formed + * from these pointers. You must hold the + * notifierMutex lock before accessing these + * fields. */ + Tcl_Condition waitCV; /* Any other thread alerts a notifier + * that an event is ready to be processed + * by signaling this condition variable. */ + int eventReady; /* True if an event is ready to be processed. + * Used as condition flag together with + * waitCV above. */ +#endif +} ThreadSpecificData; + +static Tcl_ThreadDataKey dataKey; + +#ifdef TCL_THREADS +/* + * The following static indicates the number of threads that have + * initialized notifiers. + * + * You must hold the notifierMutex lock before accessing this variable. + */ + +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. + * + * You must hold the notifierMutex lock 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 notifierMutex lock before accessing this list. + */ + +static int triggerPipe = -1; + +/* + * The notifierMutex locks access to all of the global notifier state. + */ + +TCL_DECLARE_MUTEX(notifierMutex) + +/* + * The notifier thread signals the notifierCV when it has finished + * initializing the triggerPipe and right before the notifier + * thread terminates. + */ + +static Tcl_Condition notifierCV; + +/* + * 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. + */ +#define POLL_WANT 0x1 +#define POLL_DONE 0x2 + +/* + * This is the thread ID of the notifier thread that does select. + */ +static Tcl_ThreadId notifierThread; + +#endif + +/* + * Static routines defined in this file. + */ + +#ifdef TCL_THREADS +static void NotifierThreadProc _ANSI_ARGS_((ClientData clientData)); +#endif +static int FileHandlerEventProc _ANSI_ARGS_((Tcl_Event *evPtr, + int flags)); + +void TkMacOSXSetTimer(Tcl_Time *timePtr); +void TkMacOSXCreateFileHandler(int fd, int mask, Tcl_FileProc *proc, ClientData clientData); +void TkMacOSXDeleteFileHandler(int fd); +int TkMacOSXWaitForEvent(Tcl_Time *timePtr); +void TkMacOSXAlertNotifier(ClientData clientData); +ClientData TkMacOSXInitNotifier(); +void TkMacOSXFinalizeNotifier(ClientData clientData); +void TkMacOSXServiceModeHook(int mode); +EventRef TkMacOSXCreateFakeEvent (); + /* + *---------------------------------------------------------------------- + * + * TkMacOSXSetupTkNotifier -- + * + * Replaces the Tcl notifier (from tclUnixNotfy.c) with + * the Mac notifier that melds the Unix select based notifer + * with the Carbon event handling side of the Tk notifier. + * + * Results: + * Replaces the notifier callbacks with MacOS X specific ones. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +void +Tk_MacOSXSetupTkNotifier() +{ + Tcl_NotifierProcs macNotifierProcs = { + TkMacOSXSetTimer, + TkMacOSXWaitForEvent, + TkMacOSXCreateFileHandler, + TkMacOSXDeleteFileHandler, + TkMacOSXInitNotifier, + TkMacOSXFinalizeNotifier, + TkMacOSXAlertNotifier, + TkMacOSXServiceModeHook + }; + + Tcl_SetNotifier(&macNotifierProcs); + + /* + * Tcl_SetNotifier doesn't call the TclInitNotifier + * so we call it now. If we don't do this the + * ThreadSpecificData will keep a pointer to the original + * InitNotifier. See tclNotify.c:TclInitNotifier(). + */ + + TclInitNotifier(); +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_InitNotifier -- + * + * Initializes the platform specific notifier state. + * + * Results: + * Returns a handle to the notifier state for this thread.. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +ClientData +TkMacOSXInitNotifier() +{ + ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); + +#ifdef TCL_THREADS + tsdPtr->eventReady = 0; + + /* + * Start the Notifier thread if necessary. + */ + + Tcl_MutexLock(¬ifierMutex); + if (notifierCount == 0) { + if (Tcl_CreateThread(¬ifierThread, NotifierThreadProc, NULL, + TCL_THREAD_STACK_DEFAULT, TCL_THREAD_NOFLAGS) != TCL_OK) { + panic("Tcl_InitNotifier: unable to start notifier thread"); + } + } + notifierCount++; + + if (GetCurrentEventLoop() == GetMainEventLoop()) { + tsdPtr->isMainLoop = 1; + } else { + tsdPtr->isMainLoop = 0; + } + + /* + * Wait for the notifier pipe to be created. + */ + + while (triggerPipe < 0) { + Tcl_ConditionWait(¬ifierCV, ¬ifierMutex, NULL); + } + + Tcl_MutexUnlock(¬ifierMutex); +#endif + return (ClientData) tsdPtr; +} + +/* + *---------------------------------------------------------------------- + * + * 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 +TkMacOSXFinalizeNotifier(clientData) + ClientData clientData; /* Not used. */ +{ +#ifdef TCL_THREADS + ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); + + Tcl_MutexLock(¬ifierMutex); + notifierCount--; + + /* + * 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 < 0) { + 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] + */ + write(triggerPipe, "q", 1); + close(triggerPipe); + + Tcl_ConditionWait(¬ifierCV, ¬ifierMutex, NULL); + } + + /* + * Clean up any synchronization objects in the thread local storage. + */ + + Tcl_ConditionFinalize(&(tsdPtr->waitCV)); + + Tcl_MutexUnlock(¬ifierMutex); +#endif +} + +/* + *---------------------------------------------------------------------- + * + * 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 +TkMacOSXAlertNotifier(clientData) + ClientData clientData; +{ +#ifdef TCL_THREADS + ThreadSpecificData *tsdPtr = (ThreadSpecificData *) clientData; + Tcl_MutexLock(¬ifierMutex); + tsdPtr->eventReady = 1; + Tcl_ConditionNotify(&tsdPtr->waitCV); + Tcl_MutexUnlock(¬ifierMutex); +#endif +} + +/* + *---------------------------------------------------------------------- + * + * 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. + * + * Results: + * None. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +void +TkMacOSXSetTimer(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. + */ + +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_ServiceModeHook -- + * + * This function is invoked whenever the service mode changes. + * + * Results: + * None. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +void +TkMacOSXServiceModeHook(mode) + int mode; /* Either TCL_SERVICE_ALL, or + * TCL_SERVICE_NONE. */ +{ +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_CreateFileHandler -- + * + * This procedure registers a file handler with the select notifier. + * + * Results: + * None. + * + * Side effects: + * Creates a new file handler structure. + * + *---------------------------------------------------------------------- + */ + +void +TkMacOSXCreateFileHandler(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 + * selected event. */ + ClientData clientData; /* Arbitrary data to pass to proc. */ +{ + ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); + FileHandler *filePtr; + int index, bit; + + 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. + */ + + index = fd/(NBBY*sizeof(fd_mask)); + bit = 1 << (fd%(NBBY*sizeof(fd_mask))); + if (mask & TCL_READABLE) { + tsdPtr->checkMasks[index] |= bit; + } else { + tsdPtr->checkMasks[index] &= ~bit; + } + if (mask & TCL_WRITABLE) { + (tsdPtr->checkMasks+MASK_SIZE)[index] |= bit; + } else { + (tsdPtr->checkMasks+MASK_SIZE)[index] &= ~bit; + } + if (mask & TCL_EXCEPTION) { + (tsdPtr->checkMasks+2*(MASK_SIZE))[index] |= bit; + } else { + (tsdPtr->checkMasks+2*(MASK_SIZE))[index] &= ~bit; + } + if (tsdPtr->numFdBits <= fd) { + tsdPtr->numFdBits = fd+1; + } +} + +/* + *---------------------------------------------------------------------- + * + * 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 +TkMacOSXDeleteFileHandler(fd) + int fd; /* Stream id for which to remove callback procedure. */ +{ + FileHandler *filePtr, *prevPtr; + int index, bit, i; + unsigned long flags; + ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); + + /* + * 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; + } + } + + /* + * Update the check masks for this file. + */ + + index = fd/(NBBY*sizeof(fd_mask)); + bit = 1 << (fd%(NBBY*sizeof(fd_mask))); + + if (filePtr->mask & TCL_READABLE) { + tsdPtr->checkMasks[index] &= ~bit; + } + if (filePtr->mask & TCL_WRITABLE) { + (tsdPtr->checkMasks+MASK_SIZE)[index] &= ~bit; + } + if (filePtr->mask & TCL_EXCEPTION) { + (tsdPtr->checkMasks+2*(MASK_SIZE))[index] &= ~bit; + } + + /* + * Find current max fd. + */ + + if (fd+1 == tsdPtr->numFdBits) { + for (tsdPtr->numFdBits = 0; index >= 0; index--) { + flags = tsdPtr->checkMasks[index] + | (tsdPtr->checkMasks+MASK_SIZE)[index] + | (tsdPtr->checkMasks+2*(MASK_SIZE))[index]; + if (flags) { + for (i = (NBBY*sizeof(fd_mask)); i > 0; i--) { + if (flags & (((unsigned long)1) << (i-1))) { + break; + } + } + tsdPtr->numFdBits = index * (NBBY*sizeof(fd_mask)) + i; + break; + } + } + } + + /* + * Clean up information in the callback record. + */ + + if (prevPtr == NULL) { + tsdPtr->firstFileHandlerPtr = filePtr->nextPtr; + } else { + prevPtr->nextPtr = filePtr->nextPtr; + } + ckfree((char *) filePtr); +} + +/* + *---------------------------------------------------------------------- + * + * 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. + * + * 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 procedure does. + * + *---------------------------------------------------------------------- + */ + +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 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) { + (*filePtr->proc)(filePtr->clientData, mask); + } + break; + } + return 1; +} + +void +DoActualWait(timePtr) + Tcl_Time *timePtr; /* Maximum block time, or NULL. */ +{ + ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); + + if (!tsdPtr->isMainLoop) { + Tcl_ConditionWait(&tsdPtr->waitCV, ¬ifierMutex, timePtr); + } else { + EventRef eventRef; + EventTime waitTime; + Tcl_MutexUnlock(¬ifierMutex); + + if (timePtr == NULL) { + waitTime = kEventDurationForever; + } else { + waitTime = timePtr->sec * kEventDurationSecond + + timePtr->usec * kEventDurationMicrosecond; + } + ReceiveNextEvent(0, NULL, waitTime, false, &eventRef); + Tcl_MutexLock(¬ifierMutex); + } +} + +/* + *---------------------------------------------------------------------- + * + * 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 -1 if the select would block forever, otherwise + * returns 0. + * + * Side effects: + * Queues file events that are detected by the select. + * + *---------------------------------------------------------------------- + */ + +int +TkMacOSXWaitForEvent(timePtr) + Tcl_Time *timePtr; /* Maximum block time, or NULL. */ +{ + FileHandler *filePtr; + FileHandlerEvent *fileEvPtr; + struct timeval timeout, *timeoutPtr; + int bit, index, mask; +#ifdef TCL_THREADS + int waitForFiles; +#else + int numFound; +#endif + + ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); + + /* + * Set up the timeout structure. Note that if there are no events to + * check for, we return with a negative result rather than blocking + * forever. + */ + + if (timePtr) { + timeout.tv_sec = timePtr->sec; + timeout.tv_usec = timePtr->usec; + timeoutPtr = &timeout; +#ifndef TCL_THREADS + } else if (tsdPtr->numFdBits == 0) { + /* + * If there are no threads, no timeout, and no fds registered, + * then there are no events possible and we must avoid deadlock. + * Note that this is not entirely correct because there might + * be a signal that could interrupt the select call, but we + * don't handle that case if we aren't using threads. + */ + + return -1; +#endif + } else { + timeoutPtr = NULL; + } + +#ifdef TCL_THREADS + /* + * Place this thread on the list of interested threads, signal the + * notifier thread, and wait for a response or a timeout. + */ + + Tcl_MutexLock(¬ifierMutex); + + waitForFiles = (tsdPtr->numFdBits > 0); + if (timePtr != NULL && timePtr->sec == 0 && timePtr->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. + */ + + waitForFiles = 1; + tsdPtr->pollState = POLL_WANT; + timePtr = NULL; + } else { + tsdPtr->pollState = 0; + } + + if (waitForFiles) { + /* + * 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; + if (waitingListPtr) { + waitingListPtr->prevPtr = tsdPtr; + } + tsdPtr->prevPtr = 0; + waitingListPtr = tsdPtr; + tsdPtr->onList = 1; + + write(triggerPipe, "", 1); + } + + memset((VOID *) tsdPtr->readyMasks, 0, 3*MASK_SIZE*sizeof(fd_mask)); + + if (!tsdPtr->eventReady) { + DoActualWait(timePtr); + } + 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 + * masks - skipping this caused a hang when trying to close a pipe + * which the notifier thread was still doing a select on. + */ + + 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; + write(triggerPipe, "", 1); + } + + +#else + memcpy((VOID *) tsdPtr->readyMasks, (VOID *) tsdPtr->checkMasks, + 3*MASK_SIZE*sizeof(fd_mask)); + numFound = select(tsdPtr->numFdBits, + (SELECT_MASK *) &tsdPtr->readyMasks[0], + (SELECT_MASK *) &tsdPtr->readyMasks[MASK_SIZE], + (SELECT_MASK *) &tsdPtr->readyMasks[2*MASK_SIZE], timeoutPtr); + + /* + * Some systems don't clear the masks after an error, so + * we have to do it here. + */ + + if (numFound == -1) { + memset((VOID *) tsdPtr->readyMasks, 0, 3*MASK_SIZE*sizeof(fd_mask)); + } +#endif + + /* + * Queue all detected file events before returning. + */ + + for (filePtr = tsdPtr->firstFileHandlerPtr; (filePtr != NULL); + filePtr = filePtr->nextPtr) { + index = filePtr->fd / (NBBY*sizeof(fd_mask)); + bit = 1 << (filePtr->fd % (NBBY*sizeof(fd_mask))); + mask = 0; + + if (tsdPtr->readyMasks[index] & bit) { + mask |= TCL_READABLE; + } + if ((tsdPtr->readyMasks+MASK_SIZE)[index] & bit) { + mask |= TCL_WRITABLE; + } + if ((tsdPtr->readyMasks+2*(MASK_SIZE))[index] & bit) { + 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) { + fileEvPtr = (FileHandlerEvent *) ckalloc( + sizeof(FileHandlerEvent)); + fileEvPtr->header.proc = FileHandlerEventProc; + fileEvPtr->fd = filePtr->fd; + Tcl_QueueEvent((Tcl_Event *) fileEvPtr, TCL_QUEUE_TAIL); + } + filePtr->readyMask = mask; + } + + /* + * Also queue the Mac Events found... + */ + +#ifdef TCL_THREADS + Tcl_MutexUnlock(¬ifierMutex); +#endif + + if (tsdPtr->isMainLoop) { + TkMacOSXCountAndProcessMacEvents(); + } + + return 0; +} + +#ifdef TCL_THREADS +/* + *---------------------------------------------------------------------- + * + * 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 void +NotifierThreadProc(clientData) + ClientData clientData; /* Not used. */ +{ + ThreadSpecificData *tsdPtr; + fd_mask masks[3*MASK_SIZE]; + long *maskPtr = (long *)masks; /* masks[] cast to type long[] */ + int fds[2]; + int i, status, index, bit, numFdBits, found, receivePipe, word; + struct timeval poll = {0., 0.}, *timePtr; + int maskSize = 3 * ((MASK_SIZE) / sizeof(long)) * sizeof(fd_mask); + char buf[2]; + + if (pipe(fds) != 0) { + panic("NotifierThreadProc: could not create trigger pipe."); + } + + receivePipe = fds[0]; + +#ifndef USE_FIONBIO + status = fcntl(receivePipe, F_GETFL); + status |= O_NONBLOCK; + if (fcntl(receivePipe, F_SETFL, status) < 0) { + panic("NotifierThreadProc: could not make receive pipe non blocking."); + } + status = fcntl(fds[1], F_GETFL); + status |= O_NONBLOCK; + if (fcntl(fds[1], F_SETFL, status) < 0) { + panic("NotifierThreadProc: could not make trigger pipe non blocking."); + } +#else + if (ioctl(receivePipe, (int) FIONBIO, &status) < 0) { + panic("NotifierThreadProc: could not make receive pipe non blocking."); + } + if (ioctl(fds[1], (int) FIONBIO, &status) < 0) { + panic("NotifierThreadProc: could not make trigger pipe non blocking."); + } +#endif + + /* + * Install the write end of the pipe into the global variable. + */ + + Tcl_MutexLock(¬ifierMutex); + triggerPipe = fds[1]; + + /* + * Signal any threads that are waiting. + */ + + Tcl_ConditionNotify(¬ifierCV); + Tcl_MutexUnlock(¬ifierMutex); + + /* + * Look for file events and report them to interested threads. + */ + + while (1) { + /* + * Set up the select mask to include the receive pipe. + */ + + memset((VOID *)masks, 0, 3*MASK_SIZE*sizeof(fd_mask)); + numFdBits = receivePipe + 1; + index = receivePipe / (NBBY*sizeof(fd_mask)); + bit = 1 << (receivePipe % (NBBY*sizeof(fd_mask))); + masks[index] |= bit; + + /* + * Add in the check masks from all of the waiting notifiers. + */ + + Tcl_MutexLock(¬ifierMutex); + timePtr = NULL; + for (tsdPtr = waitingListPtr; tsdPtr; tsdPtr = tsdPtr->nextPtr) { + for (i = 0; i < maskSize; i++) { + maskPtr[i] |= ((long*)tsdPtr->checkMasks)[i]; + } + if (tsdPtr->numFdBits > numFdBits) { + numFdBits = tsdPtr->numFdBits; + } + 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. + */ + + tsdPtr->pollState |= POLL_DONE; + timePtr = &poll; + } + } + Tcl_MutexUnlock(¬ifierMutex); + + maskSize = 3 * ((MASK_SIZE) / sizeof(long)) * sizeof(fd_mask); + + if (select(numFdBits, (SELECT_MASK *) &masks[0], + (SELECT_MASK *) &masks[MASK_SIZE], + (SELECT_MASK *) &masks[2*MASK_SIZE], timePtr) == -1) { + /* + * Try again immediately on an error. + */ + + continue; + } + + /* + * Alert any threads that are waiting on a ready file descriptor. + */ + + Tcl_MutexLock(¬ifierMutex); + for (tsdPtr = waitingListPtr; tsdPtr; tsdPtr = tsdPtr->nextPtr) { + found = 0; + + for (i = 0; i < maskSize; i++) { + word = maskPtr[i] & ((long*)tsdPtr->checkMasks)[i]; + found |= word; + (((long*)(tsdPtr->readyMasks))[i]) = word; + } + if (found || (tsdPtr->pollState & POLL_DONE)) { + 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. + */ + + 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; + tsdPtr->pollState = 0; + } + tsdPtr->eventReady = 1; + if (tsdPtr->isMainLoop) { + /* We need to wake up the main loop, and let it have the event. */ + EventRef fakeEvent = TkMacOSXCreateFakeEvent(); + PostEventToQueue(GetMainEventQueue(), fakeEvent, kEventPriorityHigh); + ReleaseEvent(fakeEvent); + } else { + Tcl_ConditionNotify(&tsdPtr->waitCV); + } + } + } + Tcl_MutexUnlock(¬ifierMutex); + + /* + * 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 (masks[index] & bit) { + 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; + } + } + } + + /* + * Clean up the read end of the pipe and signal any threads waiting on + * termination of the notifier thread. + */ + + close(receivePipe); + Tcl_MutexLock(¬ifierMutex); + triggerPipe = -1; + Tcl_ConditionNotify(¬ifierCV); + Tcl_MutexUnlock(¬ifierMutex); +} +#endif + +EventRef +TkMacOSXCreateFakeEvent () +{ + EventKind eKind; + EventClass eClass; + EventTime eTime; + EventRef eventRef; + EventAttributes flags; + eClass=kEventClassWish; + eKind = 0xffff; + eTime =GetLastUserEventTime() + 0.001; + flags=kEventAttributeUserEvent; + if (CreateEvent(NULL,eClass,eKind,eTime,flags,&eventRef)!=noErr) { + fprintf(stderr,"CreateEvent failed\n"); + return NULL; + } + return eventRef; +} |