tclNotify.c Go to the documentation of this file. /* * tclNotify.c -- * * This file implements the generic portion of the Tcl notifier. The * notifier is lowest-level part of the event system. It manages an event * queue that holds Tcl_Event structures. The platform specific portion * of the notifier is defined in the tcl*Notify.c files in each platform * directory. * * Copyright (c) 1995-1997 Sun Microsystems, Inc. * Copyright (c) 1998 by Scriptics Corporation. * Copyright (c) 2003 by Kevin B. Kenny. All rights reserved. * * See the file "license.terms" for information on usage and redistribution of * this file, and for a DISCLAIMER OF ALL WARRANTIES. * * RCS: @(#) $Id: tclNotify.c,v 1.25 2006/09/25 15:02:54 dkf Exp $ */ #include "tclInt.h" extern TclStubs tclStubs; /* * For each event source (created with Tcl_CreateEventSource) there is a * structure of the following type: */ typedef struct EventSource { Tcl_EventSetupProc *setupProc; Tcl_EventCheckProc *checkProc; ClientData clientData; struct EventSource *nextPtr; } EventSource; /* * The following structure keeps track of the state of the notifier on a * per-thread basis. The first three elements keep track of the event queue. * In addition to the first (next to be serviced) and last events in the * queue, we keep track of a "marker" event. This provides a simple priority * mechanism whereby events can be inserted at the front of the queue but * behind all other high-priority events already in the queue (this is used * for things like a sequence of Enter and Leave events generated during a * grab in Tk). These elements are protected by the queueMutex so that any * thread can queue an event on any notifier. Note that all of the values in * this structure will be initialized to 0. */ typedef struct ThreadSpecificData { Tcl_Event *firstEventPtr; /* First pending event, or NULL if none. */ Tcl_Event *lastEventPtr; /* Last pending event, or NULL if none. */ Tcl_Event *markerEventPtr; /* Last high-priority event in queue, or NULL * if none. */ Tcl_Mutex queueMutex; /* Mutex to protect access to the previous * three fields. */ int serviceMode; /* One of TCL_SERVICE_NONE or * TCL_SERVICE_ALL. */ int blockTimeSet; /* 0 means there is no maximum block time: * block forever. */ Tcl_Time blockTime; /* If blockTimeSet is 1, gives the maximum * elapsed time for the next block. */ int inTraversal; /* 1 if Tcl_SetMaxBlockTime is being called * during an event source traversal. */ EventSource *firstEventSourcePtr; /* Pointer to first event source in list of * event sources for this thread. */ Tcl_ThreadId threadId; /* Thread that owns this notifier instance. */ ClientData clientData; /* Opaque handle for platform specific * notifier. */ int initialized; /* 1 if notifier has been initialized. */ struct ThreadSpecificData *nextPtr; /* Next notifier in global list of notifiers. * Access is controlled by the listLock global * mutex. */ } ThreadSpecificData; static Tcl_ThreadDataKey dataKey; /* * Global list of notifiers. Access to this list is controlled by the listLock * mutex. If this becomes a performance bottleneck, this could be replaced * with a hashtable. */ static ThreadSpecificData *firstNotifierPtr = NULL; TCL_DECLARE_MUTEX(listLock) /* * Declarations for routines used only in this file. */ static void QueueEvent(ThreadSpecificData *tsdPtr, Tcl_Event* evPtr, Tcl_QueuePosition position);  /* *---------------------------------------------------------------------- * * TclInitNotifier -- * * Initialize the thread local data structures for the notifier * subsystem. * * Results: * None. * * Side effects: * Adds the current thread to the global list of notifiers. * *---------------------------------------------------------------------- */ void TclInitNotifier(void) { ThreadSpecificData *tsdPtr; Tcl_ThreadId threadId = Tcl_GetCurrentThread(); Tcl_MutexLock(&listLock); for (tsdPtr = firstNotifierPtr; tsdPtr && tsdPtr->threadId != threadId; tsdPtr = tsdPtr->nextPtr) { /* Empty loop body. */ } if (NULL == tsdPtr) { /* * Notifier not yet initialized in this thread. */ tsdPtr = TCL_TSD_INIT(&dataKey); tsdPtr->threadId = threadId; tsdPtr->clientData = tclStubs.tcl_InitNotifier(); tsdPtr->initialized = 1; tsdPtr->nextPtr = firstNotifierPtr; firstNotifierPtr = tsdPtr; } Tcl_MutexUnlock(&listLock); }  /* *---------------------------------------------------------------------- * * TclFinalizeNotifier -- * * Finalize the thread local data structures for the notifier subsystem. * * Results: * None. * * Side effects: * Removes the notifier associated with the current thread from the * global notifier list. This is done only if the notifier was * initialized for this thread by call to TclInitNotifier(). This is * always true for threads which have been seeded with an Tcl * interpreter, since the call to Tcl_CreateInterp will, among other * things, call TclInitializeSubsystems() and this one will, in turn, * call the TclInitNotifier() for the thread. For threads created without * the Tcl interpreter, though, nobody is explicitly nor implicitly * calling the TclInitNotifier hence, TclFinalizeNotifier should not be * performed at all. * *---------------------------------------------------------------------- */ void TclFinalizeNotifier(void) { ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); ThreadSpecificData **prevPtrPtr; Tcl_Event *evPtr, *hold; if (!tsdPtr->initialized) { return; /* Notifier not initialized for the current thread */ } Tcl_MutexLock(&(tsdPtr->queueMutex)); for (evPtr = tsdPtr->firstEventPtr; evPtr != NULL; ) { hold = evPtr; evPtr = evPtr->nextPtr; ckfree((char *) hold); } tsdPtr->firstEventPtr = NULL; tsdPtr->lastEventPtr = NULL; Tcl_MutexUnlock(&(tsdPtr->queueMutex)); Tcl_MutexLock(&listLock); if (tclStubs.tcl_FinalizeNotifier) { tclStubs.tcl_FinalizeNotifier(tsdPtr->clientData); } Tcl_MutexFinalize(&(tsdPtr->queueMutex)); for (prevPtrPtr = &firstNotifierPtr; *prevPtrPtr != NULL; prevPtrPtr = &((*prevPtrPtr)->nextPtr)) { if (*prevPtrPtr == tsdPtr) { *prevPtrPtr = tsdPtr->nextPtr; break; } } tsdPtr->initialized = 0; Tcl_MutexUnlock(&listLock); }  /* *---------------------------------------------------------------------- * * Tcl_SetNotifier -- * * Install a set of alternate functions for use with the notifier. In * particular, this can be used to install the Xt-based notifier for use * with the Browser plugin. * * Results: * None. * * Side effects: * Overstomps part of the stub vector. This relies on hooks added to the * default functions in case those are called directly (i.e., not through * the stub table.) * *---------------------------------------------------------------------- */ void Tcl_SetNotifier( Tcl_NotifierProcs *notifierProcPtr) { #if !defined(__WIN32__) /* UNIX */ tclStubs.tcl_CreateFileHandler = notifierProcPtr->createFileHandlerProc; tclStubs.tcl_DeleteFileHandler = notifierProcPtr->deleteFileHandlerProc; #endif tclStubs.tcl_SetTimer = notifierProcPtr->setTimerProc; tclStubs.tcl_WaitForEvent = notifierProcPtr->waitForEventProc; tclStubs.tcl_InitNotifier = notifierProcPtr->initNotifierProc; tclStubs.tcl_FinalizeNotifier = notifierProcPtr->finalizeNotifierProc; tclStubs.tcl_AlertNotifier = notifierProcPtr->alertNotifierProc; tclStubs.tcl_ServiceModeHook = notifierProcPtr->serviceModeHookProc; }  /* *---------------------------------------------------------------------- * * Tcl_CreateEventSource -- * * This function is invoked to create a new source of events. The source * is identified by a function that gets invoked during Tcl_DoOneEvent to * check for events on that source and queue them. * * * Results: * None. * * Side effects: * SetupProc and checkProc will be invoked each time that Tcl_DoOneEvent * runs out of things to do. SetupProc will be invoked before * Tcl_DoOneEvent calls select or whatever else it uses to wait for * events. SetupProc typically calls functions like Tcl_SetMaxBlockTime * to indicate what to wait for. * * CheckProc is called after select or whatever operation was actually * used to wait. It figures out whether anything interesting actually * happened (e.g. by calling Tcl_AsyncReady), and then calls * Tcl_QueueEvent to queue any events that are ready. * * Each of these functions is passed two arguments, e.g. * (*checkProc)(ClientData clientData, int flags)); * ClientData is the same as the clientData argument here, and flags is a * combination of things like TCL_FILE_EVENTS that indicates what events * are of interest: setupProc and checkProc use flags to figure out * whether their events are relevant or not. * *---------------------------------------------------------------------- */ void Tcl_CreateEventSource( Tcl_EventSetupProc *setupProc, /* Function to invoke to figure out what to * wait for. */ Tcl_EventCheckProc *checkProc, /* Function to call after waiting to see what * happened. */ ClientData clientData) /* One-word argument to pass to setupProc and * checkProc. */ { ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); EventSource *sourcePtr = (EventSource *) ckalloc(sizeof(EventSource)); sourcePtr->setupProc = setupProc; sourcePtr->checkProc = checkProc; sourcePtr->clientData = clientData; sourcePtr->nextPtr = tsdPtr->firstEventSourcePtr; tsdPtr->firstEventSourcePtr = sourcePtr; }  /* *---------------------------------------------------------------------- * * Tcl_DeleteEventSource -- * * This function is invoked to delete the source of events given by proc * and clientData. * * Results: * None. * * Side effects: * The given event source is cancelled, so its function will never again * be called. If no such source exists, nothing happens. * *---------------------------------------------------------------------- */ void Tcl_DeleteEventSource( Tcl_EventSetupProc *setupProc, /* Function to invoke to figure out what to * wait for. */ Tcl_EventCheckProc *checkProc, /* Function to call after waiting to see what * happened. */ ClientData clientData) /* One-word argument to pass to setupProc and * checkProc. */ { ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); EventSource *sourcePtr, *prevPtr; for (sourcePtr = tsdPtr->firstEventSourcePtr, prevPtr = NULL; sourcePtr != NULL; prevPtr = sourcePtr, sourcePtr = sourcePtr->nextPtr) { if ((sourcePtr->setupProc != setupProc) || (sourcePtr->checkProc != checkProc) || (sourcePtr->clientData != clientData)) { continue; } if (prevPtr == NULL) { tsdPtr->firstEventSourcePtr = sourcePtr->nextPtr; } else { prevPtr->nextPtr = sourcePtr->nextPtr; } ckfree((char *) sourcePtr); return; } }  /* *---------------------------------------------------------------------- * * Tcl_QueueEvent -- * * Queue an event on the event queue associated with the current thread. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------- */ void Tcl_QueueEvent( Tcl_Event* evPtr, /* Event to add to queue. The storage space * must have been allocated the caller with * malloc (ckalloc), and it becomes the * property of the event queue. It will be * freed after the event has been handled. */ Tcl_QueuePosition position) /* One of TCL_QUEUE_TAIL, TCL_QUEUE_HEAD, * TCL_QUEUE_MARK. */ { ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); QueueEvent(tsdPtr, evPtr, position); }  /* *---------------------------------------------------------------------- * * Tcl_ThreadQueueEvent -- * * Queue an event on the specified thread's event queue. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------- */ void Tcl_ThreadQueueEvent( Tcl_ThreadId threadId, /* Identifier for thread to use. */ Tcl_Event *evPtr, /* Event to add to queue. The storage space * must have been allocated the caller with * malloc (ckalloc), and it becomes the * property of the event queue. It will be * freed after the event has been handled. */ Tcl_QueuePosition position) /* One of TCL_QUEUE_TAIL, TCL_QUEUE_HEAD, * TCL_QUEUE_MARK. */ { ThreadSpecificData *tsdPtr; /* * Find the notifier associated with the specified thread. */ Tcl_MutexLock(&listLock); for (tsdPtr = firstNotifierPtr; tsdPtr && tsdPtr->threadId != threadId; tsdPtr = tsdPtr->nextPtr) { /* Empty loop body. */ } /* * Queue the event if there was a notifier associated with the thread. */ if (tsdPtr) { QueueEvent(tsdPtr, evPtr, position); } Tcl_MutexUnlock(&listLock); }  /* *---------------------------------------------------------------------- * * QueueEvent -- * * Insert an event into the specified thread's event queue at one of * three positions: the head, the tail, or before a floating marker. * Events inserted before the marker will be processed in first-in- * first-out order, but before any events inserted at the tail of the * queue. Events inserted at the head of the queue will be processed in * last-in-first-out order. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------- */ static void QueueEvent( ThreadSpecificData *tsdPtr, /* Handle to thread local data that indicates * which event queue to use. */ Tcl_Event *evPtr, /* Event to add to queue. The storage space * must have been allocated the caller with * malloc (ckalloc), and it becomes the * property of the event queue. It will be * freed after the event has been handled. */ Tcl_QueuePosition position) /* One of TCL_QUEUE_TAIL, TCL_QUEUE_HEAD, * TCL_QUEUE_MARK. */ { Tcl_MutexLock(&(tsdPtr->queueMutex)); if (position == TCL_QUEUE_TAIL) { /* * Append the event on the end of the queue. */ evPtr->nextPtr = NULL; if (tsdPtr->firstEventPtr == NULL) { tsdPtr->firstEventPtr = evPtr; } else { tsdPtr->lastEventPtr->nextPtr = evPtr; } tsdPtr->lastEventPtr = evPtr; } else if (position == TCL_QUEUE_HEAD) { /* * Push the event on the head of the queue. */ evPtr->nextPtr = tsdPtr->firstEventPtr; if (tsdPtr->firstEventPtr == NULL) { tsdPtr->lastEventPtr = evPtr; } tsdPtr->firstEventPtr = evPtr; } else if (position == TCL_QUEUE_MARK) { /* * Insert the event after the current marker event and advance the * marker to the new event. */ if (tsdPtr->markerEventPtr == NULL) { evPtr->nextPtr = tsdPtr->firstEventPtr; tsdPtr->firstEventPtr = evPtr; } else { evPtr->nextPtr = tsdPtr->markerEventPtr->nextPtr; tsdPtr->markerEventPtr->nextPtr = evPtr; } tsdPtr->markerEventPtr = evPtr; if (evPtr->nextPtr == NULL) { tsdPtr->lastEventPtr = evPtr; } } Tcl_MutexUnlock(&(tsdPtr->queueMutex)); }  /* *---------------------------------------------------------------------- * * Tcl_DeleteEvents -- * * Calls a function for each event in the queue and deletes those for * which the function returns 1. Events for which the function returns 0 * are left in the queue. Operates on the queue associated with the * current thread. * * Results: * None. * * Side effects: * Potentially removes one or more events from the event queue. * *---------------------------------------------------------------------- */ void Tcl_DeleteEvents( Tcl_EventDeleteProc *proc, /* The function to call. */ ClientData clientData) /* The type-specific data. */ { Tcl_Event *evPtr; /* Pointer to the event being examined */ Tcl_Event *prevPtr; /* Pointer to evPtr's predecessor, or NULL if * evPtr designates the first event in the * queue for the thread. */ Tcl_Event* hold; ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); Tcl_MutexLock(&(tsdPtr->queueMutex)); /* * Walk the queue of events for the thread, applying 'proc' to each to * decide whether to eliminate the event. */ prevPtr = NULL; evPtr = tsdPtr->firstEventPtr; while (evPtr != NULL) { if ((*proc)(evPtr, clientData) == 1) { /* * This event should be deleted. Unlink it. */ if (prevPtr == NULL) { tsdPtr->firstEventPtr = evPtr->nextPtr; } else { prevPtr->nextPtr = evPtr->nextPtr; } /* * Update 'last' and 'marker' events if either has been deleted. */ if (evPtr->nextPtr == NULL) { tsdPtr->lastEventPtr = prevPtr; } if (tsdPtr->markerEventPtr == evPtr) { tsdPtr->markerEventPtr = prevPtr; } /* * Delete the event data structure. */ hold = evPtr; evPtr = evPtr->nextPtr; ckfree((char *) hold); } else { /* * Event is to be retained. */ prevPtr = evPtr; evPtr = evPtr->nextPtr; } } Tcl_MutexUnlock(&(tsdPtr->queueMutex)); }  /* *---------------------------------------------------------------------- * * Tcl_ServiceEvent -- * * Process one event from the event queue, or invoke an asynchronous * event handler. Operates on event queue for current thread. * * Results: * The return value is 1 if the function actually found an event to * process. If no processing occurred, then 0 is returned. * * Side effects: * Invokes all of the event handlers for the highest priority event in * the event queue. May collapse some events into a single event or * discard stale events. * *---------------------------------------------------------------------- */ int Tcl_ServiceEvent( int flags) /* Indicates what events should be processed. * May be any combination of TCL_WINDOW_EVENTS * TCL_FILE_EVENTS, TCL_TIMER_EVENTS, or other * flags defined elsewhere. Events not * matching this will be skipped for * processing later. */ { Tcl_Event *evPtr, *prevPtr; Tcl_EventProc *proc; int result; ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); /* * Asynchronous event handlers are considered to be the highest priority * events, and so must be invoked before we process events on the event * queue. */ if (Tcl_AsyncReady()) { (void) Tcl_AsyncInvoke(NULL, 0); return 1; } /* * No event flags is equivalent to TCL_ALL_EVENTS. */ if ((flags & TCL_ALL_EVENTS) == 0) { flags |= TCL_ALL_EVENTS; } /* * Loop through all the events in the queue until we find one that can * actually be handled. */ Tcl_MutexLock(&(tsdPtr->queueMutex)); for (evPtr = tsdPtr->firstEventPtr; evPtr != NULL; evPtr = evPtr->nextPtr) { /* * Call the handler for the event. If it actually handles the event * then free the storage for the event. There are two tricky things * here, both stemming from the fact that the event code may be * re-entered while servicing the event: * * 1. Set the "proc" field to NULL. This is a signal to ourselves * that we shouldn't reexecute the handler if the event loop is * re-entered. * 2. When freeing the event, must search the queue again from the * front to find it. This is because the event queue could change * almost arbitrarily while handling the event, so we can't depend * on pointers found now still being valid when the handler * returns. */ proc = evPtr->proc; if (proc == NULL) { continue; } evPtr->proc = NULL; /* * Release the lock before calling the event function. This allows * other threads to post events if we enter a recursive event loop in * this thread. Note that we are making the assumption that if the * proc returns 0, the event is still in the list. */ Tcl_MutexUnlock(&(tsdPtr->queueMutex)); result = (*proc)(evPtr, flags); Tcl_MutexLock(&(tsdPtr->queueMutex)); if (result) { /* * The event was processed, so remove it from the queue. */ if (tsdPtr->firstEventPtr == evPtr) { tsdPtr->firstEventPtr = evPtr->nextPtr; if (evPtr->nextPtr == NULL) { tsdPtr->lastEventPtr = NULL; } if (tsdPtr->markerEventPtr == evPtr) { tsdPtr->markerEventPtr = NULL; } } else { for (prevPtr = tsdPtr->firstEventPtr; prevPtr && prevPtr->nextPtr != evPtr; prevPtr = prevPtr->nextPtr) { /* Empty loop body. */ } if (prevPtr) { prevPtr->nextPtr = evPtr->nextPtr; if (evPtr->nextPtr == NULL) { tsdPtr->lastEventPtr = prevPtr; } if (tsdPtr->markerEventPtr == evPtr) { tsdPtr->markerEventPtr = prevPtr; } } else { evPtr = NULL; } } if (evPtr) { ckfree((char *) evPtr); } Tcl_MutexUnlock(&(tsdPtr->queueMutex)); return 1; } else { /* * The event wasn't actually handled, so we have to restore the * proc field to allow the event to be attempted again. */ evPtr->proc = proc; } } Tcl_MutexUnlock(&(tsdPtr->queueMutex)); return 0; }  /* *---------------------------------------------------------------------- * * Tcl_GetServiceMode -- * * This routine returns the current service mode of the notifier. * * Results: * Returns either TCL_SERVICE_ALL or TCL_SERVICE_NONE. * * Side effects: * None. * *---------------------------------------------------------------------- */ int Tcl_GetServiceMode(void) { ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); return tsdPtr->serviceMode; }  /* *---------------------------------------------------------------------- * * Tcl_SetServiceMode -- * * This routine sets the current service mode of the tsdPtr-> * * Results: * Returns the previous service mode. * * Side effects: * Invokes the notifier service mode hook function. * *---------------------------------------------------------------------- */ int Tcl_SetServiceMode( int mode) /* New service mode: TCL_SERVICE_ALL or * TCL_SERVICE_NONE */ { int oldMode; ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); oldMode = tsdPtr->serviceMode; tsdPtr->serviceMode = mode; if (tclStubs.tcl_ServiceModeHook) { tclStubs.tcl_ServiceModeHook(mode); } return oldMode; }  /* *---------------------------------------------------------------------- * * Tcl_SetMaxBlockTime -- * * This function is invoked by event sources to tell the notifier how * long it may block the next time it blocks. The timePtr argument gives * a maximum time; the actual time may be less if some other event source * requested a smaller time. * * Results: * None. * * Side effects: * May reduce the length of the next sleep in the tsdPtr-> * *---------------------------------------------------------------------- */ void Tcl_SetMaxBlockTime( Tcl_Time *timePtr) /* Specifies a maximum elapsed time for the * next blocking operation in the event * tsdPtr-> */ { ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); if (!tsdPtr->blockTimeSet || (timePtr->sec < tsdPtr->blockTime.sec) || ((timePtr->sec == tsdPtr->blockTime.sec) && (timePtr->usec < tsdPtr->blockTime.usec))) { tsdPtr->blockTime = *timePtr; tsdPtr->blockTimeSet = 1; } /* * If we are called outside an event source traversal, set the timeout * immediately. */ if (!tsdPtr->inTraversal) { if (tsdPtr->blockTimeSet) { Tcl_SetTimer(&tsdPtr->blockTime); } else { Tcl_SetTimer(NULL); } } }  /* *---------------------------------------------------------------------- * * Tcl_DoOneEvent -- * * Process a single event of some sort. If there's no work to do, wait * for an event to occur, then process it. * * Results: * The return value is 1 if the function actually found an event to * process. If no processing occurred, then 0 is returned (this can * happen if the TCL_DONT_WAIT flag is set or if there are no event * handlers to wait for in the set specified by flags). * * Side effects: * May delay execution of process while waiting for an event, unless * TCL_DONT_WAIT is set in the flags argument. Event sources are invoked * to check for and queue events. Event handlers may produce arbitrary * side effects. * *---------------------------------------------------------------------- */ int Tcl_DoOneEvent( int flags) /* Miscellaneous flag values: may be any * combination of TCL_DONT_WAIT, * TCL_WINDOW_EVENTS, TCL_FILE_EVENTS, * TCL_TIMER_EVENTS, TCL_IDLE_EVENTS, or * others defined by event sources. */ { int result = 0, oldMode; EventSource *sourcePtr; Tcl_Time *timePtr; ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); /* * The first thing we do is to service any asynchronous event handlers. */ if (Tcl_AsyncReady()) { (void) Tcl_AsyncInvoke(NULL, 0); return 1; } /* * No event flags is equivalent to TCL_ALL_EVENTS. */ if ((flags & TCL_ALL_EVENTS) == 0) { flags |= TCL_ALL_EVENTS; } /* * Set the service mode to none so notifier event routines won't try to * service events recursively. */ oldMode = tsdPtr->serviceMode; tsdPtr->serviceMode = TCL_SERVICE_NONE; /* * The core of this function is an infinite loop, even though we only * service one event. The reason for this is that we may be processing * events that don't do anything inside of Tcl. */ while (1) { /* * If idle events are the only things to service, skip the main part * of the loop and go directly to handle idle events (i.e. don't wait * even if TCL_DONT_WAIT isn't set). */ if ((flags & TCL_ALL_EVENTS) == TCL_IDLE_EVENTS) { flags = TCL_IDLE_EVENTS | TCL_DONT_WAIT; goto idleEvents; } /* * Ask Tcl to service a queued event, if there are any. */ if (Tcl_ServiceEvent(flags)) { result = 1; break; } /* * If TCL_DONT_WAIT is set, be sure to poll rather than blocking, * otherwise reset the block time to infinity. */ if (flags & TCL_DONT_WAIT) { tsdPtr->blockTime.sec = 0; tsdPtr->blockTime.usec = 0; tsdPtr->blockTimeSet = 1; } else { tsdPtr->blockTimeSet = 0; } /* * Set up all the event sources for new events. This will cause the * block time to be updated if necessary. */ tsdPtr->inTraversal = 1; for (sourcePtr = tsdPtr->firstEventSourcePtr; sourcePtr != NULL; sourcePtr = sourcePtr->nextPtr) { if (sourcePtr->setupProc) { (sourcePtr->setupProc)(sourcePtr->clientData, flags); } } tsdPtr->inTraversal = 0; if ((flags & TCL_DONT_WAIT) || tsdPtr->blockTimeSet) { timePtr = &tsdPtr->blockTime; } else { timePtr = NULL; } /* * Wait for a new event or a timeout. If Tcl_WaitForEvent returns -1, * we should abort Tcl_DoOneEvent. */ result = Tcl_WaitForEvent(timePtr); if (result < 0) { result = 0; break; } /* * Check all the event sources for new events. */ for (sourcePtr = tsdPtr->firstEventSourcePtr; sourcePtr != NULL; sourcePtr = sourcePtr->nextPtr) { if (sourcePtr->checkProc) { (sourcePtr->checkProc)(sourcePtr->clientData, flags); } } /* * Check for events queued by the notifier or event sources. */ if (Tcl_ServiceEvent(flags)) { result = 1; break; } /* * We've tried everything at this point, but nobody we know about had * anything to do. Check for idle events. If none, either quit or go * back to the top and try again. */ idleEvents: if (flags & TCL_IDLE_EVENTS) { if (TclServiceIdle()) { result = 1; break; } } if (flags & TCL_DONT_WAIT) { break; } /* * If Tcl_WaitForEvent has returned 1, indicating that one system * event has been dispatched (and thus that some Tcl code might have * been indirectly executed), we break out of the loop. We do this to * give VwaitCmd for instance a chance to check if that system event * had the side effect of changing the variable (so the vwait can * return and unwind properly). * * NB: We will process idle events if any first, because otherwise we * might never do the idle events if the notifier always gets * system events. */ if (result) { break; } } tsdPtr->serviceMode = oldMode; return result; }  /* *---------------------------------------------------------------------- * * Tcl_ServiceAll -- * * This routine checks all of the event sources, processes events that * are on the Tcl event queue, and then calls the any idle handlers. * Platform specific notifier callbacks that generate events should call * this routine before returning to the system in order to ensure that * Tcl gets a chance to process the new events. * * Results: * Returns 1 if an event or idle handler was invoked, else 0. * * Side effects: * Anything that an event or idle handler may do. * *---------------------------------------------------------------------- */ int Tcl_ServiceAll(void) { int result = 0; EventSource *sourcePtr; ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); if (tsdPtr->serviceMode == TCL_SERVICE_NONE) { return result; } /* * We need to turn off event servicing like we to in Tcl_DoOneEvent, to * avoid recursive calls. */ tsdPtr->serviceMode = TCL_SERVICE_NONE; /* * Check async handlers first. */ if (Tcl_AsyncReady()) { (void) Tcl_AsyncInvoke(NULL, 0); } /* * Make a single pass through all event sources, queued events, and idle * handlers. Note that we wait to update the notifier timer until the end * so we can avoid multiple changes. */ tsdPtr->inTraversal = 1; tsdPtr->blockTimeSet = 0; for (sourcePtr = tsdPtr->firstEventSourcePtr; sourcePtr != NULL; sourcePtr = sourcePtr->nextPtr) { if (sourcePtr->setupProc) { (sourcePtr->setupProc)(sourcePtr->clientData, TCL_ALL_EVENTS); } } for (sourcePtr = tsdPtr->firstEventSourcePtr; sourcePtr != NULL; sourcePtr = sourcePtr->nextPtr) { if (sourcePtr->checkProc) { (sourcePtr->checkProc)(sourcePtr->clientData, TCL_ALL_EVENTS); } } while (Tcl_ServiceEvent(0)) { result = 1; } if (TclServiceIdle()) { result = 1; } if (!tsdPtr->blockTimeSet) { Tcl_SetTimer(NULL); } else { Tcl_SetTimer(&tsdPtr->blockTime); } tsdPtr->inTraversal = 0; tsdPtr->serviceMode = TCL_SERVICE_ALL; return result; }  /* *---------------------------------------------------------------------- * * Tcl_ThreadAlert -- * * This function wakes up the notifier associated with the specified * thread (if there is one). * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------- */ void Tcl_ThreadAlert( Tcl_ThreadId threadId) /* Identifier for thread to use. */ { ThreadSpecificData *tsdPtr; /* * Find the notifier associated with the specified thread. Note that we * need to hold the listLock while calling Tcl_AlertNotifier to avoid a * race condition where the specified thread might destroy its notifier. */ Tcl_MutexLock(&listLock); for (tsdPtr = firstNotifierPtr; tsdPtr; tsdPtr = tsdPtr->nextPtr) { if (tsdPtr->threadId == threadId) { if (tclStubs.tcl_AlertNotifier) { tclStubs.tcl_AlertNotifier(tsdPtr->clientData); } break; } } Tcl_MutexUnlock(&listLock); }  /* * Local Variables: * mode: c * c-basic-offset: 4 * fill-column: 78 * End: */

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