diff options
Diffstat (limited to 'generic')
| -rw-r--r-- | generic/tclNotify.c | 2254 |
1 files changed, 1127 insertions, 1127 deletions
diff --git a/generic/tclNotify.c b/generic/tclNotify.c index c5a0c3a..56dca6a 100644 --- a/generic/tclNotify.c +++ b/generic/tclNotify.c @@ -1,1127 +1,1127 @@ -/*
- * 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 1.21 2006/09/25 00:09:34 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, *prevPtr, *hold;
- ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
-
- Tcl_MutexLock(&(tsdPtr->queueMutex));
- for (prevPtr=NULL, evPtr=tsdPtr->firstEventPtr; evPtr!=NULL; ) {
- if ((*proc) (evPtr, clientData) == 1) {
- if (tsdPtr->firstEventPtr == evPtr) {
- tsdPtr->firstEventPtr = evPtr->nextPtr;
- } else {
- if (prevPtr == NULL) {
- Tcl_Panic("badly connected event list");
- } else {
- prevPtr->nextPtr = evPtr->nextPtr;
- }
- }
- if (evPtr->nextPtr == NULL) {
- tsdPtr->lastEventPtr = prevPtr;
- }
- if (tsdPtr->markerEventPtr == evPtr) {
- tsdPtr->markerEventPtr = prevPtr;
- }
- hold = evPtr;
- evPtr = evPtr->nextPtr;
- ckfree((char *) hold);
- } else {
- 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:
- */
+/* + * 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 1.22 2006/09/25 13:35:10 dgp 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, *prevPtr, *hold; + ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); + + Tcl_MutexLock(&(tsdPtr->queueMutex)); + for (prevPtr=NULL, evPtr=tsdPtr->firstEventPtr; evPtr!=NULL; ) { + if ((*proc) (evPtr, clientData) == 1) { + if (tsdPtr->firstEventPtr == evPtr) { + tsdPtr->firstEventPtr = evPtr->nextPtr; + } else { + if (prevPtr == NULL) { + Tcl_Panic("badly connected event list"); + } else { + prevPtr->nextPtr = evPtr->nextPtr; + } + } + if (evPtr->nextPtr == NULL) { + tsdPtr->lastEventPtr = prevPtr; + } + if (tsdPtr->markerEventPtr == evPtr) { + tsdPtr->markerEventPtr = prevPtr; + } + hold = evPtr; + evPtr = evPtr->nextPtr; + ckfree((char *) hold); + } else { + 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: + */ |