Clean up the notifier code to not spread the hooks quite so widely

1 files changed, 198 insertions, 263 deletions

diff --git a/unix/tclEpollNotfy.c b/unix/tclEpollNotfy.c
index 18abacd..a6a183b 100644
--- a/unix/tclEpollNotfy.c
+++ b/unix/tclEpollNotfy.c
@@ -97,7 +97,7 @@ typedef struct ThreadSpecificData {
 				 * that are ready for I/O. */
     pthread_mutex_t notifierMutex;
 				/* Mutex protecting notifier termination in
-				 * PlatformEventsFinalize. */
+				 * TclpFinalizeNotifier. */
 #ifdef HAVE_EVENTFD
     int triggerEventFd;		/* eventfd(2) used by other threads to wake
 				 * up this thread for inter-thread IPC. */
@@ -121,14 +121,13 @@ static Tcl_ThreadDataKey dataKey;
 
 static void		PlatformEventsControl(FileHandler *filePtr,
 			    ThreadSpecificData *tsdPtr, int op, int isNew);
-static void		PlatformEventsFinalize(void);
 static void		PlatformEventsInit(void);
 static int		PlatformEventsTranslate(struct epoll_event *event);
 static int		PlatformEventsWait(struct epoll_event *events,
 			    size_t numEvents, struct timeval *timePtr);
-
+
 /*
- * Incorporate the base notifier API.
+ * Incorporate the base notifier implementation.
  */
 
 #include "tclUnixNotfy.c"
@@ -136,7 +135,7 @@ static int		PlatformEventsWait(struct epoll_event *events,
 /*
  *----------------------------------------------------------------------
  *
- * Tcl_InitNotifier --
+ * TclpInitNotifier --
  *
  *	Initializes the platform specific notifier state.
  *
@@ -144,54 +143,21 @@ static int		PlatformEventsWait(struct epoll_event *events,
  *	Returns a handle to the notifier state for this thread.
  *
  * Side effects:
- *	If no initNotifierProc notifier hook exists, PlatformEventsInit
- *	is called.
+ *	If no initNotifierProc notifier hook exists, PlatformEventsInit is
+ *	called.
  *
  *----------------------------------------------------------------------
  */
 
 ClientData
-Tcl_InitNotifier(void)
+TclpInitNotifier(void)
 {
-    if (tclNotifierHooks.initNotifierProc) {
-	return tclNotifierHooks.initNotifierProc();
-    } else {
-	ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
+    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
 
-	PlatformEventsInit();
-	return tsdPtr;
-    }
+    PlatformEventsInit();
+    return tsdPtr;
 }
 
-/*
- *----------------------------------------------------------------------
- *
- * Tcl_FinalizeNotifier --
- *
- *	This function is called to cleanup the notifier state before a thread
- *	is terminated.
- *
- * Results:
- *	None.
- *
- * Side effects:
- *	If no finalizeNotifierProc notifier hook exists, PlatformEvents-
- *	Finalize is called.
- *
- *----------------------------------------------------------------------
- */
-
-void
-Tcl_FinalizeNotifier(
-    ClientData clientData)
-{
-    if (tclNotifierHooks.finalizeNotifierProc) {
-	tclNotifierHooks.finalizeNotifierProc(clientData);
-	return;
-    } else {
-	PlatformEventsFinalize();
-    }
-}
 
 /*
  *----------------------------------------------------------------------
@@ -221,7 +187,7 @@ Tcl_FinalizeNotifier(
  *----------------------------------------------------------------------
  */
 
-void
+static void
 PlatformEventsControl(
     FileHandler *filePtr,
     ThreadSpecificData *tsdPtr,
@@ -240,7 +206,8 @@ PlatformEventsControl(
 	newEvent.events |= EPOLLOUT;
     }
     if (isNew) {
-        newPedPtr = (struct PlatformEventData *)Tcl_Alloc(sizeof(struct PlatformEventData));
+        newPedPtr = (struct PlatformEventData *)
+		Tcl_Alloc(sizeof(struct PlatformEventData));
         newPedPtr->filePtr = filePtr;
         newPedPtr->tsdPtr = tsdPtr;
 	filePtr->pedPtr = newPedPtr;
@@ -249,7 +216,7 @@ PlatformEventsControl(
 
     /*
      * N.B. As discussed in Tcl_WaitForEvent(), epoll(7) does not support
-     * regular files (S_IFREG.) Therefore, filePtr is in these cases simply
+     * regular files (S_IFREG). Therefore, filePtr is in these cases simply
      * added or deleted from the list of FileHandlers associated with regular
      * files belonging to tsdPtr.
      */
@@ -277,7 +244,7 @@ PlatformEventsControl(
 /*
  *----------------------------------------------------------------------
  *
- * PlatformEventsFinalize --
+ * TclpFinalizeNotifier --
  *
  *	This function closes the eventfd and the epoll file descriptor and
  *	frees the epoll_event structs owned by the thread of the caller.  The
@@ -299,8 +266,8 @@ PlatformEventsControl(
  */
 
 void
-PlatformEventsFinalize(
-	void)
+TclpFinalizeNotifier(
+    TCL_UNUSED(ClientData))
 {
     ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
 
@@ -362,7 +329,7 @@ PlatformEventsFinalize(
  *----------------------------------------------------------------------
  */
 
-void
+static void
 PlatformEventsInit(void)
 {
     ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
@@ -372,7 +339,7 @@ PlatformEventsInit(void)
     if (errno) {
 	Tcl_Panic("Tcl_InitNotifier: %s", "could not create mutex");
     }
-    filePtr = (FileHandler *)Tcl_Alloc(sizeof(FileHandler));
+    filePtr = (FileHandler *) Tcl_Alloc(sizeof(FileHandler));
 #ifdef HAVE_EVENTFD
     tsdPtr->triggerEventFd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
     if (tsdPtr->triggerEventFd <= 0) {
@@ -393,7 +360,7 @@ PlatformEventsInit(void)
     PlatformEventsControl(filePtr, tsdPtr, EPOLL_CTL_ADD, 1);
     if (!tsdPtr->readyEvents) {
         tsdPtr->maxReadyEvents = 512;
-	tsdPtr->readyEvents = (struct epoll_event *)Tcl_Alloc(
+	tsdPtr->readyEvents = (struct epoll_event *) Tcl_Alloc(
 		tsdPtr->maxReadyEvents * sizeof(tsdPtr->readyEvents[0]));
     }
     LIST_INIT(&tsdPtr->firstReadyFileHandlerPtr);
@@ -416,7 +383,7 @@ PlatformEventsInit(void)
  *----------------------------------------------------------------------
  */
 
-int
+static int
 PlatformEventsTranslate(
     struct epoll_event *eventPtr)
 {
@@ -457,7 +424,7 @@ PlatformEventsTranslate(
  *----------------------------------------------------------------------
  */
 
-int
+static int
 PlatformEventsWait(
     struct epoll_event *events,
     size_t numEvents,
@@ -480,9 +447,9 @@ PlatformEventsWait(
     } else if (!timePtr->tv_sec && !timePtr->tv_usec) {
 	timeout = 0;
     } else {
-	timeout = (int)timePtr->tv_sec * 1000;
+	timeout = (int) timePtr->tv_sec * 1000;
 	if (timePtr->tv_usec) {
-	    timeout += (int)timePtr->tv_usec / 1000;
+	    timeout += (int) timePtr->tv_usec / 1000;
 	}
     }
 
@@ -493,7 +460,7 @@ PlatformEventsWait(
      */
 
     gettimeofday(&tv0, NULL);
-    numFound = epoll_wait(tsdPtr->eventsFd, events, (int)numEvents, timeout);
+    numFound = epoll_wait(tsdPtr->eventsFd, events, (int) numEvents, timeout);
     gettimeofday(&tv1, NULL);
     if (timePtr && (timePtr->tv_sec && timePtr->tv_usec)) {
 	timersub(&tv1, &tv0, &tv_delta);
@@ -510,7 +477,7 @@ PlatformEventsWait(
 /*
  *----------------------------------------------------------------------
  *
- * Tcl_CreateFileHandler --
+ * TclpCreateFileHandler --
  *
  *	This function registers a file handler with the epoll notifier of the
  *	thread of the caller.
@@ -526,7 +493,7 @@ PlatformEventsWait(
  */
 
 void
-Tcl_CreateFileHandler(
+TclpCreateFileHandler(
     int fd,			/* Handle of stream to watch. */
     int mask,			/* OR'ed combination of TCL_READABLE,
 				 * TCL_WRITABLE, and TCL_EXCEPTION: indicates
@@ -536,44 +503,29 @@ Tcl_CreateFileHandler(
 				 * event. */
     ClientData clientData)	/* Arbitrary data to pass to proc. */
 {
-    int isNew;
-
-    if (tclNotifierHooks.createFileHandlerProc) {
-	tclNotifierHooks.createFileHandlerProc(fd, mask, proc, clientData);
-	return;
-    } else {
-	ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
-	FileHandler *filePtr;
-
-	for (filePtr = tsdPtr->firstFileHandlerPtr; filePtr != NULL;
-		filePtr = filePtr->nextPtr) {
-	    if (filePtr->fd == fd) {
-		break;
-	    }
-	}
-	if (filePtr == NULL) {
-	    filePtr = (FileHandler *)Tcl_Alloc(sizeof(FileHandler));
-	    filePtr->fd = fd;
-	    filePtr->readyMask = 0;
-	    filePtr->nextPtr = tsdPtr->firstFileHandlerPtr;
-	    tsdPtr->firstFileHandlerPtr = filePtr;
-	    isNew = 1;
-	} else {
-	    isNew = 0;
-	}
-	filePtr->proc = proc;
-	filePtr->clientData = clientData;
-	filePtr->mask = mask;
+    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
+    FileHandler *filePtr = LookUpFileHandler(tsdPtr, fd, NULL);
+    int isNew = (filePtr == NULL);
 
-	PlatformEventsControl(filePtr, tsdPtr,
-		isNew ? EPOLL_CTL_ADD : EPOLL_CTL_MOD, isNew);
+    if (isNew) {
+	filePtr = (FileHandler *) Tcl_Alloc(sizeof(FileHandler));
+	filePtr->fd = fd;
+	filePtr->readyMask = 0;
+	filePtr->nextPtr = tsdPtr->firstFileHandlerPtr;
+	tsdPtr->firstFileHandlerPtr = filePtr;
     }
+    filePtr->proc = proc;
+    filePtr->clientData = clientData;
+    filePtr->mask = mask;
+
+    PlatformEventsControl(filePtr, tsdPtr,
+	    isNew ? EPOLL_CTL_ADD : EPOLL_CTL_MOD, isNew);
 }
 
 /*
  *----------------------------------------------------------------------
  *
- * Tcl_DeleteFileHandler --
+ * TclpDeleteFileHandler --
  *
  *	Cancel a previously-arranged callback arrangement for a file on the
  *	epoll file descriptor of the thread of the caller.
@@ -591,60 +543,50 @@ Tcl_CreateFileHandler(
  */
 
 void
-Tcl_DeleteFileHandler(
+TclpDeleteFileHandler(
     int fd)			/* Stream id for which to remove callback
 				 * function. */
 {
-    if (tclNotifierHooks.deleteFileHandlerProc) {
-	tclNotifierHooks.deleteFileHandlerProc(fd);
-	return;
-    } else {
-	FileHandler *filePtr, *prevPtr;
-	ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
+    FileHandler *filePtr, *prevPtr;
+    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
 
-	/*
-	 * Find the entry for the given file (and return if there isn't one).
-	 */
+    /*
+     * 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;
-	    }
-	}
+    filePtr = LookUpFileHandler(tsdPtr, fd, &prevPtr);
+    if (filePtr == NULL) {
+	return;
+    }
 
-	/*
-	 * Update the check masks for this file.
-	 */
+    /*
+     * Update the check masks for this file.
+     */
 
-	PlatformEventsControl(filePtr, tsdPtr, EPOLL_CTL_DEL, 0);
-	if (filePtr->pedPtr) {
-	    Tcl_Free(filePtr->pedPtr);
-	}
+    PlatformEventsControl(filePtr, tsdPtr, EPOLL_CTL_DEL, 0);
+    if (filePtr->pedPtr) {
+	Tcl_Free(filePtr->pedPtr);
+    }
 
-	/*
-	 * Clean up information in the callback record.
-	 */
+    /*
+     * Clean up information in the callback record.
+     */
 
-	if (prevPtr == NULL) {
-	    tsdPtr->firstFileHandlerPtr = filePtr->nextPtr;
-	} else {
-	    prevPtr->nextPtr = filePtr->nextPtr;
-	}
-	Tcl_Free(filePtr);
+    if (prevPtr == NULL) {
+	tsdPtr->firstFileHandlerPtr = filePtr->nextPtr;
+    } else {
+	prevPtr->nextPtr = filePtr->nextPtr;
     }
+    Tcl_Free(filePtr);
 }
 
 /*
  *----------------------------------------------------------------------
  *
- * Tcl_WaitForEvent --
+ * TclpWaitForEvent --
  *
  *	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
+ *	the message queue. If the block time is 0, then TclpWaitForEvent just
  *	polls without blocking.
  *
  *	The waiting logic is implemented in PlatformEventsWait.
@@ -660,172 +602,165 @@ Tcl_DeleteFileHandler(
  */
 
 int
-Tcl_WaitForEvent(
+TclpWaitForEvent(
     const Tcl_Time *timePtr)	/* Maximum block time, or NULL. */
 {
-    if (tclNotifierHooks.waitForEventProc) {
-	return tclNotifierHooks.waitForEventProc(timePtr);
-    } else {
-	FileHandler *filePtr;
-	int mask;
-	Tcl_Time vTime;
-	/*
-	 * Impl. notes: timeout & timeoutPtr are used if, and only if threads
-	 * are not enabled. They are the arguments for the regular epoll_wait()
-	 * used when the core is not thread-enabled.
-	 */
+    FileHandler *filePtr;
+    Tcl_Time vTime;
+    struct timeval timeout, *timeoutPtr;
+				/* Impl. notes: timeout & timeoutPtr are used
+				 * if, and only if threads are not enabled.
+				 * They are the arguments for the regular
+				 * epoll_wait() used when the core is not
+				 * thread-enabled. */
+    int mask, numFound, numEvent;
+    struct PlatformEventData *pedPtr;
+    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
+    int numQueued;
+    ssize_t i;
 
-	struct timeval timeout, *timeoutPtr;
-	int numFound, numEvent;
-	struct PlatformEventData *pedPtr;
-	ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
-	int numQueued;
-	ssize_t i;
+    /*
+     * 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 != NULL) {
 	/*
-	 * 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.
+	 * TIP #233 (Virtualized Time). Is virtual time in effect? And do we
+	 * actually have something to scale? If yes to both then we call the
+	 * handler to do this scaling.
 	 */
 
-	if (timePtr != NULL) {
-	    /*
-	     * TIP #233 (Virtualized Time). Is virtual time in effect? And do
-	     * we actually have something to scale? If yes to both then we
-	     * call the handler to do this scaling.
-	     */
-
-	    if (timePtr->sec != 0 || timePtr->usec != 0) {
-		vTime = *timePtr;
-		tclScaleTimeProcPtr(&vTime, tclTimeClientData);
-		timePtr = &vTime;
-	    }
-	    timeout.tv_sec = timePtr->sec;
-	    timeout.tv_usec = timePtr->usec;
-	    timeoutPtr = &timeout;
-	} else {
-	    timeoutPtr = NULL;
+	if (timePtr->sec != 0 || timePtr->usec != 0) {
+	    vTime = *timePtr;
+	    TclScaleTime(&vTime);
+	    timePtr = &vTime;
 	}
+	timeout.tv_sec = timePtr->sec;
+	timeout.tv_usec = timePtr->usec;
+	timeoutPtr = &timeout;
+    } else {
+	timeoutPtr = NULL;
+    }
 
-	/*
-	 * Walk the list of FileHandlers associated with regular files
-	 * (S_IFREG) belonging to tsdPtr, queue Tcl events for them, and
-	 * update their mask of events of interest.
-	 *
-	 * As epoll(7) does not support regular files, the behaviour of
-	 * {select,poll}(2) is simply simulated here: fds associated with
-	 * regular files are added to this list by PlatformEventsControl() and
-	 * processed here before calling (and possibly blocking) on
-	 * PlatformEventsWait().
-	 */
-
-	numQueued = 0;
-	LIST_FOREACH(filePtr, &tsdPtr->firstReadyFileHandlerPtr, readyNode) {
-	    mask = 0;
-	    if (filePtr->mask & TCL_READABLE) {
-		mask |= TCL_READABLE;
-	    }
-	    if (filePtr->mask & TCL_WRITABLE) {
-		mask |= TCL_WRITABLE;
-	    }
-
-	    /*
-	     * Don't bother to queue an event if the mask was previously
-	     * non-zero since an event must still be on the queue.
-	     */
-
-	    if (filePtr->readyMask == 0) {
-		FileHandlerEvent *fileEvPtr = (FileHandlerEvent *)
-			Tcl_Alloc(sizeof(FileHandlerEvent));
+    /*
+     * Walk the list of FileHandlers associated with regular files (S_IFREG)
+     * belonging to tsdPtr, queue Tcl events for them, and update their mask
+     * of events of interest.
+     *
+     * As epoll(7) does not support regular files, the behaviour of
+     * {select,poll}(2) is simply simulated here: fds associated with regular
+     * files are added to this list by PlatformEventsControl() and processed
+     * here before calling (and possibly blocking) on PlatformEventsWait().
+     */
 
-		fileEvPtr->header.proc = FileHandlerEventProc;
-		fileEvPtr->fd = filePtr->fd;
-		Tcl_QueueEvent((Tcl_Event *) fileEvPtr, TCL_QUEUE_TAIL);
-		numQueued++;
-	    }
-	    filePtr->readyMask = mask;
+    numQueued = 0;
+    LIST_FOREACH(filePtr, &tsdPtr->firstReadyFileHandlerPtr, readyNode) {
+	mask = 0;
+	if (filePtr->mask & TCL_READABLE) {
+	    mask |= TCL_READABLE;
+	}
+	if (filePtr->mask & TCL_WRITABLE) {
+	    mask |= TCL_WRITABLE;
 	}
 
 	/*
-	 * If any events were queued in the above loop, force
-	 * PlatformEventsWait() to poll as there already are events that need
-	 * to be processed at this point.
+	 * Don't bother to queue an event if the mask was previously non-zero
+	 * since an event must still be on the queue.
 	 */
 
-	if (numQueued) {
-	    timeout.tv_sec = 0;
-	    timeout.tv_usec = 0;
-	    timeoutPtr = &timeout;
+	if (filePtr->readyMask == 0) {
+	    FileHandlerEvent *fileEvPtr = (FileHandlerEvent *)
+		    Tcl_Alloc(sizeof(FileHandlerEvent));
+
+	    fileEvPtr->header.proc = FileHandlerEventProc;
+	    fileEvPtr->fd = filePtr->fd;
+	    Tcl_QueueEvent((Tcl_Event *) fileEvPtr, TCL_QUEUE_TAIL);
+	    numQueued++;
 	}
+	filePtr->readyMask = mask;
+    }
 
-	/*
-	 * Wait or poll for new events, queue Tcl events for the FileHandlers
-	 * corresponding to them, and update the FileHandlers' mask of events
-	 * of interest registered by the last call to Tcl_CreateFileHandler().
-	 *
-	 * Events for the eventfd(2)/trigger pipe are processed here in order
-	 * to facilitate inter-thread IPC. If another thread intends to wake
-	 * up this thread whilst it's blocking on PlatformEventsWait(), it
-	 * write(2)s to the eventfd(2)/trigger pipe (see Tcl_AlertNotifier(),)
-	 * which in turn will cause PlatformEventsWait() to return
-	 * immediately.
-	 */
+    /*
+     * If any events were queued in the above loop, force PlatformEventsWait()
+     * to poll as there already are events that need to be processed at this
+     * point.
+     */
+
+    if (numQueued) {
+	timeout.tv_sec = 0;
+	timeout.tv_usec = 0;
+	timeoutPtr = &timeout;
+    }
+
+    /*
+     * Wait or poll for new events, queue Tcl events for the FileHandlers
+     * corresponding to them, and update the FileHandlers' mask of events of
+     * interest registered by the last call to Tcl_CreateFileHandler().
+     *
+     * Events for the eventfd(2)/trigger pipe are processed here in order to
+     * facilitate inter-thread IPC. If another thread intends to wake up this
+     * thread whilst it's blocking on PlatformEventsWait(), it write(2)s to
+     * the eventfd(2)/trigger pipe (see Tcl_AlertNotifier(),) which in turn
+     * will cause PlatformEventsWait() to return immediately.
+     */
 
-	numFound = PlatformEventsWait(tsdPtr->readyEvents,
-		tsdPtr->maxReadyEvents, timeoutPtr);
-	for (numEvent = 0; numEvent < numFound; numEvent++) {
-	    pedPtr = (struct PlatformEventData*)tsdPtr->readyEvents[numEvent].data.ptr;
-	    filePtr = pedPtr->filePtr;
-	    mask = PlatformEventsTranslate(&tsdPtr->readyEvents[numEvent]);
+    numFound = PlatformEventsWait(tsdPtr->readyEvents,
+	    tsdPtr->maxReadyEvents, timeoutPtr);
+    for (numEvent = 0; numEvent < numFound; numEvent++) {
+	pedPtr = (struct PlatformEventData *)
+		tsdPtr->readyEvents[numEvent].data.ptr;
+	filePtr = pedPtr->filePtr;
+	mask = PlatformEventsTranslate(&tsdPtr->readyEvents[numEvent]);
 #ifdef HAVE_EVENTFD
-	    if (filePtr->fd == tsdPtr->triggerEventFd) {
-		uint64_t eventFdVal;
-		i = read(tsdPtr->triggerEventFd, &eventFdVal,
-			sizeof(eventFdVal));
-		if ((i != sizeof(eventFdVal)) && (errno != EAGAIN)) {
-		    Tcl_Panic(
-			    "Tcl_WaitForEvent: read from %p->triggerEventFd: %s",
-			    (void *) tsdPtr, strerror(errno));
-		}
-		continue;
+	if (filePtr->fd == tsdPtr->triggerEventFd) {
+	    uint64_t eventFdVal;
+
+	    i = read(tsdPtr->triggerEventFd, &eventFdVal, sizeof(eventFdVal));
+	    if ((i != sizeof(eventFdVal)) && (errno != EAGAIN)) {
+		Tcl_Panic("%s: read from %p->triggerEventFd: %s",
+			"Tcl_WaitForEvent", (void *) tsdPtr, strerror(errno));
 	    }
+	    continue;
+	}
 #else /* !HAVE_EVENTFD */
-	    if (filePtr->fd == tsdPtr->triggerPipe[0]) {
-		char triggerPipeVal;
-		i = read(tsdPtr->triggerPipe[0], &triggerPipeVal,
-			sizeof(triggerPipeVal));
-		if ((i != sizeof(triggerPipeVal)) && (errno != EAGAIN)) {
-		    Tcl_Panic(
-			    "Tcl_WaitForEvent: read from %p->triggerPipe[0]: %s",
-			    (void *) tsdPtr, strerror(errno));
-		}
-		continue;
+	if (filePtr->fd == tsdPtr->triggerPipe[0]) {
+	    char triggerPipeVal;
+
+	    i = read(tsdPtr->triggerPipe[0], &triggerPipeVal,
+		    sizeof(triggerPipeVal));
+	    if ((i != sizeof(triggerPipeVal)) && (errno != EAGAIN)) {
+		Tcl_Panic("%s: read from %p->triggerPipe[0]: %s",
+			"Tcl_WaitForEvent", (void *) tsdPtr, strerror(errno));
 	    }
+	    continue;
+	}
 #endif /* HAVE_EVENTFD */
-	    if (!mask) {
-		continue;
-	    }
+	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.
-	     */
+	/*
+	 * Don't bother to queue an event if the mask was previously non-zero
+	 * since an event must still be on the queue.
+	 */
 
-	    if (filePtr->readyMask == 0) {
-		FileHandlerEvent *fileEvPtr = (FileHandlerEvent *)
-			Tcl_Alloc(sizeof(FileHandlerEvent));
+	if (filePtr->readyMask == 0) {
+	    FileHandlerEvent *fileEvPtr = (FileHandlerEvent *)
+		    Tcl_Alloc(sizeof(FileHandlerEvent));
 
-		fileEvPtr->header.proc = FileHandlerEventProc;
-		fileEvPtr->fd = filePtr->fd;
-		Tcl_QueueEvent((Tcl_Event *) fileEvPtr, TCL_QUEUE_TAIL);
-	    }
-	    filePtr->readyMask = mask;
+	    fileEvPtr->header.proc = FileHandlerEventProc;
+	    fileEvPtr->fd = filePtr->fd;
+	    Tcl_QueueEvent((Tcl_Event *) fileEvPtr, TCL_QUEUE_TAIL);
 	}
-	return 0;
+	filePtr->readyMask = mask;
     }
+    return 0;
 }
 
 #endif /* NOTIFIER_EPOLL && TCL_THREADS */
+#else
+TCL_MAC_EMPTY_FILE(unix_tclEpollNotfy_c)
 #endif /* !HAVE_COREFOUNDATION */
 
 /*