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

1 files changed, 375 insertions, 402 deletions

diff --git a/unix/tclSelectNotfy.c b/unix/tclSelectNotfy.c
index 2c63575..e1d577f 100644
--- a/unix/tclSelectNotfy.c
+++ b/unix/tclSelectNotfy.c
@@ -216,8 +216,8 @@ extern "C" {
 typedef struct {
     void *hwnd;			/* Messaging window. */
     unsigned int *message;	/* Message payload. */
-    size_t wParam;			/* Event-specific "word" parameter. */
-    size_t lParam;			/* Event-specific "long" parameter. */
+    size_t wParam;		/* Event-specific "word" parameter. */
+    size_t lParam;		/* Event-specific "long" parameter. */
     int time;			/* Event timestamp. */
     int x;			/* Event location (where meaningful). */
     int y;
@@ -244,8 +244,8 @@ extern void __stdcall	CloseHandle(void *);
 extern void *__stdcall	CreateEventW(void *, unsigned char, unsigned char,
 			    void *);
 extern void *__stdcall	CreateWindowExW(void *, const void *, const void *,
-			    unsigned int, int, int, int, int, void *, void *, void *,
-			    void *);
+			    unsigned int, int, int, int, int, void *, void *,
+			    void *, void *);
 extern unsigned int __stdcall	DefWindowProcW(void *, int, void *, void *);
 extern unsigned char __stdcall	DestroyWindow(void *);
 extern int __stdcall	DispatchMessageW(const MSG *);
@@ -271,14 +271,17 @@ static unsigned int __stdcall	NotifierProc(void *hwnd, unsigned int message,
 }
 #endif
 #endif /* TCL_THREADS && __CYGWIN__ */
-
 
+/*
+ * Incorporate the base notifier implementation.
+ */
+
 #include "tclUnixNotfy.c"
 
 /*
  *----------------------------------------------------------------------
  *
- * Tcl_InitNotifier --
+ * TclpInitNotifier --
  *
  *	Initializes the platform specific notifier state.
  *
@@ -292,75 +295,72 @@ static unsigned int __stdcall	NotifierProc(void *hwnd, unsigned int message,
  */
 
 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);
 
 #if TCL_THREADS
-	tsdPtr->eventReady = 0;
+    tsdPtr->eventReady = 0;
 
-	/*
-	 * Initialize thread specific condition variable for this thread.
-	 */
-	if (tsdPtr->waitCVinitialized == 0) {
+    /*
+     * Initialize thread specific condition variable for this thread.
+     */
+
+    if (tsdPtr->waitCVinitialized == 0) {
 #ifdef __CYGWIN__
-	    WNDCLASSW clazz;
-
-	    clazz.style = 0;
-	    clazz.cbClsExtra = 0;
-	    clazz.cbWndExtra = 0;
-	    clazz.hInstance = TclWinGetTclInstance();
-	    clazz.hbrBackground = NULL;
-	    clazz.lpszMenuName = NULL;
-	    clazz.lpszClassName = className;
-	    clazz.lpfnWndProc = (void *)NotifierProc;
-	    clazz.hIcon = NULL;
-	    clazz.hCursor = NULL;
-
-	    RegisterClassW(&clazz);
-	    tsdPtr->hwnd = CreateWindowExW(NULL, clazz.lpszClassName,
-		    clazz.lpszClassName, 0, 0, 0, 0, 0, NULL, NULL,
-		    clazz.hInstance, NULL);
-	    tsdPtr->event = CreateEventW(NULL, 1 /* manual */,
-		    0 /* !signaled */, NULL);
-#else
-	    pthread_cond_init(&tsdPtr->waitCV, NULL);
+	WNDCLASSW clazz;
+
+	clazz.style = 0;
+	clazz.cbClsExtra = 0;
+	clazz.cbWndExtra = 0;
+	clazz.hInstance = TclWinGetTclInstance();
+	clazz.hbrBackground = NULL;
+	clazz.lpszMenuName = NULL;
+	clazz.lpszClassName = className;
+	clazz.lpfnWndProc = (void *) NotifierProc;
+	clazz.hIcon = NULL;
+	clazz.hCursor = NULL;
+
+	RegisterClassW(&clazz);
+	tsdPtr->hwnd = CreateWindowExW(NULL, clazz.lpszClassName,
+		clazz.lpszClassName, 0, 0, 0, 0, 0, NULL, NULL,
+		clazz.hInstance, NULL);
+	tsdPtr->event = CreateEventW(NULL, 1 /* manual */,
+		0 /* !signaled */, NULL);
+#else /* !__CYGWIN__ */
+	pthread_cond_init(&tsdPtr->waitCV, NULL);
 #endif /* __CYGWIN__ */
-	    tsdPtr->waitCVinitialized = 1;
-	}
+	tsdPtr->waitCVinitialized = 1;
+    }
 
-	pthread_mutex_lock(&notifierInitMutex);
+    pthread_mutex_lock(&notifierInitMutex);
 #if defined(HAVE_PTHREAD_ATFORK)
-	/*
-	 * Install pthread_atfork handlers to clean up the notifier in the
-	 * child of a fork.
-	 */
+    /*
+     * Install pthread_atfork handlers to clean up the notifier in the child
+     * of a fork.
+     */
 
-	if (!atForkInit) {
-	    int result = pthread_atfork(NULL, NULL, AtForkChild);
+    if (!atForkInit) {
+	int result = pthread_atfork(NULL, NULL, AtForkChild);
 
-	    if (result) {
-		Tcl_Panic("Tcl_InitNotifier: pthread_atfork failed");
-	    }
-	    atForkInit = 1;
+	if (result) {
+	    Tcl_Panic("Tcl_InitNotifier: %s", "pthread_atfork failed");
 	}
+	atForkInit = 1;
+    }
 #endif /* HAVE_PTHREAD_ATFORK */
 
-	notifierCount++;
-	pthread_mutex_unlock(&notifierInitMutex);
-
+    notifierCount++;
+    pthread_mutex_unlock(&notifierInitMutex);
 #endif /* TCL_THREADS */
-	return tsdPtr;
-    }
+
+    return tsdPtr;
 }
 
 /*
  *----------------------------------------------------------------------
  *
- * Tcl_FinalizeNotifier --
+ * TclpFinalizeNotifier --
  *
  *	This function is called to cleanup the notifier state before a thread
  *	is terminated.
@@ -376,67 +376,62 @@ Tcl_InitNotifier(void)
  */
 
 void
-Tcl_FinalizeNotifier(
+TclpFinalizeNotifier(
     ClientData clientData)
 {
-    if (tclNotifierHooks.finalizeNotifierProc) {
-	tclNotifierHooks.finalizeNotifierProc(clientData);
-	return;
-    } else {
 #if TCL_THREADS
-	ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
+    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
 
-	pthread_mutex_lock(&notifierInitMutex);
-	notifierCount--;
+    pthread_mutex_lock(&notifierInitMutex);
+    notifierCount--;
 
-	/*
-	 * If this is the last thread to use the notifier, close the notifier
-	 * pipe and wait for the background thread to terminate.
-	 */
+    /*
+     * If this is the last thread to use the notifier, close the notifier pipe
+     * and wait for the background thread to terminate.
+     */
 
-	if (notifierCount == 0 && triggerPipe != -1) {
-	    if (write(triggerPipe, "q", 1) != 1) {
-		Tcl_Panic("Tcl_FinalizeNotifier: %s",
-			"unable to write 'q' to triggerPipe");
-	    }
-	    close(triggerPipe);
-	    pthread_mutex_lock(&notifierMutex);
-	    while(triggerPipe != -1) {
-		pthread_cond_wait(&notifierCV, &notifierMutex);
-	    }
-	    pthread_mutex_unlock(&notifierMutex);
-	    if (notifierThreadRunning) {
-		int result = pthread_join((pthread_t) notifierThread, NULL);
+    if (notifierCount == 0 && triggerPipe != -1) {
+	if (write(triggerPipe, "q", 1) != 1) {
+	    Tcl_Panic("Tcl_FinalizeNotifier: %s",
+		    "unable to write 'q' to triggerPipe");
+	}
+	close(triggerPipe);
+	pthread_mutex_lock(&notifierMutex);
+	while(triggerPipe != -1) {
+	    pthread_cond_wait(&notifierCV, &notifierMutex);
+	}
+	pthread_mutex_unlock(&notifierMutex);
+	if (notifierThreadRunning) {
+	    int result = pthread_join((pthread_t) notifierThread, NULL);
 
-		if (result) {
-		    Tcl_Panic("Tcl_FinalizeNotifier: %s",
-			    "unable to join notifier thread");
-		}
-		notifierThreadRunning = 0;
+	    if (result) {
+		Tcl_Panic("Tcl_FinalizeNotifier: %s",
+			"unable to join notifier thread");
 	    }
+	    notifierThreadRunning = 0;
 	}
+    }
 
-	/*
-	 * Clean up any synchronization objects in the thread local storage.
-	 */
+    /*
+     * Clean up any synchronization objects in the thread local storage.
+     */
 
 #ifdef __CYGWIN__
-	DestroyWindow(tsdPtr->hwnd);
-	CloseHandle(tsdPtr->event);
-#else /* __CYGWIN__ */
-	pthread_cond_destroy(&tsdPtr->waitCV);
+    DestroyWindow(tsdPtr->hwnd);
+    CloseHandle(tsdPtr->event);
+#else /* !__CYGWIN__ */
+    pthread_cond_destroy(&tsdPtr->waitCV);
 #endif /* __CYGWIN__ */
-	tsdPtr->waitCVinitialized = 0;
+    tsdPtr->waitCVinitialized = 0;
 
-	pthread_mutex_unlock(&notifierInitMutex);
+    pthread_mutex_unlock(&notifierInitMutex);
 #endif /* TCL_THREADS */
-    }
 }
 
 /*
  *----------------------------------------------------------------------
  *
- * Tcl_CreateFileHandler --
+ * TclpCreateFileHandler --
  *
  *	This function registers a file handler with the select notifier.
  *
@@ -450,7 +445,7 @@ Tcl_FinalizeNotifier(
  */
 
 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
@@ -460,59 +455,48 @@ Tcl_CreateFileHandler(
 				 * event. */
     ClientData clientData)	/* Arbitrary data to pass to proc. */
 {
-    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;
-	}
-	filePtr->proc = proc;
-	filePtr->clientData = clientData;
-	filePtr->mask = mask;
+    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
+    FileHandler *filePtr = LookUpFileHandler(tsdPtr, fd, NULL);
+
+    if (filePtr == NULL) {
+	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;
 
-	/*
-	 * Update the check masks for this file.
-	 */
+    /*
+     * Update the check masks for this file.
+     */
 
-	if (mask & TCL_READABLE) {
-	    FD_SET(fd, &tsdPtr->checkMasks.readable);
-	} else {
-	    FD_CLR(fd, &tsdPtr->checkMasks.readable);
-	}
-	if (mask & TCL_WRITABLE) {
-	    FD_SET(fd, &tsdPtr->checkMasks.writable);
-	} else {
-	    FD_CLR(fd, &tsdPtr->checkMasks.writable);
-	}
-	if (mask & TCL_EXCEPTION) {
-	    FD_SET(fd, &tsdPtr->checkMasks.exception);
-	} else {
-	    FD_CLR(fd, &tsdPtr->checkMasks.exception);
-	}
-	if (tsdPtr->numFdBits <= fd) {
-	    tsdPtr->numFdBits = fd+1;
-	}
+    if (mask & TCL_READABLE) {
+	FD_SET(fd, &tsdPtr->checkMasks.readable);
+    } else {
+	FD_CLR(fd, &tsdPtr->checkMasks.readable);
+    }
+    if (mask & TCL_WRITABLE) {
+	FD_SET(fd, &tsdPtr->checkMasks.writable);
+    } else {
+	FD_CLR(fd, &tsdPtr->checkMasks.writable);
+    }
+    if (mask & TCL_EXCEPTION) {
+	FD_SET(fd, &tsdPtr->checkMasks.exception);
+    } else {
+	FD_CLR(fd, &tsdPtr->checkMasks.exception);
+    }
+    if (tsdPtr->numFdBits <= fd) {
+	tsdPtr->numFdBits = fd + 1;
     }
 }
 
 /*
  *----------------------------------------------------------------------
  *
- * Tcl_DeleteFileHandler --
+ * TclpDeleteFileHandler --
  *
  *	Cancel a previously-arranged callback arrangement for a file.
  *
@@ -526,75 +510,65 @@ 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;
-	int i;
-	ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
+    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
+    FileHandler *filePtr, *prevPtr;
+    int i;
 
-	/*
-	 * 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.
+     */
 
-	if (filePtr->mask & TCL_READABLE) {
-	    FD_CLR(fd, &tsdPtr->checkMasks.readable);
-	}
-	if (filePtr->mask & TCL_WRITABLE) {
-	    FD_CLR(fd, &tsdPtr->checkMasks.writable);
-	}
-	if (filePtr->mask & TCL_EXCEPTION) {
-	    FD_CLR(fd, &tsdPtr->checkMasks.exception);
-	}
+    if (filePtr->mask & TCL_READABLE) {
+	FD_CLR(fd, &tsdPtr->checkMasks.readable);
+    }
+    if (filePtr->mask & TCL_WRITABLE) {
+	FD_CLR(fd, &tsdPtr->checkMasks.writable);
+    }
+    if (filePtr->mask & TCL_EXCEPTION) {
+	FD_CLR(fd, &tsdPtr->checkMasks.exception);
+    }
 
-	/*
-	 * Find current max fd.
-	 */
+    /*
+     * Find current max fd.
+     */
 
-	if (fd+1 == tsdPtr->numFdBits) {
-	    int numFdBits = 0;
+    if (fd + 1 == tsdPtr->numFdBits) {
+	int numFdBits = 0;
 
-	    for (i = fd-1; i >= 0; i--) {
-		if (FD_ISSET(i, &tsdPtr->checkMasks.readable)
-			|| FD_ISSET(i, &tsdPtr->checkMasks.writable)
-			|| FD_ISSET(i, &tsdPtr->checkMasks.exception)) {
-		    numFdBits = i+1;
-		    break;
-		}
+	for (i = fd - 1; i >= 0; i--) {
+	    if (FD_ISSET(i, &tsdPtr->checkMasks.readable)
+		    || FD_ISSET(i, &tsdPtr->checkMasks.writable)
+		    || FD_ISSET(i, &tsdPtr->checkMasks.exception)) {
+		numFdBits = i + 1;
+		break;
 	    }
-	    tsdPtr->numFdBits = numFdBits;
 	}
+	tsdPtr->numFdBits = numFdBits;
+    }
 
-	/*
-	 * 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);
 }
 
 #if defined(__CYGWIN__)
@@ -625,7 +599,7 @@ NotifierProc(
 /*
  *----------------------------------------------------------------------
  *
- * 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
@@ -641,265 +615,261 @@ NotifierProc(
  */
 
 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;
-	ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
+    FileHandler *filePtr;
+    int mask;
+    Tcl_Time vTime;
+    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
 #if TCL_THREADS
-	int waitForFiles;
+    int waitForFiles;
 #   ifdef __CYGWIN__
-	MSG msg;
+    MSG msg;
 #   endif /* __CYGWIN__ */
 #else /* !TCL_THREADS */
-	/*
-	 * Impl. notes: timeout & timeoutPtr are used if, and only if threads
-	 * are not enabled. They are the arguments for the regular select()
-	 * used when the core is not thread-enabled.
-	 */
+    /*
+     * Impl. notes: timeout & timeoutPtr are used if, and only if threads are
+     * not enabled. They are the arguments for the regular select() used when
+     * the core is not thread-enabled.
+     */
 
-	struct timeval timeout, *timeoutPtr;
-	int numFound;
+    struct timeval timeout, *timeoutPtr;
+    int numFound;
 #endif /* TCL_THREADS */
 
+    /*
+     * 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;
-	    }
+	if (timePtr->sec != 0 || timePtr->usec != 0) {
+	    vTime = *timePtr;
+	    TclScaleTime(&vTime);
+	    timePtr = &vTime;
+	}
 #if !TCL_THREADS
-	    timeout.tv_sec = timePtr->sec;
-	    timeout.tv_usec = timePtr->usec;
-	    timeoutPtr = &timeout;
-	} else if (tsdPtr->numFdBits == 0) {
-	    /*
-	     * If there are no threads, no timeout, and no fds registered,
-	     * then there are no events possible and we must avoid deadlock.
-	     * Note that this is not entirely correct because there might be a
-	     * signal that could interrupt the select call, but we don't
-	     * handle that case if we aren't using threads.
-	     */
+	timeout.tv_sec = timePtr->sec;
+	timeout.tv_usec = timePtr->usec;
+	timeoutPtr = &timeout;
+    } else if (tsdPtr->numFdBits == 0) {
+	/*
+	 * If there are no threads, no timeout, and no fds registered, then
+	 * there are no events possible and we must avoid deadlock.  Note that
+	 * this is not entirely correct because there might be a signal that
+	 * could interrupt the select call, but we don't handle that case if
+	 * we aren't using threads.
+	 */
 
-	    return -1;
-	} else {
-	    timeoutPtr = NULL;
+	return -1;
+    } else {
+	timeoutPtr = NULL;
 #endif /* !TCL_THREADS */
-	}
+    }
 
 #if TCL_THREADS
-	/*
-	 * Start notifier thread and place this thread on the list of
-	 * interested threads, signal the notifier thread, and wait for a
-	 * response or a timeout.
-	 */
-	StartNotifierThread("Tcl_WaitForEvent");
+    /*
+     * Start notifier thread and place this thread on the list of interested
+     * threads, signal the notifier thread, and wait for a response or a
+     * timeout.
+     */
 
-	pthread_mutex_lock(&notifierMutex);
+    StartNotifierThread("Tcl_WaitForEvent");
+
+    pthread_mutex_lock(&notifierMutex);
 
-	if (timePtr != NULL && timePtr->sec == 0 && (timePtr->usec == 0
+    if (timePtr != NULL && timePtr->sec == 0 && (timePtr->usec == 0
 #if defined(__APPLE__) && defined(__LP64__)
-		/*
-		 * On 64-bit Darwin, pthread_cond_timedwait() appears to have
-		 * a bug that causes it to wait forever when passed an
-		 * absolute time which has already been exceeded by the system
-		 * time; as a workaround, when given a very brief timeout,
-		 * just do a poll. [Bug 1457797]
-		 */
-		|| timePtr->usec < 10
-#endif /* __APPLE__ && __LP64__ */
-		)) {
 	    /*
-	     * Cannot emulate a polling select with a polling condition
-	     * variable. Instead, pretend to wait for files and tell the
-	     * notifier thread what we are doing. The notifier thread makes
-	     * sure it goes through select with its select mask in the same
-	     * state as ours currently is. We block until that happens.
+	     * On 64-bit Darwin, pthread_cond_timedwait() appears to have a
+	     * bug that causes it to wait forever when passed an absolute time
+	     * which has already been exceeded by the system time; as a
+	     * workaround, when given a very brief timeout, just do a poll.
+	     * [Bug 1457797]
 	     */
+	    || timePtr->usec < 10
+#endif /* __APPLE__ && __LP64__ */
+	    )) {
+	/*
+	 * Cannot emulate a polling select with a polling condition variable.
+	 * Instead, pretend to wait for files and tell the notifier thread
+	 * what we are doing. The notifier thread makes sure it goes through
+	 * select with its select mask in the same state as ours currently is.
+	 * We block until that happens.
+	 */
 
-	    waitForFiles = 1;
-	    tsdPtr->pollState = POLL_WANT;
-	    timePtr = NULL;
-	} else {
-	    waitForFiles = (tsdPtr->numFdBits > 0);
-	    tsdPtr->pollState = 0;
-	}
+	waitForFiles = 1;
+	tsdPtr->pollState = POLL_WANT;
+	timePtr = NULL;
+    } else {
+	waitForFiles = (tsdPtr->numFdBits > 0);
+	tsdPtr->pollState = 0;
+    }
 
-	if (waitForFiles) {
-	    /*
-	     * Add the ThreadSpecificData structure of this thread to the list
-	     * of ThreadSpecificData structures of all threads that are
-	     * waiting on file events.
-	     */
+    if (waitForFiles) {
+	/*
+	 * Add the ThreadSpecificData structure of this thread to the list of
+	 * ThreadSpecificData structures of all threads that are waiting on
+	 * file events.
+	 */
 
-	    tsdPtr->nextPtr = waitingListPtr;
-	    if (waitingListPtr) {
-		waitingListPtr->prevPtr = tsdPtr;
-	    }
-	    tsdPtr->prevPtr = 0;
-	    waitingListPtr = tsdPtr;
-	    tsdPtr->onList = 1;
+	tsdPtr->nextPtr = waitingListPtr;
+	if (waitingListPtr) {
+	    waitingListPtr->prevPtr = tsdPtr;
+	}
+	tsdPtr->prevPtr = 0;
+	waitingListPtr = tsdPtr;
+	tsdPtr->onList = 1;
 
-	    if ((write(triggerPipe, "", 1) == -1) && (errno != EAGAIN)) {
-		Tcl_Panic("Tcl_WaitForEvent: %s",
-			"unable to write to triggerPipe");
-	    }
+	if ((write(triggerPipe, "", 1) == -1) && (errno != EAGAIN)) {
+	    Tcl_Panic("Tcl_WaitForEvent: %s",
+		    "unable to write to triggerPipe");
 	}
+    }
 
-	FD_ZERO(&tsdPtr->readyMasks.readable);
-	FD_ZERO(&tsdPtr->readyMasks.writable);
-	FD_ZERO(&tsdPtr->readyMasks.exception);
+    FD_ZERO(&tsdPtr->readyMasks.readable);
+    FD_ZERO(&tsdPtr->readyMasks.writable);
+    FD_ZERO(&tsdPtr->readyMasks.exception);
 
-	if (!tsdPtr->eventReady) {
+    if (!tsdPtr->eventReady) {
 #ifdef __CYGWIN__
-	    if (!PeekMessageW(&msg, NULL, 0, 0, 0)) {
-		unsigned int timeout;
+	if (!PeekMessageW(&msg, NULL, 0, 0, 0)) {
+	    unsigned int timeout;
 
-		if (timePtr) {
-		    timeout = timePtr->sec * 1000 + timePtr->usec / 1000;
-		} else {
-		    timeout = 0xFFFFFFFF;
-		}
-		pthread_mutex_unlock(&notifierMutex);
-		MsgWaitForMultipleObjects(1, &tsdPtr->event, 0, timeout, 1279);
-		pthread_mutex_lock(&notifierMutex);
+	    if (timePtr) {
+		timeout = timePtr->sec * 1000 + timePtr->usec / 1000;
+	    } else {
+		timeout = 0xFFFFFFFF;
 	    }
+	    pthread_mutex_unlock(&notifierMutex);
+	    MsgWaitForMultipleObjects(1, &tsdPtr->event, 0, timeout, 1279);
+	    pthread_mutex_lock(&notifierMutex);
+	}
 #else /* !__CYGWIN__ */
-	    if (timePtr != NULL) {
-		Tcl_Time now;
-		struct timespec ptime;
+	if (timePtr != NULL) {
+	    Tcl_Time now;
+	    struct timespec ptime;
 
-		Tcl_GetTime(&now);
-		ptime.tv_sec = timePtr->sec + now.sec +
-			(timePtr->usec + now.usec) / 1000000;
-		ptime.tv_nsec = 1000 * ((timePtr->usec + now.usec) % 1000000);
+	    Tcl_GetTime(&now);
+	    ptime.tv_sec = timePtr->sec + now.sec +
+		    (timePtr->usec + now.usec) / 1000000;
+	    ptime.tv_nsec = 1000 * ((timePtr->usec + now.usec) % 1000000);
 
-		pthread_cond_timedwait(&tsdPtr->waitCV, &notifierMutex, &ptime);
-	    } else {
-		pthread_cond_wait(&tsdPtr->waitCV, &notifierMutex);
-	    }
-#endif /* __CYGWIN__ */
+	    pthread_cond_timedwait(&tsdPtr->waitCV, &notifierMutex, &ptime);
+	} else {
+	    pthread_cond_wait(&tsdPtr->waitCV, &notifierMutex);
 	}
-	tsdPtr->eventReady = 0;
+#endif /* __CYGWIN__ */
+    }
+    tsdPtr->eventReady = 0;
 
 #ifdef __CYGWIN__
-	while (PeekMessageW(&msg, NULL, 0, 0, 0)) {
-	    /*
-	     * Retrieve and dispatch the message.
-	     */
+    while (PeekMessageW(&msg, NULL, 0, 0, 0)) {
+	/*
+	 * Retrieve and dispatch the message.
+	 */
 
-	    unsigned int result = GetMessageW(&msg, NULL, 0, 0);
+	unsigned int result = GetMessageW(&msg, NULL, 0, 0);
 
-	    if (result == 0) {
-		PostQuitMessage(msg.wParam);
-		/* What to do here? */
-	    } else if (result != (unsigned int) -1) {
-		TranslateMessage(&msg);
-		DispatchMessageW(&msg);
-	    }
+	if (result == 0) {
+	    PostQuitMessage(msg.wParam);
+	    /* What to do here? */
+	} else if (result != (unsigned int) -1) {
+	    TranslateMessage(&msg);
+	    DispatchMessageW(&msg);
 	}
-	ResetEvent(tsdPtr->event);
+    }
+    ResetEvent(tsdPtr->event);
 #endif /* __CYGWIN__ */
 
-	if (waitForFiles && tsdPtr->onList) {
-	    /*
-	     * Remove the ThreadSpecificData structure of this thread from the
-	     * waiting list. Alert the notifier thread to recompute its select
-	     * masks - skipping this caused a hang when trying to close a pipe
-	     * which the notifier thread was still doing a select on.
-	     */
+    if (waitForFiles && tsdPtr->onList) {
+	/*
+	 * Remove the ThreadSpecificData structure of this thread from the
+	 * waiting list. Alert the notifier thread to recompute its select
+	 * masks - skipping this caused a hang when trying to close a pipe
+	 * which the notifier thread was still doing a select on.
+	 */
 
-	    if (tsdPtr->prevPtr) {
-		tsdPtr->prevPtr->nextPtr = tsdPtr->nextPtr;
-	    } else {
-		waitingListPtr = tsdPtr->nextPtr;
-	    }
-	    if (tsdPtr->nextPtr) {
-		tsdPtr->nextPtr->prevPtr = tsdPtr->prevPtr;
-	    }
-	    tsdPtr->nextPtr = tsdPtr->prevPtr = NULL;
-	    tsdPtr->onList = 0;
-	    if ((write(triggerPipe, "", 1) == -1) && (errno != EAGAIN)) {
-		Tcl_Panic("Tcl_WaitForEvent: %s",
-			"unable to write to triggerPipe");
-	    }
+	if (tsdPtr->prevPtr) {
+	    tsdPtr->prevPtr->nextPtr = tsdPtr->nextPtr;
+	} else {
+	    waitingListPtr = tsdPtr->nextPtr;
+	}
+	if (tsdPtr->nextPtr) {
+	    tsdPtr->nextPtr->prevPtr = tsdPtr->prevPtr;
 	}
+	tsdPtr->nextPtr = tsdPtr->prevPtr = NULL;
+	tsdPtr->onList = 0;
+	if ((write(triggerPipe, "", 1) == -1) && (errno != EAGAIN)) {
+	    Tcl_Panic("Tcl_WaitForEvent: %s",
+		    "unable to write to triggerPipe");
+	}
+    }
 #else /* !TCL_THREADS */
-	tsdPtr->readyMasks = tsdPtr->checkMasks;
-	numFound = select(tsdPtr->numFdBits, &tsdPtr->readyMasks.readable,
-		&tsdPtr->readyMasks.writable, &tsdPtr->readyMasks.exception,
-		timeoutPtr);
+    tsdPtr->readyMasks = tsdPtr->checkMasks;
+    numFound = select(tsdPtr->numFdBits, &tsdPtr->readyMasks.readable,
+	    &tsdPtr->readyMasks.writable, &tsdPtr->readyMasks.exception,
+	    timeoutPtr);
 
-	/*
-	 * Some systems don't clear the masks after an error, so we have to do
-	 * it here.
-	 */
+    /*
+     * Some systems don't clear the masks after an error, so we have to do it
+     * here.
+     */
 
-	if (numFound == -1) {
-	    FD_ZERO(&tsdPtr->readyMasks.readable);
-	    FD_ZERO(&tsdPtr->readyMasks.writable);
-	    FD_ZERO(&tsdPtr->readyMasks.exception);
-	}
+    if (numFound == -1) {
+	FD_ZERO(&tsdPtr->readyMasks.readable);
+	FD_ZERO(&tsdPtr->readyMasks.writable);
+	FD_ZERO(&tsdPtr->readyMasks.exception);
+    }
 #endif /* TCL_THREADS */
 
-	/*
-	 * Queue all detected file events before returning.
-	 */
+    /*
+     * Queue all detected file events before returning.
+     */
 
-	for (filePtr = tsdPtr->firstFileHandlerPtr; (filePtr != NULL);
-		filePtr = filePtr->nextPtr) {
-	    mask = 0;
-	    if (FD_ISSET(filePtr->fd, &tsdPtr->readyMasks.readable)) {
-		mask |= TCL_READABLE;
-	    }
-	    if (FD_ISSET(filePtr->fd, &tsdPtr->readyMasks.writable)) {
-		mask |= TCL_WRITABLE;
-	    }
-	    if (FD_ISSET(filePtr->fd, &tsdPtr->readyMasks.exception)) {
-		mask |= TCL_EXCEPTION;
-	    }
+    for (filePtr = tsdPtr->firstFileHandlerPtr; (filePtr != NULL);
+	    filePtr = filePtr->nextPtr) {
+	mask = 0;
+	if (FD_ISSET(filePtr->fd, &tsdPtr->readyMasks.readable)) {
+	    mask |= TCL_READABLE;
+	}
+	if (FD_ISSET(filePtr->fd, &tsdPtr->readyMasks.writable)) {
+	    mask |= TCL_WRITABLE;
+	}
+	if (FD_ISSET(filePtr->fd, &tsdPtr->readyMasks.exception)) {
+	    mask |= TCL_EXCEPTION;
+	}
 
-	    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);
 	}
+	filePtr->readyMask = mask;
+    }
 #if TCL_THREADS
-	pthread_mutex_unlock(&notifierMutex);
+    pthread_mutex_unlock(&notifierMutex);
 #endif /* TCL_THREADS */
-	return 0;
-    }
+    return 0;
 }
 
 /*
@@ -916,8 +886,9 @@ Tcl_WaitForEvent(
  *	byte to a special pipe that the notifier thread is monitoring.
  *
  * Result:
- *	None. Once started, this routine never exits. It dies with the overall
- *	process.
+ *	None. Once started, this routine normally never exits and usually dies
+ *	with the overall process, but it can be shut down if the Tcl library
+ *	is finalized.
  *
  * Side effects:
  *	The trigger pipe used to signal the notifier thread is created when
@@ -1048,7 +1019,7 @@ NotifierThreadProc(
 	for (tsdPtr = waitingListPtr; tsdPtr; tsdPtr = tsdPtr->nextPtr) {
 	    found = 0;
 
-	    for (i = tsdPtr->numFdBits-1; i >= 0; --i) {
+	    for (i = tsdPtr->numFdBits - 1; i >= 0; --i) {
 		if (FD_ISSET(i, &tsdPtr->checkMasks.readable)
 			&& FD_ISSET(i, &readableMask)) {
 		    FD_SET(i, &tsdPtr->readyMasks.readable);
@@ -1113,6 +1084,8 @@ NotifierThreadProc(
 #endif /* TCL_THREADS */
 
 #endif /* (!NOTIFIER_EPOLL && !NOTIFIER_KQUEUE) || !TCL_THREADS */
+#else
+TCL_MAC_EMPTY_FILE(unix_tclSelectNotfy_c)
 #endif /* !HAVE_COREFOUNDATION */
 
 /*