merge trunktip_463

1 files changed, 216 insertions, 1078 deletions

diff --git a/unix/tclUnixNotfy.c b/unix/tclUnixNotfy.c
index e37962d..5bc753a 100644
--- a/unix/tclUnixNotfy.c
+++ b/unix/tclUnixNotfy.c
@@ -1,262 +1,33 @@
 /*
  * tclUnixNotfy.c --
  *
- *	This file contains the implementation of the select()-based
- *	Unix-specific notifier, which is the lowest-level part of the Tcl
- *	event loop. This file works together with generic/tclNotify.c.
+ *	This file contains subroutines shared by all notifier backend
+ *	implementations on *nix platforms.
  *
  * Copyright (c) 1995-1997 Sun Microsystems, Inc.
+ * Copyright (c) 2016 Lucio Andrés Illanes Albornoz <l.illanes@gmx.de>
  *
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  */
 
-#include "tclInt.h"
-#ifndef HAVE_COREFOUNDATION	/* Darwin/Mac OS X CoreFoundation notifier is
-				 * in tclMacOSXNotify.c */
-#include <signal.h>
-
-/*
- * This structure is used to keep track of the notifier info for a registered
- * file.
- */
-
-typedef struct FileHandler {
-    int fd;
-    int mask;			/* Mask of desired events: TCL_READABLE,
-				 * etc. */
-    int readyMask;		/* Mask of events that have been seen since
-				 * the last time file handlers were invoked
-				 * for this file. */
-    Tcl_FileProc *proc;		/* Function to call, in the style of
-				 * Tcl_CreateFileHandler. */
-    ClientData clientData;	/* Argument to pass to proc. */
-    struct FileHandler *nextPtr;/* Next in list of all files we care about. */
-} FileHandler;
-
-/*
- * The following structure is what is added to the Tcl event queue when file
- * handlers are ready to fire.
- */
-
-typedef struct {
-    Tcl_Event header;		/* Information that is standard for all
-				 * events. */
-    int fd;			/* File descriptor that is ready. Used to find
-				 * the FileHandler structure for the file
-				 * (can't point directly to the FileHandler
-				 * structure because it could go away while
-				 * the event is queued). */
-} FileHandlerEvent;
-
-/*
- * The following structure contains a set of select() masks to track readable,
- * writable, and exception conditions.
- */
-
-typedef struct {
-    fd_set readable;
-    fd_set writable;
-    fd_set exception;
-} SelectMasks;
-
-/*
- * The following static structure contains the state information for the
- * select based implementation of the Tcl notifier. One of these structures is
- * created for each thread that is using the notifier.
- */
-
-typedef struct ThreadSpecificData {
-    FileHandler *firstFileHandlerPtr;
-				/* Pointer to head of file handler list. */
-    SelectMasks checkMasks;	/* This structure is used to build up the
-				 * masks to be used in the next call to
-				 * select. Bits are set in response to calls
-				 * to Tcl_CreateFileHandler. */
-    SelectMasks readyMasks;	/* This array reflects the readable/writable
-				 * conditions that were found to exist by the
-				 * last call to select. */
-    int numFdBits;		/* Number of valid bits in checkMasks (one
-				 * more than highest fd for which
-				 * Tcl_WatchFile has been called). */
-#ifdef TCL_THREADS
-    int onList;			/* True if it is in this list */
-    unsigned int pollState;	/* pollState is used to implement a polling
-				 * handshake between each thread and the
-				 * notifier thread. Bits defined below. */
-    struct ThreadSpecificData *nextPtr, *prevPtr;
-				/* All threads that are currently waiting on
-				 * an event have their ThreadSpecificData
-				 * structure on a doubly-linked listed formed
-				 * from these pointers. You must hold the
-				 * notifierMutex lock before accessing these
-				 * fields. */
-#ifdef __CYGWIN__
-    void *event;     /* Any other thread alerts a notifier
-	 * that an event is ready to be processed
-	 * by sending this event. */
-    void *hwnd;			/* Messaging window. */
-#else /* !__CYGWIN__ */
-    pthread_cond_t waitCV;	/* Any other thread alerts a notifier that an
-				 * event is ready to be processed by signaling
-				 * this condition variable. */
-#endif /* __CYGWIN__ */
-    int waitCVinitialized;	/* Variable to flag initialization of the structure */
-    int eventReady;		/* True if an event is ready to be processed.
-				 * Used as condition flag together with waitCV
-				 * above. */
-#endif /* TCL_THREADS */
-} ThreadSpecificData;
-
-static Tcl_ThreadDataKey dataKey;
-
-#ifdef TCL_THREADS
-/*
- * The following static indicates the number of threads that have initialized
- * notifiers.
- *
- * You must hold the notifierMutex lock before accessing this variable.
- */
-
-static int notifierCount = 0;
-
-/*
- * The following variable points to the head of a doubly-linked list of
- * ThreadSpecificData structures for all threads that are currently waiting on
- * an event.
- *
- * You must hold the notifierMutex lock before accessing this list.
- */
-
-static ThreadSpecificData *waitingListPtr = NULL;
-
-/*
- * The notifier thread spends all its time in select() waiting for a file
- * descriptor associated with one of the threads on the waitingListPtr list to
- * do something interesting. But if the contents of the waitingListPtr list
- * ever changes, we need to wake up and restart the select() system call. You
- * can wake up the notifier thread by writing a single byte to the file
- * descriptor defined below. This file descriptor is the input-end of a pipe
- * and the notifier thread is listening for data on the output-end of the same
- * pipe. Hence writing to this file descriptor will cause the select() system
- * call to return and wake up the notifier thread.
- *
- * You must hold the notifierMutex lock before writing to the pipe.
- */
-
-static int triggerPipe = -1;
-
-/*
- * The notifierMutex locks access to all of the global notifier state.
- */
-
-static pthread_mutex_t notifierInitMutex = PTHREAD_MUTEX_INITIALIZER;
-static pthread_mutex_t notifierMutex     = PTHREAD_MUTEX_INITIALIZER;
-/*
- * The following static indicates if the notifier thread is running.
- *
- * You must hold the notifierInitMutex before accessing this variable.
- */
-
-static int notifierThreadRunning = 0;
-
-/*
- * The notifier thread signals the notifierCV when it has finished
- * initializing the triggerPipe and right before the notifier thread
- * terminates.
- */
-
-static pthread_cond_t notifierCV = PTHREAD_COND_INITIALIZER;
-
-/*
- * The pollState bits
- *	POLL_WANT is set by each thread before it waits on its condition
- *		variable. It is checked by the notifier before it does select.
- *	POLL_DONE is set by the notifier if it goes into select after seeing
- *		POLL_WANT. The idea is to ensure it tries a select with the
- *		same bits the initial thread had set.
- */
-
-#define POLL_WANT	0x1
-#define POLL_DONE	0x2
-
-/*
- * This is the thread ID of the notifier thread that does select.
- */
-
-static Tcl_ThreadId notifierThread;
-
-#endif /* TCL_THREADS */
+#include <poll.h>
 
 /*
  * Static routines defined in this file.
  */
 
+#ifdef NOTIFIER_SELECT
 #ifdef TCL_THREADS
-static void	NotifierThreadProc(ClientData clientData);
+static TCL_NORETURN void NotifierThreadProc(ClientData clientData);
 #if defined(HAVE_PTHREAD_ATFORK)
-static int	atForkInit = 0;
 static void	AtForkChild(void);
 #endif /* HAVE_PTHREAD_ATFORK */
 #endif /* TCL_THREADS */
+#endif /* NOTIFIER_SELECT */
 static int	FileHandlerEventProc(Tcl_Event *evPtr, int flags);
 
-/*
- * Import of Windows API when building threaded with Cygwin.
- */
-
-#if defined(TCL_THREADS) && defined(__CYGWIN__)
-typedef struct {
-    void *hwnd;
-    unsigned int *message;
-    int wParam;
-    int lParam;
-    int time;
-    int x;
-    int y;
-} MSG;
-
-typedef struct {
-    unsigned int style;
-    void *lpfnWndProc;
-    int cbClsExtra;
-    int cbWndExtra;
-    void *hInstance;
-    void *hIcon;
-    void *hCursor;
-    void *hbrBackground;
-    void *lpszMenuName;
-    const void *lpszClassName;
-} WNDCLASS;
-
-extern void __stdcall	CloseHandle(void *);
-extern void *__stdcall	CreateEventW(void *, unsigned char, unsigned char,
-			    void *);
-extern void * __stdcall	CreateWindowExW(void *, const void *, const void *,
-			    DWORD, int, int, int, int, void *, void *, void *, void *);
-extern DWORD __stdcall	DefWindowProcW(void *, int, void *, void *);
-extern unsigned char __stdcall	DestroyWindow(void *);
-extern int __stdcall	DispatchMessageW(const MSG *);
-extern unsigned char __stdcall	GetMessageW(MSG *, void *, int, int);
-extern void __stdcall	MsgWaitForMultipleObjects(DWORD, void *,
-			    unsigned char, DWORD, DWORD);
-extern unsigned char __stdcall	PeekMessageW(MSG *, void *, int, int, int);
-extern unsigned char __stdcall	PostMessageW(void *, unsigned int, void *,
-				    void *);
-extern void __stdcall	PostQuitMessage(int);
-extern void *__stdcall	RegisterClassW(const WNDCLASS *);
-extern unsigned char __stdcall	ResetEvent(void *);
-extern unsigned char __stdcall	TranslateMessage(const MSG *);
-
-/*
- * Threaded-cygwin specific constants and functions in this file:
- */
-
-static const WCHAR className[] = L"TclNotifier";
-static DWORD __stdcall	NotifierProc(void *hwnd, unsigned int message,
-			    void *wParam, void *lParam);
-#endif /* TCL_THREADS && __CYGWIN__ */
-
+#ifdef NOTIFIER_SELECT
 #if TCL_THREADS
 /*
  *----------------------------------------------------------------------
@@ -300,168 +71,7 @@ StartNotifierThread(const char *proc)
     }
 }
 #endif /* TCL_THREADS */
-
-/*
- *----------------------------------------------------------------------
- *
- * Tcl_InitNotifier --
- *
- *	Initializes the platform specific notifier state.
- *
- * Results:
- *	Returns a handle to the notifier state for this thread.
- *
- * Side effects:
- *	None.
- *
- *----------------------------------------------------------------------
- */
-
-ClientData
-Tcl_InitNotifier(void)
-{
-    if (tclNotifierHooks.initNotifierProc) {
-	return tclNotifierHooks.initNotifierProc();
-    } else {
-	ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
-
-#ifdef TCL_THREADS
-	tsdPtr->eventReady = 0;
-
-	/*
-	 * Initialize thread specific condition variable for this thread.
-	 */
-	if (tsdPtr->waitCVinitialized == 0) {
-#ifdef __CYGWIN__
-	    WNDCLASS class;
-
-	    class.style = 0;
-	    class.cbClsExtra = 0;
-	    class.cbWndExtra = 0;
-	    class.hInstance = TclWinGetTclInstance();
-	    class.hbrBackground = NULL;
-	    class.lpszMenuName = NULL;
-	    class.lpszClassName = className;
-	    class.lpfnWndProc = NotifierProc;
-	    class.hIcon = NULL;
-	    class.hCursor = NULL;
-
-	    RegisterClassW(&class);
-	    tsdPtr->hwnd = CreateWindowExW(NULL, class.lpszClassName,
-		    class.lpszClassName, 0, 0, 0, 0, 0, NULL, NULL,
-		    TclWinGetTclInstance(), NULL);
-	    tsdPtr->event = CreateEventW(NULL, 1 /* manual */,
-		    0 /* !signaled */, NULL);
-#else
-	    pthread_cond_init(&tsdPtr->waitCV, NULL);
-#endif /* __CYGWIN__ */
-	    tsdPtr->waitCVinitialized = 1;
-	}
-
-	pthread_mutex_lock(&notifierInitMutex);
-#if defined(HAVE_PTHREAD_ATFORK)
-	/*
-	 * 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 (result) {
-		Tcl_Panic("Tcl_InitNotifier: pthread_atfork failed");
-	    }
-	    atForkInit = 1;
-	}
-#endif /* HAVE_PTHREAD_ATFORK */
-
-	notifierCount++;
-
-	pthread_mutex_unlock(&notifierInitMutex);
-
-#endif /* TCL_THREADS */
-	return tsdPtr;
-    }
-}
-
-/*
- *----------------------------------------------------------------------
- *
- * Tcl_FinalizeNotifier --
- *
- *	This function is called to cleanup the notifier state before a thread
- *	is terminated.
- *
- * Results:
- *	None.
- *
- * Side effects:
- *	May terminate the background notifier thread if this is the last
- *	notifier instance.
- *
- *----------------------------------------------------------------------
- */
-
-void
-Tcl_FinalizeNotifier(
-    ClientData clientData)		/* Not used. */
-{
-    if (tclNotifierHooks.finalizeNotifierProc) {
-	tclNotifierHooks.finalizeNotifierProc(clientData);
-	return;
-    } else {
-#ifdef TCL_THREADS
-	ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
-
-	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 (notifierCount == 0) {
-
-	    if (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: unable to join notifier "
-				"thread");
-		    }
-		    notifierThreadRunning = 0;
-		}
-	    }
-	}
-
-	/*
-	 * 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);
-#endif /* __CYGWIN__ */
-	tsdPtr->waitCVinitialized = 0;
-
-	pthread_mutex_unlock(&notifierInitMutex);
-#endif /* TCL_THREADS */
-    }
-}
+#endif /* NOTIFIER_SELECT */
 
 /*
  *----------------------------------------------------------------------
@@ -477,7 +87,13 @@ Tcl_FinalizeNotifier(
  *	None.
  *
  * Side effects:
- *	Signals the notifier condition variable for the specified notifier.
+ *	select(2) notifier:
+ *		signals the notifier condition variable for the specified
+ *		notifier.
+ *	epoll(7) notifier:
+ *		write(2)s to the eventfd(2) of the specified thread.
+ *	kqueue(2) notifier:
+ *		write(2)s to the trigger pipe(2) of the specified thread.
  *
  *----------------------------------------------------------------------
  */
@@ -490,6 +106,7 @@ Tcl_AlertNotifier(
 	tclNotifierHooks.alertNotifierProc(clientData);
 	return;
     } else {
+#ifdef NOTIFIER_SELECT
 #ifdef TCL_THREADS
 	ThreadSpecificData *tsdPtr = clientData;
 
@@ -503,6 +120,21 @@ Tcl_AlertNotifier(
 #   endif /* __CYGWIN__ */
 	pthread_mutex_unlock(&notifierMutex);
 #endif /* TCL_THREADS */
+#else
+	ThreadSpecificData *tsdPtr = clientData;
+#if defined(NOTIFIER_EPOLL) && defined(HAVE_EVENTFD)
+	uint64_t eventFdVal = 1;
+	if (write(tsdPtr->triggerEventFd, &eventFdVal,
+		sizeof(eventFdVal)) != sizeof(eventFdVal)) {
+	    Tcl_Panic("Tcl_AlertNotifier: unable to write to %p->triggerEventFd",
+		(void *)tsdPtr);
+#else
+	if (write(tsdPtr->triggerPipe[1], "", 1) != 1) {
+	    Tcl_Panic("Tcl_AlertNotifier: unable to write to %p->triggerPipe",
+		(void *)tsdPtr);
+#endif /* NOTIFIER_EPOLL && HAVE_EVENTFD */
+	}
+#endif /* NOTIFIER_SELECT */
     }
 }
 
@@ -565,173 +197,11 @@ Tcl_ServiceModeHook(
 	tclNotifierHooks.serviceModeHookProc(mode);
 	return;
     } else if (mode == TCL_SERVICE_ALL) {
+#ifdef NOTIFIER_SELECT
 #if TCL_THREADS
 	StartNotifierThread("Tcl_ServiceModeHook");
 #endif
-    }
-}
-
-/*
- *----------------------------------------------------------------------
- *
- * Tcl_CreateFileHandler --
- *
- *	This function registers a file handler with the select notifier.
- *
- * Results:
- *	None.
- *
- * Side effects:
- *	Creates a new file handler structure.
- *
- *----------------------------------------------------------------------
- */
-
-void
-Tcl_CreateFileHandler(
-    int fd,			/* Handle of stream to watch. */
-    int mask,			/* OR'ed combination of TCL_READABLE,
-				 * TCL_WRITABLE, and TCL_EXCEPTION: indicates
-				 * conditions under which proc should be
-				 * called. */
-    Tcl_FileProc *proc,		/* Function to call for each selected
-				 * 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 = ckalloc(sizeof(FileHandler));
-	    filePtr->fd = fd;
-	    filePtr->readyMask = 0;
-	    filePtr->nextPtr = tsdPtr->firstFileHandlerPtr;
-	    tsdPtr->firstFileHandlerPtr = filePtr;
-	}
-	filePtr->proc = proc;
-	filePtr->clientData = clientData;
-	filePtr->mask = mask;
-
-	/*
-	 * Update the check masks for this file.
-	 */
-
-	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 --
- *
- *	Cancel a previously-arranged callback arrangement for a file.
- *
- * Results:
- *	None.
- *
- * Side effects:
- *	If a callback was previously registered on file, remove it.
- *
- *----------------------------------------------------------------------
- */
-
-void
-Tcl_DeleteFileHandler(
-    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);
-
-	/*
-	 * Find the entry for the given file (and return if there isn't one).
-	 */
-
-	for (prevPtr = NULL, filePtr = tsdPtr->firstFileHandlerPtr; ;
-		prevPtr = filePtr, filePtr = filePtr->nextPtr) {
-	    if (filePtr == NULL) {
-		return;
-	    }
-	    if (filePtr->fd == fd) {
-		break;
-	    }
-	}
-
-	/*
-	 * Update the check masks for this file.
-	 */
-
-	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.
-	 */
-
-	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;
-		}
-	    }
-	    tsdPtr->numFdBits = numFdBits;
-	}
-
-	/*
-	 * Clean up information in the callback record.
-	 */
-
-	if (prevPtr == NULL) {
-	    tsdPtr->firstFileHandlerPtr = filePtr->nextPtr;
-	} else {
-	    prevPtr->nextPtr = filePtr->nextPtr;
-	}
-	ckfree(filePtr);
+#endif /* NOTIFIER_SELECT */
     }
 }
 
@@ -809,538 +279,56 @@ FileHandlerEventProc(
     return 1;
 }
 
-#if defined(TCL_THREADS) && defined(__CYGWIN__)
-
-static DWORD __stdcall
-NotifierProc(
-    void *hwnd,
-    unsigned int message,
-    void *wParam,
-    void *lParam)
-{
-    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
-
-    if (message != 1024) {
-	return DefWindowProcW(hwnd, message, wParam, lParam);
-    }
-
-    /*
-     * Process all of the runnable events.
-     */
-
-    tsdPtr->eventReady = 1;
-    Tcl_ServiceAll();
-    return 0;
-}
-#endif /* TCL_THREADS && __CYGWIN__ */
-
-/*
- *----------------------------------------------------------------------
- *
- * Tcl_WaitForEvent --
- *
- *	This function is called by Tcl_DoOneEvent to wait for new events on
- *	the message queue. If the block time is 0, then Tcl_WaitForEvent just
- *	polls without blocking.
- *
- * Results:
- *	Returns -1 if the select would block forever, otherwise returns 0.
- *
- * Side effects:
- *	Queues file events that are detected by the select.
- *
- *----------------------------------------------------------------------
- */
-
-int
-Tcl_WaitForEvent(
-    const Tcl_Time *timePtr)		/* Maximum block time, or NULL. */
-{
-    if (tclNotifierHooks.waitForEventProc) {
-	return tclNotifierHooks.waitForEventProc(timePtr);
-    } else {
-	FileHandler *filePtr;
-	int mask;
-	Tcl_Time vTime;
-#ifdef TCL_THREADS
-	int waitForFiles;
-#   ifdef __CYGWIN__
-	MSG msg;
-#   endif /* __CYGWIN__ */
-#else
-	/*
-	 * 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;
-#endif /* TCL_THREADS */
-	ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
-
-	/*
-	 * Set up the timeout structure. Note that if there are no events to
-	 * check for, we return with a negative result rather than blocking
-	 * forever.
-	 */
-
-	if (timePtr != 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;
-	    }
-#ifndef 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.
-	     */
-
-	    return -1;
-	} else {
-	    timeoutPtr = NULL;
-#endif /* !TCL_THREADS */
-	}
-
-#ifdef 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");
-
-	pthread_mutex_lock(&notifierMutex);
-
-	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.
-	     */
-
-	    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.
-	     */
-
-	    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");
-	    }
-	}
-
-	FD_ZERO(&tsdPtr->readyMasks.readable);
-	FD_ZERO(&tsdPtr->readyMasks.writable);
-	FD_ZERO(&tsdPtr->readyMasks.exception);
-
-	if (!tsdPtr->eventReady) {
-#ifdef __CYGWIN__
-	    if (!PeekMessageW(&msg, NULL, 0, 0, 0)) {
-		DWORD 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);
-	    }
-#else
-	    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);
-
-	       pthread_cond_timedwait(&tsdPtr->waitCV, &notifierMutex, &ptime);
-	    } else {
-	       pthread_cond_wait(&tsdPtr->waitCV, &notifierMutex);
-	    }
-#endif /* __CYGWIN__ */
-	}
-	tsdPtr->eventReady = 0;
-
-#ifdef __CYGWIN__
-	while (PeekMessageW(&msg, NULL, 0, 0, 0)) {
-	    /*
-	     * Retrieve and dispatch the message.
-	     */
-
-	    DWORD result = GetMessageW(&msg, NULL, 0, 0);
-
-	    if (result == 0) {
-		PostQuitMessage(msg.wParam);
-		/* What to do here? */
-	    } else if (result != (DWORD) -1) {
-		TranslateMessage(&msg);
-		DispatchMessageW(&msg);
-	    }
-	}
-	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 (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
-	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.
-	 */
-
-	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.
-	 */
-
-	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;
-	    }
-
-	    /*
-	     * 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 =
-			ckalloc(sizeof(FileHandlerEvent));
-
-		fileEvPtr->header.proc = FileHandlerEventProc;
-		fileEvPtr->fd = filePtr->fd;
-		Tcl_QueueEvent((Tcl_Event *) fileEvPtr, TCL_QUEUE_TAIL);
-	    }
-	    filePtr->readyMask = mask;
-	}
-#ifdef TCL_THREADS
-	pthread_mutex_unlock(&notifierMutex);
-#endif /* TCL_THREADS */
-	return 0;
-    }
-}
-
+#ifdef NOTIFIER_SELECT
 #ifdef TCL_THREADS
 /*
  *----------------------------------------------------------------------
  *
- * NotifierThreadProc --
+ * AlertSingleThread --
  *
- *	This routine is the initial (and only) function executed by the
- *	special notifier thread. Its job is to wait for file descriptors to
- *	become readable or writable or to have an exception condition and then
- *	to notify other threads who are interested in this information by
- *	signalling a condition variable. Other threads can signal this
- *	notifier thread of a change in their interests by writing a single
- *	byte to a special pipe that the notifier thread is monitoring.
+ *	Notify a single thread that is waiting on a file descriptor to become
+ *	readable or writable or to have an exception condition.
+ *	notifierMutex must be held.
  *
  * Result:
- *	None. Once started, this routine never exits. It dies with the overall
- *	process.
+ *	None.
  *
  * Side effects:
- *	The trigger pipe used to signal the notifier thread is created when
- *	the notifier thread first starts.
+ *	The condition variable associated with the thread is broadcasted.
  *
  *----------------------------------------------------------------------
  */
 
 static void
-NotifierThreadProc(
-    ClientData clientData)	/* Not used. */
+AlertSingleThread(
+	ThreadSpecificData *tsdPtr)
 {
-    ThreadSpecificData *tsdPtr;
-    fd_set readableMask;
-    fd_set writableMask;
-    fd_set exceptionMask;
-    int fds[2];
-    int i, numFdBits = 0, receivePipe;
-    long found;
-    struct timeval poll = {0., 0.}, *timePtr;
-    char buf[2];
-
-    if (pipe(fds) != 0) {
-	Tcl_Panic("NotifierThreadProc: %s", "could not create trigger pipe");
-    }
-
-    receivePipe = fds[0];
-
-    if (TclUnixSetBlockingMode(receivePipe, TCL_MODE_NONBLOCKING) < 0) {
-	Tcl_Panic("NotifierThreadProc: %s",
-		"could not make receive pipe non blocking");
-    }
-    if (TclUnixSetBlockingMode(fds[1], TCL_MODE_NONBLOCKING) < 0) {
-	Tcl_Panic("NotifierThreadProc: %s",
-		"could not make trigger pipe non blocking");
-    }
-    if (fcntl(receivePipe, F_SETFD, FD_CLOEXEC) < 0) {
-	Tcl_Panic("NotifierThreadProc: %s",
-		"could not make receive pipe close-on-exec");
-    }
-    if (fcntl(fds[1], F_SETFD, FD_CLOEXEC) < 0) {
-	Tcl_Panic("NotifierThreadProc: %s",
-		"could not make trigger pipe close-on-exec");
+    tsdPtr->eventReady = 1;
+    if (tsdPtr->onList) {
+        /*
+         * Remove the ThreadSpecificData structure of this thread
+         * from the waiting list. This prevents us from
+         * continuously spinning on epoll_wait until the other
+         * threads runs and services the file event.
+         */
+
+        if (tsdPtr->prevPtr) {
+    	    tsdPtr->prevPtr->nextPtr = tsdPtr->nextPtr;
+        } else {
+    	    waitingListPtr = tsdPtr->nextPtr;
+        }
+        if (tsdPtr->nextPtr) {
+    	    tsdPtr->nextPtr->prevPtr = tsdPtr->prevPtr;
+        }
+        tsdPtr->nextPtr = tsdPtr->prevPtr = NULL;
+        tsdPtr->onList = 0;
+        tsdPtr->pollState = 0;
     }
-
-    /*
-     * Install the write end of the pipe into the global variable.
-     */
-
-    pthread_mutex_lock(&notifierMutex);
-    triggerPipe = fds[1];
-
-    /*
-     * Signal any threads that are waiting.
-     */
-
-    pthread_cond_broadcast(&notifierCV);
-    pthread_mutex_unlock(&notifierMutex);
-
-    /*
-     * Look for file events and report them to interested threads.
-     */
-
-    while (1) {
-	FD_ZERO(&readableMask);
-	FD_ZERO(&writableMask);
-	FD_ZERO(&exceptionMask);
-
-	/*
-	 * Compute the logical OR of the select masks from all the waiting
-	 * notifiers.
-	 */
-
-	pthread_mutex_lock(&notifierMutex);
-	timePtr = NULL;
-	for (tsdPtr = waitingListPtr; tsdPtr; tsdPtr = tsdPtr->nextPtr) {
-	    for (i = tsdPtr->numFdBits-1; i >= 0; --i) {
-		if (FD_ISSET(i, &tsdPtr->checkMasks.readable)) {
-		    FD_SET(i, &readableMask);
-		}
-		if (FD_ISSET(i, &tsdPtr->checkMasks.writable)) {
-		    FD_SET(i, &writableMask);
-		}
-		if (FD_ISSET(i, &tsdPtr->checkMasks.exception)) {
-		    FD_SET(i, &exceptionMask);
-		}
-	    }
-	    if (tsdPtr->numFdBits > numFdBits) {
-		numFdBits = tsdPtr->numFdBits;
-	    }
-	    if (tsdPtr->pollState & POLL_WANT) {
-		/*
-		 * Here we make sure we go through select() with the same mask
-		 * bits that were present when the thread tried to poll.
-		 */
-
-		tsdPtr->pollState |= POLL_DONE;
-		timePtr = &poll;
-	    }
-	}
-	pthread_mutex_unlock(&notifierMutex);
-
-	/*
-	 * Set up the select mask to include the receive pipe.
-	 */
-
-	if (receivePipe >= numFdBits) {
-	    numFdBits = receivePipe + 1;
-	}
-	FD_SET(receivePipe, &readableMask);
-
-	if (select(numFdBits, &readableMask, &writableMask, &exceptionMask,
-		timePtr) == -1) {
-	    /*
-	     * Try again immediately on an error.
-	     */
-
-	    continue;
-	}
-
-	/*
-	 * Alert any threads that are waiting on a ready file descriptor.
-	 */
-
-	pthread_mutex_lock(&notifierMutex);
-	for (tsdPtr = waitingListPtr; tsdPtr; tsdPtr = tsdPtr->nextPtr) {
-	    found = 0;
-
-	    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);
-		    found = 1;
-		}
-		if (FD_ISSET(i, &tsdPtr->checkMasks.writable)
-			&& FD_ISSET(i, &writableMask)) {
-		    FD_SET(i, &tsdPtr->readyMasks.writable);
-		    found = 1;
-		}
-		if (FD_ISSET(i, &tsdPtr->checkMasks.exception)
-			&& FD_ISSET(i, &exceptionMask)) {
-		    FD_SET(i, &tsdPtr->readyMasks.exception);
-		    found = 1;
-		}
-	    }
-
-	    if (found || (tsdPtr->pollState & POLL_DONE)) {
-		tsdPtr->eventReady = 1;
-		if (tsdPtr->onList) {
-		    /*
-		     * Remove the ThreadSpecificData structure of this thread
-		     * from the waiting list. This prevents us from
-		     * continuously spining on select until the other threads
-		     * runs and services the file event.
-		     */
-
-		    if (tsdPtr->prevPtr) {
-			tsdPtr->prevPtr->nextPtr = tsdPtr->nextPtr;
-		    } else {
-			waitingListPtr = tsdPtr->nextPtr;
-		    }
-		    if (tsdPtr->nextPtr) {
-			tsdPtr->nextPtr->prevPtr = tsdPtr->prevPtr;
-		    }
-		    tsdPtr->nextPtr = tsdPtr->prevPtr = NULL;
-		    tsdPtr->onList = 0;
-		    tsdPtr->pollState = 0;
-		}
 #ifdef __CYGWIN__
-		PostMessageW(tsdPtr->hwnd, 1024, 0, 0);
+    PostMessageW(tsdPtr->hwnd, 1024, 0, 0);
 #else /* __CYGWIN__ */
-		pthread_cond_broadcast(&tsdPtr->waitCV);
+    pthread_cond_broadcast(&tsdPtr->waitCV);
 #endif /* __CYGWIN__ */
-	    }
-	}
-	pthread_mutex_unlock(&notifierMutex);
-
-	/*
-	 * Consume the next byte from the notifier pipe if the pipe was
-	 * readable. Note that there may be multiple bytes pending, but to
-	 * avoid a race condition we only read one at a time.
-	 */
-
-	if (FD_ISSET(receivePipe, &readableMask)) {
-	    i = read(receivePipe, buf, 1);
-
-	    if ((i == 0) || ((i == 1) && (buf[0] == 'q'))) {
-		/*
-		 * Someone closed the write end of the pipe or sent us a Quit
-		 * message [Bug: 4139] and then closed the write end of the
-		 * pipe so we need to shut down the notifier thread.
-		 */
-
-		break;
-	    }
-	}
-    }
-
-    /*
-     * Clean up the read end of the pipe and signal any threads waiting on
-     * termination of the notifier thread.
-     */
-
-    close(receivePipe);
-    pthread_mutex_lock(&notifierMutex);
-    triggerPipe = -1;
-    pthread_cond_broadcast(&notifierCV);
-    pthread_mutex_unlock(&notifierMutex);
-
-    TclpThreadExit(0);
 }
 
 #if defined(HAVE_PTHREAD_ATFORK)
@@ -1407,6 +395,7 @@ AtForkChild(void)
 	    pthread_cond_destroy(&tsdPtr->waitCV);
 	    pthread_cond_init(&tsdPtr->waitCV, NULL);
 #endif
+
 	    /*
 	     * In case, we had multiple threads running before the fork,
 	     * make sure, we don't try to reach out to their thread local data.
@@ -1426,8 +415,157 @@ AtForkChild(void)
 
 #endif /* TCL_THREADS */
 
+#endif /* NOTIFIER_SELECT */
+#ifndef HAVE_COREFOUNDATION	/* Darwin/Mac OS X CoreFoundation notifier is
+				 * in tclMacOSXNotify.c */
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclUnixWaitForFile --
+ *
+ *	This function waits synchronously for a file to become readable or
+ *	writable, with an optional timeout.
+ *
+ * Results:
+ *	The return value is an OR'ed combination of TCL_READABLE,
+ *	TCL_WRITABLE, and TCL_EXCEPTION, indicating the conditions that are
+ *	present on file at the time of the return. This function will not
+ *	return until either "timeout" milliseconds have elapsed or at least
+ *	one of the conditions given by mask has occurred for file (a return
+ *	value of 0 means that a timeout occurred). No normal events will be
+ *	serviced during the execution of this function.
+ *
+ * Side effects:
+ *	Time passes.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclUnixWaitForFile(
+    int fd,			/* Handle for file on which to wait. */
+    int mask,			/* What to wait for: OR'ed combination of
+				 * TCL_READABLE, TCL_WRITABLE, and
+				 * TCL_EXCEPTION. */
+    int timeout)		/* Maximum amount of time to wait for one of
+				 * the conditions in mask to occur, in
+				 * milliseconds. A value of 0 means don't wait
+				 * at all, and a value of -1 means wait
+				 * forever. */
+{
+    Tcl_Time abortTime = {0, 0}, now; /* silence gcc 4 warning */
+    struct timeval blockTime, *timeoutPtr;
+    struct pollfd pollFds[1];
+    int numFound, result = 0, pollTimeout;
+
+    /*
+     * If there is a non-zero finite timeout, compute the time when we give
+     * up.
+     */
+
+    if (timeout > 0) {
+	Tcl_GetTime(&now);
+	abortTime.sec = now.sec + timeout/1000;
+	abortTime.usec = now.usec + (timeout%1000)*1000;
+	if (abortTime.usec >= 1000000) {
+	    abortTime.usec -= 1000000;
+	    abortTime.sec += 1;
+	}
+	timeoutPtr = &blockTime;
+    } else if (timeout == 0) {
+	timeoutPtr = &blockTime;
+	blockTime.tv_sec = 0;
+	blockTime.tv_usec = 0;
+    } else {
+	timeoutPtr = NULL;
+    }
+
+    /*
+     * Setup the pollfd structure for the fd.
+     */
+
+    pollFds[0].fd = fd;
+    pollFds[0].events = pollFds[0].revents = 0;
+    if (mask & TCL_READABLE) {
+	pollFds[0].events |= (POLLIN | POLLHUP);
+    }
+    if (mask & TCL_WRITABLE) {
+	pollFds[0].events |= POLLOUT;
+    }
+    if (mask & TCL_EXCEPTION) {
+	pollFds[0].events |= POLLERR;
+    }
+
+    /*
+     * Loop in a mini-event loop of our own, waiting for either the file to
+     * become ready or a timeout to occur.
+     */
+
+    while (1) {
+	if (timeout > 0) {
+	    blockTime.tv_sec = abortTime.sec - now.sec;
+	    blockTime.tv_usec = abortTime.usec - now.usec;
+	    if (blockTime.tv_usec < 0) {
+		blockTime.tv_sec -= 1;
+		blockTime.tv_usec += 1000000;
+	    }
+	    if (blockTime.tv_sec < 0) {
+		blockTime.tv_sec = 0;
+		blockTime.tv_usec = 0;
+	    }
+	}
+
+	/*
+	 * Wait for the event or a timeout.
+	 */
+
+	if (!timeoutPtr) {
+	    pollTimeout = -1;
+	} else if (!timeoutPtr->tv_sec && !timeoutPtr->tv_usec) {
+	    pollTimeout = 0;
+	} else {
+	    pollTimeout = (int)timeoutPtr->tv_sec * 1000;
+	    if (timeoutPtr->tv_usec) {
+		pollTimeout += ((int)timeoutPtr->tv_usec / 1000);
+	    }
+	}
+	numFound = poll(pollFds, 1, pollTimeout);
+	if (numFound == 1) {
+	    result = 0;
+	    if (pollFds[0].events & (POLLIN | POLLHUP)) {
+		result |= TCL_READABLE;
+	    }
+	    if (pollFds[0].events & POLLOUT) {
+		result |= TCL_WRITABLE;
+	    }
+	    if (pollFds[0].events & POLLERR) {
+		result |= TCL_EXCEPTION;
+	    }
+	    if (result) {
+		break;
+	    }
+	}
+	if (timeout == 0) {
+	    break;
+	}
+	if (timeout < 0) {
+	    continue;
+	}
+
+	/*
+	 * The select returned early, so we need to recompute the timeout.
+	 */
+
+	Tcl_GetTime(&now);
+	if ((abortTime.sec < now.sec)
+		|| (abortTime.sec==now.sec && abortTime.usec<=now.usec)) {
+	    break;
+	}
+    }
+    return result;
+}
 #endif /* !HAVE_COREFOUNDATION */
-
+
 /*
  * Local Variables:
  * mode: c