sl@0: /*
sl@0:  * tclMacOSXNotify.c --
sl@0:  *
sl@0:  *	This file contains the implementation of a merged CFRunLoop/select()
sl@0:  *	based notifier, which is the lowest-level part of the Tcl event loop.
sl@0:  *	This file works together with generic/tclNotify.c.
sl@0:  *
sl@0:  * Copyright (c) 1995-1997 Sun Microsystems, Inc.
sl@0:  * Copyright 2001, Apple Computer, Inc.
sl@0:  * Copyright (c) 2005-2007 Daniel A. Steffen <das@users.sourceforge.net>
sl@0:  *
sl@0:  * See the file "license.terms" for information on usage and redistribution of
sl@0:  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
sl@0:  *
sl@0:  * RCS: @(#) $Id: tclMacOSXNotify.c,v 1.1.2.12 2007/04/29 02:21:33 das Exp $
sl@0:  */
sl@0: 
sl@0: #include "tclInt.h"
sl@0: #include "tclPort.h"
sl@0: #ifdef HAVE_COREFOUNDATION	/* Traditional unix select-based notifier is
sl@0: 				 * in tclUnixNotfy.c */
sl@0: #include <CoreFoundation/CoreFoundation.h>
sl@0: #include <pthread.h>
sl@0: 
sl@0: extern TclStubs tclStubs;
sl@0: extern Tcl_NotifierProcs tclOriginalNotifier;
sl@0: 
sl@0: /*
sl@0:  * This structure is used to keep track of the notifier info for a registered
sl@0:  * file.
sl@0:  */
sl@0: 
sl@0: typedef struct FileHandler {
sl@0:     int fd;
sl@0:     int mask;			/* Mask of desired events: TCL_READABLE,
sl@0: 				 * etc. */
sl@0:     int readyMask;		/* Mask of events that have been seen since
sl@0: 				 * the last time file handlers were invoked
sl@0: 				 * for this file. */
sl@0:     Tcl_FileProc *proc;		/* Function to call, in the style of
sl@0: 				 * Tcl_CreateFileHandler. */
sl@0:     ClientData clientData;	/* Argument to pass to proc. */
sl@0:     struct FileHandler *nextPtr;/* Next in list of all files we care about. */
sl@0: } FileHandler;
sl@0: 
sl@0: /*
sl@0:  * The following structure is what is added to the Tcl event queue when file
sl@0:  * handlers are ready to fire.
sl@0:  */
sl@0: 
sl@0: typedef struct FileHandlerEvent {
sl@0:     Tcl_Event header;		/* Information that is standard for all
sl@0: 				 * events. */
sl@0:     int fd;			/* File descriptor that is ready. Used to find
sl@0: 				 * the FileHandler structure for the file
sl@0: 				 * (can't point directly to the FileHandler
sl@0: 				 * structure because it could go away while
sl@0: 				 * the event is queued). */
sl@0: } FileHandlerEvent;
sl@0: 
sl@0: /*
sl@0:  * The following structure contains a set of select() masks to track readable,
sl@0:  * writable, and exceptional conditions.
sl@0:  */
sl@0: 
sl@0: typedef struct SelectMasks {
sl@0:     fd_set readable;
sl@0:     fd_set writable;
sl@0:     fd_set exceptional;
sl@0: } SelectMasks;
sl@0: 
sl@0: /*
sl@0:  * The following static structure contains the state information for the
sl@0:  * select based implementation of the Tcl notifier. One of these structures is
sl@0:  * created for each thread that is using the notifier.
sl@0:  */
sl@0: 
sl@0: typedef struct ThreadSpecificData {
sl@0:     FileHandler *firstFileHandlerPtr;
sl@0: 				/* Pointer to head of file handler list. */
sl@0:     SelectMasks checkMasks;	/* This structure is used to build up the
sl@0: 				 * masks to be used in the next call to
sl@0: 				 * select. Bits are set in response to calls
sl@0: 				 * to Tcl_CreateFileHandler. */
sl@0:     SelectMasks readyMasks;	/* This array reflects the readable/writable
sl@0: 				 * conditions that were found to exist by the
sl@0: 				 * last call to select. */
sl@0:     int numFdBits;		/* Number of valid bits in checkMasks (one
sl@0: 				 * more than highest fd for which
sl@0: 				 * Tcl_WatchFile has been called). */
sl@0:     int onList;			/* True if it is in this list */
sl@0:     unsigned int pollState;	/* pollState is used to implement a polling
sl@0: 				 * handshake between each thread and the
sl@0: 				 * notifier thread. Bits defined below. */
sl@0:     struct ThreadSpecificData *nextPtr, *prevPtr;
sl@0: 				/* All threads that are currently waiting on
sl@0: 				 * an event have their ThreadSpecificData
sl@0: 				 * structure on a doubly-linked listed formed
sl@0: 				 * from these pointers. You must hold the
sl@0: 				 * notifierLock before accessing these
sl@0: 				 * fields. */
sl@0:     CFRunLoopSourceRef runLoopSource;
sl@0: 				/* Any other thread alerts a notifier that an
sl@0: 				 * event is ready to be processed by signaling
sl@0: 				 * this CFRunLoopSource. */
sl@0:     CFRunLoopRef runLoop;	/* This thread's CFRunLoop, needs to be woken
sl@0: 				 * up whenever the runLoopSource is
sl@0: 				 * signaled. */
sl@0:     int eventReady;		/* True if an event is ready to be
sl@0: 				 * processed. */
sl@0: } ThreadSpecificData;
sl@0: 
sl@0: static Tcl_ThreadDataKey dataKey;
sl@0: 
sl@0: /*
sl@0:  * The following static indicates the number of threads that have initialized
sl@0:  * notifiers.
sl@0:  *
sl@0:  * You must hold the notifierInitLock before accessing this variable.
sl@0:  */
sl@0: 
sl@0: static int notifierCount = 0;
sl@0: 
sl@0: /*
sl@0:  * The following variable points to the head of a doubly-linked list of
sl@0:  * ThreadSpecificData structures for all threads that are currently waiting on
sl@0:  * an event.
sl@0:  *
sl@0:  * You must hold the notifierLock before accessing this list.
sl@0:  */
sl@0: 
sl@0: static ThreadSpecificData *waitingListPtr = NULL;
sl@0: 
sl@0: /*
sl@0:  * The notifier thread spends all its time in select() waiting for a file
sl@0:  * descriptor associated with one of the threads on the waitingListPtr list to
sl@0:  * do something interesting. But if the contents of the waitingListPtr list
sl@0:  * ever changes, we need to wake up and restart the select() system call. You
sl@0:  * can wake up the notifier thread by writing a single byte to the file
sl@0:  * descriptor defined below. This file descriptor is the input-end of a pipe
sl@0:  * and the notifier thread is listening for data on the output-end of the same
sl@0:  * pipe. Hence writing to this file descriptor will cause the select() system
sl@0:  * call to return and wake up the notifier thread.
sl@0:  *
sl@0:  * You must hold the notifierLock lock before writing to the pipe.
sl@0:  */
sl@0: 
sl@0: static int triggerPipe = -1;
sl@0: static int receivePipe = -1; /* Output end of triggerPipe */
sl@0: 
sl@0: /*
sl@0:  * We use the Darwin-native spinlock API rather than pthread mutexes for
sl@0:  * notifier locking: this radically simplifies the implementation and lowers
sl@0:  * overhead. Note that these are not pure spinlocks, they employ various
sl@0:  * strategies to back off and relinquish the processor, making them immune to
sl@0:  * most priority-inversion livelocks (c.f. 'man 3 OSSpinLockLock' and Darwin
sl@0:  * sources: xnu/osfmk/{ppc,i386}/commpage/spinlocks.s).
sl@0:  */
sl@0: 
sl@0: #if defined(HAVE_LIBKERN_OSATOMIC_H) && defined(HAVE_OSSPINLOCKLOCK)
sl@0: /*
sl@0:  * Use OSSpinLock API where available (Tiger or later).
sl@0:  */
sl@0: 
sl@0: #include <libkern/OSAtomic.h>
sl@0: 
sl@0: #if defined(HAVE_WEAK_IMPORT) && MAC_OS_X_VERSION_MIN_REQUIRED < 1040
sl@0: /*
sl@0:  * Support for weakly importing spinlock API.
sl@0:  */
sl@0: #define WEAK_IMPORT_SPINLOCKLOCK
sl@0: #if MAC_OS_X_VERSION_MAX_ALLOWED >= 1050
sl@0: #define VOLATILE volatile
sl@0: #else
sl@0: #define VOLATILE
sl@0: #endif
sl@0: #ifndef bool
sl@0: #define bool int
sl@0: #endif
sl@0: extern void OSSpinLockLock(VOLATILE OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE;
sl@0: extern void OSSpinLockUnlock(VOLATILE OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE;
sl@0: extern bool OSSpinLockTry(VOLATILE OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE;
sl@0: extern void _spin_lock(VOLATILE OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE;
sl@0: extern void _spin_unlock(VOLATILE OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE;
sl@0: extern bool _spin_lock_try(VOLATILE OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE;
sl@0: static void (* lockLock)(VOLATILE OSSpinLock *lock) = NULL;
sl@0: static void (* lockUnlock)(VOLATILE OSSpinLock *lock) = NULL;
sl@0: static bool (* lockTry)(VOLATILE OSSpinLock *lock) = NULL;
sl@0: #undef VOLATILE
sl@0: static pthread_once_t spinLockLockInitControl = PTHREAD_ONCE_INIT;
sl@0: static void SpinLockLockInit(void) {
sl@0:     lockLock   = OSSpinLockLock   != NULL ? OSSpinLockLock   : _spin_lock;
sl@0:     lockUnlock = OSSpinLockUnlock != NULL ? OSSpinLockUnlock : _spin_unlock;
sl@0:     lockTry    = OSSpinLockTry    != NULL ? OSSpinLockTry    : _spin_lock_try;
sl@0:     if (lockLock == NULL || lockUnlock == NULL) {
sl@0: 	Tcl_Panic("SpinLockLockInit: no spinlock API available");
sl@0:     }
sl@0: }
sl@0: #define SpinLockLock(p) 	lockLock(p)
sl@0: #define SpinLockUnlock(p)	lockUnlock(p)
sl@0: #define SpinLockTry(p)  	lockTry(p)
sl@0: #else
sl@0: #define SpinLockLock(p) 	OSSpinLockLock(p)
sl@0: #define SpinLockUnlock(p)	OSSpinLockUnlock(p)
sl@0: #define SpinLockTry(p)  	OSSpinLockTry(p)
sl@0: #endif /* HAVE_WEAK_IMPORT */
sl@0: #define SPINLOCK_INIT   	OS_SPINLOCK_INIT
sl@0: 
sl@0: #else
sl@0: /*
sl@0:  * Otherwise, use commpage spinlock SPI directly.
sl@0:  */
sl@0: 
sl@0: typedef uint32_t OSSpinLock;
sl@0: extern void _spin_lock(OSSpinLock *lock);
sl@0: extern void _spin_unlock(OSSpinLock *lock);
sl@0: extern int  _spin_lock_try(OSSpinLock *lock);
sl@0: #define SpinLockLock(p) 	_spin_lock(p)
sl@0: #define SpinLockUnlock(p)	_spin_unlock(p)
sl@0: #define SpinLockTry(p)  	_spin_lock_try(p)
sl@0: #define SPINLOCK_INIT   	0
sl@0: 
sl@0: #endif /* HAVE_LIBKERN_OSATOMIC_H && HAVE_OSSPINLOCKLOCK */
sl@0: 
sl@0: /*
sl@0:  * These spinlocks lock access to the global notifier state.
sl@0:  */
sl@0: 
sl@0: static OSSpinLock notifierInitLock = SPINLOCK_INIT;
sl@0: static OSSpinLock notifierLock     = SPINLOCK_INIT;
sl@0: 
sl@0: /*
sl@0:  * Macros abstracting notifier locking/unlocking
sl@0:  */
sl@0: 
sl@0: #define LOCK_NOTIFIER_INIT	SpinLockLock(&notifierInitLock)
sl@0: #define UNLOCK_NOTIFIER_INIT	SpinLockUnlock(&notifierInitLock)
sl@0: #define LOCK_NOTIFIER		SpinLockLock(&notifierLock)
sl@0: #define UNLOCK_NOTIFIER		SpinLockUnlock(&notifierLock)
sl@0: 
sl@0: /*
sl@0:  * The pollState bits
sl@0:  *	POLL_WANT is set by each thread before it waits on its condition
sl@0:  *		variable. It is checked by the notifier before it does select.
sl@0:  *	POLL_DONE is set by the notifier if it goes into select after seeing
sl@0:  *		POLL_WANT. The idea is to ensure it tries a select with the
sl@0:  *		same bits the initial thread had set.
sl@0:  */
sl@0: 
sl@0: #define POLL_WANT	0x1
sl@0: #define POLL_DONE	0x2
sl@0: 
sl@0: /*
sl@0:  * This is the thread ID of the notifier thread that does select.
sl@0:  */
sl@0: 
sl@0: static pthread_t notifierThread;
sl@0: 
sl@0: /*
sl@0:  * Custom run loop mode containing only the run loop source for the
sl@0:  * notifier thread.
sl@0:  */
sl@0: 
sl@0: #ifndef TCL_EVENTS_ONLY_RUN_LOOP_MODE
sl@0: #define TCL_EVENTS_ONLY_RUN_LOOP_MODE "com.tcltk.tclEventsOnlyRunLoopMode"
sl@0: #endif
sl@0: #ifdef __CONSTANT_CFSTRINGS__
sl@0: #define tclEventsOnlyRunLoopMode CFSTR(TCL_EVENTS_ONLY_RUN_LOOP_MODE)
sl@0: #else
sl@0: static CFStringRef tclEventsOnlyRunLoopMode = NULL;
sl@0: #endif
sl@0: 
sl@0: /*
sl@0:  * Static routines defined in this file.
sl@0:  */
sl@0: 
sl@0: static void	NotifierThreadProc(ClientData clientData)
sl@0: 	__attribute__ ((__noreturn__));
sl@0: static int	FileHandlerEventProc(Tcl_Event *evPtr, int flags);
sl@0: 
sl@0: #ifdef HAVE_PTHREAD_ATFORK
sl@0: static int	atForkInit = 0;
sl@0: static void	AtForkPrepare(void);
sl@0: static void	AtForkParent(void);
sl@0: static void	AtForkChild(void);
sl@0: #if defined(HAVE_WEAK_IMPORT) && MAC_OS_X_VERSION_MIN_REQUIRED < 1040
sl@0: /* Support for weakly importing pthread_atfork. */
sl@0: #define WEAK_IMPORT_PTHREAD_ATFORK
sl@0: extern int pthread_atfork(void (*prepare)(void), void (*parent)(void),
sl@0:                           void (*child)(void)) WEAK_IMPORT_ATTRIBUTE;
sl@0: #endif /* HAVE_WEAK_IMPORT */
sl@0: #endif /* HAVE_PTHREAD_ATFORK */
sl@0: 
sl@0: /*
sl@0:  *----------------------------------------------------------------------
sl@0:  *
sl@0:  * Tcl_InitNotifier --
sl@0:  *
sl@0:  *	Initializes the platform specific notifier state.
sl@0:  *
sl@0:  * Results:
sl@0:  *	Returns a handle to the notifier state for this thread.
sl@0:  *
sl@0:  * Side effects:
sl@0:  *	None.
sl@0:  *
sl@0:  *----------------------------------------------------------------------
sl@0:  */
sl@0: 
sl@0: ClientData
sl@0: Tcl_InitNotifier(void)
sl@0: {
sl@0:     ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
sl@0: 
sl@0:     tsdPtr->eventReady = 0;
sl@0: 
sl@0: #ifdef WEAK_IMPORT_SPINLOCKLOCK
sl@0:     /*
sl@0:      * Initialize support for weakly imported spinlock API.
sl@0:      */
sl@0:     if (pthread_once(&spinLockLockInitControl, SpinLockLockInit)) {
sl@0: 	Tcl_Panic("Tcl_InitNotifier: pthread_once failed");
sl@0:     }
sl@0: #endif
sl@0: 
sl@0: #ifndef __CONSTANT_CFSTRINGS__
sl@0:     if (!tclEventsOnlyRunLoopMode) {
sl@0: 	tclEventsOnlyRunLoopMode = CFSTR(TCL_EVENTS_ONLY_RUN_LOOP_MODE);
sl@0:     }
sl@0: #endif
sl@0: 
sl@0:     /*
sl@0:      * Initialize CFRunLoopSource and add it to CFRunLoop of this thread.
sl@0:      */
sl@0: 
sl@0:     if (!tsdPtr->runLoop) {
sl@0: 	CFRunLoopRef runLoop = CFRunLoopGetCurrent();
sl@0: 	CFRunLoopSourceRef runLoopSource;
sl@0: 	CFRunLoopSourceContext runLoopSourceContext;
sl@0: 
sl@0: 	bzero(&runLoopSourceContext, sizeof(CFRunLoopSourceContext));
sl@0: 	runLoopSourceContext.info = tsdPtr;
sl@0: 	runLoopSource = CFRunLoopSourceCreate(NULL, 0, &runLoopSourceContext);
sl@0: 	if (!runLoopSource) {
sl@0: 	    Tcl_Panic("Tcl_InitNotifier: could not create CFRunLoopSource");
sl@0: 	}
sl@0: 	CFRunLoopAddSource(runLoop, runLoopSource, kCFRunLoopCommonModes);
sl@0: 	CFRunLoopAddSource(runLoop, runLoopSource, tclEventsOnlyRunLoopMode);
sl@0: 	tsdPtr->runLoopSource = runLoopSource;
sl@0: 	tsdPtr->runLoop = runLoop;
sl@0:     }
sl@0: 
sl@0:     LOCK_NOTIFIER_INIT;
sl@0: #ifdef HAVE_PTHREAD_ATFORK
sl@0:     /*
sl@0:      * Install pthread_atfork handlers to reinitialize the notifier in the
sl@0:      * child of a fork.
sl@0:      */
sl@0: 
sl@0:     if (
sl@0: #ifdef WEAK_IMPORT_PTHREAD_ATFORK
sl@0: 	    pthread_atfork != NULL &&
sl@0: #endif
sl@0: 	    !atForkInit) {
sl@0: 	int result = pthread_atfork(AtForkPrepare, AtForkParent, AtForkChild);
sl@0: 	if (result) {
sl@0: 	    Tcl_Panic("Tcl_InitNotifier: pthread_atfork failed");
sl@0: 	}
sl@0: 	atForkInit = 1;
sl@0:     }
sl@0: #endif
sl@0:     if (notifierCount == 0) {
sl@0: 	int fds[2], status;
sl@0: 
sl@0: 	/*
sl@0: 	 * Initialize trigger pipe.
sl@0: 	 */
sl@0: 
sl@0: 	if (pipe(fds) != 0) {
sl@0: 	    Tcl_Panic("Tcl_InitNotifier: could not create trigger pipe");
sl@0: 	}
sl@0: 
sl@0: 	status = fcntl(fds[0], F_GETFL);
sl@0: 	status |= O_NONBLOCK;
sl@0: 	if (fcntl(fds[0], F_SETFL, status) < 0) {
sl@0: 	    Tcl_Panic("Tcl_InitNotifier: could not make receive pipe non blocking");
sl@0: 	}
sl@0: 	status = fcntl(fds[1], F_GETFL);
sl@0: 	status |= O_NONBLOCK;
sl@0: 	if (fcntl(fds[1], F_SETFL, status) < 0) {
sl@0: 	    Tcl_Panic("Tcl_InitNotifier: could not make trigger pipe non blocking");
sl@0: 	}
sl@0: 
sl@0: 	receivePipe = fds[0];
sl@0: 	triggerPipe = fds[1];
sl@0: 
sl@0: 	/*
sl@0: 	 * Create notifier thread lazily in Tcl_WaitForEvent() to avoid
sl@0: 	 * interfering with fork() followed immediately by execve()
sl@0: 	 * (cannot execve() when more than one thread is present).
sl@0: 	 */
sl@0: 
sl@0: 	notifierThread = 0;
sl@0:     }
sl@0:     notifierCount++;
sl@0:     UNLOCK_NOTIFIER_INIT;
sl@0: 
sl@0:     return (ClientData) tsdPtr;
sl@0: }
sl@0: 
sl@0: /*
sl@0:  *----------------------------------------------------------------------
sl@0:  *
sl@0:  * Tcl_FinalizeNotifier --
sl@0:  *
sl@0:  *	This function is called to cleanup the notifier state before a thread
sl@0:  *	is terminated.
sl@0:  *
sl@0:  * Results:
sl@0:  *	None.
sl@0:  *
sl@0:  * Side effects:
sl@0:  *	May terminate the background notifier thread if this is the last
sl@0:  *	notifier instance.
sl@0:  *
sl@0:  *----------------------------------------------------------------------
sl@0:  */
sl@0: 
sl@0: void
sl@0: Tcl_FinalizeNotifier(
sl@0:     ClientData clientData)		/* Not used. */
sl@0: {
sl@0:     ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
sl@0: 
sl@0:     LOCK_NOTIFIER_INIT;
sl@0:     notifierCount--;
sl@0: 
sl@0:     /*
sl@0:      * If this is the last thread to use the notifier, close the notifier pipe
sl@0:      * and wait for the background thread to terminate.
sl@0:      */
sl@0: 
sl@0:     if (notifierCount == 0) {
sl@0: 	int result;
sl@0: 
sl@0: 	if (triggerPipe < 0) {
sl@0: 	    Tcl_Panic("Tcl_FinalizeNotifier: notifier pipe not initialized");
sl@0: 	}
sl@0: 
sl@0: 	/*
sl@0: 	 * Send "q" message to the notifier thread so that it will terminate.
sl@0: 	 * The notifier will return from its call to select() and notice that
sl@0: 	 * a "q" message has arrived, it will then close its side of the pipe
sl@0: 	 * and terminate its thread. Note the we can not just close the pipe
sl@0: 	 * and check for EOF in the notifier thread because if a background
sl@0: 	 * child process was created with exec, select() would not register
sl@0: 	 * the EOF on the pipe until the child processes had terminated. [Bug:
sl@0: 	 * 4139] [Bug: 1222872]
sl@0: 	 */
sl@0: 
sl@0: 	write(triggerPipe, "q", 1);
sl@0: 	close(triggerPipe);
sl@0: 
sl@0: 	if (notifierThread) {
sl@0: 	    result = pthread_join(notifierThread, NULL);
sl@0: 	    if (result) {
sl@0: 		Tcl_Panic("Tcl_FinalizeNotifier: unable to join notifier thread");
sl@0: 	    }
sl@0: 	    notifierThread = 0;
sl@0: 	}
sl@0: 
sl@0: 	close(receivePipe);
sl@0: 	triggerPipe = -1;
sl@0:     }
sl@0:     UNLOCK_NOTIFIER_INIT;
sl@0: 
sl@0:     LOCK_NOTIFIER;		/* for concurrency with Tcl_AlertNotifier */
sl@0:     if (tsdPtr->runLoop) {
sl@0: 	tsdPtr->runLoop = NULL;
sl@0: 
sl@0: 	/*
sl@0: 	 * Remove runLoopSource from all CFRunLoops and release it.
sl@0: 	 */
sl@0: 
sl@0: 	CFRunLoopSourceInvalidate(tsdPtr->runLoopSource);
sl@0: 	CFRelease(tsdPtr->runLoopSource);
sl@0: 	tsdPtr->runLoopSource = NULL;
sl@0:     }
sl@0:     UNLOCK_NOTIFIER;
sl@0: }
sl@0: 
sl@0: /*
sl@0:  *----------------------------------------------------------------------
sl@0:  *
sl@0:  * Tcl_AlertNotifier --
sl@0:  *
sl@0:  *	Wake up the specified notifier from any thread. This routine is called
sl@0:  *	by the platform independent notifier code whenever the Tcl_ThreadAlert
sl@0:  *	routine is called. This routine is guaranteed not to be called on a
sl@0:  *	given notifier after Tcl_FinalizeNotifier is called for that notifier.
sl@0:  *
sl@0:  * Results:
sl@0:  *	None.
sl@0:  *
sl@0:  * Side effects:
sl@0:  *	Signals the notifier condition variable for the specified notifier.
sl@0:  *
sl@0:  *----------------------------------------------------------------------
sl@0:  */
sl@0: 
sl@0: void
sl@0: Tcl_AlertNotifier(
sl@0:     ClientData clientData)
sl@0: {
sl@0:     ThreadSpecificData *tsdPtr = (ThreadSpecificData *) clientData;
sl@0: 
sl@0:     LOCK_NOTIFIER;
sl@0:     if (tsdPtr->runLoop) {
sl@0: 	tsdPtr->eventReady = 1;
sl@0: 	CFRunLoopSourceSignal(tsdPtr->runLoopSource);
sl@0: 	CFRunLoopWakeUp(tsdPtr->runLoop);
sl@0:     }
sl@0:     UNLOCK_NOTIFIER;
sl@0: }
sl@0: 
sl@0: /*
sl@0:  *----------------------------------------------------------------------
sl@0:  *
sl@0:  * Tcl_SetTimer --
sl@0:  *
sl@0:  *	This function sets the current notifier timer value. This interface is
sl@0:  *	not implemented in this notifier because we are always running inside
sl@0:  *	of Tcl_DoOneEvent.
sl@0:  *
sl@0:  * Results:
sl@0:  *	None.
sl@0:  *
sl@0:  * Side effects:
sl@0:  *	None.
sl@0:  *
sl@0:  *----------------------------------------------------------------------
sl@0:  */
sl@0: 
sl@0: void
sl@0: Tcl_SetTimer(
sl@0:     Tcl_Time *timePtr)		/* Timeout value, may be NULL. */
sl@0: {
sl@0:     /*
sl@0:      * The interval timer doesn't do anything in this implementation, because
sl@0:      * the only event loop is via Tcl_DoOneEvent, which passes timeout values
sl@0:      * to Tcl_WaitForEvent.
sl@0:      */
sl@0: 
sl@0:     if (tclStubs.tcl_SetTimer != tclOriginalNotifier.setTimerProc) {
sl@0: 	tclStubs.tcl_SetTimer(timePtr);
sl@0:     }
sl@0: }
sl@0: 
sl@0: /*
sl@0:  *----------------------------------------------------------------------
sl@0:  *
sl@0:  * Tcl_ServiceModeHook --
sl@0:  *
sl@0:  *	This function is invoked whenever the service mode changes.
sl@0:  *
sl@0:  * Results:
sl@0:  *	None.
sl@0:  *
sl@0:  * Side effects:
sl@0:  *	None.
sl@0:  *
sl@0:  *----------------------------------------------------------------------
sl@0:  */
sl@0: 
sl@0: void
sl@0: Tcl_ServiceModeHook(
sl@0:     int mode)			/* Either TCL_SERVICE_ALL, or
sl@0: 				 * TCL_SERVICE_NONE. */
sl@0: {
sl@0: }
sl@0: 
sl@0: /*
sl@0:  *----------------------------------------------------------------------
sl@0:  *
sl@0:  * Tcl_CreateFileHandler --
sl@0:  *
sl@0:  *	This function registers a file handler with the select notifier.
sl@0:  *
sl@0:  * Results:
sl@0:  *	None.
sl@0:  *
sl@0:  * Side effects:
sl@0:  *	Creates a new file handler structure.
sl@0:  *
sl@0:  *----------------------------------------------------------------------
sl@0:  */
sl@0: 
sl@0: void
sl@0: Tcl_CreateFileHandler(
sl@0:     int fd,			/* Handle of stream to watch. */
sl@0:     int mask,			/* OR'ed combination of TCL_READABLE,
sl@0: 				 * TCL_WRITABLE, and TCL_EXCEPTION: indicates
sl@0: 				 * conditions under which proc should be
sl@0: 				 * called. */
sl@0:     Tcl_FileProc *proc,		/* Function to call for each selected
sl@0: 				 * event. */
sl@0:     ClientData clientData)	/* Arbitrary data to pass to proc. */
sl@0: {
sl@0:     ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
sl@0:     FileHandler *filePtr;
sl@0: 
sl@0:     if (tclStubs.tcl_CreateFileHandler !=
sl@0: 	    tclOriginalNotifier.createFileHandlerProc) {
sl@0: 	tclStubs.tcl_CreateFileHandler(fd, mask, proc, clientData);
sl@0: 	return;
sl@0:     }
sl@0: 
sl@0:     for (filePtr = tsdPtr->firstFileHandlerPtr; filePtr != NULL;
sl@0: 	    filePtr = filePtr->nextPtr) {
sl@0: 	if (filePtr->fd == fd) {
sl@0: 	    break;
sl@0: 	}
sl@0:     }
sl@0:     if (filePtr == NULL) {
sl@0: 	filePtr = (FileHandler*) ckalloc(sizeof(FileHandler));
sl@0: 	filePtr->fd = fd;
sl@0: 	filePtr->readyMask = 0;
sl@0: 	filePtr->nextPtr = tsdPtr->firstFileHandlerPtr;
sl@0: 	tsdPtr->firstFileHandlerPtr = filePtr;
sl@0:     }
sl@0:     filePtr->proc = proc;
sl@0:     filePtr->clientData = clientData;
sl@0:     filePtr->mask = mask;
sl@0: 
sl@0:     /*
sl@0:      * Update the check masks for this file.
sl@0:      */
sl@0: 
sl@0:     if (mask & TCL_READABLE) {
sl@0: 	FD_SET(fd, &(tsdPtr->checkMasks.readable));
sl@0:     } else {
sl@0: 	FD_CLR(fd, &(tsdPtr->checkMasks.readable));
sl@0:     }
sl@0:     if (mask & TCL_WRITABLE) {
sl@0: 	FD_SET(fd, &(tsdPtr->checkMasks.writable));
sl@0:     } else {
sl@0: 	FD_CLR(fd, &(tsdPtr->checkMasks.writable));
sl@0:     }
sl@0:     if (mask & TCL_EXCEPTION) {
sl@0: 	FD_SET(fd, &(tsdPtr->checkMasks.exceptional));
sl@0:     } else {
sl@0: 	FD_CLR(fd, &(tsdPtr->checkMasks.exceptional));
sl@0:     }
sl@0:     if (tsdPtr->numFdBits <= fd) {
sl@0: 	tsdPtr->numFdBits = fd+1;
sl@0:     }
sl@0: }
sl@0: 
sl@0: /*
sl@0:  *----------------------------------------------------------------------
sl@0:  *
sl@0:  * Tcl_DeleteFileHandler --
sl@0:  *
sl@0:  *	Cancel a previously-arranged callback arrangement for a file.
sl@0:  *
sl@0:  * Results:
sl@0:  *	None.
sl@0:  *
sl@0:  * Side effects:
sl@0:  *	If a callback was previously registered on file, remove it.
sl@0:  *
sl@0:  *----------------------------------------------------------------------
sl@0:  */
sl@0: 
sl@0: void
sl@0: Tcl_DeleteFileHandler(
sl@0:     int fd)			/* Stream id for which to remove callback
sl@0: 				 * function. */
sl@0: {
sl@0:     FileHandler *filePtr, *prevPtr;
sl@0:     int i;
sl@0:     ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
sl@0: 
sl@0:     if (tclStubs.tcl_DeleteFileHandler !=
sl@0: 	    tclOriginalNotifier.deleteFileHandlerProc) {
sl@0: 	tclStubs.tcl_DeleteFileHandler(fd);
sl@0: 	return;
sl@0:     }
sl@0: 
sl@0:     /*
sl@0:      * Find the entry for the given file (and return if there isn't one).
sl@0:      */
sl@0: 
sl@0:     for (prevPtr = NULL, filePtr = tsdPtr->firstFileHandlerPtr; ;
sl@0: 	 prevPtr = filePtr, filePtr = filePtr->nextPtr) {
sl@0: 	if (filePtr == NULL) {
sl@0: 	    return;
sl@0: 	}
sl@0: 	if (filePtr->fd == fd) {
sl@0: 	    break;
sl@0: 	}
sl@0:     }
sl@0: 
sl@0:     /*
sl@0:      * Update the check masks for this file.
sl@0:      */
sl@0: 
sl@0:     if (filePtr->mask & TCL_READABLE) {
sl@0: 	FD_CLR(fd, &(tsdPtr->checkMasks.readable));
sl@0:     }
sl@0:     if (filePtr->mask & TCL_WRITABLE) {
sl@0: 	FD_CLR(fd, &(tsdPtr->checkMasks.writable));
sl@0:     }
sl@0:     if (filePtr->mask & TCL_EXCEPTION) {
sl@0: 	FD_CLR(fd, &(tsdPtr->checkMasks.exceptional));
sl@0:     }
sl@0: 
sl@0:     /*
sl@0:      * Find current max fd.
sl@0:      */
sl@0: 
sl@0:     if (fd+1 == tsdPtr->numFdBits) {
sl@0: 	tsdPtr->numFdBits = 0;
sl@0: 	for (i = fd-1; i >= 0; i--) {
sl@0: 	    if (FD_ISSET(i, &(tsdPtr->checkMasks.readable))
sl@0: 		    || FD_ISSET(i, &(tsdPtr->checkMasks.writable))
sl@0: 		    || FD_ISSET(i, &(tsdPtr->checkMasks.exceptional))) {
sl@0: 		tsdPtr->numFdBits = i+1;
sl@0: 		break;
sl@0: 	    }
sl@0: 	}
sl@0:     }
sl@0: 
sl@0:     /*
sl@0:      * Clean up information in the callback record.
sl@0:      */
sl@0: 
sl@0:     if (prevPtr == NULL) {
sl@0: 	tsdPtr->firstFileHandlerPtr = filePtr->nextPtr;
sl@0:     } else {
sl@0: 	prevPtr->nextPtr = filePtr->nextPtr;
sl@0:     }
sl@0:     ckfree((char *) filePtr);
sl@0: }
sl@0: 
sl@0: /*
sl@0:  *----------------------------------------------------------------------
sl@0:  *
sl@0:  * FileHandlerEventProc --
sl@0:  *
sl@0:  *	This function is called by Tcl_ServiceEvent when a file event reaches
sl@0:  *	the front of the event queue. This function is responsible for
sl@0:  *	actually handling the event by invoking the callback for the file
sl@0:  *	handler.
sl@0:  *
sl@0:  * Results:
sl@0:  *	Returns 1 if the event was handled, meaning it should be removed from
sl@0:  *	the queue. Returns 0 if the event was not handled, meaning it should
sl@0:  *	stay on the queue. The only time the event isn't handled is if the
sl@0:  *	TCL_FILE_EVENTS flag bit isn't set.
sl@0:  *
sl@0:  * Side effects:
sl@0:  *	Whatever the file handler's callback function does.
sl@0:  *
sl@0:  *----------------------------------------------------------------------
sl@0:  */
sl@0: 
sl@0: static int
sl@0: FileHandlerEventProc(
sl@0:     Tcl_Event *evPtr,		/* Event to service. */
sl@0:     int flags)			/* Flags that indicate what events to handle,
sl@0: 				 * such as TCL_FILE_EVENTS. */
sl@0: {
sl@0:     int mask;
sl@0:     FileHandler *filePtr;
sl@0:     FileHandlerEvent *fileEvPtr = (FileHandlerEvent *) evPtr;
sl@0:     ThreadSpecificData *tsdPtr;
sl@0: 
sl@0:     if (!(flags & TCL_FILE_EVENTS)) {
sl@0: 	return 0;
sl@0:     }
sl@0: 
sl@0:     /*
sl@0:      * Search through the file handlers to find the one whose handle matches
sl@0:      * the event. We do this rather than keeping a pointer to the file handler
sl@0:      * directly in the event, so that the handler can be deleted while the
sl@0:      * event is queued without leaving a dangling pointer.
sl@0:      */
sl@0: 
sl@0:     tsdPtr = TCL_TSD_INIT(&dataKey);
sl@0:     for (filePtr = tsdPtr->firstFileHandlerPtr; filePtr != NULL;
sl@0: 	    filePtr = filePtr->nextPtr) {
sl@0: 	if (filePtr->fd != fileEvPtr->fd) {
sl@0: 	    continue;
sl@0: 	}
sl@0: 
sl@0: 	/*
sl@0: 	 * The code is tricky for two reasons:
sl@0: 	 * 1. The file handler's desired events could have changed since the
sl@0: 	 *    time when the event was queued, so AND the ready mask with the
sl@0: 	 *    desired mask.
sl@0: 	 * 2. The file could have been closed and re-opened since the time
sl@0: 	 *    when the event was queued. This is why the ready mask is stored
sl@0: 	 *    in the file handler rather than the queued event: it will be
sl@0: 	 *    zeroed when a new file handler is created for the newly opened
sl@0: 	 *    file.
sl@0: 	 */
sl@0: 
sl@0: 	mask = filePtr->readyMask & filePtr->mask;
sl@0: 	filePtr->readyMask = 0;
sl@0: 	if (mask != 0) {
sl@0: 	    (*filePtr->proc)(filePtr->clientData, mask);
sl@0: 	}
sl@0: 	break;
sl@0:     }
sl@0:     return 1;
sl@0: }
sl@0: 
sl@0: /*
sl@0:  *----------------------------------------------------------------------
sl@0:  *
sl@0:  * Tcl_WaitForEvent --
sl@0:  *
sl@0:  *	This function is called by Tcl_DoOneEvent to wait for new events on
sl@0:  *	the message queue. If the block time is 0, then Tcl_WaitForEvent just
sl@0:  *	polls without blocking.
sl@0:  *
sl@0:  * Results:
sl@0:  *	Returns -1 if the select would block forever, otherwise returns 0.
sl@0:  *
sl@0:  * Side effects:
sl@0:  *	Queues file events that are detected by the select.
sl@0:  *
sl@0:  *----------------------------------------------------------------------
sl@0:  */
sl@0: 
sl@0: int
sl@0: Tcl_WaitForEvent(
sl@0:     Tcl_Time *timePtr)		/* Maximum block time, or NULL. */
sl@0: {
sl@0:     FileHandler *filePtr;
sl@0:     FileHandlerEvent *fileEvPtr;
sl@0:     int mask;
sl@0:     int waitForFiles;
sl@0:     ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
sl@0: 
sl@0:     if (tclStubs.tcl_WaitForEvent != tclOriginalNotifier.waitForEventProc) {
sl@0: 	return tclStubs.tcl_WaitForEvent(timePtr);
sl@0:     }
sl@0: 
sl@0:     /*
sl@0:      * Start notifier thread if necessary.
sl@0:      */
sl@0: 
sl@0:     LOCK_NOTIFIER_INIT;
sl@0:     if (!notifierCount) {
sl@0:         Tcl_Panic("Tcl_WaitForEvent: notifier not initialized");
sl@0:     }
sl@0:     if (!notifierThread) {
sl@0: 	int result;
sl@0: 	pthread_attr_t attr;
sl@0: 
sl@0: 	pthread_attr_init(&attr);
sl@0: 	pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM);
sl@0: 	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
sl@0: 	pthread_attr_setstacksize(&attr, 60 * 1024);
sl@0: 	result = pthread_create(&notifierThread, &attr,
sl@0: 		(void * (*)(void *))NotifierThreadProc, NULL);
sl@0: 	pthread_attr_destroy(&attr);
sl@0: 	if (result || !notifierThread) {
sl@0: 	    Tcl_Panic("Tcl_WaitForEvent: unable to start notifier thread");
sl@0: 	}
sl@0:     }
sl@0:     UNLOCK_NOTIFIER_INIT;
sl@0: 
sl@0:     /*
sl@0:      * Place this thread on the list of interested threads, signal the
sl@0:      * notifier thread, and wait for a response or a timeout.
sl@0:      */
sl@0: 
sl@0:     LOCK_NOTIFIER;
sl@0:     if (!tsdPtr->runLoop) {
sl@0:         Tcl_Panic("Tcl_WaitForEvent: CFRunLoop not initialized");
sl@0:     }
sl@0:     waitForFiles = (tsdPtr->numFdBits > 0);
sl@0:     if (timePtr != NULL && timePtr->sec == 0 && timePtr->usec == 0) {
sl@0: 	/*
sl@0: 	 * Cannot emulate a polling select with a polling condition variable.
sl@0: 	 * Instead, pretend to wait for files and tell the notifier thread
sl@0: 	 * what we are doing. The notifier thread makes sure it goes through
sl@0: 	 * select with its select mask in the same state as ours currently is.
sl@0: 	 * We block until that happens.
sl@0: 	 */
sl@0: 
sl@0: 	waitForFiles = 1;
sl@0: 	tsdPtr->pollState = POLL_WANT;
sl@0: 	timePtr = NULL;
sl@0:     } else {
sl@0: 	tsdPtr->pollState = 0;
sl@0:     }
sl@0: 
sl@0:     if (waitForFiles) {
sl@0: 	/*
sl@0: 	 * Add the ThreadSpecificData structure of this thread to the list of
sl@0: 	 * ThreadSpecificData structures of all threads that are waiting on
sl@0: 	 * file events.
sl@0: 	 */
sl@0: 
sl@0: 	tsdPtr->nextPtr = waitingListPtr;
sl@0: 	if (waitingListPtr) {
sl@0: 	    waitingListPtr->prevPtr = tsdPtr;
sl@0: 	}
sl@0: 	tsdPtr->prevPtr = 0;
sl@0: 	waitingListPtr = tsdPtr;
sl@0: 	tsdPtr->onList = 1;
sl@0: 
sl@0: 	write(triggerPipe, "", 1);
sl@0:     }
sl@0: 
sl@0:     FD_ZERO(&(tsdPtr->readyMasks.readable));
sl@0:     FD_ZERO(&(tsdPtr->readyMasks.writable));
sl@0:     FD_ZERO(&(tsdPtr->readyMasks.exceptional));
sl@0: 
sl@0:     if (!tsdPtr->eventReady) {
sl@0: 	CFTimeInterval waitTime;
sl@0: 	CFStringRef runLoopMode;
sl@0: 
sl@0: 	if (timePtr == NULL) {
sl@0: 	    waitTime = 1.0e10; /* Wait forever, as per CFRunLoop.c */
sl@0: 	} else {
sl@0: 	    waitTime = timePtr->sec + 1.0e-6 * timePtr->usec;
sl@0: 	}
sl@0: 	/*
sl@0: 	 * If the run loop is already running (e.g. if Tcl_WaitForEvent was
sl@0: 	 * called recursively), re-run it in a custom run loop mode containing
sl@0: 	 * only the source for the notifier thread, otherwise wakeups from other
sl@0: 	 * sources added to the common run loop modes might get lost.
sl@0: 	 */
sl@0: 	if ((runLoopMode = CFRunLoopCopyCurrentMode(tsdPtr->runLoop))) {
sl@0: 	    CFRelease(runLoopMode);
sl@0: 	    runLoopMode = tclEventsOnlyRunLoopMode;
sl@0: 	} else {
sl@0: 	    runLoopMode = kCFRunLoopDefaultMode;
sl@0: 	}
sl@0: 	UNLOCK_NOTIFIER;
sl@0: 	CFRunLoopRunInMode(runLoopMode, waitTime, TRUE);
sl@0: 	LOCK_NOTIFIER;
sl@0:     }
sl@0:     tsdPtr->eventReady = 0;
sl@0: 
sl@0:     if (waitForFiles && tsdPtr->onList) {
sl@0: 	/*
sl@0: 	 * Remove the ThreadSpecificData structure of this thread from the
sl@0: 	 * waiting list. Alert the notifier thread to recompute its select
sl@0: 	 * masks - skipping this caused a hang when trying to close a pipe
sl@0: 	 * which the notifier thread was still doing a select on.
sl@0: 	 */
sl@0: 
sl@0: 	if (tsdPtr->prevPtr) {
sl@0: 	    tsdPtr->prevPtr->nextPtr = tsdPtr->nextPtr;
sl@0: 	} else {
sl@0: 	    waitingListPtr = tsdPtr->nextPtr;
sl@0: 	}
sl@0: 	if (tsdPtr->nextPtr) {
sl@0: 	    tsdPtr->nextPtr->prevPtr = tsdPtr->prevPtr;
sl@0: 	}
sl@0: 	tsdPtr->nextPtr = tsdPtr->prevPtr = NULL;
sl@0: 	tsdPtr->onList = 0;
sl@0: 	write(triggerPipe, "", 1);
sl@0:     }
sl@0: 
sl@0:     /*
sl@0:      * Queue all detected file events before returning.
sl@0:      */
sl@0: 
sl@0:     for (filePtr = tsdPtr->firstFileHandlerPtr; (filePtr != NULL);
sl@0: 	    filePtr = filePtr->nextPtr) {
sl@0: 
sl@0: 	mask = 0;
sl@0: 	if (FD_ISSET(filePtr->fd, &(tsdPtr->readyMasks.readable))) {
sl@0: 	    mask |= TCL_READABLE;
sl@0: 	}
sl@0: 	if (FD_ISSET(filePtr->fd, &(tsdPtr->readyMasks.writable))) {
sl@0: 	    mask |= TCL_WRITABLE;
sl@0: 	}
sl@0: 	if (FD_ISSET(filePtr->fd, &(tsdPtr->readyMasks.exceptional))) {
sl@0: 	    mask |= TCL_EXCEPTION;
sl@0: 	}
sl@0: 
sl@0: 	if (!mask) {
sl@0: 	    continue;
sl@0: 	}
sl@0: 
sl@0: 	/*
sl@0: 	 * Don't bother to queue an event if the mask was previously non-zero
sl@0: 	 * since an event must still be on the queue.
sl@0: 	 */
sl@0: 
sl@0: 	if (filePtr->readyMask == 0) {
sl@0: 	    fileEvPtr = (FileHandlerEvent *) ckalloc(sizeof(FileHandlerEvent));
sl@0: 	    fileEvPtr->header.proc = FileHandlerEventProc;
sl@0: 	    fileEvPtr->fd = filePtr->fd;
sl@0: 	    Tcl_QueueEvent((Tcl_Event *) fileEvPtr, TCL_QUEUE_TAIL);
sl@0: 	}
sl@0: 	filePtr->readyMask = mask;
sl@0:     }
sl@0:     UNLOCK_NOTIFIER;
sl@0:     return 0;
sl@0: }
sl@0: 
sl@0: /*
sl@0:  *----------------------------------------------------------------------
sl@0:  *
sl@0:  * NotifierThreadProc --
sl@0:  *
sl@0:  *	This routine is the initial (and only) function executed by the
sl@0:  *	special notifier thread. Its job is to wait for file descriptors to
sl@0:  *	become readable or writable or to have an exception condition and then
sl@0:  *	to notify other threads who are interested in this information by
sl@0:  *	signalling a condition variable. Other threads can signal this
sl@0:  *	notifier thread of a change in their interests by writing a single
sl@0:  *	byte to a special pipe that the notifier thread is monitoring.
sl@0:  *
sl@0:  * Result:
sl@0:  *	None. Once started, this routine never exits. It dies with the overall
sl@0:  *	process.
sl@0:  *
sl@0:  * Side effects:
sl@0:  *	The trigger pipe used to signal the notifier thread is created when
sl@0:  *	the notifier thread first starts.
sl@0:  *
sl@0:  *----------------------------------------------------------------------
sl@0:  */
sl@0: 
sl@0: static void
sl@0: NotifierThreadProc(
sl@0:     ClientData clientData)	/* Not used. */
sl@0: {
sl@0:     ThreadSpecificData *tsdPtr;
sl@0:     fd_set readableMask;
sl@0:     fd_set writableMask;
sl@0:     fd_set exceptionalMask;
sl@0:     int i, numFdBits = 0;
sl@0:     long found;
sl@0:     struct timeval poll = {0., 0.}, *timePtr;
sl@0:     char buf[2];
sl@0: 
sl@0:     /*
sl@0:      * Look for file events and report them to interested threads.
sl@0:      */
sl@0: 
sl@0:     while (1) {
sl@0: 	FD_ZERO(&readableMask);
sl@0: 	FD_ZERO(&writableMask);
sl@0: 	FD_ZERO(&exceptionalMask);
sl@0: 
sl@0: 	/*
sl@0: 	 * Compute the logical OR of the select masks from all the waiting
sl@0: 	 * notifiers.
sl@0: 	 */
sl@0: 
sl@0: 	LOCK_NOTIFIER;
sl@0: 	timePtr = NULL;
sl@0: 	for (tsdPtr = waitingListPtr; tsdPtr; tsdPtr = tsdPtr->nextPtr) {
sl@0: 	    for (i = tsdPtr->numFdBits-1; i >= 0; --i) {
sl@0: 		if (FD_ISSET(i, &(tsdPtr->checkMasks.readable))) {
sl@0: 		    FD_SET(i, &readableMask);
sl@0: 		}
sl@0: 		if (FD_ISSET(i, &(tsdPtr->checkMasks.writable))) {
sl@0: 		    FD_SET(i, &writableMask);
sl@0: 		}
sl@0: 		if (FD_ISSET(i, &(tsdPtr->checkMasks.exceptional))) {
sl@0: 		    FD_SET(i, &exceptionalMask);
sl@0: 		}
sl@0: 	    }
sl@0: 	    if (tsdPtr->numFdBits > numFdBits) {
sl@0: 		numFdBits = tsdPtr->numFdBits;
sl@0: 	    }
sl@0: 	    if (tsdPtr->pollState & POLL_WANT) {
sl@0: 		/*
sl@0: 		 * Here we make sure we go through select() with the same mask
sl@0: 		 * bits that were present when the thread tried to poll.
sl@0: 		 */
sl@0: 
sl@0: 		tsdPtr->pollState |= POLL_DONE;
sl@0: 		timePtr = &poll;
sl@0: 	    }
sl@0: 	}
sl@0: 	UNLOCK_NOTIFIER;
sl@0: 
sl@0: 	/*
sl@0: 	 * Set up the select mask to include the receive pipe.
sl@0: 	 */
sl@0: 
sl@0: 	if (receivePipe >= numFdBits) {
sl@0: 	    numFdBits = receivePipe + 1;
sl@0: 	}
sl@0: 	FD_SET(receivePipe, &readableMask);
sl@0: 
sl@0: 	if (select(numFdBits, &readableMask, &writableMask, &exceptionalMask,
sl@0: 		timePtr) == -1) {
sl@0: 	    /*
sl@0: 	     * Try again immediately on an error.
sl@0: 	     */
sl@0: 
sl@0: 	    continue;
sl@0: 	}
sl@0: 
sl@0: 	/*
sl@0: 	 * Alert any threads that are waiting on a ready file descriptor.
sl@0: 	 */
sl@0: 
sl@0: 	LOCK_NOTIFIER;
sl@0: 	for (tsdPtr = waitingListPtr; tsdPtr; tsdPtr = tsdPtr->nextPtr) {
sl@0: 	    found = 0;
sl@0: 
sl@0: 	    for (i = tsdPtr->numFdBits-1; i >= 0; --i) {
sl@0: 		if (FD_ISSET(i, &(tsdPtr->checkMasks.readable))
sl@0: 			&& FD_ISSET(i, &readableMask)) {
sl@0: 		    FD_SET(i, &(tsdPtr->readyMasks.readable));
sl@0: 		    found = 1;
sl@0: 		}
sl@0: 		if (FD_ISSET(i, &(tsdPtr->checkMasks.writable))
sl@0: 			&& FD_ISSET(i, &writableMask)) {
sl@0: 		    FD_SET(i, &(tsdPtr->readyMasks.writable));
sl@0: 		    found = 1;
sl@0: 		}
sl@0: 		if (FD_ISSET(i, &(tsdPtr->checkMasks.exceptional))
sl@0: 			&& FD_ISSET(i, &exceptionalMask)) {
sl@0: 		    FD_SET(i, &(tsdPtr->readyMasks.exceptional));
sl@0: 		    found = 1;
sl@0: 		}
sl@0: 	    }
sl@0: 
sl@0: 	    if (found || (tsdPtr->pollState & POLL_DONE)) {
sl@0: 		tsdPtr->eventReady = 1;
sl@0: 		if (tsdPtr->onList) {
sl@0: 		    /*
sl@0: 		     * Remove the ThreadSpecificData structure of this thread
sl@0: 		     * from the waiting list. This prevents us from
sl@0: 		     * continuously spining on select until the other threads
sl@0: 		     * runs and services the file event.
sl@0: 		     */
sl@0: 
sl@0: 		    if (tsdPtr->prevPtr) {
sl@0: 			tsdPtr->prevPtr->nextPtr = tsdPtr->nextPtr;
sl@0: 		    } else {
sl@0: 			waitingListPtr = tsdPtr->nextPtr;
sl@0: 		    }
sl@0: 		    if (tsdPtr->nextPtr) {
sl@0: 			tsdPtr->nextPtr->prevPtr = tsdPtr->prevPtr;
sl@0: 		    }
sl@0: 		    tsdPtr->nextPtr = tsdPtr->prevPtr = NULL;
sl@0: 		    tsdPtr->onList = 0;
sl@0: 		    tsdPtr->pollState = 0;
sl@0: 		}
sl@0: 		if (tsdPtr->runLoop) {
sl@0: 		    CFRunLoopSourceSignal(tsdPtr->runLoopSource);
sl@0: 		    CFRunLoopWakeUp(tsdPtr->runLoop);
sl@0: 		}
sl@0: 	    }
sl@0: 	}
sl@0: 	UNLOCK_NOTIFIER;
sl@0: 
sl@0: 	/*
sl@0: 	 * Consume the next byte from the notifier pipe if the pipe was
sl@0: 	 * readable. Note that there may be multiple bytes pending, but to
sl@0: 	 * avoid a race condition we only read one at a time.
sl@0: 	 */
sl@0: 
sl@0: 	if (FD_ISSET(receivePipe, &readableMask)) {
sl@0: 	    i = read(receivePipe, buf, 1);
sl@0: 
sl@0: 	    if ((i == 0) || ((i == 1) && (buf[0] == 'q'))) {
sl@0: 		/*
sl@0: 		 * Someone closed the write end of the pipe or sent us a Quit
sl@0: 		 * message [Bug: 4139] and then closed the write end of the
sl@0: 		 * pipe so we need to shut down the notifier thread.
sl@0: 		 */
sl@0: 
sl@0: 		break;
sl@0: 	    }
sl@0: 	}
sl@0:     }
sl@0:     pthread_exit(0);
sl@0: }
sl@0: 
sl@0: #ifdef HAVE_PTHREAD_ATFORK
sl@0: /*
sl@0:  *----------------------------------------------------------------------
sl@0:  *
sl@0:  * AtForkPrepare --
sl@0:  *
sl@0:  *	Lock the notifier in preparation for a fork.
sl@0:  *
sl@0:  * Results:
sl@0:  *	None.
sl@0:  *
sl@0:  * Side effects:
sl@0:  *	None.
sl@0:  *
sl@0:  *----------------------------------------------------------------------
sl@0:  */
sl@0: 
sl@0: static void
sl@0: AtForkPrepare(void)
sl@0: {
sl@0:     LOCK_NOTIFIER_INIT;
sl@0:     LOCK_NOTIFIER;
sl@0: }
sl@0: 
sl@0: /*
sl@0:  *----------------------------------------------------------------------
sl@0:  *
sl@0:  * AtForkParent --
sl@0:  *
sl@0:  *	Unlock the notifier in the parent after a fork.
sl@0:  *
sl@0:  * Results:
sl@0:  *	None.
sl@0:  *
sl@0:  * Side effects:
sl@0:  *	None.
sl@0:  *
sl@0:  *----------------------------------------------------------------------
sl@0:  */
sl@0: 
sl@0: static void
sl@0: AtForkParent(void)
sl@0: {
sl@0:     UNLOCK_NOTIFIER;
sl@0:     UNLOCK_NOTIFIER_INIT;
sl@0: }
sl@0: 
sl@0: /*
sl@0:  *----------------------------------------------------------------------
sl@0:  *
sl@0:  * AtForkChild --
sl@0:  *
sl@0:  *	Unlock and reinstall the notifier in the child after a fork.
sl@0:  *
sl@0:  * Results:
sl@0:  *	None.
sl@0:  *
sl@0:  * Side effects:
sl@0:  *	None.
sl@0:  *
sl@0:  *----------------------------------------------------------------------
sl@0:  */
sl@0: 
sl@0: static void
sl@0: AtForkChild(void)
sl@0: {
sl@0:     ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
sl@0: 
sl@0:     UNLOCK_NOTIFIER;
sl@0:     UNLOCK_NOTIFIER_INIT;
sl@0:     if (tsdPtr->runLoop) {
sl@0: 	tsdPtr->runLoop = NULL;
sl@0: 	CFRunLoopSourceInvalidate(tsdPtr->runLoopSource);
sl@0: 	CFRelease(tsdPtr->runLoopSource);
sl@0: 	tsdPtr->runLoopSource = NULL;
sl@0:     }
sl@0:     if (notifierCount > 0) {
sl@0: 	notifierCount = 0;
sl@0: 
sl@0: 	/*
sl@0: 	 * Assume that the return value of Tcl_InitNotifier in the child will
sl@0: 	 * be identical to the one stored as clientData in tclNotify.c's
sl@0: 	 * ThreadSpecificData by the parent's TclInitNotifier, so discard the
sl@0: 	 * return value here. This assumption may require the fork() to be
sl@0: 	 * executed in the main thread of the parent, otherwise
sl@0: 	 * Tcl_AlertNotifier may break in the child.
sl@0: 	 */
sl@0: 
sl@0: 	Tcl_InitNotifier();
sl@0:     }
sl@0: }
sl@0: #endif /* HAVE_PTHREAD_ATFORK */
sl@0: 
sl@0: #endif /* HAVE_COREFOUNDATION */