/*
* tclMacOSXNotify.c --
*
* This file contains the implementation of a merged CFRunLoop/select()
* based notifier, which is the lowest-level part of the Tcl event loop.
* This file works together with generic/tclNotify.c.
*
* Copyright (c) 1995-1997 Sun Microsystems, Inc.
* Copyright 2001-2009, Apple Inc.
* Copyright (c) 2005-2009 Daniel A. Steffen <das@users.sourceforge.net>
*
* See the file "license.terms" for information on usage and redistribution of
* this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
* RCS: @(#) $Id: tclMacOSXNotify.c,v 1.18.2.5 2009/08/24 00:27:53 das Exp $
*/
#include "tclInt.h"
#ifdef HAVE_COREFOUNDATION /* Traditional unix select-based notifier is
* in tclUnixNotfy.c */
#include <CoreFoundation/CoreFoundation.h>
#include <pthread.h>
/* #define TCL_MAC_DEBUG_NOTIFIER 1 */
extern TclStubs tclStubs;
extern Tcl_NotifierProcs tclOriginalNotifier;
/*
* We use the Darwin-native spinlock API rather than pthread mutexes for
* notifier locking: this radically simplifies the implementation and lowers
* overhead. Note that these are not pure spinlocks, they employ various
* strategies to back off and relinquish the processor, making them immune to
* most priority-inversion livelocks (c.f. 'man 3 OSSpinLockLock' and Darwin
* sources: xnu/osfmk/{ppc,i386}/commpage/spinlocks.s).
*/
#if defined(HAVE_LIBKERN_OSATOMIC_H) && defined(HAVE_OSSPINLOCKLOCK)
/*
* Use OSSpinLock API where available (Tiger or later).
*/
#include <libkern/OSAtomic.h>
#if defined(HAVE_WEAK_IMPORT) && MAC_OS_X_VERSION_MIN_REQUIRED < 1040
/*
* Support for weakly importing spinlock API.
*/
#define WEAK_IMPORT_SPINLOCKLOCK
#if MAC_OS_X_VERSION_MAX_ALLOWED >= 1050
#define VOLATILE volatile
#else
#define VOLATILE
#endif
#ifndef bool
#define bool int
#endif
extern void OSSpinLockLock(VOLATILE OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE;
extern void OSSpinLockUnlock(VOLATILE OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE;
extern bool OSSpinLockTry(VOLATILE OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE;
extern void _spin_lock(VOLATILE OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE;
extern void _spin_unlock(VOLATILE OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE;
extern bool _spin_lock_try(VOLATILE OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE;
static void (* lockLock)(VOLATILE OSSpinLock *lock) = NULL;
static void (* lockUnlock)(VOLATILE OSSpinLock *lock) = NULL;
static bool (* lockTry)(VOLATILE OSSpinLock *lock) = NULL;
#undef VOLATILE
static pthread_once_t spinLockLockInitControl = PTHREAD_ONCE_INIT;
static void SpinLockLockInit(void) {
lockLock = OSSpinLockLock != NULL ? OSSpinLockLock : _spin_lock;
lockUnlock = OSSpinLockUnlock != NULL ? OSSpinLockUnlock : _spin_unlock;
lockTry = OSSpinLockTry != NULL ? OSSpinLockTry : _spin_lock_try;
if (lockLock == NULL || lockUnlock == NULL) {
Tcl_Panic("SpinLockLockInit: no spinlock API available");
}
}
#define SpinLockLock(p) lockLock(p)
#define SpinLockUnlock(p) lockUnlock(p)
#define SpinLockTry(p) lockTry(p)
#else
#define SpinLockLock(p) OSSpinLockLock(p)
#define SpinLockUnlock(p) OSSpinLockUnlock(p)
#define SpinLockTry(p) OSSpinLockTry(p)
#endif /* HAVE_WEAK_IMPORT */
#define SPINLOCK_INIT OS_SPINLOCK_INIT
#else
/*
* Otherwise, use commpage spinlock SPI directly.
*/
typedef uint32_t OSSpinLock;
extern void _spin_lock(OSSpinLock *lock);
extern void _spin_unlock(OSSpinLock *lock);
extern int _spin_lock_try(OSSpinLock *lock);
#define SpinLockLock(p) _spin_lock(p)
#define SpinLockUnlock(p) _spin_unlock(p)
#define SpinLockTry(p) _spin_lock_try(p)
#define SPINLOCK_INIT 0
#endif /* HAVE_LIBKERN_OSATOMIC_H && HAVE_OSSPINLOCKLOCK */
/*
* These spinlocks lock access to the global notifier state.
*/
static OSSpinLock notifierInitLock = SPINLOCK_INIT;
static OSSpinLock notifierLock = SPINLOCK_INIT;
/*
* Macros abstracting notifier locking/unlocking
*/
#define LOCK_NOTIFIER_INIT SpinLockLock(¬ifierInitLock)
#define UNLOCK_NOTIFIER_INIT SpinLockUnlock(¬ifierInitLock)
#define LOCK_NOTIFIER SpinLockLock(¬ifierLock)
#define UNLOCK_NOTIFIER SpinLockUnlock(¬ifierLock)
#define LOCK_NOTIFIER_TSD SpinLockLock(&tsdPtr->tsdLock)
#define UNLOCK_NOTIFIER_TSD SpinLockUnlock(&tsdPtr->tsdLock)
#ifdef TCL_MAC_DEBUG_NOTIFIER
#define TclMacOSXNotifierDbgMsg(m, ...) do { \
fprintf(notifierLog?notifierLog:stderr, "tclMacOSXNotify.c:%d: " \
"%s() pid %5d thread %10p: " m "\n", __LINE__, __func__, \
getpid(), pthread_self(), ##__VA_ARGS__); \
fflush(notifierLog?notifierLog:stderr); \
} while (0)
/*
* Debug version of SpinLockLock that logs the time spent waiting for the lock
*/
#define SpinLockLockDbg(p) if (!SpinLockTry(p)) { \
Tcl_WideInt s = TclpGetWideClicks(), e; \
SpinLockLock(p); e = TclpGetWideClicks(); \
TclMacOSXNotifierDbgMsg("waited on %s for %8.0f ns", \
#p, TclpWideClicksToNanoseconds(e-s)); \
}
#undef LOCK_NOTIFIER_INIT
#define LOCK_NOTIFIER_INIT SpinLockLockDbg(¬ifierInitLock)
#undef LOCK_NOTIFIER
#define LOCK_NOTIFIER SpinLockLockDbg(¬ifierLock)
#undef LOCK_NOTIFIER_TSD
#define LOCK_NOTIFIER_TSD SpinLockLockDbg(&tsdPtr->tsdLock)
#include <asl.h>
static FILE *notifierLog = NULL;
#ifndef NOTIFIER_LOG
#define NOTIFIER_LOG "/tmp/tclMacOSXNotify.log"
#endif
#define OPEN_NOTIFIER_LOG if (!notifierLog) { \
notifierLog = fopen(NOTIFIER_LOG, "a"); \
/*TclMacOSXNotifierDbgMsg("open log"); \
asl_set_filter(NULL, \
ASL_FILTER_MASK_UPTO(ASL_LEVEL_DEBUG)); \
asl_add_log_file(NULL, \
fileno(notifierLog));*/ \
}
#define CLOSE_NOTIFIER_LOG if (notifierLog) { \
/*asl_remove_log_file(NULL, \
fileno(notifierLog)); \
TclMacOSXNotifierDbgMsg("close log");*/ \
fclose(notifierLog); \
notifierLog = NULL; \
}
#define ENABLE_ASL if (notifierLog) { \
/*tsdPtr->asl = asl_open(NULL, "com.apple.console", ASL_OPT_NO_REMOTE); \
asl_set_filter(tsdPtr->asl, \
ASL_FILTER_MASK_UPTO(ASL_LEVEL_DEBUG)); \
asl_add_log_file(tsdPtr->asl, \
fileno(notifierLog));*/ \
}
#define DISABLE_ASL /*if (tsdPtr->asl) { \
if (notifierLog) { \
asl_remove_log_file(tsdPtr->asl, \
fileno(notifierLog)); \
} \
asl_close(tsdPtr->asl); \
}*/
#define ASLCLIENT /*aslclient asl*/
#else
#define TclMacOSXNotifierDbgMsg(m, ...)
#define OPEN_NOTIFIER_LOG
#define CLOSE_NOTIFIER_LOG
#define ENABLE_ASL
#define DISABLE_ASL
#endif /* TCL_MAC_DEBUG_NOTIFIER */
/*
* 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 FileHandlerEvent {
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 exceptional conditions.
*/
typedef struct SelectMasks {
fd_set readable;
fd_set writable;
fd_set exceptional;
} 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. */
int polled; /* True if the notifier thread has polled for
* this thread.
*/
int sleeping; /* True if runloop is inside Tcl_Sleep. */
int runLoopSourcePerformed; /* True after the runLoopSource callack was
* performed. */
int runLoopRunning; /* True if this thread's Tcl runLoop is running */
int runLoopNestingLevel; /* Level of nested runLoop invocations */
int runLoopServicingEvents; /* True if this thread's runLoop is servicing
* tcl events */
/* Must hold the notifierLock before accessing the following fields: */
/* Start notifierLock section */
int onList; /* True if this thread is on the waitingList */
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.
*/
/* End notifierLock section */
OSSpinLock tsdLock; /* Must hold this lock before acessing the
* following fields from more than one thread.
*/
/* Start tsdLock section */
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). */
int polling; /* True if this thread is polling for events */
CFRunLoopRef runLoop; /* This thread's CFRunLoop, needs to be woken
* up whenever the runLoopSource is signaled */
CFRunLoopSourceRef runLoopSource;
/* Any other thread alerts a notifier that an
* event is ready to be processed by signaling
* this CFRunLoopSource. */
CFRunLoopObserverRef runLoopObserver, runLoopObserverTcl;
/* Adds/removes this thread from waitingList
* when the CFRunLoop starts/stops. */
CFRunLoopTimerRef runLoopTimer;
/* Wakes up CFRunLoop after given timeout when
* running embedded. */
/* End tsdLock section */
CFTimeInterval waitTime; /* runLoopTimer wait time when running
* embedded. */
#ifdef TCL_MAC_DEBUG_NOTIFIER
ASLCLIENT;
#endif
} ThreadSpecificData;
static Tcl_ThreadDataKey dataKey;
/*
* The following static indicates the number of threads that have initialized
* notifiers.
*
* You must hold the notifierInitLock 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 notifierLock 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 notifierLock lock before writing to the pipe.
*/
static int triggerPipe = -1;
static int receivePipe = -1; /* Output end of triggerPipe */
/*
* The following static indicates if the notifier thread is running.
*
* You must hold the notifierInitLock before accessing this variable.
*/
static int notifierThreadRunning;
/*
* This is the thread ID of the notifier thread that does select.
* Only valid when notifierThreadRunning is non-zero.
*
* You must hold the notifierInitLock before accessing this variable.
*/
static pthread_t notifierThread;
/*
* Custom runloop mode for running with only the runloop source for the
* notifier thread
*/
#ifndef TCL_EVENTS_ONLY_RUN_LOOP_MODE
#define TCL_EVENTS_ONLY_RUN_LOOP_MODE "com.tcltk.tclEventsOnlyRunLoopMode"
#endif
#ifdef __CONSTANT_CFSTRINGS__
#define tclEventsOnlyRunLoopMode CFSTR(TCL_EVENTS_ONLY_RUN_LOOP_MODE)
#else
static CFStringRef tclEventsOnlyRunLoopMode = NULL;
#endif
/*
* CFTimeInterval to wait forever.
*/
#define CF_TIMEINTERVAL_FOREVER 5.05e8
/*
* Static routines defined in this file.
*/
static void StartNotifierThread(void);
static void NotifierThreadProc(ClientData clientData)
__attribute__ ((__noreturn__));
static int FileHandlerEventProc(Tcl_Event *evPtr, int flags);
static void TimerWakeUp(CFRunLoopTimerRef timer, void *info);
static void QueueFileEvents(void *info);
static void UpdateWaitingListAndServiceEvents(CFRunLoopObserverRef observer,
CFRunLoopActivity activity, void *info);
static int OnOffWaitingList(ThreadSpecificData *tsdPtr, int onList,
int signalNotifier);
#ifdef HAVE_PTHREAD_ATFORK
static int atForkInit = 0;
static void AtForkPrepare(void);
static void AtForkParent(void);
static void AtForkChild(void);
#if defined(HAVE_WEAK_IMPORT) && MAC_OS_X_VERSION_MIN_REQUIRED < 1040
/* Support for weakly importing pthread_atfork. */
#define WEAK_IMPORT_PTHREAD_ATFORK
extern int pthread_atfork(void (*prepare)(void), void (*parent)(void),
void (*child)(void)) WEAK_IMPORT_ATTRIBUTE;
#endif /* HAVE_WEAK_IMPORT */
/*
* On Darwin 9 and later, it is not possible to call CoreFoundation after
* a fork.
*/
#if !defined(MAC_OS_X_VERSION_MIN_REQUIRED) || \
MAC_OS_X_VERSION_MIN_REQUIRED < 1050
MODULE_SCOPE long tclMacOSXDarwinRelease;
#define noCFafterFork (tclMacOSXDarwinRelease >= 9)
#else /* MAC_OS_X_VERSION_MIN_REQUIRED */
#define noCFafterFork 1
#endif /* MAC_OS_X_VERSION_MIN_REQUIRED */
#endif /* HAVE_PTHREAD_ATFORK */
/*
*----------------------------------------------------------------------
*
* 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)
{
ThreadSpecificData *tsdPtr;
tsdPtr = TCL_TSD_INIT(&dataKey);
#ifdef WEAK_IMPORT_SPINLOCKLOCK
/*
* Initialize support for weakly imported spinlock API.
*/
if (pthread_once(&spinLockLockInitControl, SpinLockLockInit)) {
Tcl_Panic("Tcl_InitNotifier: pthread_once failed");
}
#endif
#ifndef __CONSTANT_CFSTRINGS__
if (!tclEventsOnlyRunLoopMode) {
tclEventsOnlyRunLoopMode = CFSTR(TCL_EVENTS_ONLY_RUN_LOOP_MODE);
}
#endif
/*
* Initialize CFRunLoopSource and add it to CFRunLoop of this thread.
*/
if (!tsdPtr->runLoop) {
CFRunLoopRef runLoop = CFRunLoopGetCurrent();
CFRunLoopSourceRef runLoopSource;
CFRunLoopSourceContext runLoopSourceContext;
CFRunLoopObserverContext runLoopObserverContext;
CFRunLoopObserverRef runLoopObserver, runLoopObserverTcl;
bzero(&runLoopSourceContext, sizeof(CFRunLoopSourceContext));
runLoopSourceContext.info = tsdPtr;
runLoopSourceContext.perform = QueueFileEvents;
runLoopSource = CFRunLoopSourceCreate(NULL, LONG_MIN,
&runLoopSourceContext);
if (!runLoopSource) {
Tcl_Panic("Tcl_InitNotifier: could not create CFRunLoopSource");
}
CFRunLoopAddSource(runLoop, runLoopSource, kCFRunLoopCommonModes);
CFRunLoopAddSource(runLoop, runLoopSource, tclEventsOnlyRunLoopMode);
bzero(&runLoopObserverContext, sizeof(CFRunLoopObserverContext));
runLoopObserverContext.info = tsdPtr;
runLoopObserver = CFRunLoopObserverCreate(NULL,
kCFRunLoopEntry|kCFRunLoopExit|kCFRunLoopBeforeWaiting, TRUE,
LONG_MIN, UpdateWaitingListAndServiceEvents,
&runLoopObserverContext);
if (!runLoopObserver) {
Tcl_Panic("Tcl_InitNotifier: could not create "
"CFRunLoopObserver");
}
CFRunLoopAddObserver(runLoop, runLoopObserver, kCFRunLoopCommonModes);
/*
* Create a second CFRunLoopObserver with the same callback as above
* for the tclEventsOnlyRunLoopMode to ensure that the callback can be
* re-entered via Tcl_ServiceAll() in the kCFRunLoopBeforeWaiting case
* (CFRunLoop prevents observer callback re-entry of a given observer
* instance).
*/
runLoopObserverTcl = CFRunLoopObserverCreate(NULL,
kCFRunLoopEntry|kCFRunLoopExit|kCFRunLoopBeforeWaiting, TRUE,
LONG_MIN, UpdateWaitingListAndServiceEvents,
&runLoopObserverContext);
if (!runLoopObserverTcl) {
Tcl_Panic("Tcl_InitNotifier: could not create "
"CFRunLoopObserver");
}
CFRunLoopAddObserver(runLoop, runLoopObserverTcl,
tclEventsOnlyRunLoopMode);
tsdPtr->runLoop = runLoop;
tsdPtr->runLoopSource = runLoopSource;
tsdPtr->runLoopObserver = runLoopObserver;
tsdPtr->runLoopObserverTcl = runLoopObserverTcl;
tsdPtr->runLoopTimer = NULL;
tsdPtr->waitTime = CF_TIMEINTERVAL_FOREVER;
tsdPtr->tsdLock = SPINLOCK_INIT;
}
LOCK_NOTIFIER_INIT;
#ifdef HAVE_PTHREAD_ATFORK
/*
* Install pthread_atfork handlers to reinitialize the notifier in the
* child of a fork.
*/
if (
#ifdef WEAK_IMPORT_PTHREAD_ATFORK
pthread_atfork != NULL &&
#endif
!atForkInit) {
int result = pthread_atfork(AtForkPrepare, AtForkParent, AtForkChild);
if (result) {
Tcl_Panic("Tcl_InitNotifier: pthread_atfork failed");
}
atForkInit = 1;
}
#endif
if (notifierCount == 0) {
int fds[2], status;
/*
* Initialize trigger pipe.
*/
if (pipe(fds) != 0) {
Tcl_Panic("Tcl_InitNotifier: could not create trigger pipe");
}
status = fcntl(fds[0], F_GETFL);
status |= O_NONBLOCK;
if (fcntl(fds[0], F_SETFL, status) < 0) {
Tcl_Panic("Tcl_InitNotifier: could not make receive pipe non "
"blocking");
}
status = fcntl(fds[1], F_GETFL);
status |= O_NONBLOCK;
if (fcntl(fds[1], F_SETFL, status) < 0) {
Tcl_Panic("Tcl_InitNotifier: could not make trigger pipe non "
"blocking");
}
receivePipe = fds[0];
triggerPipe = fds[1];
/*
* Create notifier thread lazily in Tcl_WaitForEvent() to avoid
* interfering with fork() followed immediately by execve() (we cannot
* execve() when more than one thread is present).
*/
notifierThreadRunning = 0;
OPEN_NOTIFIER_LOG;
}
ENABLE_ASL;
notifierCount++;
UNLOCK_NOTIFIER_INIT;
return (ClientData) tsdPtr;
}
/*
*----------------------------------------------------------------------
*
* TclMacOSXNotifierAddRunLoopMode --
*
* Add the tcl notifier RunLoop source, observer and timer (if any)
* to the given RunLoop mode.
*
* Results:
* None.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
void
TclMacOSXNotifierAddRunLoopMode(
CONST void *runLoopMode)
{
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
CFStringRef mode = (CFStringRef) runLoopMode;
if (tsdPtr->runLoop) {
CFRunLoopAddSource(tsdPtr->runLoop, tsdPtr->runLoopSource, mode);
CFRunLoopAddObserver(tsdPtr->runLoop, tsdPtr->runLoopObserver, mode);
if (tsdPtr->runLoopTimer) {
CFRunLoopAddTimer(tsdPtr->runLoop, tsdPtr->runLoopTimer, mode);
}
}
}
/*
*----------------------------------------------------------------------
*
* StartNotifierThread --
*
* Start notifier thread if necessary.
*
* Results:
* None.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static void
StartNotifierThread(void)
{
LOCK_NOTIFIER_INIT;
if (!notifierCount) {
Tcl_Panic("StartNotifierThread: notifier not initialized");
}
if (!notifierThreadRunning) {
int result;
pthread_attr_t attr;
pthread_attr_init(&attr);
pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM);
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
pthread_attr_setstacksize(&attr, 60 * 1024);
result = pthread_create(¬ifierThread, &attr,
(void * (*)(void *))NotifierThreadProc, NULL);
pthread_attr_destroy(&attr);
if (result) {
Tcl_Panic("StartNotifierThread: unable to start notifier thread");
}
notifierThreadRunning = 1;
}
UNLOCK_NOTIFIER_INIT;
}
/*
*----------------------------------------------------------------------
*
* 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. */
{
ThreadSpecificData *tsdPtr;
tsdPtr = TCL_TSD_INIT(&dataKey);
LOCK_NOTIFIER_INIT;
notifierCount--;
DISABLE_ASL;
/*
* 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) {
/*
* Send "q" message to the notifier thread so that it will
* terminate. The notifier will return from its call to select()
* and notice that a "q" message has arrived, it will then close
* its side of the pipe and terminate its thread. Note the we can
* not just close the pipe and check for EOF in the notifier thread
* because if a background child process was created with exec,
* select() would not register the EOF on the pipe until the child
* processes had terminated. [Bug: 4139] [Bug: 1222872]
*/
write(triggerPipe, "q", 1);
close(triggerPipe);
if (notifierThreadRunning) {
int result = pthread_join(notifierThread, NULL);
if (result) {
Tcl_Panic("Tcl_FinalizeNotifier: unable to join notifier "
"thread");
}
notifierThreadRunning = 0;
}
close(receivePipe);
triggerPipe = -1;
}
CLOSE_NOTIFIER_LOG;
}
UNLOCK_NOTIFIER_INIT;
LOCK_NOTIFIER_TSD; /* For concurrency with Tcl_AlertNotifier */
if (tsdPtr->runLoop) {
tsdPtr->runLoop = NULL;
/*
* Remove runLoopSource, runLoopObserver and runLoopTimer from all
* CFRunLoops.
*/
CFRunLoopSourceInvalidate(tsdPtr->runLoopSource);
CFRelease(tsdPtr->runLoopSource);
tsdPtr->runLoopSource = NULL;
CFRunLoopObserverInvalidate(tsdPtr->runLoopObserver);
CFRelease(tsdPtr->runLoopObserver);
tsdPtr->runLoopObserver = NULL;
CFRunLoopObserverInvalidate(tsdPtr->runLoopObserverTcl);
CFRelease(tsdPtr->runLoopObserverTcl);
tsdPtr->runLoopObserverTcl = NULL;
if (tsdPtr->runLoopTimer) {
CFRunLoopTimerInvalidate(tsdPtr->runLoopTimer);
CFRelease(tsdPtr->runLoopTimer);
tsdPtr->runLoopTimer = NULL;
}
}
UNLOCK_NOTIFIER_TSD;
}
/*
*----------------------------------------------------------------------
*
* Tcl_AlertNotifier --
*
* Wake up the specified notifier from any thread. This routine is called
* by the platform independent notifier code whenever the Tcl_ThreadAlert
* routine is called. This routine is guaranteed not to be called on a
* given notifier after Tcl_FinalizeNotifier is called for that notifier.
*
* Results:
* None.
*
* Side effects:
* Signals the notifier condition variable for the specified notifier.
*
*----------------------------------------------------------------------
*/
void
Tcl_AlertNotifier(
ClientData clientData)
{
ThreadSpecificData *tsdPtr = clientData;
LOCK_NOTIFIER_TSD;
if (tsdPtr->runLoop) {
CFRunLoopSourceSignal(tsdPtr->runLoopSource);
CFRunLoopWakeUp(tsdPtr->runLoop);
}
UNLOCK_NOTIFIER_TSD;
}
/*
*----------------------------------------------------------------------
*
* Tcl_SetTimer --
*
* This function sets the current notifier timer value.
*
* Results:
* None.
*
* Side effects:
* Replaces any previous timer.
*
*----------------------------------------------------------------------
*/
void
Tcl_SetTimer(
Tcl_Time *timePtr) /* Timeout value, may be NULL. */
{
ThreadSpecificData *tsdPtr;
CFRunLoopTimerRef runLoopTimer;
CFTimeInterval waitTime;
if (tclStubs.tcl_SetTimer != tclOriginalNotifier.setTimerProc) {
tclStubs.tcl_SetTimer(timePtr);
return;
}
tsdPtr = TCL_TSD_INIT(&dataKey);
runLoopTimer = tsdPtr->runLoopTimer;
if (!runLoopTimer) {
return;
}
if (timePtr) {
Tcl_Time vTime = *timePtr;
if (vTime.sec != 0 || vTime.usec != 0) {
tclScaleTimeProcPtr(&vTime, tclTimeClientData);
waitTime = vTime.sec + 1.0e-6 * vTime.usec;
} else {
waitTime = 0;
}
} else {
waitTime = CF_TIMEINTERVAL_FOREVER;
}
tsdPtr->waitTime = waitTime;
CFRunLoopTimerSetNextFireDate(runLoopTimer,
CFAbsoluteTimeGetCurrent() + waitTime);
}
/*
*----------------------------------------------------------------------
*
* TimerWakeUp --
*
* CFRunLoopTimer callback.
*
* Results:
* None.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static void
TimerWakeUp(
CFRunLoopTimerRef timer,
void *info)
{
}
/*
*----------------------------------------------------------------------
*
* Tcl_ServiceModeHook --
*
* This function is invoked whenever the service mode changes.
*
* Results:
* None.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
void
Tcl_ServiceModeHook(
int mode) /* Either TCL_SERVICE_ALL, or
* TCL_SERVICE_NONE. */
{
ThreadSpecificData *tsdPtr;
tsdPtr = TCL_TSD_INIT(&dataKey);
if (mode == TCL_SERVICE_ALL && !tsdPtr->runLoopTimer) {
if (!tsdPtr->runLoop) {
Tcl_Panic("Tcl_ServiceModeHook: Notifier not initialized");
}
tsdPtr->runLoopTimer = CFRunLoopTimerCreate(NULL,
CFAbsoluteTimeGetCurrent() + CF_TIMEINTERVAL_FOREVER,
CF_TIMEINTERVAL_FOREVER, 0, 0, TimerWakeUp, NULL);
if (tsdPtr->runLoopTimer) {
CFRunLoopAddTimer(tsdPtr->runLoop, tsdPtr->runLoopTimer,
kCFRunLoopCommonModes);
StartNotifierThread();
}
}
}
/*
*----------------------------------------------------------------------
*
* 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. */
{
ThreadSpecificData *tsdPtr;
FileHandler *filePtr;
if (tclStubs.tcl_CreateFileHandler !=
tclOriginalNotifier.createFileHandlerProc) {
tclStubs.tcl_CreateFileHandler(fd, mask, proc, clientData);
return;
}
tsdPtr = TCL_TSD_INIT(&dataKey);
for (filePtr = tsdPtr->firstFileHandlerPtr; filePtr != NULL;
filePtr = filePtr->nextPtr) {
if (filePtr->fd == fd) {
break;
}
}
if (filePtr == NULL) {
filePtr = (FileHandler *) 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.
*/
LOCK_NOTIFIER_TSD;
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.exceptional));
} else {
FD_CLR(fd, &(tsdPtr->checkMasks.exceptional));
}
if (tsdPtr->numFdBits <= fd) {
tsdPtr->numFdBits = fd+1;
}
UNLOCK_NOTIFIER_TSD;
}
/*
*----------------------------------------------------------------------
*
* 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. */
{
FileHandler *filePtr, *prevPtr;
int i, numFdBits;
ThreadSpecificData *tsdPtr;
if (tclStubs.tcl_DeleteFileHandler !=
tclOriginalNotifier.deleteFileHandlerProc) {
tclStubs.tcl_DeleteFileHandler(fd);
return;
}
tsdPtr = TCL_TSD_INIT(&dataKey);
numFdBits = -1;
/*
* 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;
}
}
/*
* Find current max fd.
*/
if (fd+1 == tsdPtr->numFdBits) {
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.exceptional))) {
numFdBits = i+1;
break;
}
}
}
LOCK_NOTIFIER_TSD;
if (numFdBits != -1) {
tsdPtr->numFdBits = numFdBits;
}
/*
* 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.exceptional));
}
UNLOCK_NOTIFIER_TSD;
/*
* Clean up information in the callback record.
*/
if (prevPtr == NULL) {
tsdPtr->firstFileHandlerPtr = filePtr->nextPtr;
} else {
prevPtr->nextPtr = filePtr->nextPtr;
}
ckfree((char *) filePtr);
}
/*
*----------------------------------------------------------------------
*
* FileHandlerEventProc --
*
* This function is called by Tcl_ServiceEvent when a file event reaches
* the front of the event queue. This function is responsible for
* actually handling the event by invoking the callback for the file
* handler.
*
* Results:
* Returns 1 if the event was handled, meaning it should be removed from
* the queue. Returns 0 if the event was not handled, meaning it should
* stay on the queue. The only time the event isn't handled is if the
* TCL_FILE_EVENTS flag bit isn't set.
*
* Side effects:
* Whatever the file handler's callback function does.
*
*----------------------------------------------------------------------
*/
static int
FileHandlerEventProc(
Tcl_Event *evPtr, /* Event to service. */
int flags) /* Flags that indicate what events to handle,
* such as TCL_FILE_EVENTS. */
{
int mask;
FileHandler *filePtr;
FileHandlerEvent *fileEvPtr = (FileHandlerEvent *) evPtr;
ThreadSpecificData *tsdPtr;
if (!(flags & TCL_FILE_EVENTS)) {
return 0;
}
/*
* Search through the file handlers to find the one whose handle matches
* the event. We do this rather than keeping a pointer to the file handler
* directly in the event, so that the handler can be deleted while the
* event is queued without leaving a dangling pointer.
*/
tsdPtr = TCL_TSD_INIT(&dataKey);
for (filePtr = tsdPtr->firstFileHandlerPtr; filePtr != NULL;
filePtr = filePtr->nextPtr) {
if (filePtr->fd != fileEvPtr->fd) {
continue;
}
/*
* The code is tricky for two reasons:
* 1. The file handler's desired events could have changed since the
* time when the event was queued, so AND the ready mask with the
* desired mask.
* 2. The file could have been closed and re-opened since the time
* when the event was queued. This is why the ready mask is stored
* in the file handler rather than the queued event: it will be
* zeroed when a new file handler is created for the newly opened
* file.
*/
mask = filePtr->readyMask & filePtr->mask;
filePtr->readyMask = 0;
if (mask != 0) {
LOCK_NOTIFIER_TSD;
if (mask & TCL_READABLE) {
FD_CLR(filePtr->fd, &(tsdPtr->readyMasks.readable));
}
if (mask & TCL_WRITABLE) {
FD_CLR(filePtr->fd, &(tsdPtr->readyMasks.writable));
}
if (mask & TCL_EXCEPTION) {
FD_CLR(filePtr->fd, &(tsdPtr->readyMasks.exceptional));
}
UNLOCK_NOTIFIER_TSD;
filePtr->proc(filePtr->clientData, mask);
}
break;
}
return 1;
}
/*
*----------------------------------------------------------------------
*
* 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 0 if a tcl event or timeout ocurred and 1 if a non-tcl
* CFRunLoop source was processed.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
int
Tcl_WaitForEvent(
Tcl_Time *timePtr) /* Maximum block time, or NULL. */
{
int result, polling, runLoopRunning;
CFTimeInterval waitTime;
SInt32 runLoopStatus;
ThreadSpecificData *tsdPtr;
if (tclStubs.tcl_WaitForEvent != tclOriginalNotifier.waitForEventProc) {
return tclStubs.tcl_WaitForEvent(timePtr);
}
result = -1;
polling = 0;
waitTime = CF_TIMEINTERVAL_FOREVER;
tsdPtr = TCL_TSD_INIT(&dataKey);
if (!tsdPtr->runLoop) {
Tcl_Panic("Tcl_WaitForEvent: Notifier not initialized");
}
if (timePtr) {
Tcl_Time vTime = *timePtr;
/*
* 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 (vTime.sec != 0 || vTime.usec != 0) {
tclScaleTimeProcPtr(&vTime, tclTimeClientData);
waitTime = vTime.sec + 1.0e-6 * vTime.usec;
} else {
/*
* Polling: 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.
*/
polling = 1;
}
}
StartNotifierThread();
LOCK_NOTIFIER_TSD;
tsdPtr->polling = polling;
UNLOCK_NOTIFIER_TSD;
tsdPtr->runLoopSourcePerformed = 0;
/*
* If the Tcl runloop is already running (e.g. if Tcl_WaitForEvent was
* called recursively) or is servicing events via the runloop observer,
* re-run it in a custom runloop mode containing only the source for the
* notifier thread, otherwise wakeups from other sources added to the
* common runloop modes might get lost or 3rd party event handlers might
* get called when they do not expect to be.
*/
runLoopRunning = tsdPtr->runLoopRunning;
tsdPtr->runLoopRunning = 1;
runLoopStatus = CFRunLoopRunInMode(tsdPtr->runLoopServicingEvents ||
runLoopRunning ? tclEventsOnlyRunLoopMode : kCFRunLoopDefaultMode,
waitTime, TRUE);
tsdPtr->runLoopRunning = runLoopRunning;
LOCK_NOTIFIER_TSD;
tsdPtr->polling = 0;
UNLOCK_NOTIFIER_TSD;
switch (runLoopStatus) {
case kCFRunLoopRunFinished:
Tcl_Panic("Tcl_WaitForEvent: CFRunLoop finished");
break;
case kCFRunLoopRunTimedOut:
QueueFileEvents(tsdPtr);
result = 0;
break;
case kCFRunLoopRunStopped:
case kCFRunLoopRunHandledSource:
result = tsdPtr->runLoopSourcePerformed ? 0 : 1;
break;
}
return result;
}
/*
*----------------------------------------------------------------------
*
* QueueFileEvents --
*
* CFRunLoopSource callback for queueing file events.
*
* Results:
* None.
*
* Side effects:
* Queues file events that are detected by the select.
*
*----------------------------------------------------------------------
*/
static void
QueueFileEvents(
void *info)
{
SelectMasks readyMasks;
FileHandler *filePtr;
ThreadSpecificData *tsdPtr = (ThreadSpecificData *) info;
/*
* Queue all detected file events.
*/
LOCK_NOTIFIER_TSD;
FD_COPY(&(tsdPtr->readyMasks.readable), &readyMasks.readable);
FD_COPY(&(tsdPtr->readyMasks.writable), &readyMasks.writable);
FD_COPY(&(tsdPtr->readyMasks.exceptional), &readyMasks.exceptional);
FD_ZERO(&(tsdPtr->readyMasks.readable));
FD_ZERO(&(tsdPtr->readyMasks.writable));
FD_ZERO(&(tsdPtr->readyMasks.exceptional));
UNLOCK_NOTIFIER_TSD;
tsdPtr->runLoopSourcePerformed = 1;
for (filePtr = tsdPtr->firstFileHandlerPtr; (filePtr != NULL);
filePtr = filePtr->nextPtr) {
int mask = 0;
if (FD_ISSET(filePtr->fd, &readyMasks.readable)) {
mask |= TCL_READABLE;
}
if (FD_ISSET(filePtr->fd, &readyMasks.writable)) {
mask |= TCL_WRITABLE;
}
if (FD_ISSET(filePtr->fd, &readyMasks.exceptional)) {
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 = (FileHandlerEvent *)
ckalloc(sizeof(FileHandlerEvent));
fileEvPtr->header.proc = FileHandlerEventProc;
fileEvPtr->fd = filePtr->fd;
Tcl_QueueEvent((Tcl_Event *) fileEvPtr, TCL_QUEUE_TAIL);
}
filePtr->readyMask = mask;
}
}
/*
*----------------------------------------------------------------------
*
* UpdateWaitingListAndServiceEvents --
*
* CFRunLoopObserver callback for updating waitingList and
* servicing Tcl events.
*
* Results:
* None.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static void
UpdateWaitingListAndServiceEvents(
CFRunLoopObserverRef observer,
CFRunLoopActivity activity,
void *info)
{
ThreadSpecificData *tsdPtr = (ThreadSpecificData*) info;
if (tsdPtr->sleeping) {
return;
}
switch (activity) {
case kCFRunLoopEntry:
tsdPtr->runLoopNestingLevel++;
if (tsdPtr->numFdBits > 0 || tsdPtr->polling) {
LOCK_NOTIFIER;
if (!OnOffWaitingList(tsdPtr, 1, 1) && tsdPtr->polling) {
write(triggerPipe, "", 1);
}
UNLOCK_NOTIFIER;
}
break;
case kCFRunLoopExit:
if (tsdPtr->runLoopNestingLevel == 1) {
LOCK_NOTIFIER;
OnOffWaitingList(tsdPtr, 0, 1);
UNLOCK_NOTIFIER;
}
tsdPtr->runLoopNestingLevel--;
break;
case kCFRunLoopBeforeWaiting:
if (tsdPtr->runLoopTimer && !tsdPtr->runLoopServicingEvents &&
(tsdPtr->runLoopNestingLevel > 1 || !tsdPtr->runLoopRunning)) {
tsdPtr->runLoopServicingEvents = 1;
while (Tcl_ServiceAll() && tsdPtr->waitTime == 0) {}
tsdPtr->runLoopServicingEvents = 0;
}
break;
default:
break;
}
}
/*
*----------------------------------------------------------------------
*
* OnOffWaitingList --
*
* Add/remove the specified thread to/from the global waitingList
* and optionally signal the notifier.
*
* !!! Requires notifierLock to be held !!!
*
* Results:
* Boolean indicating whether the waitingList was changed.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static int
OnOffWaitingList(
ThreadSpecificData *tsdPtr,
int onList,
int signalNotifier)
{
int changeWaitingList;
#ifdef TCL_MAC_DEBUG_NOTIFIER
if(SpinLockTry(¬ifierLock)) {
Tcl_Panic("OnOffWaitingList: notifierLock unlocked");
}
#endif
changeWaitingList = (!onList ^ !tsdPtr->onList);
if (changeWaitingList) {
if (onList) {
tsdPtr->nextPtr = waitingListPtr;
if (waitingListPtr) {
waitingListPtr->prevPtr = tsdPtr;
}
tsdPtr->prevPtr = NULL;
waitingListPtr = tsdPtr;
tsdPtr->onList = 1;
} else {
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 (signalNotifier) {
write(triggerPipe, "", 1);
}
}
return changeWaitingList;
}
/*
*----------------------------------------------------------------------
*
* Tcl_Sleep --
*
* Delay execution for the specified number of milliseconds.
*
* Results:
* None.
*
* Side effects:
* Time passes.
*
*----------------------------------------------------------------------
*/
void
Tcl_Sleep(
int ms) /* Number of milliseconds to sleep. */
{
Tcl_Time vdelay;
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
if (ms <= 0) {
return;
}
/*
* TIP #233: Scale from virtual time to real-time.
*/
vdelay.sec = ms / 1000;
vdelay.usec = (ms % 1000) * 1000;
tclScaleTimeProcPtr(&vdelay, tclTimeClientData);
if (tsdPtr->runLoop) {
CFTimeInterval waitTime;
CFRunLoopTimerRef runLoopTimer = tsdPtr->runLoopTimer;
CFAbsoluteTime nextTimerFire = 0, waitEnd, now;
SInt32 runLoopStatus;
waitTime = vdelay.sec + 1.0e-6 * vdelay.usec;
now = CFAbsoluteTimeGetCurrent();
waitEnd = now + waitTime;
if (runLoopTimer) {
nextTimerFire = CFRunLoopTimerGetNextFireDate(runLoopTimer);
if (nextTimerFire < waitEnd) {
CFRunLoopTimerSetNextFireDate(runLoopTimer, now +
CF_TIMEINTERVAL_FOREVER);
} else {
runLoopTimer = NULL;
}
}
tsdPtr->sleeping = 1;
do {
runLoopStatus = CFRunLoopRunInMode(kCFRunLoopDefaultMode, waitTime,
FALSE);
switch (runLoopStatus) {
case kCFRunLoopRunFinished:
Tcl_Panic("Tcl_Sleep: CFRunLoop finished");
break;
case kCFRunLoopRunStopped:
TclMacOSXNotifierDbgMsg("CFRunLoop stopped");
waitTime = waitEnd - CFAbsoluteTimeGetCurrent();
break;
case kCFRunLoopRunTimedOut:
waitTime = 0;
break;
}
} while (waitTime > 0);
tsdPtr->sleeping = 0;
if (runLoopTimer) {
CFRunLoopTimerSetNextFireDate(runLoopTimer, nextTimerFire);
}
} else {
struct timespec waitTime;
waitTime.tv_sec = vdelay.sec;
waitTime.tv_nsec = vdelay.usec * 1000;
while (nanosleep(&waitTime, &waitTime));
}
}
/*
*----------------------------------------------------------------------
*
* 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;
int numFound, result = 0;
fd_set readableMask;
fd_set writableMask;
fd_set exceptionalMask;
#define SET_BITS(var, bits) ((var) |= (bits))
#define CLEAR_BITS(var, bits) ((var) &= ~(bits))
#ifndef _DARWIN_C_SOURCE
/*
* Sanity check fd.
*/
if (fd >= FD_SETSIZE) {
Tcl_Panic("TclUnixWaitForFile can't handle file id %d", fd);
/* must never get here, or select masks overrun will occur below */
}
#endif
/*
* 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;
}
/*
* Initialize the select masks.
*/
FD_ZERO(&readableMask);
FD_ZERO(&writableMask);
FD_ZERO(&exceptionalMask);
/*
* 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;
}
}
/*
* Setup the select masks for the fd.
*/
if (mask & TCL_READABLE) {
FD_SET(fd, &readableMask);
}
if (mask & TCL_WRITABLE) {
FD_SET(fd, &writableMask);
}
if (mask & TCL_EXCEPTION) {
FD_SET(fd, &exceptionalMask);
}
/*
* Wait for the event or a timeout.
*/
numFound = select(fd + 1, &readableMask, &writableMask,
&exceptionalMask, timeoutPtr);
if (numFound == 1) {
if (FD_ISSET(fd, &readableMask)) {
SET_BITS(result, TCL_READABLE);
}
if (FD_ISSET(fd, &writableMask)) {
SET_BITS(result, TCL_WRITABLE);
}
if (FD_ISSET(fd, &exceptionalMask)) {
SET_BITS(result, TCL_EXCEPTION);
}
result &= mask;
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;
}
/*
*----------------------------------------------------------------------
*
* NotifierThreadProc --
*
* 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.
*
* Result:
* None. Once started, this routine never exits. It dies with the overall
* process.
*
* Side effects:
* The trigger pipe used to signal the notifier thread is created when
* the notifier thread first starts.
*
*----------------------------------------------------------------------
*/
static void
NotifierThreadProc(
ClientData clientData) /* Not used. */
{
ThreadSpecificData *tsdPtr;
fd_set readableMask, writableMask, exceptionalMask;
int i, numFdBits = 0, polling;
struct timeval poll = {0., 0.}, *timePtr;
char buf[2];
/*
* Look for file events and report them to interested threads.
*/
while (1) {
FD_ZERO(&readableMask);
FD_ZERO(&writableMask);
FD_ZERO(&exceptionalMask);
/*
* Compute the logical OR of the select masks from all the waiting
* notifiers.
*/
timePtr = NULL;
LOCK_NOTIFIER;
for (tsdPtr = waitingListPtr; tsdPtr; tsdPtr = tsdPtr->nextPtr) {
LOCK_NOTIFIER_TSD;
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.exceptional))) {
FD_SET(i, &exceptionalMask);
}
}
if (tsdPtr->numFdBits > numFdBits) {
numFdBits = tsdPtr->numFdBits;
}
polling = tsdPtr->polling;
UNLOCK_NOTIFIER_TSD;
if ((tsdPtr->polled = polling)) {
timePtr = &poll;
}
}
UNLOCK_NOTIFIER;
/*
* 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, &exceptionalMask,
timePtr) == -1) {
/*
* Try again immediately on an error.
*/
continue;
}
/*
* Alert any threads that are waiting on a ready file descriptor.
*/
LOCK_NOTIFIER;
for (tsdPtr = waitingListPtr; tsdPtr; tsdPtr = tsdPtr->nextPtr) {
int found = 0;
SelectMasks readyMasks, checkMasks;
LOCK_NOTIFIER_TSD;
FD_COPY(&(tsdPtr->checkMasks.readable), &checkMasks.readable);
FD_COPY(&(tsdPtr->checkMasks.writable), &checkMasks.writable);
FD_COPY(&(tsdPtr->checkMasks.exceptional), &checkMasks.exceptional);
UNLOCK_NOTIFIER_TSD;
found = tsdPtr->polled;
FD_ZERO(&readyMasks.readable);
FD_ZERO(&readyMasks.writable);
FD_ZERO(&readyMasks.exceptional);
for (i = tsdPtr->numFdBits-1; i >= 0; --i) {
if (FD_ISSET(i, &checkMasks.readable)
&& FD_ISSET(i, &readableMask)) {
FD_SET(i, &readyMasks.readable);
found = 1;
}
if (FD_ISSET(i, &checkMasks.writable)
&& FD_ISSET(i, &writableMask)) {
FD_SET(i, &readyMasks.writable);
found = 1;
}
if (FD_ISSET(i, &checkMasks.exceptional)
&& FD_ISSET(i, &exceptionalMask)) {
FD_SET(i, &readyMasks.exceptional);
found = 1;
}
}
if (found) {
/*
* Remove the ThreadSpecificData structure of this thread from
* the waiting list. This prevents us from spinning
* continuously on select until the other threads runs and
* services the file event.
*/
OnOffWaitingList(tsdPtr, 0, 0);
LOCK_NOTIFIER_TSD;
FD_COPY(&readyMasks.readable, &(tsdPtr->readyMasks.readable));
FD_COPY(&readyMasks.writable, &(tsdPtr->readyMasks.writable));
FD_COPY(&readyMasks.exceptional, &(tsdPtr->readyMasks.exceptional));
UNLOCK_NOTIFIER_TSD;
tsdPtr->polled = 0;
if (tsdPtr->runLoop) {
CFRunLoopSourceSignal(tsdPtr->runLoopSource);
CFRunLoopWakeUp(tsdPtr->runLoop);
}
}
}
UNLOCK_NOTIFIER;
/*
* 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;
}
}
}
pthread_exit(0);
}
#ifdef HAVE_PTHREAD_ATFORK
/*
*----------------------------------------------------------------------
*
* AtForkPrepare --
*
* Lock the notifier in preparation for a fork.
*
* Results:
* None.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static void
AtForkPrepare(void)
{
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
LOCK_NOTIFIER_INIT;
LOCK_NOTIFIER;
LOCK_NOTIFIER_TSD;
}
/*
*----------------------------------------------------------------------
*
* AtForkParent --
*
* Unlock the notifier in the parent after a fork.
*
* Results:
* None.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static void
AtForkParent(void)
{
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
UNLOCK_NOTIFIER_TSD;
UNLOCK_NOTIFIER;
UNLOCK_NOTIFIER_INIT;
}
/*
*----------------------------------------------------------------------
*
* AtForkChild --
*
* Unlock and reinstall the notifier in the child after a fork.
*
* Results:
* None.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static void
AtForkChild(void)
{
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
UNLOCK_NOTIFIER_TSD;
UNLOCK_NOTIFIER;
UNLOCK_NOTIFIER_INIT;
if (tsdPtr->runLoop) {
tsdPtr->runLoop = NULL;
if (!noCFafterFork) {
CFRunLoopSourceInvalidate(tsdPtr->runLoopSource);
CFRelease(tsdPtr->runLoopSource);
if (tsdPtr->runLoopTimer) {
CFRunLoopTimerInvalidate(tsdPtr->runLoopTimer);
CFRelease(tsdPtr->runLoopTimer);
}
}
tsdPtr->runLoopSource = NULL;
tsdPtr->runLoopTimer = NULL;
}
if (notifierCount > 0) {
notifierCount = 1;
notifierThreadRunning = 0;
/*
* Assume that the return value of Tcl_InitNotifier in the child will
* be identical to the one stored as clientData in tclNotify.c's
* ThreadSpecificData by the parent's TclInitNotifier, so discard the
* return value here. This assumption may require the fork() to be
* executed in the main thread of the parent, otherwise
* Tcl_AlertNotifier may break in the child.
*/
if (!noCFafterFork) {
Tcl_InitNotifier();
}
}
}
#endif /* HAVE_PTHREAD_ATFORK */
#else /* HAVE_COREFOUNDATION */
void
TclMacOSXNotifierAddRunLoopMode(
CONST void *runLoopMode)
{
Tcl_Panic("TclMacOSXNotifierAddRunLoopMode: "
"Tcl not built with CoreFoundation support");
}
#endif /* HAVE_COREFOUNDATION */
/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* End:
*/
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