diff options
Diffstat (limited to 'unix/tclUnixNotfy.c')
| -rw-r--r-- | unix/tclUnixNotfy.c | 1294 |
1 files changed, 216 insertions, 1078 deletions
diff --git a/unix/tclUnixNotfy.c b/unix/tclUnixNotfy.c index 6b7669d..5bc753a 100644 --- a/unix/tclUnixNotfy.c +++ b/unix/tclUnixNotfy.c @@ -1,262 +1,33 @@ /* * tclUnixNotfy.c -- * - * This file contains the implementation of the select()-based - * Unix-specific notifier, which is the lowest-level part of the Tcl - * event loop. This file works together with generic/tclNotify.c. + * This file contains subroutines shared by all notifier backend + * implementations on *nix platforms. * * Copyright (c) 1995-1997 Sun Microsystems, Inc. + * Copyright (c) 2016 Lucio AndrĂ©s Illanes Albornoz <l.illanes@gmx.de> * * See the file "license.terms" for information on usage and redistribution * of this file, and for a DISCLAIMER OF ALL WARRANTIES. */ -#include "tclInt.h" -#ifndef HAVE_COREFOUNDATION /* Darwin/Mac OS X CoreFoundation notifier is - * in tclMacOSXNotify.c */ -#include <signal.h> - -/* - * This structure is used to keep track of the notifier info for a registered - * file. - */ - -typedef struct FileHandler { - int fd; - int mask; /* Mask of desired events: TCL_READABLE, - * etc. */ - int readyMask; /* Mask of events that have been seen since - * the last time file handlers were invoked - * for this file. */ - Tcl_FileProc *proc; /* Function to call, in the style of - * Tcl_CreateFileHandler. */ - ClientData clientData; /* Argument to pass to proc. */ - struct FileHandler *nextPtr;/* Next in list of all files we care about. */ -} FileHandler; - -/* - * The following structure is what is added to the Tcl event queue when file - * handlers are ready to fire. - */ - -typedef struct { - Tcl_Event header; /* Information that is standard for all - * events. */ - int fd; /* File descriptor that is ready. Used to find - * the FileHandler structure for the file - * (can't point directly to the FileHandler - * structure because it could go away while - * the event is queued). */ -} FileHandlerEvent; - -/* - * The following structure contains a set of select() masks to track readable, - * writable, and exception conditions. - */ - -typedef struct { - fd_set readable; - fd_set writable; - fd_set exception; -} SelectMasks; - -/* - * The following static structure contains the state information for the - * select based implementation of the Tcl notifier. One of these structures is - * created for each thread that is using the notifier. - */ - -typedef struct ThreadSpecificData { - FileHandler *firstFileHandlerPtr; - /* Pointer to head of file handler list. */ - SelectMasks checkMasks; /* This structure is used to build up the - * masks to be used in the next call to - * select. Bits are set in response to calls - * to Tcl_CreateFileHandler. */ - SelectMasks readyMasks; /* This array reflects the readable/writable - * conditions that were found to exist by the - * last call to select. */ - int numFdBits; /* Number of valid bits in checkMasks (one - * more than highest fd for which - * Tcl_WatchFile has been called). */ -#ifdef TCL_THREADS - int onList; /* True if it is in this list */ - unsigned int pollState; /* pollState is used to implement a polling - * handshake between each thread and the - * notifier thread. Bits defined below. */ - struct ThreadSpecificData *nextPtr, *prevPtr; - /* All threads that are currently waiting on - * an event have their ThreadSpecificData - * structure on a doubly-linked listed formed - * from these pointers. You must hold the - * notifierMutex lock before accessing these - * fields. */ -#ifdef __CYGWIN__ - void *event; /* Any other thread alerts a notifier - * that an event is ready to be processed - * by sending this event. */ - void *hwnd; /* Messaging window. */ -#else /* !__CYGWIN__ */ - pthread_cond_t waitCV; /* Any other thread alerts a notifier that an - * event is ready to be processed by signaling - * this condition variable. */ -#endif /* __CYGWIN__ */ - int waitCVinitialized; /* Variable to flag initialization of the structure */ - int eventReady; /* True if an event is ready to be processed. - * Used as condition flag together with waitCV - * above. */ -#endif /* TCL_THREADS */ -} ThreadSpecificData; - -static Tcl_ThreadDataKey dataKey; - -#ifdef TCL_THREADS -/* - * The following static indicates the number of threads that have initialized - * notifiers. - * - * You must hold the notifierMutex lock before accessing this variable. - */ - -static int notifierCount = 0; - -/* - * The following variable points to the head of a doubly-linked list of - * ThreadSpecificData structures for all threads that are currently waiting on - * an event. - * - * You must hold the notifierMutex lock before accessing this list. - */ - -static ThreadSpecificData *waitingListPtr = NULL; - -/* - * The notifier thread spends all its time in select() waiting for a file - * descriptor associated with one of the threads on the waitingListPtr list to - * do something interesting. But if the contents of the waitingListPtr list - * ever changes, we need to wake up and restart the select() system call. You - * can wake up the notifier thread by writing a single byte to the file - * descriptor defined below. This file descriptor is the input-end of a pipe - * and the notifier thread is listening for data on the output-end of the same - * pipe. Hence writing to this file descriptor will cause the select() system - * call to return and wake up the notifier thread. - * - * You must hold the notifierMutex lock before writing to the pipe. - */ - -static int triggerPipe = -1; - -/* - * The notifierMutex locks access to all of the global notifier state. - */ - -static pthread_mutex_t notifierInitMutex = PTHREAD_MUTEX_INITIALIZER; -static pthread_mutex_t notifierMutex = PTHREAD_MUTEX_INITIALIZER; -/* - * The following static indicates if the notifier thread is running. - * - * You must hold the notifierInitMutex before accessing this variable. - */ - -static int notifierThreadRunning = 0; - -/* - * The notifier thread signals the notifierCV when it has finished - * initializing the triggerPipe and right before the notifier thread - * terminates. - */ - -static pthread_cond_t notifierCV = PTHREAD_COND_INITIALIZER; - -/* - * The pollState bits - * POLL_WANT is set by each thread before it waits on its condition - * variable. It is checked by the notifier before it does select. - * POLL_DONE is set by the notifier if it goes into select after seeing - * POLL_WANT. The idea is to ensure it tries a select with the - * same bits the initial thread had set. - */ - -#define POLL_WANT 0x1 -#define POLL_DONE 0x2 - -/* - * This is the thread ID of the notifier thread that does select. - */ - -static Tcl_ThreadId notifierThread; - -#endif /* TCL_THREADS */ +#include <poll.h> /* * Static routines defined in this file. */ +#ifdef NOTIFIER_SELECT #ifdef TCL_THREADS static TCL_NORETURN void NotifierThreadProc(ClientData clientData); #if defined(HAVE_PTHREAD_ATFORK) -static int atForkInit = 0; static void AtForkChild(void); #endif /* HAVE_PTHREAD_ATFORK */ #endif /* TCL_THREADS */ +#endif /* NOTIFIER_SELECT */ static int FileHandlerEventProc(Tcl_Event *evPtr, int flags); -/* - * Import of Windows API when building threaded with Cygwin. - */ - -#if defined(TCL_THREADS) && defined(__CYGWIN__) -typedef struct { - void *hwnd; - unsigned int *message; - int wParam; - int lParam; - int time; - int x; - int y; -} MSG; - -typedef struct { - unsigned int style; - void *lpfnWndProc; - int cbClsExtra; - int cbWndExtra; - void *hInstance; - void *hIcon; - void *hCursor; - void *hbrBackground; - void *lpszMenuName; - const void *lpszClassName; -} WNDCLASS; - -extern void __stdcall CloseHandle(void *); -extern void *__stdcall CreateEventW(void *, unsigned char, unsigned char, - void *); -extern void * __stdcall CreateWindowExW(void *, const void *, const void *, - DWORD, int, int, int, int, void *, void *, void *, void *); -extern DWORD __stdcall DefWindowProcW(void *, int, void *, void *); -extern unsigned char __stdcall DestroyWindow(void *); -extern int __stdcall DispatchMessageW(const MSG *); -extern unsigned char __stdcall GetMessageW(MSG *, void *, int, int); -extern void __stdcall MsgWaitForMultipleObjects(DWORD, void *, - unsigned char, DWORD, DWORD); -extern unsigned char __stdcall PeekMessageW(MSG *, void *, int, int, int); -extern unsigned char __stdcall PostMessageW(void *, unsigned int, void *, - void *); -extern void __stdcall PostQuitMessage(int); -extern void *__stdcall RegisterClassW(const WNDCLASS *); -extern unsigned char __stdcall ResetEvent(void *); -extern unsigned char __stdcall TranslateMessage(const MSG *); - -/* - * Threaded-cygwin specific constants and functions in this file: - */ - -static const WCHAR className[] = L"TclNotifier"; -static DWORD __stdcall NotifierProc(void *hwnd, unsigned int message, - void *wParam, void *lParam); -#endif /* TCL_THREADS && __CYGWIN__ */ - +#ifdef NOTIFIER_SELECT #if TCL_THREADS /* *---------------------------------------------------------------------- @@ -300,168 +71,7 @@ StartNotifierThread(const char *proc) } } #endif /* TCL_THREADS */ - -/* - *---------------------------------------------------------------------- - * - * Tcl_InitNotifier -- - * - * Initializes the platform specific notifier state. - * - * Results: - * Returns a handle to the notifier state for this thread. - * - * Side effects: - * None. - * - *---------------------------------------------------------------------- - */ - -ClientData -Tcl_InitNotifier(void) -{ - if (tclNotifierHooks.initNotifierProc) { - return tclNotifierHooks.initNotifierProc(); - } else { - ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); - -#ifdef TCL_THREADS - tsdPtr->eventReady = 0; - - /* - * Initialize thread specific condition variable for this thread. - */ - if (tsdPtr->waitCVinitialized == 0) { -#ifdef __CYGWIN__ - WNDCLASS class; - - class.style = 0; - class.cbClsExtra = 0; - class.cbWndExtra = 0; - class.hInstance = TclWinGetTclInstance(); - class.hbrBackground = NULL; - class.lpszMenuName = NULL; - class.lpszClassName = className; - class.lpfnWndProc = NotifierProc; - class.hIcon = NULL; - class.hCursor = NULL; - - RegisterClassW(&class); - tsdPtr->hwnd = CreateWindowExW(NULL, class.lpszClassName, - class.lpszClassName, 0, 0, 0, 0, 0, NULL, NULL, - TclWinGetTclInstance(), NULL); - tsdPtr->event = CreateEventW(NULL, 1 /* manual */, - 0 /* !signaled */, NULL); -#else - pthread_cond_init(&tsdPtr->waitCV, NULL); -#endif /* __CYGWIN__ */ - tsdPtr->waitCVinitialized = 1; - } - - pthread_mutex_lock(¬ifierInitMutex); -#if defined(HAVE_PTHREAD_ATFORK) - /* - * Install pthread_atfork handlers to clean up the notifier in the - * child of a fork. - */ - - if (!atForkInit) { - int result = pthread_atfork(NULL, NULL, AtForkChild); - - if (result) { - Tcl_Panic("Tcl_InitNotifier: pthread_atfork failed"); - } - atForkInit = 1; - } -#endif /* HAVE_PTHREAD_ATFORK */ - - notifierCount++; - - pthread_mutex_unlock(¬ifierInitMutex); - -#endif /* TCL_THREADS */ - return tsdPtr; - } -} - -/* - *---------------------------------------------------------------------- - * - * Tcl_FinalizeNotifier -- - * - * This function is called to cleanup the notifier state before a thread - * is terminated. - * - * Results: - * None. - * - * Side effects: - * May terminate the background notifier thread if this is the last - * notifier instance. - * - *---------------------------------------------------------------------- - */ - -void -Tcl_FinalizeNotifier( - ClientData clientData) /* Not used. */ -{ - if (tclNotifierHooks.finalizeNotifierProc) { - tclNotifierHooks.finalizeNotifierProc(clientData); - return; - } else { -#ifdef TCL_THREADS - ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); - - pthread_mutex_lock(¬ifierInitMutex); - notifierCount--; - - /* - * If this is the last thread to use the notifier, close the notifier - * pipe and wait for the background thread to terminate. - */ - - if (notifierCount == 0) { - - if (triggerPipe != -1) { - if (write(triggerPipe, "q", 1) != 1) { - Tcl_Panic("Tcl_FinalizeNotifier: %s", - "unable to write q to triggerPipe"); - } - close(triggerPipe); - pthread_mutex_lock(¬ifierMutex); - while(triggerPipe != -1) { - pthread_cond_wait(¬ifierCV, ¬ifierMutex); - } - pthread_mutex_unlock(¬ifierMutex); - if (notifierThreadRunning) { - int result = pthread_join((pthread_t) notifierThread, NULL); - - if (result) { - Tcl_Panic("Tcl_FinalizeNotifier: unable to join notifier " - "thread"); - } - notifierThreadRunning = 0; - } - } - } - - /* - * Clean up any synchronization objects in the thread local storage. - */ - -#ifdef __CYGWIN__ - DestroyWindow(tsdPtr->hwnd); - CloseHandle(tsdPtr->event); -#else /* __CYGWIN__ */ - pthread_cond_destroy(&tsdPtr->waitCV); -#endif /* __CYGWIN__ */ - tsdPtr->waitCVinitialized = 0; - - pthread_mutex_unlock(¬ifierInitMutex); -#endif /* TCL_THREADS */ - } -} +#endif /* NOTIFIER_SELECT */ /* *---------------------------------------------------------------------- @@ -477,7 +87,13 @@ Tcl_FinalizeNotifier( * None. * * Side effects: - * Signals the notifier condition variable for the specified notifier. + * select(2) notifier: + * signals the notifier condition variable for the specified + * notifier. + * epoll(7) notifier: + * write(2)s to the eventfd(2) of the specified thread. + * kqueue(2) notifier: + * write(2)s to the trigger pipe(2) of the specified thread. * *---------------------------------------------------------------------- */ @@ -490,6 +106,7 @@ Tcl_AlertNotifier( tclNotifierHooks.alertNotifierProc(clientData); return; } else { +#ifdef NOTIFIER_SELECT #ifdef TCL_THREADS ThreadSpecificData *tsdPtr = clientData; @@ -503,6 +120,21 @@ Tcl_AlertNotifier( # endif /* __CYGWIN__ */ pthread_mutex_unlock(¬ifierMutex); #endif /* TCL_THREADS */ +#else + ThreadSpecificData *tsdPtr = clientData; +#if defined(NOTIFIER_EPOLL) && defined(HAVE_EVENTFD) + uint64_t eventFdVal = 1; + if (write(tsdPtr->triggerEventFd, &eventFdVal, + sizeof(eventFdVal)) != sizeof(eventFdVal)) { + Tcl_Panic("Tcl_AlertNotifier: unable to write to %p->triggerEventFd", + (void *)tsdPtr); +#else + if (write(tsdPtr->triggerPipe[1], "", 1) != 1) { + Tcl_Panic("Tcl_AlertNotifier: unable to write to %p->triggerPipe", + (void *)tsdPtr); +#endif /* NOTIFIER_EPOLL && HAVE_EVENTFD */ + } +#endif /* NOTIFIER_SELECT */ } } @@ -565,173 +197,11 @@ Tcl_ServiceModeHook( tclNotifierHooks.serviceModeHookProc(mode); return; } else if (mode == TCL_SERVICE_ALL) { +#ifdef NOTIFIER_SELECT #if TCL_THREADS StartNotifierThread("Tcl_ServiceModeHook"); #endif - } -} - -/* - *---------------------------------------------------------------------- - * - * Tcl_CreateFileHandler -- - * - * This function registers a file handler with the select notifier. - * - * Results: - * None. - * - * Side effects: - * Creates a new file handler structure. - * - *---------------------------------------------------------------------- - */ - -void -Tcl_CreateFileHandler( - int fd, /* Handle of stream to watch. */ - int mask, /* OR'ed combination of TCL_READABLE, - * TCL_WRITABLE, and TCL_EXCEPTION: indicates - * conditions under which proc should be - * called. */ - Tcl_FileProc *proc, /* Function to call for each selected - * event. */ - ClientData clientData) /* Arbitrary data to pass to proc. */ -{ - if (tclNotifierHooks.createFileHandlerProc) { - tclNotifierHooks.createFileHandlerProc(fd, mask, proc, clientData); - return; - } else { - ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); - FileHandler *filePtr; - - for (filePtr = tsdPtr->firstFileHandlerPtr; filePtr != NULL; - filePtr = filePtr->nextPtr) { - if (filePtr->fd == fd) { - break; - } - } - if (filePtr == NULL) { - filePtr = ckalloc(sizeof(FileHandler)); - filePtr->fd = fd; - filePtr->readyMask = 0; - filePtr->nextPtr = tsdPtr->firstFileHandlerPtr; - tsdPtr->firstFileHandlerPtr = filePtr; - } - filePtr->proc = proc; - filePtr->clientData = clientData; - filePtr->mask = mask; - - /* - * Update the check masks for this file. - */ - - if (mask & TCL_READABLE) { - FD_SET(fd, &tsdPtr->checkMasks.readable); - } else { - FD_CLR(fd, &tsdPtr->checkMasks.readable); - } - if (mask & TCL_WRITABLE) { - FD_SET(fd, &tsdPtr->checkMasks.writable); - } else { - FD_CLR(fd, &tsdPtr->checkMasks.writable); - } - if (mask & TCL_EXCEPTION) { - FD_SET(fd, &tsdPtr->checkMasks.exception); - } else { - FD_CLR(fd, &tsdPtr->checkMasks.exception); - } - if (tsdPtr->numFdBits <= fd) { - tsdPtr->numFdBits = fd+1; - } - } -} - -/* - *---------------------------------------------------------------------- - * - * Tcl_DeleteFileHandler -- - * - * Cancel a previously-arranged callback arrangement for a file. - * - * Results: - * None. - * - * Side effects: - * If a callback was previously registered on file, remove it. - * - *---------------------------------------------------------------------- - */ - -void -Tcl_DeleteFileHandler( - int fd) /* Stream id for which to remove callback - * function. */ -{ - if (tclNotifierHooks.deleteFileHandlerProc) { - tclNotifierHooks.deleteFileHandlerProc(fd); - return; - } else { - FileHandler *filePtr, *prevPtr; - int i; - ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); - - /* - * Find the entry for the given file (and return if there isn't one). - */ - - for (prevPtr = NULL, filePtr = tsdPtr->firstFileHandlerPtr; ; - prevPtr = filePtr, filePtr = filePtr->nextPtr) { - if (filePtr == NULL) { - return; - } - if (filePtr->fd == fd) { - break; - } - } - - /* - * Update the check masks for this file. - */ - - if (filePtr->mask & TCL_READABLE) { - FD_CLR(fd, &tsdPtr->checkMasks.readable); - } - if (filePtr->mask & TCL_WRITABLE) { - FD_CLR(fd, &tsdPtr->checkMasks.writable); - } - if (filePtr->mask & TCL_EXCEPTION) { - FD_CLR(fd, &tsdPtr->checkMasks.exception); - } - - /* - * Find current max fd. - */ - - if (fd+1 == tsdPtr->numFdBits) { - int numFdBits = 0; - - for (i = fd-1; i >= 0; i--) { - if (FD_ISSET(i, &tsdPtr->checkMasks.readable) - || FD_ISSET(i, &tsdPtr->checkMasks.writable) - || FD_ISSET(i, &tsdPtr->checkMasks.exception)) { - numFdBits = i+1; - break; - } - } - tsdPtr->numFdBits = numFdBits; - } - - /* - * Clean up information in the callback record. - */ - - if (prevPtr == NULL) { - tsdPtr->firstFileHandlerPtr = filePtr->nextPtr; - } else { - prevPtr->nextPtr = filePtr->nextPtr; - } - ckfree(filePtr); +#endif /* NOTIFIER_SELECT */ } } @@ -809,538 +279,56 @@ FileHandlerEventProc( return 1; } -#if defined(TCL_THREADS) && defined(__CYGWIN__) - -static DWORD __stdcall -NotifierProc( - void *hwnd, - unsigned int message, - void *wParam, - void *lParam) -{ - ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); - - if (message != 1024) { - return DefWindowProcW(hwnd, message, wParam, lParam); - } - - /* - * Process all of the runnable events. - */ - - tsdPtr->eventReady = 1; - Tcl_ServiceAll(); - return 0; -} -#endif /* TCL_THREADS && __CYGWIN__ */ - -/* - *---------------------------------------------------------------------- - * - * Tcl_WaitForEvent -- - * - * This function is called by Tcl_DoOneEvent to wait for new events on - * the message queue. If the block time is 0, then Tcl_WaitForEvent just - * polls without blocking. - * - * Results: - * Returns -1 if the select would block forever, otherwise returns 0. - * - * Side effects: - * Queues file events that are detected by the select. - * - *---------------------------------------------------------------------- - */ - -int -Tcl_WaitForEvent( - const Tcl_Time *timePtr) /* Maximum block time, or NULL. */ -{ - if (tclNotifierHooks.waitForEventProc) { - return tclNotifierHooks.waitForEventProc(timePtr); - } else { - FileHandler *filePtr; - int mask; - Tcl_Time vTime; -#ifdef TCL_THREADS - int waitForFiles; -# ifdef __CYGWIN__ - MSG msg; -# endif /* __CYGWIN__ */ -#else - /* - * Impl. notes: timeout & timeoutPtr are used if, and only if threads - * are not enabled. They are the arguments for the regular select() - * used when the core is not thread-enabled. - */ - - struct timeval timeout, *timeoutPtr; - int numFound; -#endif /* TCL_THREADS */ - ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); - - /* - * Set up the timeout structure. Note that if there are no events to - * check for, we return with a negative result rather than blocking - * forever. - */ - - if (timePtr != NULL) { - /* - * TIP #233 (Virtualized Time). Is virtual time in effect? And do - * we actually have something to scale? If yes to both then we - * call the handler to do this scaling. - */ - - if (timePtr->sec != 0 || timePtr->usec != 0) { - vTime = *timePtr; - tclScaleTimeProcPtr(&vTime, tclTimeClientData); - timePtr = &vTime; - } -#ifndef TCL_THREADS - timeout.tv_sec = timePtr->sec; - timeout.tv_usec = timePtr->usec; - timeoutPtr = &timeout; - } else if (tsdPtr->numFdBits == 0) { - /* - * If there are no threads, no timeout, and no fds registered, - * then there are no events possible and we must avoid deadlock. - * Note that this is not entirely correct because there might be a - * signal that could interrupt the select call, but we don't - * handle that case if we aren't using threads. - */ - - return -1; - } else { - timeoutPtr = NULL; -#endif /* !TCL_THREADS */ - } - -#ifdef TCL_THREADS - /* - * Start notifier thread and place this thread on the list of - * interested threads, signal the notifier thread, and wait for a - * response or a timeout. - */ - StartNotifierThread("Tcl_WaitForEvent"); - - pthread_mutex_lock(¬ifierMutex); - - if (timePtr != NULL && timePtr->sec == 0 && (timePtr->usec == 0 -#if defined(__APPLE__) && defined(__LP64__) - /* - * On 64-bit Darwin, pthread_cond_timedwait() appears to have - * a bug that causes it to wait forever when passed an - * absolute time which has already been exceeded by the system - * time; as a workaround, when given a very brief timeout, - * just do a poll. [Bug 1457797] - */ - || timePtr->usec < 10 -#endif /* __APPLE__ && __LP64__ */ - )) { - /* - * Cannot emulate a polling select with a polling condition - * variable. Instead, pretend to wait for files and tell the - * notifier thread what we are doing. The notifier thread makes - * sure it goes through select with its select mask in the same - * state as ours currently is. We block until that happens. - */ - - waitForFiles = 1; - tsdPtr->pollState = POLL_WANT; - timePtr = NULL; - } else { - waitForFiles = (tsdPtr->numFdBits > 0); - tsdPtr->pollState = 0; - } - - if (waitForFiles) { - /* - * Add the ThreadSpecificData structure of this thread to the list - * of ThreadSpecificData structures of all threads that are - * waiting on file events. - */ - - tsdPtr->nextPtr = waitingListPtr; - if (waitingListPtr) { - waitingListPtr->prevPtr = tsdPtr; - } - tsdPtr->prevPtr = 0; - waitingListPtr = tsdPtr; - tsdPtr->onList = 1; - - if ((write(triggerPipe, "", 1) == -1) && (errno != EAGAIN)) { - Tcl_Panic("Tcl_WaitForEvent: %s", - "unable to write to triggerPipe"); - } - } - - FD_ZERO(&tsdPtr->readyMasks.readable); - FD_ZERO(&tsdPtr->readyMasks.writable); - FD_ZERO(&tsdPtr->readyMasks.exception); - - if (!tsdPtr->eventReady) { -#ifdef __CYGWIN__ - if (!PeekMessageW(&msg, NULL, 0, 0, 0)) { - DWORD timeout; - - if (timePtr) { - timeout = timePtr->sec * 1000 + timePtr->usec / 1000; - } else { - timeout = 0xFFFFFFFF; - } - pthread_mutex_unlock(¬ifierMutex); - MsgWaitForMultipleObjects(1, &tsdPtr->event, 0, timeout, 1279); - pthread_mutex_lock(¬ifierMutex); - } -#else - if (timePtr != NULL) { - Tcl_Time now; - struct timespec ptime; - - Tcl_GetTime(&now); - ptime.tv_sec = timePtr->sec + now.sec + (timePtr->usec + now.usec) / 1000000; - ptime.tv_nsec = 1000 * ((timePtr->usec + now.usec) % 1000000); - - pthread_cond_timedwait(&tsdPtr->waitCV, ¬ifierMutex, &ptime); - } else { - pthread_cond_wait(&tsdPtr->waitCV, ¬ifierMutex); - } -#endif /* __CYGWIN__ */ - } - tsdPtr->eventReady = 0; - -#ifdef __CYGWIN__ - while (PeekMessageW(&msg, NULL, 0, 0, 0)) { - /* - * Retrieve and dispatch the message. - */ - - DWORD result = GetMessageW(&msg, NULL, 0, 0); - - if (result == 0) { - PostQuitMessage(msg.wParam); - /* What to do here? */ - } else if (result != (DWORD) -1) { - TranslateMessage(&msg); - DispatchMessageW(&msg); - } - } - ResetEvent(tsdPtr->event); -#endif /* __CYGWIN__ */ - - if (waitForFiles && tsdPtr->onList) { - /* - * Remove the ThreadSpecificData structure of this thread from the - * waiting list. Alert the notifier thread to recompute its select - * masks - skipping this caused a hang when trying to close a pipe - * which the notifier thread was still doing a select on. - */ - - if (tsdPtr->prevPtr) { - tsdPtr->prevPtr->nextPtr = tsdPtr->nextPtr; - } else { - waitingListPtr = tsdPtr->nextPtr; - } - if (tsdPtr->nextPtr) { - tsdPtr->nextPtr->prevPtr = tsdPtr->prevPtr; - } - tsdPtr->nextPtr = tsdPtr->prevPtr = NULL; - tsdPtr->onList = 0; - if ((write(triggerPipe, "", 1) == -1) && (errno != EAGAIN)) { - Tcl_Panic("Tcl_WaitForEvent: %s", - "unable to write to triggerPipe"); - } - } - -#else - tsdPtr->readyMasks = tsdPtr->checkMasks; - numFound = select(tsdPtr->numFdBits, &tsdPtr->readyMasks.readable, - &tsdPtr->readyMasks.writable, &tsdPtr->readyMasks.exception, - timeoutPtr); - - /* - * Some systems don't clear the masks after an error, so we have to do - * it here. - */ - - if (numFound == -1) { - FD_ZERO(&tsdPtr->readyMasks.readable); - FD_ZERO(&tsdPtr->readyMasks.writable); - FD_ZERO(&tsdPtr->readyMasks.exception); - } -#endif /* TCL_THREADS */ - - /* - * Queue all detected file events before returning. - */ - - for (filePtr = tsdPtr->firstFileHandlerPtr; (filePtr != NULL); - filePtr = filePtr->nextPtr) { - mask = 0; - if (FD_ISSET(filePtr->fd, &tsdPtr->readyMasks.readable)) { - mask |= TCL_READABLE; - } - if (FD_ISSET(filePtr->fd, &tsdPtr->readyMasks.writable)) { - mask |= TCL_WRITABLE; - } - if (FD_ISSET(filePtr->fd, &tsdPtr->readyMasks.exception)) { - mask |= TCL_EXCEPTION; - } - - if (!mask) { - continue; - } - - /* - * Don't bother to queue an event if the mask was previously - * non-zero since an event must still be on the queue. - */ - - if (filePtr->readyMask == 0) { - FileHandlerEvent *fileEvPtr = - ckalloc(sizeof(FileHandlerEvent)); - - fileEvPtr->header.proc = FileHandlerEventProc; - fileEvPtr->fd = filePtr->fd; - Tcl_QueueEvent((Tcl_Event *) fileEvPtr, TCL_QUEUE_TAIL); - } - filePtr->readyMask = mask; - } -#ifdef TCL_THREADS - pthread_mutex_unlock(¬ifierMutex); -#endif /* TCL_THREADS */ - return 0; - } -} - +#ifdef NOTIFIER_SELECT #ifdef TCL_THREADS /* *---------------------------------------------------------------------- * - * NotifierThreadProc -- + * AlertSingleThread -- * - * This routine is the initial (and only) function executed by the - * special notifier thread. Its job is to wait for file descriptors to - * become readable or writable or to have an exception condition and then - * to notify other threads who are interested in this information by - * signalling a condition variable. Other threads can signal this - * notifier thread of a change in their interests by writing a single - * byte to a special pipe that the notifier thread is monitoring. + * Notify a single thread that is waiting on a file descriptor to become + * readable or writable or to have an exception condition. + * notifierMutex must be held. * * Result: - * None. Once started, this routine never exits. It dies with the overall - * process. + * None. * * Side effects: - * The trigger pipe used to signal the notifier thread is created when - * the notifier thread first starts. + * The condition variable associated with the thread is broadcasted. * *---------------------------------------------------------------------- */ -static TCL_NORETURN void -NotifierThreadProc( - ClientData clientData) /* Not used. */ +static void +AlertSingleThread( + ThreadSpecificData *tsdPtr) { - ThreadSpecificData *tsdPtr; - fd_set readableMask; - fd_set writableMask; - fd_set exceptionMask; - int fds[2]; - int i, numFdBits = 0, receivePipe; - long found; - struct timeval poll = {0., 0.}, *timePtr; - char buf[2]; - - if (pipe(fds) != 0) { - Tcl_Panic("NotifierThreadProc: %s", "could not create trigger pipe"); - } - - receivePipe = fds[0]; - - if (TclUnixSetBlockingMode(receivePipe, TCL_MODE_NONBLOCKING) < 0) { - Tcl_Panic("NotifierThreadProc: %s", - "could not make receive pipe non blocking"); - } - if (TclUnixSetBlockingMode(fds[1], TCL_MODE_NONBLOCKING) < 0) { - Tcl_Panic("NotifierThreadProc: %s", - "could not make trigger pipe non blocking"); - } - if (fcntl(receivePipe, F_SETFD, FD_CLOEXEC) < 0) { - Tcl_Panic("NotifierThreadProc: %s", - "could not make receive pipe close-on-exec"); - } - if (fcntl(fds[1], F_SETFD, FD_CLOEXEC) < 0) { - Tcl_Panic("NotifierThreadProc: %s", - "could not make trigger pipe close-on-exec"); + tsdPtr->eventReady = 1; + if (tsdPtr->onList) { + /* + * Remove the ThreadSpecificData structure of this thread + * from the waiting list. This prevents us from + * continuously spinning on epoll_wait until the other + * threads runs and services the file event. + */ + + if (tsdPtr->prevPtr) { + tsdPtr->prevPtr->nextPtr = tsdPtr->nextPtr; + } else { + waitingListPtr = tsdPtr->nextPtr; + } + if (tsdPtr->nextPtr) { + tsdPtr->nextPtr->prevPtr = tsdPtr->prevPtr; + } + tsdPtr->nextPtr = tsdPtr->prevPtr = NULL; + tsdPtr->onList = 0; + tsdPtr->pollState = 0; } - - /* - * Install the write end of the pipe into the global variable. - */ - - pthread_mutex_lock(¬ifierMutex); - triggerPipe = fds[1]; - - /* - * Signal any threads that are waiting. - */ - - pthread_cond_broadcast(¬ifierCV); - pthread_mutex_unlock(¬ifierMutex); - - /* - * Look for file events and report them to interested threads. - */ - - while (1) { - FD_ZERO(&readableMask); - FD_ZERO(&writableMask); - FD_ZERO(&exceptionMask); - - /* - * Compute the logical OR of the select masks from all the waiting - * notifiers. - */ - - pthread_mutex_lock(¬ifierMutex); - timePtr = NULL; - for (tsdPtr = waitingListPtr; tsdPtr; tsdPtr = tsdPtr->nextPtr) { - for (i = tsdPtr->numFdBits-1; i >= 0; --i) { - if (FD_ISSET(i, &tsdPtr->checkMasks.readable)) { - FD_SET(i, &readableMask); - } - if (FD_ISSET(i, &tsdPtr->checkMasks.writable)) { - FD_SET(i, &writableMask); - } - if (FD_ISSET(i, &tsdPtr->checkMasks.exception)) { - FD_SET(i, &exceptionMask); - } - } - if (tsdPtr->numFdBits > numFdBits) { - numFdBits = tsdPtr->numFdBits; - } - if (tsdPtr->pollState & POLL_WANT) { - /* - * Here we make sure we go through select() with the same mask - * bits that were present when the thread tried to poll. - */ - - tsdPtr->pollState |= POLL_DONE; - timePtr = &poll; - } - } - pthread_mutex_unlock(¬ifierMutex); - - /* - * Set up the select mask to include the receive pipe. - */ - - if (receivePipe >= numFdBits) { - numFdBits = receivePipe + 1; - } - FD_SET(receivePipe, &readableMask); - - if (select(numFdBits, &readableMask, &writableMask, &exceptionMask, - timePtr) == -1) { - /* - * Try again immediately on an error. - */ - - continue; - } - - /* - * Alert any threads that are waiting on a ready file descriptor. - */ - - pthread_mutex_lock(¬ifierMutex); - for (tsdPtr = waitingListPtr; tsdPtr; tsdPtr = tsdPtr->nextPtr) { - found = 0; - - for (i = tsdPtr->numFdBits-1; i >= 0; --i) { - if (FD_ISSET(i, &tsdPtr->checkMasks.readable) - && FD_ISSET(i, &readableMask)) { - FD_SET(i, &tsdPtr->readyMasks.readable); - found = 1; - } - if (FD_ISSET(i, &tsdPtr->checkMasks.writable) - && FD_ISSET(i, &writableMask)) { - FD_SET(i, &tsdPtr->readyMasks.writable); - found = 1; - } - if (FD_ISSET(i, &tsdPtr->checkMasks.exception) - && FD_ISSET(i, &exceptionMask)) { - FD_SET(i, &tsdPtr->readyMasks.exception); - found = 1; - } - } - - if (found || (tsdPtr->pollState & POLL_DONE)) { - tsdPtr->eventReady = 1; - if (tsdPtr->onList) { - /* - * Remove the ThreadSpecificData structure of this thread - * from the waiting list. This prevents us from - * continuously spining on select until the other threads - * runs and services the file event. - */ - - if (tsdPtr->prevPtr) { - tsdPtr->prevPtr->nextPtr = tsdPtr->nextPtr; - } else { - waitingListPtr = tsdPtr->nextPtr; - } - if (tsdPtr->nextPtr) { - tsdPtr->nextPtr->prevPtr = tsdPtr->prevPtr; - } - tsdPtr->nextPtr = tsdPtr->prevPtr = NULL; - tsdPtr->onList = 0; - tsdPtr->pollState = 0; - } #ifdef __CYGWIN__ - PostMessageW(tsdPtr->hwnd, 1024, 0, 0); + PostMessageW(tsdPtr->hwnd, 1024, 0, 0); #else /* __CYGWIN__ */ - pthread_cond_broadcast(&tsdPtr->waitCV); + pthread_cond_broadcast(&tsdPtr->waitCV); #endif /* __CYGWIN__ */ - } - } - pthread_mutex_unlock(¬ifierMutex); - - /* - * Consume the next byte from the notifier pipe if the pipe was - * readable. Note that there may be multiple bytes pending, but to - * avoid a race condition we only read one at a time. - */ - - if (FD_ISSET(receivePipe, &readableMask)) { - i = read(receivePipe, buf, 1); - - if ((i == 0) || ((i == 1) && (buf[0] == 'q'))) { - /* - * Someone closed the write end of the pipe or sent us a Quit - * message [Bug: 4139] and then closed the write end of the - * pipe so we need to shut down the notifier thread. - */ - - break; - } - } - } - - /* - * Clean up the read end of the pipe and signal any threads waiting on - * termination of the notifier thread. - */ - - close(receivePipe); - pthread_mutex_lock(¬ifierMutex); - triggerPipe = -1; - pthread_cond_broadcast(¬ifierCV); - pthread_mutex_unlock(¬ifierMutex); - - TclpThreadExit(0); } #if defined(HAVE_PTHREAD_ATFORK) @@ -1407,6 +395,7 @@ AtForkChild(void) pthread_cond_destroy(&tsdPtr->waitCV); pthread_cond_init(&tsdPtr->waitCV, NULL); #endif + /* * In case, we had multiple threads running before the fork, * make sure, we don't try to reach out to their thread local data. @@ -1426,8 +415,157 @@ AtForkChild(void) #endif /* TCL_THREADS */ +#endif /* NOTIFIER_SELECT */ +#ifndef HAVE_COREFOUNDATION /* Darwin/Mac OS X CoreFoundation notifier is + * in tclMacOSXNotify.c */ +/* + *---------------------------------------------------------------------- + * + * TclUnixWaitForFile -- + * + * This function waits synchronously for a file to become readable or + * writable, with an optional timeout. + * + * Results: + * The return value is an OR'ed combination of TCL_READABLE, + * TCL_WRITABLE, and TCL_EXCEPTION, indicating the conditions that are + * present on file at the time of the return. This function will not + * return until either "timeout" milliseconds have elapsed or at least + * one of the conditions given by mask has occurred for file (a return + * value of 0 means that a timeout occurred). No normal events will be + * serviced during the execution of this function. + * + * Side effects: + * Time passes. + * + *---------------------------------------------------------------------- + */ + +int +TclUnixWaitForFile( + int fd, /* Handle for file on which to wait. */ + int mask, /* What to wait for: OR'ed combination of + * TCL_READABLE, TCL_WRITABLE, and + * TCL_EXCEPTION. */ + int timeout) /* Maximum amount of time to wait for one of + * the conditions in mask to occur, in + * milliseconds. A value of 0 means don't wait + * at all, and a value of -1 means wait + * forever. */ +{ + Tcl_Time abortTime = {0, 0}, now; /* silence gcc 4 warning */ + struct timeval blockTime, *timeoutPtr; + struct pollfd pollFds[1]; + int numFound, result = 0, pollTimeout; + + /* + * If there is a non-zero finite timeout, compute the time when we give + * up. + */ + + if (timeout > 0) { + Tcl_GetTime(&now); + abortTime.sec = now.sec + timeout/1000; + abortTime.usec = now.usec + (timeout%1000)*1000; + if (abortTime.usec >= 1000000) { + abortTime.usec -= 1000000; + abortTime.sec += 1; + } + timeoutPtr = &blockTime; + } else if (timeout == 0) { + timeoutPtr = &blockTime; + blockTime.tv_sec = 0; + blockTime.tv_usec = 0; + } else { + timeoutPtr = NULL; + } + + /* + * Setup the pollfd structure for the fd. + */ + + pollFds[0].fd = fd; + pollFds[0].events = pollFds[0].revents = 0; + if (mask & TCL_READABLE) { + pollFds[0].events |= (POLLIN | POLLHUP); + } + if (mask & TCL_WRITABLE) { + pollFds[0].events |= POLLOUT; + } + if (mask & TCL_EXCEPTION) { + pollFds[0].events |= POLLERR; + } + + /* + * Loop in a mini-event loop of our own, waiting for either the file to + * become ready or a timeout to occur. + */ + + while (1) { + if (timeout > 0) { + blockTime.tv_sec = abortTime.sec - now.sec; + blockTime.tv_usec = abortTime.usec - now.usec; + if (blockTime.tv_usec < 0) { + blockTime.tv_sec -= 1; + blockTime.tv_usec += 1000000; + } + if (blockTime.tv_sec < 0) { + blockTime.tv_sec = 0; + blockTime.tv_usec = 0; + } + } + + /* + * Wait for the event or a timeout. + */ + + if (!timeoutPtr) { + pollTimeout = -1; + } else if (!timeoutPtr->tv_sec && !timeoutPtr->tv_usec) { + pollTimeout = 0; + } else { + pollTimeout = (int)timeoutPtr->tv_sec * 1000; + if (timeoutPtr->tv_usec) { + pollTimeout += ((int)timeoutPtr->tv_usec / 1000); + } + } + numFound = poll(pollFds, 1, pollTimeout); + if (numFound == 1) { + result = 0; + if (pollFds[0].events & (POLLIN | POLLHUP)) { + result |= TCL_READABLE; + } + if (pollFds[0].events & POLLOUT) { + result |= TCL_WRITABLE; + } + if (pollFds[0].events & POLLERR) { + result |= TCL_EXCEPTION; + } + if (result) { + break; + } + } + if (timeout == 0) { + break; + } + if (timeout < 0) { + continue; + } + + /* + * The select returned early, so we need to recompute the timeout. + */ + + Tcl_GetTime(&now); + if ((abortTime.sec < now.sec) + || (abortTime.sec==now.sec && abortTime.usec<=now.usec)) { + break; + } + } + return result; +} #endif /* !HAVE_COREFOUNDATION */ - + /* * Local Variables: * mode: c |