diff options
Diffstat (limited to 'unix/tclEpollNotfy.c')
| -rw-r--r-- | unix/tclEpollNotfy.c | 225 |
1 files changed, 124 insertions, 101 deletions
diff --git a/unix/tclEpollNotfy.c b/unix/tclEpollNotfy.c index 2abfd47..7a5e09d 100644 --- a/unix/tclEpollNotfy.c +++ b/unix/tclEpollNotfy.c @@ -2,8 +2,8 @@ * tclEpollNotfy.c -- * * This file contains the implementation of the epoll()-based - * Linux-specific notifier, which is the lowest-level part of the - * Tcl event loop. This file works together with generic/tclNotify.c. + * Linux-specific 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 (c) 2016 Lucio Andrés Illanes Albornoz <l.illanes@gmx.de> @@ -13,11 +13,10 @@ */ #include "tclInt.h" -#if defined(NOTIFIER_EPOLL) && TCL_THREADS - -#define _GNU_SOURCE /* For pipe2(2) */ #ifndef HAVE_COREFOUNDATION /* Darwin/Mac OS X CoreFoundation notifier is * in tclMacOSXNotify.c */ +#if defined(NOTIFIER_EPOLL) && TCL_THREADS +#define _GNU_SOURCE /* For pipe2(2) */ #include <fcntl.h> #include <signal.h> #include <sys/epoll.h> @@ -54,9 +53,9 @@ typedef struct FileHandler { } FileHandler; /* - * The following structure associates a FileHandler and the thread that owns it - * with the file descriptors of interest and their event masks passed to epoll_ctl(2) - * and their corresponding event(s) returned by epoll_wait(2). + * The following structure associates a FileHandler and the thread that owns + * it with the file descriptors of interest and their event masks passed to + * epoll_ctl(2) and their corresponding event(s) returned by epoll_wait(2). */ struct ThreadSpecificData; @@ -105,7 +104,8 @@ typedef struct ThreadSpecificData { int triggerPipe[2]; /* pipe(2) used by other threads to wake * up this thread for inter-thread IPC. */ #endif /* HAVE_EVENTFD */ - int eventsFd; /* epoll(7) file descriptor used to wait for fds */ + int eventsFd; /* epoll(7) file descriptor used to wait for + * fds */ struct epoll_event *readyEvents; /* Pointer to at most maxReadyEvents events * returned by epoll_wait(2). */ @@ -113,13 +113,23 @@ typedef struct ThreadSpecificData { } ThreadSpecificData; static Tcl_ThreadDataKey dataKey; - -static void PlatformEventsControl(FileHandler *filePtr, ThreadSpecificData *tsdPtr, int op, int isNew); -static void PlatformEventsFinalize(void); -static void PlatformEventsInit(void); -static int PlatformEventsTranslate(struct epoll_event *event); -static int PlatformEventsWait(struct epoll_event *events, size_t numEvents, struct timeval *timePtr); - + +/* + * Forward declarations. + */ + +static void PlatformEventsControl(FileHandler *filePtr, + ThreadSpecificData *tsdPtr, int op, int isNew); +static void PlatformEventsFinalize(void); +static void PlatformEventsInit(void); +static int PlatformEventsTranslate(struct epoll_event *event); +static int PlatformEventsWait(struct epoll_event *events, + size_t numEvents, struct timeval *timePtr); + +/* + * Incorporate the base notifier API. + */ + #include "tclUnixNotfy.c" /* @@ -190,31 +200,32 @@ Tcl_FinalizeNotifier( * This function registers interest for the file descriptor and the mask * of TCL_* bits associated with filePtr on the epoll file descriptor * associated with tsdPtr. - * Future calls to epoll_wait will return filePtr and tsdPtr alongside with - * the event registered here via the PlatformEventData struct. + * + * Future calls to epoll_wait will return filePtr and tsdPtr alongside + * with the event registered here via the PlatformEventData struct. * * Results: * None. * * Side effects: - * If adding a new file descriptor, a PlatformEventData struct will be - * allocated and associated with filePtr. - * fstat is called on the file descriptor; if it is associated with - * a regular file (S_IFREG,) filePtr is considered to be ready for I/O - * and added to or deleted from the corresponding list in tsdPtr. - * If it is not associated with a regular file, the file descriptor is - * added, modified concerning its mask of events of interest, or deleted - * from the epoll file descriptor of the calling thread. + * - If adding a new file descriptor, a PlatformEventData struct will be + * allocated and associated with filePtr. + * - fstat is called on the file descriptor; if it is associated with a + * regular file (S_IFREG,) filePtr is considered to be ready for I/O + * and added to or deleted from the corresponding list in tsdPtr. + * - If it is not associated with a regular file, the file descriptor is + * added, modified concerning its mask of events of interest, or + * deleted from the epoll file descriptor of the calling thread. * *---------------------------------------------------------------------- */ void PlatformEventsControl( - FileHandler *filePtr, - ThreadSpecificData *tsdPtr, - int op, - int isNew) + FileHandler *filePtr, + ThreadSpecificData *tsdPtr, + int op, + int isNew) { struct epoll_event newEvent; struct PlatformEventData *newPedPtr; @@ -236,10 +247,10 @@ PlatformEventsControl( newEvent.data.ptr = filePtr->pedPtr; /* - * N.B. As discussed in Tcl_WaitForEvent(), epoll(7) does not sup- - * port regular files (S_IFREG.) Therefore, filePtr is in these - * cases simply added or deleted from the list of FileHandlers - * associated with regular files belonging to tsdPtr. + * N.B. As discussed in Tcl_WaitForEvent(), epoll(7) does not support + * regular files (S_IFREG.) Therefore, filePtr is in these cases simply + * added or deleted from the list of FileHandlers associated with regular + * files belonging to tsdPtr. */ if (fstat(filePtr->fd, &fdStat) == -1) { @@ -248,7 +259,8 @@ PlatformEventsControl( switch (op) { case EPOLL_CTL_ADD: if (isNew) { - LIST_INSERT_HEAD(&tsdPtr->firstReadyFileHandlerPtr, filePtr, readyNode); + LIST_INSERT_HEAD(&tsdPtr->firstReadyFileHandlerPtr, filePtr, + readyNode); } break; case EPOLL_CTL_DEL: @@ -267,18 +279,18 @@ PlatformEventsControl( * PlatformEventsFinalize -- * * This function closes the eventfd and the epoll file descriptor and - * frees the epoll_event structs owned by the thread of the caller. - * The above operations are protected by tsdPtr->notifierMutex, which - * is destroyed thereafter. + * frees the epoll_event structs owned by the thread of the caller. The + * above operations are protected by tsdPtr->notifierMutex, which is + * destroyed thereafter. * * Results: * None. * * Side effects: * While tsdPtr->notifierMutex is held: - * The per-thread eventfd(2) is closed, if non-zero, and set to -1. - * The per-thread epoll(7) fd is closed, if non-zero, and set to 0. - * The per-thread epoll_event structs are freed, if any, and set to 0. + * - The per-thread eventfd(2) is closed, if non-zero, and set to -1. + * - The per-thread epoll(7) fd is closed, if non-zero, and set to 0. + * - The per-thread epoll_event structs are freed, if any, and set to 0. * * tsdPtr->notifierMutex is destroyed. * @@ -297,7 +309,7 @@ PlatformEventsFinalize( close(tsdPtr->triggerEventFd); tsdPtr->triggerEventFd = -1; } -#else +#else /* !HAVE_EVENTFD */ if (tsdPtr->triggerPipe[0]) { close(tsdPtr->triggerPipe[0]); tsdPtr->triggerPipe[0] = -1; @@ -337,20 +349,20 @@ PlatformEventsFinalize( * * Side effects: * The following per-thread entities are initialised: - * notifierMutex is initialised. - * The eventfd(2) is created w/ EFD_CLOEXEC and EFD_NONBLOCK. - * The epoll(7) fd is created w/ EPOLL_CLOEXEC. - * A FileHandler struct is allocated and initialised for the event- - * fd(2), registering interest for TCL_READABLE on it via Platform- - * EventsControl(). - * readyEvents and maxReadyEvents are initialised with 512 epoll_events. + * - notifierMutex is initialised. + * - The eventfd(2) is created w/ EFD_CLOEXEC and EFD_NONBLOCK. + * - The epoll(7) fd is created w/ EPOLL_CLOEXEC. + * - A FileHandler struct is allocated and initialised for the + * eventfd(2), registering interest for TCL_READABLE on it via + * PlatformEventsControl(). + * - readyEvents and maxReadyEvents are initialised with 512 + * epoll_events. * *---------------------------------------------------------------------- */ void -PlatformEventsInit( - void) +PlatformEventsInit(void) { ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); FileHandler *filePtr; @@ -361,16 +373,17 @@ PlatformEventsInit( } filePtr = ckalloc(sizeof(*filePtr)); #ifdef HAVE_EVENTFD - if ((tsdPtr->triggerEventFd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK)) <= 0) { + tsdPtr->triggerEventFd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK); + if (tsdPtr->triggerEventFd <= 0) { Tcl_Panic("Tcl_InitNotifier: %s", "could not create trigger eventfd"); } filePtr->fd = tsdPtr->triggerEventFd; -#else +#else /* !HAVE_EVENTFD */ if (pipe2(tsdPtr->triggerPipe, O_CLOEXEC | O_NONBLOCK) != 0) { Tcl_Panic("Tcl_InitNotifier: %s", "could not create trigger pipe"); } filePtr->fd = tsdPtr->triggerPipe[0]; -#endif +#endif /* HAVE_EVENTFD */ tsdPtr->triggerFilePtr = filePtr; if ((tsdPtr->eventsFd = epoll_create1(EPOLL_CLOEXEC)) == -1) { Tcl_Panic("epoll_create1: %s", strerror(errno)); @@ -379,8 +392,8 @@ PlatformEventsInit( PlatformEventsControl(filePtr, tsdPtr, EPOLL_CTL_ADD, 1); if (!tsdPtr->readyEvents) { tsdPtr->maxReadyEvents = 512; - tsdPtr->readyEvents = ckalloc(tsdPtr->maxReadyEvents - * sizeof(tsdPtr->readyEvents[0])); + tsdPtr->readyEvents = ckalloc( + tsdPtr->maxReadyEvents * sizeof(tsdPtr->readyEvents[0])); } LIST_INIT(&tsdPtr->firstReadyFileHandlerPtr); } @@ -390,8 +403,8 @@ PlatformEventsInit( * * PlatformEventsTranslate -- * - * This function translates the platform-specific mask of returned - * events in eventPtr to a mask of TCL_* bits. + * This function translates the platform-specific mask of returned events + * in eventPtr to a mask of TCL_* bits. * * Results: * Returns the translated mask. @@ -404,7 +417,7 @@ PlatformEventsInit( int PlatformEventsTranslate( - struct epoll_event *eventPtr) + struct epoll_event *eventPtr) { int mask; @@ -429,16 +442,16 @@ PlatformEventsTranslate( * This function abstracts waiting for I/O events via epoll_wait. * * Results: - * Returns -1 if epoll_wait failed. Returns 0 if polling and if no - * events became available whilst polling. Returns a pointer to and - * the count of all returned events in all other cases. + * Returns -1 if epoll_wait failed. Returns 0 if polling and if no events + * became available whilst polling. Returns a pointer to and the count of + * all returned events in all other cases. * * Side effects: - * gettimeofday(2), epoll_wait(2), and gettimeofday(2) are called, - * in the specified order. - * If timePtr specifies a positive value, it is updated to reflect - * the amount of time that has passed; if its value would {under, - * over}flow, it is set to zero. + * gettimeofday(2), epoll_wait(2), and gettimeofday(2) are called, in the + * specified order. + * If timePtr specifies a positive value, it is updated to reflect the + * amount of time that has passed; if its value would {under, over}flow, + * it is set to zero. * *---------------------------------------------------------------------- */ @@ -457,8 +470,8 @@ PlatformEventsWait( /* * If timePtr is NULL, epoll_wait(2) will wait indefinitely. If it - * specifies a timeout of {0,0}, epoll_wait(2) will poll. Otherwise, - * the timeout will simply be converted to milliseconds. + * specifies a timeout of {0,0}, epoll_wait(2) will poll. Otherwise, the + * timeout will simply be converted to milliseconds. */ if (!timePtr) { @@ -473,9 +486,9 @@ PlatformEventsWait( } /* - * Call (and possibly block on) epoll_wait(2) and substract the delta - * of gettimeofday(2) before and after the call from timePtr if the - * latter is not NULL. Return the number of events returned by epoll_wait(2). + * Call (and possibly block on) epoll_wait(2) and substract the delta of + * gettimeofday(2) before and after the call from timePtr if the latter is + * not NULL. Return the number of events returned by epoll_wait(2). */ gettimeofday(&tv0, NULL); @@ -484,10 +497,10 @@ PlatformEventsWait( if (timePtr && (timePtr->tv_sec && timePtr->tv_usec)) { timersub(&tv1, &tv0, &tv_delta); if (!timercmp(&tv_delta, timePtr, >)) { - timersub(timePtr, &tv_delta, timePtr); + timersub(timePtr, &tv_delta, timePtr); } else { - timePtr->tv_sec = 0; - timePtr->tv_usec = 0; + timePtr->tv_sec = 0; + timePtr->tv_usec = 0; } } return numFound; @@ -498,8 +511,8 @@ PlatformEventsWait( * * Tcl_CreateFileHandler -- * - * This function registers a file handler with the epoll notifier - * of the thread of the caller. + * This function registers a file handler with the epoll notifier of the + * thread of the caller. * * Results: * None. @@ -551,8 +564,8 @@ Tcl_CreateFileHandler( filePtr->clientData = clientData; filePtr->mask = mask; - PlatformEventsControl(filePtr, tsdPtr, isNew ? - EPOLL_CTL_ADD : EPOLL_CTL_MOD, isNew); + PlatformEventsControl(filePtr, tsdPtr, + isNew ? EPOLL_CTL_ADD : EPOLL_CTL_MOD, isNew); } } @@ -561,8 +574,8 @@ Tcl_CreateFileHandler( * * Tcl_DeleteFileHandler -- * - * Cancel a previously-arranged callback arrangement for a file on - * the epoll file descriptor of the thread of the caller. + * Cancel a previously-arranged callback arrangement for a file on the + * epoll file descriptor of the thread of the caller. * * Results: * None. @@ -632,6 +645,7 @@ Tcl_DeleteFileHandler( * 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. + * * The waiting logic is implemented in PlatformEventsWait. * * Results: @@ -646,7 +660,7 @@ Tcl_DeleteFileHandler( int Tcl_WaitForEvent( - const Tcl_Time *timePtr) /* Maximum block time, or NULL. */ + const Tcl_Time *timePtr) /* Maximum block time, or NULL. */ { if (tclNotifierHooks.waitForEventProc) { return tclNotifierHooks.waitForEventProc(timePtr); @@ -696,10 +710,11 @@ Tcl_WaitForEvent( * Walk the list of FileHandlers associated with regular files * (S_IFREG) belonging to tsdPtr, queue Tcl events for them, and * update their mask of events of interest. + * * As epoll(7) does not support regular files, the behaviour of * {select,poll}(2) is simply simulated here: fds associated with - * regular files are added to this list by PlatformEventsControl() - * and processed here before calling (and possibly blocking) on + * regular files are added to this list by PlatformEventsControl() and + * processed here before calling (and possibly blocking) on * PlatformEventsWait(). */ @@ -720,7 +735,7 @@ Tcl_WaitForEvent( if (filePtr->readyMask == 0) { FileHandlerEvent *fileEvPtr = - ckalloc(sizeof(FileHandlerEvent)); + ckalloc(sizeof(FileHandlerEvent)); fileEvPtr->header.proc = FileHandlerEventProc; fileEvPtr->fd = filePtr->fd; @@ -731,9 +746,9 @@ Tcl_WaitForEvent( } /* - * If any events were queued in the above loop, force PlatformEvents- - * Wait() to poll as there already are events that need to be processed - * at this point. + * If any events were queued in the above loop, force + * PlatformEventsWait() to poll as there already are events that need + * to be processed at this point. */ if (numQueued) { @@ -751,10 +766,12 @@ Tcl_WaitForEvent( * to facilitate inter-thread IPC. If another thread intends to wake * up this thread whilst it's blocking on PlatformEventsWait(), it * write(2)s to the eventfd(2)/trigger pipe (see Tcl_AlertNotifier(),) - * which in turn will cause PlatformEventsWait() to return immediately. + * which in turn will cause PlatformEventsWait() to return + * immediately. */ - numFound = PlatformEventsWait(tsdPtr->readyEvents, tsdPtr->maxReadyEvents, timeoutPtr); + numFound = PlatformEventsWait(tsdPtr->readyEvents, + tsdPtr->maxReadyEvents, timeoutPtr); for (numEvent = 0; numEvent < numFound; numEvent++) { pedPtr = tsdPtr->readyEvents[numEvent].data.ptr; filePtr = pedPtr->filePtr; @@ -762,21 +779,28 @@ Tcl_WaitForEvent( #ifdef HAVE_EVENTFD if (filePtr->fd == tsdPtr->triggerEventFd) { uint64_t eventFdVal; - i = read(tsdPtr->triggerEventFd, &eventFdVal, sizeof(eventFdVal)); + i = read(tsdPtr->triggerEventFd, &eventFdVal, + sizeof(eventFdVal)); if ((i != sizeof(eventFdVal)) && (errno != EAGAIN)) { -#else + Tcl_Panic( + "Tcl_WaitForEvent: read from %p->triggerEventFd: %s", + (void *) tsdPtr, strerror(errno)); + } + continue; + } +#else /* !HAVE_EVENTFD */ if (filePtr->fd == tsdPtr->triggerPipe[0]) { char triggerPipeVal; - i = read(tsdPtr->triggerPipe[0], &triggerPipeVal, sizeof(triggerPipeVal)); + i = read(tsdPtr->triggerPipe[0], &triggerPipeVal, + sizeof(triggerPipeVal)); if ((i != sizeof(triggerPipeVal)) && (errno != EAGAIN)) { -#endif - Tcl_Panic("Tcl_WaitForEvent: " - "read from %p->triggerEventFd: %s", - (void *)tsdPtr, strerror(errno)); - } else { - continue; + Tcl_Panic( + "Tcl_WaitForEvent: read from %p->triggerPipe[0]: %s", + (void *) tsdPtr, strerror(errno)); } + continue; } +#endif /* HAVE_EVENTFD */ if (!mask) { continue; } @@ -800,9 +824,8 @@ Tcl_WaitForEvent( } } +#endif /* NOTIFIER_EPOLL && TCL_THREADS */ #endif /* !HAVE_COREFOUNDATION */ - -#endif /* NOTIFIER_EPOLL */ /* * Local Variables: |