+++ /dev/null
-/* A simple event-driven programming library. Originally I wrote this code
- * for the Jim's event-loop (Jim is a Tcl interpreter) but later translated
- * it in form of a library for easy reuse.
- *
- * Copyright (c) 2006-2010, Salvatore Sanfilippo <antirez at gmail dot com>
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * * Redistributions of source code must retain the above copyright notice,
- * this list of conditions and the following disclaimer.
- * * Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * * Neither the name of Redis nor the names of its contributors may be used
- * to endorse or promote products derived from this software without
- * specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include <stdio.h>
-#include <sys/time.h>
-#include <sys/types.h>
-#include <unistd.h>
-#include <stdlib.h>
-
-#include "ae.h"
-#include "zmalloc.h"
-#include "config.h"
-
-/* Include the best multiplexing layer supported by this system.
- * The following should be ordered by performances, descending. */
-#ifdef HAVE_EPOLL
-#include "ae_epoll.c"
-#else
- #ifdef HAVE_KQUEUE
- #include "ae_kqueue.c"
- #else
- #include "ae_select.c"
- #endif
-#endif
-
-aeEventLoop *aeCreateEventLoop(void) {
- aeEventLoop *eventLoop;
- int i;
-
- eventLoop = zmalloc(sizeof(*eventLoop));
- if (!eventLoop) return NULL;
- eventLoop->timeEventHead = NULL;
- eventLoop->timeEventNextId = 0;
- eventLoop->stop = 0;
- eventLoop->maxfd = -1;
- eventLoop->beforesleep = NULL;
- if (aeApiCreate(eventLoop) == -1) {
- zfree(eventLoop);
- return NULL;
- }
- /* Events with mask == AE_NONE are not set. So let's initialize the
- * vector with it. */
- for (i = 0; i < AE_SETSIZE; i++)
- eventLoop->events[i].mask = AE_NONE;
- return eventLoop;
-}
-
-void aeDeleteEventLoop(aeEventLoop *eventLoop) {
- aeApiFree(eventLoop);
- zfree(eventLoop);
-}
-
-void aeStop(aeEventLoop *eventLoop) {
- eventLoop->stop = 1;
-}
-
-int aeCreateFileEvent(aeEventLoop *eventLoop, int fd, int mask,
- aeFileProc *proc, void *clientData)
-{
- if (fd >= AE_SETSIZE) return AE_ERR;
- aeFileEvent *fe = &eventLoop->events[fd];
-
- if (aeApiAddEvent(eventLoop, fd, mask) == -1)
- return AE_ERR;
- fe->mask |= mask;
- if (mask & AE_READABLE) fe->rfileProc = proc;
- if (mask & AE_WRITABLE) fe->wfileProc = proc;
- fe->clientData = clientData;
- if (fd > eventLoop->maxfd)
- eventLoop->maxfd = fd;
- return AE_OK;
-}
-
-void aeDeleteFileEvent(aeEventLoop *eventLoop, int fd, int mask)
-{
- if (fd >= AE_SETSIZE) return;
- aeFileEvent *fe = &eventLoop->events[fd];
-
- if (fe->mask == AE_NONE) return;
- fe->mask = fe->mask & (~mask);
- if (fd == eventLoop->maxfd && fe->mask == AE_NONE) {
- /* Update the max fd */
- int j;
-
- for (j = eventLoop->maxfd-1; j >= 0; j--)
- if (eventLoop->events[j].mask != AE_NONE) break;
- eventLoop->maxfd = j;
- }
- aeApiDelEvent(eventLoop, fd, mask);
-}
-
-static void aeGetTime(long *seconds, long *milliseconds)
-{
- struct timeval tv;
-
- gettimeofday(&tv, NULL);
- *seconds = tv.tv_sec;
- *milliseconds = tv.tv_usec/1000;
-}
-
-static void aeAddMillisecondsToNow(long long milliseconds, long *sec, long *ms) {
- long cur_sec, cur_ms, when_sec, when_ms;
-
- aeGetTime(&cur_sec, &cur_ms);
- when_sec = cur_sec + milliseconds/1000;
- when_ms = cur_ms + milliseconds%1000;
- if (when_ms >= 1000) {
- when_sec ++;
- when_ms -= 1000;
- }
- *sec = when_sec;
- *ms = when_ms;
-}
-
-long long aeCreateTimeEvent(aeEventLoop *eventLoop, long long milliseconds,
- aeTimeProc *proc, void *clientData,
- aeEventFinalizerProc *finalizerProc)
-{
- long long id = eventLoop->timeEventNextId++;
- aeTimeEvent *te;
-
- te = zmalloc(sizeof(*te));
- if (te == NULL) return AE_ERR;
- te->id = id;
- aeAddMillisecondsToNow(milliseconds,&te->when_sec,&te->when_ms);
- te->timeProc = proc;
- te->finalizerProc = finalizerProc;
- te->clientData = clientData;
- te->next = eventLoop->timeEventHead;
- eventLoop->timeEventHead = te;
- return id;
-}
-
-int aeDeleteTimeEvent(aeEventLoop *eventLoop, long long id)
-{
- aeTimeEvent *te, *prev = NULL;
-
- te = eventLoop->timeEventHead;
- while(te) {
- if (te->id == id) {
- if (prev == NULL)
- eventLoop->timeEventHead = te->next;
- else
- prev->next = te->next;
- if (te->finalizerProc)
- te->finalizerProc(eventLoop, te->clientData);
- zfree(te);
- return AE_OK;
- }
- prev = te;
- te = te->next;
- }
- return AE_ERR; /* NO event with the specified ID found */
-}
-
-/* Search the first timer to fire.
- * This operation is useful to know how many time the select can be
- * put in sleep without to delay any event.
- * If there are no timers NULL is returned.
- *
- * Note that's O(N) since time events are unsorted.
- * Possible optimizations (not needed by Redis so far, but...):
- * 1) Insert the event in order, so that the nearest is just the head.
- * Much better but still insertion or deletion of timers is O(N).
- * 2) Use a skiplist to have this operation as O(1) and insertion as O(log(N)).
- */
-static aeTimeEvent *aeSearchNearestTimer(aeEventLoop *eventLoop)
-{
- aeTimeEvent *te = eventLoop->timeEventHead;
- aeTimeEvent *nearest = NULL;
-
- while(te) {
- if (!nearest || te->when_sec < nearest->when_sec ||
- (te->when_sec == nearest->when_sec &&
- te->when_ms < nearest->when_ms))
- nearest = te;
- te = te->next;
- }
- return nearest;
-}
-
-/* Process time events */
-static int processTimeEvents(aeEventLoop *eventLoop) {
- int processed = 0;
- aeTimeEvent *te;
- long long maxId;
-
- te = eventLoop->timeEventHead;
- maxId = eventLoop->timeEventNextId-1;
- while(te) {
- long now_sec, now_ms;
- long long id;
-
- if (te->id > maxId) {
- te = te->next;
- continue;
- }
- aeGetTime(&now_sec, &now_ms);
- if (now_sec > te->when_sec ||
- (now_sec == te->when_sec && now_ms >= te->when_ms))
- {
- int retval;
-
- id = te->id;
- retval = te->timeProc(eventLoop, id, te->clientData);
- processed++;
- /* After an event is processed our time event list may
- * no longer be the same, so we restart from head.
- * Still we make sure to don't process events registered
- * by event handlers itself in order to don't loop forever.
- * To do so we saved the max ID we want to handle.
- *
- * FUTURE OPTIMIZATIONS:
- * Note that this is NOT great algorithmically. Redis uses
- * a single time event so it's not a problem but the right
- * way to do this is to add the new elements on head, and
- * to flag deleted elements in a special way for later
- * deletion (putting references to the nodes to delete into
- * another linked list). */
- if (retval != AE_NOMORE) {
- aeAddMillisecondsToNow(retval,&te->when_sec,&te->when_ms);
- } else {
- aeDeleteTimeEvent(eventLoop, id);
- }
- te = eventLoop->timeEventHead;
- } else {
- te = te->next;
- }
- }
- return processed;
-}
-
-/* Process every pending time event, then every pending file event
- * (that may be registered by time event callbacks just processed).
- * Without special flags the function sleeps until some file event
- * fires, or when the next time event occurrs (if any).
- *
- * If flags is 0, the function does nothing and returns.
- * if flags has AE_ALL_EVENTS set, all the kind of events are processed.
- * if flags has AE_FILE_EVENTS set, file events are processed.
- * if flags has AE_TIME_EVENTS set, time events are processed.
- * if flags has AE_DONT_WAIT set the function returns ASAP until all
- * the events that's possible to process without to wait are processed.
- *
- * The function returns the number of events processed. */
-int aeProcessEvents(aeEventLoop *eventLoop, int flags)
-{
- int processed = 0, numevents;
-
- /* Nothing to do? return ASAP */
- if (!(flags & AE_TIME_EVENTS) && !(flags & AE_FILE_EVENTS)) return 0;
-
- /* Note that we want call select() even if there are no
- * file events to process as long as we want to process time
- * events, in order to sleep until the next time event is ready
- * to fire. */
- if (eventLoop->maxfd != -1 ||
- ((flags & AE_TIME_EVENTS) && !(flags & AE_DONT_WAIT))) {
- int j;
- aeTimeEvent *shortest = NULL;
- struct timeval tv, *tvp;
-
- if (flags & AE_TIME_EVENTS && !(flags & AE_DONT_WAIT))
- shortest = aeSearchNearestTimer(eventLoop);
- if (shortest) {
- long now_sec, now_ms;
-
- /* Calculate the time missing for the nearest
- * timer to fire. */
- aeGetTime(&now_sec, &now_ms);
- tvp = &tv;
- tvp->tv_sec = shortest->when_sec - now_sec;
- if (shortest->when_ms < now_ms) {
- tvp->tv_usec = ((shortest->when_ms+1000) - now_ms)*1000;
- tvp->tv_sec --;
- } else {
- tvp->tv_usec = (shortest->when_ms - now_ms)*1000;
- }
- if (tvp->tv_sec < 0) tvp->tv_sec = 0;
- if (tvp->tv_usec < 0) tvp->tv_usec = 0;
- } else {
- /* If we have to check for events but need to return
- * ASAP because of AE_DONT_WAIT we need to se the timeout
- * to zero */
- if (flags & AE_DONT_WAIT) {
- tv.tv_sec = tv.tv_usec = 0;
- tvp = &tv;
- } else {
- /* Otherwise we can block */
- tvp = NULL; /* wait forever */
- }
- }
-
- numevents = aeApiPoll(eventLoop, tvp);
- for (j = 0; j < numevents; j++) {
- aeFileEvent *fe = &eventLoop->events[eventLoop->fired[j].fd];
- int mask = eventLoop->fired[j].mask;
- int fd = eventLoop->fired[j].fd;
- int rfired = 0;
-
- /* note the fe->mask & mask & ... code: maybe an already processed
- * event removed an element that fired and we still didn't
- * processed, so we check if the event is still valid. */
- if (fe->mask & mask & AE_READABLE) {
- rfired = 1;
- fe->rfileProc(eventLoop,fd,fe->clientData,mask);
- }
- if (fe->mask & mask & AE_WRITABLE) {
- if (!rfired || fe->wfileProc != fe->rfileProc)
- fe->wfileProc(eventLoop,fd,fe->clientData,mask);
- }
- processed++;
- }
- }
- /* Check time events */
- if (flags & AE_TIME_EVENTS)
- processed += processTimeEvents(eventLoop);
-
- return processed; /* return the number of processed file/time events */
-}
-
-/* Wait for millseconds until the given file descriptor becomes
- * writable/readable/exception */
-int aeWait(int fd, int mask, long long milliseconds) {
- struct timeval tv;
- fd_set rfds, wfds, efds;
- int retmask = 0, retval;
-
- tv.tv_sec = milliseconds/1000;
- tv.tv_usec = (milliseconds%1000)*1000;
- FD_ZERO(&rfds);
- FD_ZERO(&wfds);
- FD_ZERO(&efds);
-
- if (mask & AE_READABLE) FD_SET(fd,&rfds);
- if (mask & AE_WRITABLE) FD_SET(fd,&wfds);
- if ((retval = select(fd+1, &rfds, &wfds, &efds, &tv)) > 0) {
- if (FD_ISSET(fd,&rfds)) retmask |= AE_READABLE;
- if (FD_ISSET(fd,&wfds)) retmask |= AE_WRITABLE;
- return retmask;
- } else {
- return retval;
- }
-}
-
-void aeMain(aeEventLoop *eventLoop) {
- eventLoop->stop = 0;
- while (!eventLoop->stop) {
- if (eventLoop->beforesleep != NULL)
- eventLoop->beforesleep(eventLoop);
- aeProcessEvents(eventLoop, AE_ALL_EVENTS);
- }
-}
-
-char *aeGetApiName(void) {
- return aeApiName();
-}
-
-void aeSetBeforeSleepProc(aeEventLoop *eventLoop, aeBeforeSleepProc *beforesleep) {
- eventLoop->beforesleep = beforesleep;
-}
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