--- /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;
+}
projects / redis.git / blobdiff