1 /* Linux epoll(2) based ae.c module
2 *
3 * Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are met:
8 *
9 * * Redistributions of source code must retain the above copyright notice,
10 * this list of conditions and the following disclaimer.
11 * * Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * * Neither the name of Redis nor the names of its contributors may be used
15 * to endorse or promote products derived from this software without
16 * specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31
32 #include <sys/epoll.h>
33
34 typedef struct aeApiState {
35 int epfd;
36 struct epoll_event *events;
37 } aeApiState;
38
aeApiCreate(aeEventLoop * eventLoop)39 static int aeApiCreate(aeEventLoop *eventLoop) {
40 aeApiState *state = zmalloc(sizeof(aeApiState));
41
42 if (!state) return -1;
43 state->events = zmalloc(sizeof(struct epoll_event)*eventLoop->setsize);
44 if (!state->events) {
45 zfree(state);
46 return -1;
47 }
48 state->epfd = epoll_create(1024); /* 1024 is just a hint for the kernel */
49 if (state->epfd == -1) {
50 zfree(state->events);
51 zfree(state);
52 return -1;
53 }
54 eventLoop->apidata = state;
55 return 0;
56 }
57
aeApiResize(aeEventLoop * eventLoop,int setsize)58 static int aeApiResize(aeEventLoop *eventLoop, int setsize) {
59 aeApiState *state = eventLoop->apidata;
60
61 state->events = zrealloc(state->events, sizeof(struct epoll_event)*setsize);
62 return 0;
63 }
64
aeApiFree(aeEventLoop * eventLoop)65 static void aeApiFree(aeEventLoop *eventLoop) {
66 aeApiState *state = eventLoop->apidata;
67
68 close(state->epfd);
69 zfree(state->events);
70 zfree(state);
71 }
72
aeApiAddEvent(aeEventLoop * eventLoop,int fd,int mask)73 static int aeApiAddEvent(aeEventLoop *eventLoop, int fd, int mask) {
74 aeApiState *state = eventLoop->apidata;
75 struct epoll_event ee = {0}; /* avoid valgrind warning */
76 /* If the fd was already monitored for some event, we need a MOD
77 * operation. Otherwise we need an ADD operation. */
78 int op = eventLoop->events[fd].mask == AE_NONE ?
79 EPOLL_CTL_ADD : EPOLL_CTL_MOD;
80
81 ee.events = 0;
82 mask |= eventLoop->events[fd].mask; /* Merge old events */
83 if (mask & AE_READABLE) ee.events |= EPOLLIN;
84 if (mask & AE_WRITABLE) ee.events |= EPOLLOUT;
85 ee.data.fd = fd;
86 if (epoll_ctl(state->epfd,op,fd,&ee) == -1) return -1;
87 return 0;
88 }
89
aeApiDelEvent(aeEventLoop * eventLoop,int fd,int delmask)90 static void aeApiDelEvent(aeEventLoop *eventLoop, int fd, int delmask) {
91 aeApiState *state = eventLoop->apidata;
92 struct epoll_event ee = {0}; /* avoid valgrind warning */
93 int mask = eventLoop->events[fd].mask & (~delmask);
94
95 ee.events = 0;
96 if (mask & AE_READABLE) ee.events |= EPOLLIN;
97 if (mask & AE_WRITABLE) ee.events |= EPOLLOUT;
98 ee.data.fd = fd;
99 if (mask != AE_NONE) {
100 epoll_ctl(state->epfd,EPOLL_CTL_MOD,fd,&ee);
101 } else {
102 /* Note, Kernel < 2.6.9 requires a non null event pointer even for
103 * EPOLL_CTL_DEL. */
104 epoll_ctl(state->epfd,EPOLL_CTL_DEL,fd,&ee);
105 }
106 }
107
aeApiPoll(aeEventLoop * eventLoop,struct timeval * tvp)108 static int aeApiPoll(aeEventLoop *eventLoop, struct timeval *tvp) {
109 aeApiState *state = eventLoop->apidata;
110 int retval, numevents = 0;
111
112 retval = epoll_wait(state->epfd,state->events,eventLoop->setsize,
113 tvp ? (tvp->tv_sec*1000 + tvp->tv_usec/1000) : -1);
114 if (retval > 0) {
115 int j;
116
117 numevents = retval;
118 for (j = 0; j < numevents; j++) {
119 int mask = 0;
120 struct epoll_event *e = state->events+j;
121
122 if (e->events & EPOLLIN) mask |= AE_READABLE;
123 if (e->events & EPOLLOUT) mask |= AE_WRITABLE;
124 if (e->events & EPOLLERR) mask |= AE_WRITABLE;
125 if (e->events & EPOLLHUP) mask |= AE_WRITABLE;
126 eventLoop->fired[j].fd = e->data.fd;
127 eventLoop->fired[j].mask = mask;
128 }
129 }
130 return numevents;
131 }
132
aeApiName(void)133 static char *aeApiName(void) {
134 return "epoll";
135 }
136