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 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 an 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 58 static void aeApiFree(aeEventLoop *eventLoop) { 59 aeApiState *state = eventLoop->apidata; 60 61 close(state->epfd); 62 zfree(state->events); 63 zfree(state); 64 } 65 66 static int aeApiAddEvent(aeEventLoop *eventLoop, int fd, int mask) { 67 aeApiState *state = eventLoop->apidata; 68 struct epoll_event ee; 69 /* If the fd was already monitored for some event, we need a MOD 70 * operation. Otherwise we need an ADD operation. */ 71 int op = eventLoop->events[fd].mask == AE_NONE ? 72 EPOLL_CTL_ADD : EPOLL_CTL_MOD; 73 74 ee.events = 0; 75 mask |= eventLoop->events[fd].mask; /* Merge old events */ 76 if (mask & AE_READABLE) ee.events |= EPOLLIN; 77 if (mask & AE_WRITABLE) ee.events |= EPOLLOUT; 78 ee.data.u64 = 0; /* avoid valgrind warning */ 79 ee.data.fd = fd; 80 if (epoll_ctl(state->epfd,op,fd,&ee) == -1) return -1; 81 return 0; 82 } 83 84 static void aeApiDelEvent(aeEventLoop *eventLoop, int fd, int delmask) { 85 aeApiState *state = eventLoop->apidata; 86 struct epoll_event ee; 87 int mask = eventLoop->events[fd].mask & (~delmask); 88 89 ee.events = 0; 90 if (mask & AE_READABLE) ee.events |= EPOLLIN; 91 if (mask & AE_WRITABLE) ee.events |= EPOLLOUT; 92 ee.data.u64 = 0; /* avoid valgrind warning */ 93 ee.data.fd = fd; 94 if (mask != AE_NONE) { 95 epoll_ctl(state->epfd,EPOLL_CTL_MOD,fd,&ee); 96 } else { 97 /* Note, Kernel < 2.6.9 requires a non null event pointer even for 98 * EPOLL_CTL_DEL. */ 99 epoll_ctl(state->epfd,EPOLL_CTL_DEL,fd,&ee); 100 } 101 } 102 103 static int aeApiPoll(aeEventLoop *eventLoop, struct timeval *tvp) { 104 aeApiState *state = eventLoop->apidata; 105 int retval, numevents = 0; 106 107 retval = epoll_wait(state->epfd,state->events,eventLoop->setsize, 108 tvp ? (tvp->tv_sec*1000 + tvp->tv_usec/1000) : -1); 109 if (retval > 0) { 110 int j; 111 112 numevents = retval; 113 for (j = 0; j < numevents; j++) { 114 int mask = 0; 115 struct epoll_event *e = state->events+j; 116 117 if (e->events & EPOLLIN) mask |= AE_READABLE; 118 if (e->events & EPOLLOUT) mask |= AE_WRITABLE; 119 if (e->events & EPOLLERR) mask |= AE_WRITABLE; 120 if (e->events & EPOLLHUP) mask |= AE_WRITABLE; 121 eventLoop->fired[j].fd = e->data.fd; 122 eventLoop->fired[j].mask = mask; 123 } 124 } 125 return numevents; 126 } 127 128 static char *aeApiName(void) { 129 return "epoll"; 130 } 131