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 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 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 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 73 static int aeApiAddEvent(aeEventLoop *eventLoop, int fd, int mask) { 74 aeApiState *state = eventLoop->apidata; 75 struct epoll_event ee; 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.u64 = 0; /* avoid valgrind warning */ 86 ee.data.fd = fd; 87 if (epoll_ctl(state->epfd,op,fd,&ee) == -1) return -1; 88 return 0; 89 } 90 91 static void aeApiDelEvent(aeEventLoop *eventLoop, int fd, int delmask) { 92 aeApiState *state = eventLoop->apidata; 93 struct epoll_event ee; 94 int mask = eventLoop->events[fd].mask & (~delmask); 95 96 ee.events = 0; 97 if (mask & AE_READABLE) ee.events |= EPOLLIN; 98 if (mask & AE_WRITABLE) ee.events |= EPOLLOUT; 99 ee.data.u64 = 0; /* avoid valgrind warning */ 100 ee.data.fd = fd; 101 if (mask != AE_NONE) { 102 epoll_ctl(state->epfd,EPOLL_CTL_MOD,fd,&ee); 103 } else { 104 /* Note, Kernel < 2.6.9 requires a non null event pointer even for 105 * EPOLL_CTL_DEL. */ 106 epoll_ctl(state->epfd,EPOLL_CTL_DEL,fd,&ee); 107 } 108 } 109 110 static int aeApiPoll(aeEventLoop *eventLoop, struct timeval *tvp) { 111 aeApiState *state = eventLoop->apidata; 112 int retval, numevents = 0; 113 114 retval = epoll_wait(state->epfd,state->events,eventLoop->setsize, 115 tvp ? (tvp->tv_sec*1000 + tvp->tv_usec/1000) : -1); 116 if (retval > 0) { 117 int j; 118 119 numevents = retval; 120 for (j = 0; j < numevents; j++) { 121 int mask = 0; 122 struct epoll_event *e = state->events+j; 123 124 if (e->events & EPOLLIN) mask |= AE_READABLE; 125 if (e->events & EPOLLOUT) mask |= AE_WRITABLE; 126 if (e->events & EPOLLERR) mask |= AE_WRITABLE; 127 if (e->events & EPOLLHUP) mask |= AE_WRITABLE; 128 eventLoop->fired[j].fd = e->data.fd; 129 eventLoop->fired[j].mask = mask; 130 } 131 } 132 return numevents; 133 } 134 135 static char *aeApiName(void) { 136 return "epoll"; 137 } 138