1 /* Select()-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 <string.h> 33 34 typedef struct aeApiState { 35 fd_set rfds, wfds; 36 /* We need to have a copy of the fd sets as it's not safe to reuse 37 * FD sets after select(). */ 38 fd_set _rfds, _wfds; 39 } aeApiState; 40 41 static int aeApiCreate(aeEventLoop *eventLoop) { 42 aeApiState *state = zmalloc(sizeof(aeApiState)); 43 44 if (!state) return -1; 45 FD_ZERO(&state->rfds); 46 FD_ZERO(&state->wfds); 47 eventLoop->apidata = state; 48 return 0; 49 } 50 51 static void aeApiFree(aeEventLoop *eventLoop) { 52 zfree(eventLoop->apidata); 53 } 54 55 static int aeApiAddEvent(aeEventLoop *eventLoop, int fd, int mask) { 56 aeApiState *state = eventLoop->apidata; 57 58 if (mask & AE_READABLE) FD_SET(fd,&state->rfds); 59 if (mask & AE_WRITABLE) FD_SET(fd,&state->wfds); 60 return 0; 61 } 62 63 static void aeApiDelEvent(aeEventLoop *eventLoop, int fd, int mask) { 64 aeApiState *state = eventLoop->apidata; 65 66 if (mask & AE_READABLE) FD_CLR(fd,&state->rfds); 67 if (mask & AE_WRITABLE) FD_CLR(fd,&state->wfds); 68 } 69 70 static int aeApiPoll(aeEventLoop *eventLoop, struct timeval *tvp) { 71 aeApiState *state = eventLoop->apidata; 72 int retval, j, numevents = 0; 73 74 memcpy(&state->_rfds,&state->rfds,sizeof(fd_set)); 75 memcpy(&state->_wfds,&state->wfds,sizeof(fd_set)); 76 77 retval = select(eventLoop->maxfd+1, 78 &state->_rfds,&state->_wfds,NULL,tvp); 79 if (retval > 0) { 80 for (j = 0; j <= eventLoop->maxfd; j++) { 81 int mask = 0; 82 aeFileEvent *fe = &eventLoop->events[j]; 83 84 if (fe->mask == AE_NONE) continue; 85 if (fe->mask & AE_READABLE && FD_ISSET(j,&state->_rfds)) 86 mask |= AE_READABLE; 87 if (fe->mask & AE_WRITABLE && FD_ISSET(j,&state->_wfds)) 88 mask |= AE_WRITABLE; 89 eventLoop->fired[numevents].fd = j; 90 eventLoop->fired[numevents].mask = mask; 91 numevents++; 92 } 93 } 94 return numevents; 95 } 96 97 static char *aeApiName(void) { 98 return "select"; 99 } 100