1 /*************************************************************************** 2 * _ _ ____ _ 3 * Project ___| | | | _ \| | 4 * / __| | | | |_) | | 5 * | (__| |_| | _ <| |___ 6 * \___|\___/|_| \_\_____| 7 * 8 * Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel (at) haxx.se>, et al. 9 * 10 * This software is licensed as described in the file COPYING, which 11 * you should have received as part of this distribution. The terms 12 * are also available at http://curl.haxx.se/docs/copyright.html. 13 * 14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell 15 * copies of the Software, and permit persons to whom the Software is 16 * furnished to do so, under the terms of the COPYING file. 17 * 18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY 19 * KIND, either express or implied. 20 * 21 ***************************************************************************/ 22 #include <stdio.h> 23 #include <string.h> 24 25 /* somewhat unix-specific */ 26 #include <sys/time.h> 27 #include <unistd.h> 28 29 /* curl stuff */ 30 #include <curl/curl.h> 31 32 /* 33 * Simply download two HTTP files! 34 */ 35 int main(void) 36 { 37 CURL *http_handle; 38 CURL *http_handle2; 39 CURLM *multi_handle; 40 41 int still_running; /* keep number of running handles */ 42 43 http_handle = curl_easy_init(); 44 http_handle2 = curl_easy_init(); 45 46 /* set options */ 47 curl_easy_setopt(http_handle, CURLOPT_URL, "http://www.example.com/"); 48 49 /* set options */ 50 curl_easy_setopt(http_handle2, CURLOPT_URL, "http://localhost/"); 51 52 /* init a multi stack */ 53 multi_handle = curl_multi_init(); 54 55 /* add the individual transfers */ 56 curl_multi_add_handle(multi_handle, http_handle); 57 curl_multi_add_handle(multi_handle, http_handle2); 58 59 /* we start some action by calling perform right away */ 60 curl_multi_perform(multi_handle, &still_running); 61 62 do { 63 struct timeval timeout; 64 int rc; /* select() return code */ 65 CURLMcode mc; /* curl_multi_fdset() return code */ 66 67 fd_set fdread; 68 fd_set fdwrite; 69 fd_set fdexcep; 70 int maxfd = -1; 71 72 long curl_timeo = -1; 73 74 FD_ZERO(&fdread); 75 FD_ZERO(&fdwrite); 76 FD_ZERO(&fdexcep); 77 78 /* set a suitable timeout to play around with */ 79 timeout.tv_sec = 1; 80 timeout.tv_usec = 0; 81 82 curl_multi_timeout(multi_handle, &curl_timeo); 83 if(curl_timeo >= 0) { 84 timeout.tv_sec = curl_timeo / 1000; 85 if(timeout.tv_sec > 1) 86 timeout.tv_sec = 1; 87 else 88 timeout.tv_usec = (curl_timeo % 1000) * 1000; 89 } 90 91 /* get file descriptors from the transfers */ 92 mc = curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd); 93 94 if(mc != CURLM_OK) 95 { 96 fprintf(stderr, "curl_multi_fdset() failed, code %d.\n", mc); 97 break; 98 } 99 100 /* On success the value of maxfd is guaranteed to be >= -1. We call 101 select(maxfd + 1, ...); specially in case of (maxfd == -1) there are 102 no fds ready yet so we call select(0, ...) --or Sleep() on Windows-- 103 to sleep 100ms, which is the minimum suggested value in the 104 curl_multi_fdset() doc. */ 105 106 if(maxfd == -1) { 107 #ifdef _WIN32 108 Sleep(100); 109 rc = 0; 110 #else 111 /* Portable sleep for platforms other than Windows. */ 112 struct timeval wait = { 0, 100 * 1000 }; /* 100ms */ 113 rc = select(0, NULL, NULL, NULL, &wait); 114 #endif 115 } 116 else { 117 /* Note that on some platforms 'timeout' may be modified by select(). 118 If you need access to the original value save a copy beforehand. */ 119 rc = select(maxfd+1, &fdread, &fdwrite, &fdexcep, &timeout); 120 } 121 122 switch(rc) { 123 case -1: 124 /* select error */ 125 break; 126 case 0: 127 default: 128 /* timeout or readable/writable sockets */ 129 curl_multi_perform(multi_handle, &still_running); 130 break; 131 } 132 } while(still_running); 133 134 curl_multi_cleanup(multi_handle); 135 136 curl_easy_cleanup(http_handle); 137 curl_easy_cleanup(http_handle2); 138 139 return 0; 140 } 141
