1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel@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 */
main(void)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