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Annotation of embedaddon/curl/docs/examples/threaded-shared-conn.c, revision 1.1.1.1

1.1       misho       1: /***************************************************************************
                      2:  *                                  _   _ ____  _
                      3:  *  Project                     ___| | | |  _ \| |
                      4:  *                             / __| | | | |_) | |
                      5:  *                            | (__| |_| |  _ <| |___
                      6:  *                             \___|\___/|_| \_\_____|
                      7:  *
                      8:  * Copyright (C) 1998 - 2019, 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 https://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: /* <DESC>
                     23:  * Multi-threaded transfers sharing a single connection pool
                     24:  * </DESC>
                     25:  *
                     26:  * This example fires up NUM_THREADS threads and in each single thread, it
                     27:  * downloads the same fixed URL a URL_ITERATIONS number of times. The received
                     28:  * data is just thrown away. It sets up a single shared object that holds the
                     29:  * connection cache and all easy handles in all threads share that same cache.
                     30:  *
                     31:  * This example uses pthreads for threads and mutexes, but should be easy to
                     32:  * modify to use different thread/mutex system should you want to.
                     33:  *
                     34:  */
                     35: 
                     36: #include <stdio.h>
                     37: #include <pthread.h>
                     38: #include <curl/curl.h>
                     39: 
                     40: /*
                     41:   URL to fetch. If you select HTTPS, you need to use a TLS backend with mutex
                     42:   locks taken care of (OpenSSL 1.1.x, NSS, etc) or add SSL mutex callbacks!
                     43: */
                     44: #define URL "http://localhost/4KB"
                     45: 
                     46: /* number of threads to fire up in parallel */
                     47: #define NUM_THREADS 67
                     48: 
                     49: /* how many times each URL is transferred per thread */
                     50: #define URL_ITERATIONS 11235
                     51: 
                     52: static pthread_mutex_t connlock;
                     53: 
                     54: static size_t write_db(void *ptr, size_t size, size_t nmemb, void *data)
                     55: {
                     56:   /* not interested in the downloaded bytes, return the size */
                     57:   (void)ptr;  /* unused */
                     58:   (void)data; /* unused */
                     59:   return (size_t)(size * nmemb);
                     60: }
                     61: 
                     62: static void lock_cb(CURL *handle, curl_lock_data data,
                     63:                     curl_lock_access access, void *userptr)
                     64: {
                     65:   (void)access; /* unused */
                     66:   (void)userptr; /* unused */
                     67:   (void)handle; /* unused */
                     68:   (void)data; /* unused */
                     69:   pthread_mutex_lock(&connlock);
                     70: }
                     71: 
                     72: static void unlock_cb(CURL *handle, curl_lock_data data,
                     73:                       void *userptr)
                     74: {
                     75:   (void)userptr; /* unused */
                     76:   (void)handle;  /* unused */
                     77:   (void)data;    /* unused */
                     78:   pthread_mutex_unlock(&connlock);
                     79: }
                     80: 
                     81: static void init_locks(void)
                     82: {
                     83:   pthread_mutex_init(&connlock, NULL);
                     84: }
                     85: 
                     86: static void kill_locks(void)
                     87: {
                     88:   pthread_mutex_destroy(&connlock);
                     89: }
                     90: 
                     91: struct initurl {
                     92:   const char *url;
                     93:   CURLSH *share;
                     94:   int threadno;
                     95: };
                     96: 
                     97: static void *run_thread(void *ptr)
                     98: {
                     99:   struct initurl *u = (struct initurl *)ptr;
                    100:   int i;
                    101: 
                    102:   for(i = 0; i < URL_ITERATIONS; i++) {
                    103:     CURL *curl = curl_easy_init();
                    104:     curl_easy_setopt(curl, CURLOPT_URL, u->url);
                    105:     curl_easy_setopt(curl, CURLOPT_VERBOSE, 0L);
                    106:     curl_easy_setopt(curl, CURLOPT_SHARE, u->share);
                    107:     curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_db);
                    108:     curl_easy_perform(curl); /* ignores error */
                    109:     curl_easy_cleanup(curl);
                    110:     fprintf(stderr, "Thread %d transfer %d\n", u->threadno, i);
                    111:   }
                    112: 
                    113:   return NULL;
                    114: }
                    115: 
                    116: int main(void)
                    117: {
                    118:   pthread_t tid[NUM_THREADS];
                    119:   int i;
                    120:   CURLSH *share;
                    121:   struct initurl url[NUM_THREADS];
                    122: 
                    123:   /* Must initialize libcurl before any threads are started */
                    124:   curl_global_init(CURL_GLOBAL_ALL);
                    125: 
                    126:   share = curl_share_init();
                    127:   curl_share_setopt(share, CURLSHOPT_LOCKFUNC, lock_cb);
                    128:   curl_share_setopt(share, CURLSHOPT_UNLOCKFUNC, unlock_cb);
                    129:   curl_share_setopt(share, CURLSHOPT_SHARE, CURL_LOCK_DATA_CONNECT);
                    130: 
                    131:   init_locks();
                    132: 
                    133:   for(i = 0; i< NUM_THREADS; i++) {
                    134:     int error;
                    135:     url[i].url = URL;
                    136:     url[i].share = share;
                    137:     url[i].threadno = i;
                    138:     error = pthread_create(&tid[i], NULL, run_thread, &url[i]);
                    139:     if(0 != error)
                    140:       fprintf(stderr, "Couldn't run thread number %d, errno %d\n", i, error);
                    141:     else
                    142:       fprintf(stderr, "Thread %d, gets %s\n", i, URL);
                    143:   }
                    144: 
                    145:   /* now wait for all threads to terminate */
                    146:   for(i = 0; i< NUM_THREADS; i++) {
                    147:     pthread_join(tid[i], NULL);
                    148:     fprintf(stderr, "Thread %d terminated\n", i);
                    149:   }
                    150: 
                    151:   kill_locks();
                    152: 
                    153:   curl_share_cleanup(share);
                    154:   curl_global_cleanup();
                    155:   return 0;
                    156: }