1/*************************************************************************** 2 * _ _ ____ _ 3 * Project ___| | | | _ \| | 4 * / __| | | | |_) | | 5 * | (__| |_| | _ <| |___ 6 * \___|\___/|_| \_\_____| 7 * 8 * Copyright (C) 1998 - 2017, 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 52static pthread_mutex_t connlock; 53 54static 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 62static 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 72static 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 81static void init_locks(void) 82{ 83 pthread_mutex_init(&connlock, NULL); 84} 85 86static void kill_locks(void) 87{ 88 pthread_mutex_destroy(&connlock); 89} 90 91struct initurl { 92 const char *url; 93 CURLSH *share; 94 int threadno; 95}; 96 97static 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, "Tread %d transfer %d\n", u->threadno, i); 111 } 112 113 return NULL; 114} 115 116int main(void) 117{ 118 pthread_t tid[NUM_THREADS]; 119 int i; 120 int error; 121 CURLSH *share; 122 struct initurl url[NUM_THREADS]; 123 124 /* Must initialize libcurl before any threads are started */ 125 curl_global_init(CURL_GLOBAL_ALL); 126 127 share = curl_share_init(); 128 curl_share_setopt(share, CURLSHOPT_LOCKFUNC, lock_cb); 129 curl_share_setopt(share, CURLSHOPT_UNLOCKFUNC, unlock_cb); 130 curl_share_setopt(share, CURLSHOPT_SHARE, CURL_LOCK_DATA_CONNECT); 131 132 init_locks(); 133 134 for(i = 0; i< NUM_THREADS; i++) { 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 error = 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} 157