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