threaded-ssl.c is a little example that does multi-threaded downloads from

COMPLICATED_EXAMPLES = \

 curlgtk.c curlx.c htmltitle.cc cacertinmem.c ftpuploadresume.c \

 ghiper.c hiperfifo.c htmltidy.c multithread.c \

 opensslthreadlock.c sampleconv.c synctime.c

 opensslthreadlock.c sampleconv.c synctime.c threaded-ssl.c

/*****************************************************************************

 *                                  _   _ ____  _

 *  Project                     ___| | | |  _ \| |

 *                             / __| | | | |_) | |

 *                            | (__| |_| |  _ <| |___

 *                             \___|\___/|_| \_\_____|

 *

 * $Id$

 *

 * A multi-threaded example that uses pthreads and fetches 4 remote files at

 * once over HTTPS. The lock callbacks and stuff assume OpenSSL so far.

 * Should be expanded to do optional GnuTLS style locking.

 *

 * OpenSSL docs for this: http://www.openssl.org/docs/crypto/threads.html

 */

#include <stdio.h>

#include <pthread.h>

#include <curl/curl.h>

#include <openssl/crypto.h>

/* we have this global to let the callback get easy access to it */

static pthread_mutex_t *lockarray;

static void lock_callback(int mode, int type, char *file, int line)

{

  (void)file;

  (void)line;

  if (mode & CRYPTO_LOCK) {

    pthread_mutex_lock(&(lockarray[type]));

  }

  else {

    pthread_mutex_unlock(&(lockarray[type]));

  }

}

static unsigned long thread_id(void)

{

  unsigned long ret;

  ret=(unsigned long)pthread_self();

  return(ret);

}

static void init_locks(void)

{

  int i;

  lockarray=(pthread_mutex_t *)OPENSSL_malloc(CRYPTO_num_locks() *

                                            sizeof(pthread_mutex_t));

  for (i=0; i<CRYPTO_num_locks(); i++) {

    pthread_mutex_init(&(lockarray[i]),NULL);

  }

  CRYPTO_set_id_callback((unsigned long (*)())thread_id);

  CRYPTO_set_locking_callback((void (*)())lock_callback);

}

static void kill_locks(void)

{

  int i;

  CRYPTO_set_locking_callback(NULL);

  for (i=0; i<CRYPTO_num_locks(); i++)

    pthread_mutex_destroy(&(lockarray[i]));

  OPENSSL_free(lockarray);

}

/* List of URLs to fetch.*/

const char *urls[]= {

  "https://www.sf.net/",

  "https://www.openssl.org/",

  "https://www.sf.net/",

  "https://www.openssl.org/",

};

static void *pull_one_url(void *url)

{

  CURL *curl;

  curl = curl_easy_init();

  curl_easy_setopt(curl, CURLOPT_URL, url);

  /* this example doesn't verify the server's certificate, which means we

     might be downloading stuff from an impostor */

  curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0);

  curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);

  curl_easy_perform(curl); /* ignores error */

  curl_easy_cleanup(curl);

  return NULL;

}

int main(int argc, char **argv)

{

  pthread_t tid[4];

  int i;

  int error;

  (void)argc; /* we don't use any arguments in this example */

  (void)argv;

  init_locks();

  for(i=0; i< 4; i++) {

    error = pthread_create(&tid[i],

                           NULL, /* default attributes please */

                           pull_one_url,

                           (void *)urls[i]);

    if(0 != error)

      fprintf(stderr, "Couldn't run thread number %d, errno %d\n", i, error);

    else

      fprintf(stderr, "Thread %d, gets %s\n", i, urls[i]);

  }

  /* now wait for all threads to terminate */

  for(i=0; i< 4; i++) {

    error = pthread_join(tid[i], NULL);

    fprintf(stderr, "Thread %d terminated\n", i);

  }

  kill_locks();

  return 0;

}