now builds and runs with GnuTLS-built libcurls too

 * $Id$

 *

 * 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.

 * once over HTTPS. The lock callbacks and stuff assume OpenSSL or GnuTLS

 * (libgcrypt) so far.

 *

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

 * OpenSSL docs for this:

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

 * gcrypt docs for this:

 *   http://gnupg.org/documentation/manuals/gcrypt/Multi_002dThreading.html

 */

#define USE_OPENSSL /* or USE_GNUTLS accordingly */

#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;

#ifdef USE_OPENSSL

#include <openssl/crypto.h>

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

{

  (void)file;

  OPENSSL_free(lockarray);

}

#endif

#ifdef USE_GNUTLS

#include <gcrypt.h>

#include <errno.h>

GCRY_THREAD_OPTION_PTHREAD_IMPL;

void init_locks(void)

{

  gcry_control(GCRYCTL_SET_THREAD_CBS);

}

#define kill_locks()

#endif

/* List of URLs to fetch.*/

const char *urls[]= {