Add Music Manager's curl 7.21.2 source.
Change-Id: I259a43fa52d581524a5ce8ae1711467acb1d9d50
diff --git a/docs/examples/threaded-ssl.c b/docs/examples/threaded-ssl.c
new file mode 100644
index 0000000..284edc4
--- /dev/null
+++ b/docs/examples/threaded-ssl.c
@@ -0,0 +1,149 @@
+/*****************************************************************************
+ * _ _ ____ _
+ * Project ___| | | | _ \| |
+ * / __| | | | |_) | |
+ * | (__| |_| | _ <| |___
+ * \___|\___/|_| \_\_____|
+ *
+ *
+ * A multi-threaded example that uses pthreads and fetches 4 remote files at
+ * 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
+ * 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>
+
+#define NUMT 4
+
+/* 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;
+ (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);
+}
+#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 * const urls[]= {
+ "https://www.example.com/",
+ "https://www2.example.com/",
+ "https://www3.example.com/",
+ "https://www4.example.com/",
+};
+
+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, 0L);
+ curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
+ curl_easy_perform(curl); /* ignores error */
+ curl_easy_cleanup(curl);
+
+ return NULL;
+}
+
+int main(int argc, char **argv)
+{
+ pthread_t tid[NUMT];
+ int i;
+ int error;
+ (void)argc; /* we don't use any arguments in this example */
+ (void)argv;
+
+ /* Must initialize libcurl before any threads are started */
+ curl_global_init(CURL_GLOBAL_ALL);
+
+ init_locks();
+
+ for(i=0; i< NUMT; 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< NUMT; i++) {
+ error = pthread_join(tid[i], NULL);
+ fprintf(stderr, "Thread %d terminated\n", i);
+ }
+
+ kill_locks();
+
+ return 0;
+}