CDRIVER-1915 mistakes in thread example

Author: ajdavis

doc/mongoc_client_pool_t.page

@@ -22,53 +22,71 @@
   <section id="example">
     <title>Example</title>
     <screen><code mime="text/x-csrc"><![CDATA[#include <mongoc.h>
+#include <pthread.h>
+
+static pthread_mutex_t mutex;
+static bool in_shutdown = false;
 
 static void *
 worker (void *data)
 {
    mongoc_client_pool_t *pool = data;
    mongoc_client_t *client;
 
-   do {
+   while (true) {
       client = mongoc_client_pool_pop (pool);
       /*
        * Do something with client. If you are writing an HTTP server, you
        * probably only want to hold onto the client for the portion of the
        * request performing database queries.
        */
       mongoc_client_pool_push (pool, client);
-   } while (!inShutdown);
 
-   return NULL;
+      pthread_mutex_lock (&mutex);
+      if (in_shutdown) {
+         pthread_mutex_unlock (&mutex);
+         return NULL;
+      }
+
+      pthread_mutex_unlock (&mutex);
+   }
 }
 
 int main (int argc, char *argv[])
 {
    mongoc_client_pool_t *pool;
    mongoc_uri_t *uri;
-   pthread_t thread[10];
+   pthread_t threads[10];
    unsigned i;
    void *ret;
 
+   pthread_mutex_init (&mutex, NULL);
    mongoc_init ();
 
-   uri = mongoc_uri_new ("mongodb://mdb1.example.com/?minPoolSize=16");
+   uri = mongoc_uri_new ("mongodb://localhost/?minPoolSize=16");
    pool = mongoc_client_pool_new (uri);
 
    for (i = 0; i < 10; i++) {
-      pthread_create (&thread, NULL, worker, pool);
+      pthread_create (&threads[i], NULL, worker, pool);
    }
 
-   mongoc_uri_destroy (uri);
+   sleep (10);
+   pthread_mutex_lock (&mutex);
+   in_shutdown = true;
+   pthread_mutex_unlock (&mutex);
 
    for (i = 0; i < 10; i++) {
-      pthread_join (threads [i], &ret);
+      pthread_join (threads[i], &ret);
    }
 
+   mongoc_client_pool_destroy (pool);
+   mongoc_uri_destroy (uri);
+
    mongoc_cleanup ();
 
    return 0;
-}]]></code></screen>
+}
+]]></code></screen>
   </section>
 
   <links type="topic" groups="function" style="2column">