CDRIVER-1915 mistakes in thread example

Author: ajdavis

.gitignore

@@ -28,6 +28,7 @@ echo-server
 example-command-monitoring
 example-command-with-opts
 example-client
+example-pool
 example-scram
 example-gridfs
 example-matcher

CMakeLists.txt

@@ -533,6 +533,7 @@ mongoc_add_example(
    example-sdam-monitoring TRUE
    ${SOURCE_DIR}/examples/example-sdam-monitoring.c)
 mongoc_add_example(example-client TRUE ${SOURCE_DIR}/examples/example-client.c)
+mongoc_add_example(example-pool TRUE ${SOURCE_DIR}/examples/example-pool.c)
 mongoc_add_example(example-command-with-opts TRUE ${SOURCE_DIR}/examples/example-command-with-opts.c)
 mongoc_add_example(example-scram TRUE ${SOURCE_DIR}/examples/example-scram.c)
 mongoc_add_example(mongoc-dump TRUE ${SOURCE_DIR}/examples/mongoc-dump.c)

doc/mongoc_client_pool_t.page

@@ -21,72 +21,7 @@
 
   <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;
-
-   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);
-
-      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 threads[10];
-   unsigned i;
-   void *ret;
-
-   pthread_mutex_init (&mutex, NULL);
-   mongoc_init ();
-
-   uri = mongoc_uri_new ("mongodb://localhost/?minPoolSize=16");
-   pool = mongoc_client_pool_new (uri);
-
-   for (i = 0; i < 10; i++) {
-      pthread_create (&threads[i], NULL, worker, pool);
-   }
-
-   sleep (10);
-   pthread_mutex_lock (&mutex);
-   in_shutdown = true;
-   pthread_mutex_unlock (&mutex);
-
-   for (i = 0; i < 10; i++) {
-      pthread_join (threads[i], &ret);
-   }
-
-   mongoc_client_pool_destroy (pool);
-   mongoc_uri_destroy (uri);
-
-   mongoc_cleanup ();
-
-   return 0;
-}
-]]></code></screen>
+    <screen><code mime="text/x-csrc"><include parse="text" href="../examples/example-pool.c" xmlns="http://www.w3.org/2001/XInclude" /></code></screen>
   </section>
 
   <links type="topic" groups="function" style="2column">

doc/mongoc_tutorial.page

@@ -858,55 +858,7 @@ C:\> executing
     <title>6. Threading</title>
     <p>The MongoDB C Driver is thread-unaware in the vast majority of its operations. This means it is up to the programmer to guarantee thread-safety.</p>
     <p>However, <code xref="mongoc_client_pool_t">mongoc_client_pool_t</code> is thread-safe and is used to fetch a <code>mongoc_client_t</code> in a thread-safe manner. After retrieving a client from the pool, the client structure should be considered owned by the calling thread. When the thread is finished, the client should be placed back into the pool.</p>
-
-    <screen><code><![CDATA[#include <mongoc.h>
-#include <pthread.h>
-
-#define N_THREADS 10
-
-static void *
-worker (void *data) {
-   mongoc_client_pool_t *pool = data;
-   mongoc_client_t      *client;
-
-   client = mongoc_client_pool_pop (pool);
-
-   /* Do something... */
-
-   mongoc_client_pool_push (pool, client);
-
-   return NULL;
-}
-
-int
-main (int   argc,
-      char *argv[])
-{
-   mongoc_client_pool_t *pool;
-   mongoc_uri_t         *uri;
-   pthread_t             threads[N_THREADS];
-   int i;
-
-   mongoc_init ();
-
-   uri = mongoc_uri_new ("mongodb://localhost/?appname=pool-example");
-   pool = mongoc_client_pool_new (uri);
-
-   for (i = 0; i < N_THREADS; i++) {
-      pthread_create (&threads[i], NULL, worker, pool);
-   }
-
-   for (i = 0; i < N_THREADS; i++) {
-      pthread_join (threads[i], NULL);
-   }
-
-   mongoc_client_pool_destroy (pool);
-   mongoc_uri_destroy (uri);
-   mongoc_cleanup ();
-
-   return 0;
-}
-]]></code></screen>
+    <screen><code mime="text/x-csrc"><include parse="text" href="../examples/example-pool.c" xmlns="http://www.w3.org/2001/XInclude" /></code></screen>
   </section>
 
   <section id="next-steps">

examples/Makefile.am

@@ -37,6 +37,11 @@ example_client_SOURCES = examples/example-client.c
 example_client_CFLAGS = $(EXAMPLE_CFLAGS)
 example_client_LDADD = $(EXAMPLE_LDADD)
 
+noinst_PROGRAMS += example-pool
+example_pool_SOURCES = examples/example-pool.c
+example_pool_CFLAGS = $(EXAMPLE_CFLAGS)
+example_pool_LDADD = $(EXAMPLE_LDADD)
+
 noinst_PROGRAMS += example-command-with-opts
 example_command_with_opts_SOURCES = examples/example-command-with-opts.c
 example_command_with_opts_CFLAGS = $(EXAMPLE_CFLAGS)

examples/example-pool.c

@@ -0,0 +1,95 @@
+/* gcc example-pool.c -o example-pool $(pkg-config --cflags --libs libmongoc-1.0) */
+
+/* ./example-pool [CONNECTION_STRING] */
+
+#include <mongoc.h>
+#include <pthread.h>
+#include <stdio.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;
+   bson_t ping = BSON_INITIALIZER;
+   bson_error_t error;
+   bool r;
+
+   BSON_APPEND_INT32 (&ping, "ping", 1);
+
+   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.
+       */
+      r = mongoc_client_command_simple (client, "admin", &ping, NULL, NULL,
+                                        &error);
+
+      if (!r) {
+         fprintf (stderr, "%s\n", error.message);
+      }
+
+      mongoc_client_pool_push (pool, client);
+
+      pthread_mutex_lock (&mutex);
+      if (in_shutdown || !r) {
+         pthread_mutex_unlock (&mutex);
+         break;
+      }
+
+      pthread_mutex_unlock (&mutex);
+   }
+
+   bson_destroy (&ping);
+   return NULL;
+}
+
+int main (int argc, char *argv[])
+{
+   const char *uristr = "mongodb://127.0.0.1/?appname=pool-example";
+   mongoc_uri_t *uri;
+   mongoc_client_pool_t *pool;
+   pthread_t threads[10];
+   unsigned i;
+   void *ret;
+
+   pthread_mutex_init (&mutex, NULL);
+   mongoc_init ();
+
+   if (argc > 1) {
+      uristr = argv [1];
+   }
+
+   uri = mongoc_uri_new (uristr);
+   if (!uri) {
+      fprintf (stderr, "Failed to parse URI: \"%s\".\n", uristr);
+      return EXIT_FAILURE;
+   }
+
+   pool = mongoc_client_pool_new (uri);
+   mongoc_client_pool_set_error_api (pool, 2);
+
+   for (i = 0; i < 10; i++) {
+      pthread_create (&threads[i], NULL, worker, pool);
+   }
+
+   sleep (10);
+   pthread_mutex_lock (&mutex);
+   in_shutdown = true;
+   pthread_mutex_unlock (&mutex);
+
+   for (i = 0; i < 10; i++) {
+      pthread_join (threads[i], &ret);
+   }
+
+   mongoc_client_pool_destroy (pool);
+   mongoc_uri_destroy (uri);
+
+   mongoc_cleanup ();
+
+   return 0;
+}