Improve handling of server API on pooled clients

Author: alcaeus

src/libmongoc/src/mongoc/mongoc-client-pool.c

@@ -51,6 +51,7 @@ struct _mongoc_client_pool_t {
    int32_t error_api_version;
    bool error_api_set;
    mongoc_server_api_t *api;
+   bool client_initialized;
 };
 
 
@@ -240,12 +241,13 @@ _initialize_new_client (mongoc_client_pool_t *pool, mongoc_client_t *client)
       pool->topology->scanner->initiator,
       pool->topology->scanner->initiator_context);
 
+   pool->client_initialized = true;
+   client->is_pooled = true;
    client->error_api_version = pool->error_api_version;
    _mongoc_client_set_apm_callbacks_private (
       client, &pool->apm_callbacks, pool->apm_context);
 
    client->api = mongoc_server_api_copy (pool->api);
-   client->api_set = true;
 
 #ifdef MONGOC_ENABLE_SSL
    if (pool->ssl_opts_set) {
@@ -529,7 +531,7 @@ mongoc_client_pool_set_server_api (mongoc_client_pool_t *pool,
       return false;
    }
 
-   if (mongoc_client_pool_get_size (pool)) {
+   if (pool->client_initialized) {
       bson_set_error (error,
                       MONGOC_ERROR_POOL,
                       MONGOC_ERROR_POOL_API_TOO_LATE,

src/libmongoc/src/mongoc/mongoc-client-private.h

@@ -97,6 +97,7 @@ struct _mongoc_client_t {
    mongoc_uri_t *uri;
    mongoc_cluster_t cluster;
    bool in_exhaust;
+   bool is_pooled;
 
    mongoc_stream_initiator_t initiator;
    void *initiator_data;
@@ -119,7 +120,6 @@ struct _mongoc_client_t {
    bool error_api_set;
 
    mongoc_server_api_t *api;
-   bool api_set;
 
    /* mongoc_client_session_t's in use, to look up lsids and clusterTimes */
    mongoc_set_t *client_sessions;

src/libmongoc/src/mongoc/mongoc-client.c

@@ -3105,7 +3105,15 @@ mongoc_client_set_server_api (mongoc_client_t *client,
    BSON_ASSERT_PARAM (client);
    BSON_ASSERT_PARAM (api);
 
-   if (client->api_set) {
+   if (client->is_pooled) {
+      bson_set_error (error,
+                      MONGOC_ERROR_CLIENT,
+                      MONGOC_ERROR_CLIENT_API_FROM_POOL,
+                      "Cannot set server api on a client checked out from a pool");
+      return false;
+   }
+
+   if (client->api) {
       bson_set_error (error,
                       MONGOC_ERROR_CLIENT,
                       MONGOC_ERROR_CLIENT_API_ALREADY_SET,
@@ -3114,7 +3122,6 @@ mongoc_client_set_server_api (mongoc_client_t *client,
    }
 
    client->api = mongoc_server_api_copy (api);
-   client->api_set = true;
    _mongoc_topology_scanner_set_server_api (client->topology->scanner, api);
    return true;
 }

src/libmongoc/src/mongoc/mongoc-error.h

@@ -130,6 +130,7 @@ typedef enum {
 
    /* An error related to server version api */
    MONGOC_ERROR_CLIENT_API_ALREADY_SET,
+   MONGOC_ERROR_CLIENT_API_FROM_POOL,
    MONGOC_ERROR_POOL_API_ALREADY_SET,
    MONGOC_ERROR_POOL_API_TOO_LATE
 } mongoc_error_code_t;

src/libmongoc/tests/test-mongoc-versioned-api.c

@@ -126,8 +126,8 @@ _test_mongoc_server_api_client_pool (void)
    ASSERT (!mongoc_client_set_server_api (client, api, &error));
    ASSERT_ERROR_CONTAINS (error,
                           MONGOC_ERROR_CLIENT,
-                          MONGOC_ERROR_CLIENT_API_ALREADY_SET,
-                          "Cannot set server api more than once");
+                          MONGOC_ERROR_CLIENT_API_FROM_POOL,
+                          "Cannot set server api on a client checked out from a pool");
 
    mongoc_client_pool_push (pool, client);
    mongoc_client_pool_destroy (pool);
@@ -163,8 +163,8 @@ _test_mongoc_server_api_client_pool_once (void)
    ASSERT (!mongoc_client_set_server_api (client, api, &error));
    ASSERT_ERROR_CONTAINS (error,
                           MONGOC_ERROR_CLIENT,
-                          MONGOC_ERROR_CLIENT_API_ALREADY_SET,
-                          "Cannot set server api more than once");
+                          MONGOC_ERROR_CLIENT_API_FROM_POOL,
+                          "Cannot set server api on a client checked out from a pool");
 
    mongoc_client_pool_push (pool, client);
    mongoc_client_pool_destroy (pool);