[MediaController] Add locks for variable used in different threads

Handles for client and server can be used in different threads.
It may cause segmentation fault when already freed handle will be used.

Verification: Build successful

Change-Id: Iba90d1a85be51710ccda169389ce393f5ce1d1a3
Signed-off-by: Rafal Walczyna <r.walczyna@samsung.com>

diff --git a/src/mediacontroller/mediacontroller_client.cc b/src/mediacontroller/mediacontroller_client.cc
index 55dccb2..7bfb7dd 100644 (file)
--- a/src/mediacontroller/mediacontroller_client.cc
+++ b/src/mediacontroller/mediacontroller_client.cc
@@ -38,10 +38,12 @@ MediaControllerClient::MediaControllerClient() : handle_(nullptr) {
 MediaControllerClient::~MediaControllerClient() {
   ScopeLogger();
   if (handle_) {
+    std::lock_guard<std::mutex> lock(handle_mutex_);
     int ret = mc_client_destroy(handle_);
     if (ret != MEDIA_CONTROLLER_ERROR_NONE) {
       LOGGER(ERROR) << "Unable to destroy media controller client";
     }
+    handle_ = nullptr;
   }
 }
 
@@ -60,9 +62,11 @@ PlatformResult MediaControllerClient::Init() {
 PlatformResult MediaControllerClient::FindServers(picojson::array* servers) {
   ScopeLogger();
   int ret;
-
-  ret = mc_client_foreach_server(handle_, FindServersCallback, servers);
-  if (ret != MEDIA_CONTROLLER_ERROR_NONE) {
+  {
+    std::lock_guard<std::mutex> lock(handle_mutex_);
+    ret = mc_client_foreach_server(handle_, FindServersCallback, servers);
+  }
+  if (MEDIA_CONTROLLER_ERROR_NONE != ret) {
     return LogAndCreateResult(
         ErrorCode::UNKNOWN_ERR, "Unable to fetch active servers, error",
         ("mc_client_foreach_server() error: %d, message: %s", ret, get_error_message(ret)));
@@ -119,8 +123,11 @@ PlatformResult MediaControllerClient::GetLatestServerInfo(picojson::value* serve
     free(name);
   };
   mc_server_state_e state;
-  ret = mc_client_get_latest_server_info(handle_, &name, &state);
-  if (ret != MEDIA_CONTROLLER_ERROR_NONE) {
+  {
+    std::lock_guard<std::mutex> lock(handle_mutex_);
+    ret = mc_client_get_latest_server_info(handle_, &name, &state);
+  }
+  if (MEDIA_CONTROLLER_ERROR_NONE != ret) {
     return LogAndCreateResult(
         ErrorCode::UNKNOWN_ERR, "Error getting latest server info",
         ("mc_client_get_latest_server_info() error: %d, message: %s", ret, get_error_message(ret)));
@@ -567,6 +574,7 @@ PlatformResult MediaControllerClient::SendPlaybackState(const std::string& serve
   }
 
   int ret;
+  std::lock_guard<std::mutex> lock(handle_mutex_);
   ret = mc_client_send_playback_state_command(handle_, server_name.c_str(),
                                               static_cast<mc_playback_states_e>(state_e));
   if (ret != MEDIA_CONTROLLER_ERROR_NONE) {

diff --git a/src/mediacontroller/mediacontroller_client.h b/src/mediacontroller/mediacontroller_client.h
index f359dc5..2ebbc16 100644 (file)
--- a/src/mediacontroller/mediacontroller_client.h
+++ b/src/mediacontroller/mediacontroller_client.h
@@ -18,6 +18,7 @@
 #define MEDIACONTROLLER_MEDIACONTROLLER_CLIENT_H_
 
 #include <media_controller_client.h>
+#include <mutex>
 #include <string>
 
 #include "common/platform_result.h"
@@ -55,6 +56,11 @@ class MediaControllerClient {
  private:
   mc_client_h handle_;
 
+  // This mutex is used to guard handle_ usage in TaskQueue
+  // and its destruction, but there is no need to
+  // guard every call on main thread.
+  std::mutex handle_mutex_;
+
   JsonCallback playback_info_listener_;
   JsonCallback server_status_listener_;
   JsonCallback command_reply_callback_;

diff --git a/src/mediacontroller/mediacontroller_server.cc b/src/mediacontroller/mediacontroller_server.cc
index bd88e3f..d280d8a 100644 (file)
--- a/src/mediacontroller/mediacontroller_server.cc
+++ b/src/mediacontroller/mediacontroller_server.cc
@@ -56,6 +56,7 @@ MediaControllerServer::~MediaControllerServer() {
       LOGGER(ERROR) << "mc_server_destroy() failed, error: " << ret;
     }
   }
+  handle_ = nullptr;
 }
 
 PlatformResult MediaControllerServer::Init() {