[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 1cdcfef..44b6e0e 100644 (file)
--- a/src/mediacontroller/mediacontroller_client.cc
+++ b/src/mediacontroller/mediacontroller_client.cc
@@ -98,8 +98,12 @@ MediaControllerClient::~MediaControllerClient() {
     LoggerE("Failed to unset custom event listener");
   }
 
-  if (nullptr != handle_ && MEDIA_CONTROLLER_ERROR_NONE != mc_client_destroy(handle_)) {
-    LoggerE("Unable to destroy media controller client");
+  {
+    std::lock_guard<std::mutex> lock(handle_mutex_);
+    if (nullptr != handle_ && MEDIA_CONTROLLER_ERROR_NONE != mc_client_destroy(handle_)) {
+      LoggerE("Unable to destroy media controller client");
+    }
+    handle_ = nullptr;
   }
 }
 
@@ -183,7 +187,10 @@ PlatformResult MediaControllerClient::FindServers(picojson::array* servers) {
   ScopeLogger();
   int ret;
 
-  ret = mc_client_foreach_server(handle_, FindServersCallback, servers);
+  {
+    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",
@@ -241,7 +248,10 @@ PlatformResult MediaControllerClient::GetLatestServerInfo(picojson::value* serve
     free(name);
   };
   mc_server_state_e state;
-  ret = mc_client_get_latest_server_info(handle_, &name, &state);
+  {
+    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",
@@ -857,6 +867,7 @@ PlatformResult MediaControllerClient::FindSubscribedServers(picojson::array* ser
    * If subscription is successful, then servers are subscribed to every subscription type,
    * so we can check only the one type of subscription to receive all subscribed servers.
    */
+  std::lock_guard<std::mutex> lock(handle_mutex_);
   int ret = mc_client_foreach_server_subscribed(handle_, MC_SUBSCRIPTION_TYPE_ABILITY_SUPPORT,
                                                 FindServersCallback, servers);
   if (MEDIA_CONTROLLER_ERROR_NONE != ret) {
@@ -1216,6 +1227,7 @@ PlatformResult MediaControllerClient::SendPlaybackState(const std::string& serve
   SCOPE_EXIT {
     free(request_id);
   };*/
+  std::lock_guard<std::mutex> lock(handle_mutex_);
   int ret = mc_client_send_playback_action_cmd(handle_, server_name.c_str(), action_e, nullptr);
   if (MEDIA_CONTROLLER_ERROR_NONE != ret) {
     return LogAndCreateResult(ErrorCode::UNKNOWN_ERR, "Error sending playback state",
@@ -1234,6 +1246,7 @@ PlatformResult MediaControllerClient::SendPlaybackPosition(const std::string& se
   SCOPE_EXIT {
     free(request_id);
   };*/
+  std::lock_guard<std::mutex> lock(handle_mutex_);
   int ret = mc_client_send_playback_position_cmd(handle_, server_name.c_str(),
                                                  static_cast<unsigned long long>(position),
                                                  /*&request_id*/ nullptr);
@@ -1253,6 +1266,7 @@ PlatformResult MediaControllerClient::SendShuffleMode(const std::string& server_
   SCOPE_EXIT {
     free(request_id);
   };*/
+  std::lock_guard<std::mutex> lock(handle_mutex_);
   int ret = mc_client_send_shuffle_mode_cmd(handle_, server_name.c_str(),
                                             mode ? MC_SHUFFLE_MODE_ON : MC_SHUFFLE_MODE_OFF,
                                             /*&request_id*/ nullptr);
@@ -1272,6 +1286,7 @@ PlatformResult MediaControllerClient::SendRepeatMode(const std::string& server_n
   SCOPE_EXIT {
     free(request_id);
   };*/
+  std::lock_guard<std::mutex> lock(handle_mutex_);
   int ret = mc_client_send_repeat_mode_cmd(handle_, server_name.c_str(),
                                            mode ? MC_REPEAT_MODE_ON : MC_REPEAT_MODE_OFF,
                                            /*&request_id*/ nullptr);
@@ -1298,6 +1313,7 @@ PlatformResult MediaControllerClient::SendRepeatState(const std::string& server_
     return result;
   }
 
+  std::lock_guard<std::mutex> lock(handle_mutex_);
   int ret = mc_client_send_repeat_mode_cmd(handle_, server_name.c_str(), state_e, nullptr);
   if (MEDIA_CONTROLLER_ERROR_NONE != ret) {
     return LogAndCreateResult(

diff --git a/src/mediacontroller/mediacontroller_client.h b/src/mediacontroller/mediacontroller_client.h
index e4b255b..59e2370 100644 (file)
--- a/src/mediacontroller/mediacontroller_client.h
+++ b/src/mediacontroller/mediacontroller_client.h
@@ -19,6 +19,7 @@
 
 #include <media_controller_client.h>
 #include <list>
+#include <mutex>
 #include <string>
 
 #include "common/optional.h"
@@ -114,6 +115,11 @@ 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 2e9b1c6..71d61f3 100644 (file)
--- a/src/mediacontroller/mediacontroller_server.cc
+++ b/src/mediacontroller/mediacontroller_server.cc
@@ -99,8 +99,12 @@ MediaControllerServer::~MediaControllerServer() {
     }
   }
 
-  if (nullptr != handle_ && MEDIA_CONTROLLER_ERROR_NONE != mc_server_destroy(handle_)) {
-    LoggerE("Unable to destroy media controller server");
+  {
+    std::lock_guard<std::mutex> lock(handle_mutex_);
+    if (nullptr != handle_ && MEDIA_CONTROLLER_ERROR_NONE != mc_server_destroy(handle_)) {
+      LoggerE("Unable to destroy media controller server");
+    }
+    handle_ = nullptr;
   }
 }
 
@@ -564,6 +568,7 @@ PlatformResult MediaControllerServer::SavePlaylist(const std::string& name) {
                               "Playlist with given name doesn't exist");
   }
 
+  std::lock_guard<std::mutex> lock(handle_mutex_);
   int ret = mc_server_update_playlist_done(handle_, playlist_handle_map_[name]);
 
   if (MEDIA_CONTROLLER_ERROR_NONE != ret) {
@@ -583,6 +588,7 @@ PlatformResult MediaControllerServer::DeletePlaylist(const std::string& name) {
                               "Playlist with given name doesn't exist");
   }
 
+  std::lock_guard<std::mutex> lock(handle_mutex_);
   int ret = mc_server_delete_playlist(handle_, playlist_handle_map_[name]);
 
   if (MEDIA_CONTROLLER_ERROR_NONE != ret) {

diff --git a/src/mediacontroller/mediacontroller_server.h b/src/mediacontroller/mediacontroller_server.h
index 421847e..a9af304 100644 (file)
--- a/src/mediacontroller/mediacontroller_server.h
+++ b/src/mediacontroller/mediacontroller_server.h
@@ -18,6 +18,7 @@
 #define MEDIACONTROLLER_MEDIACONTROLLER_SERVER_H_
 
 #include <media_controller_server.h>
+#include <mutex>
 #include <string>
 
 #include "common/platform_result.h"
@@ -99,6 +100,11 @@ class MediaControllerServer {
  private:
   mc_server_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 change_request_playback_info_listener_;
   JsonCallback event_reply_callback_;
   JsonCallback command_listener_;