Block to do not access mTasks from multiple threads

 - RoundRobinContainerView is not ThreadSafe.
 - If 2 or more Thread call GetNext() method at the same time,
   it can return cend().
 - This patch blocks to do not access mTasks from multiple threads.
 - Blocked code is works for only simple request with O(n).

Change-Id: I134a846cfa04935d4e492f4d3a92c65eaa169261
Signed-off-by: Seungho Baek <sbsh.baek@samsung.com>

2 files changed, 12 insertions, 8 deletions

diff --git a/dali/internal/system/common/async-task-manager-impl.cpp b/dali/internal/system/common/async-task-manager-impl.cpp
index 2f2a2bf8a..ab0c6465d 100644
--- a/dali/internal/system/common/async-task-manager-impl.cpp
+++ b/dali/internal/system/common/async-task-manager-impl.cpp
@@ -670,17 +670,20 @@ void AsyncTaskManager::AddTask(AsyncTaskPtr task)
     }
   }
 
-  size_t count = mTasks.GetElementCount();
-  size_t index = 0;
-  while(index++ < count)
   {
-    auto processHelperIt = mTasks.GetNext();
-    DALI_ASSERT_ALWAYS(processHelperIt != mTasks.End());
-    if(processHelperIt->Request())
+    Mutex::ScopedLock lock(mTasksMutex);
+    size_t count = mTasks.GetElementCount();
+    size_t index = 0;
+    while(index++ < count)
     {
-      break;
+      auto processHelperIt = mTasks.GetNext();
+      DALI_ASSERT_ALWAYS(processHelperIt != mTasks.End());
+      if(processHelperIt->Request())
+      {
+        break;
+      }
+      // If all threads are busy, then it's ok just to push the task because they will try to get the next job.
     }
-    // If all threads are busy, then it's ok just to push the task because they will try to get the next job.
   }
 
   // Register Process (Since mTrigger execute too late timing if event thread running a lots of events.)
diff --git a/dali/internal/system/common/async-task-manager-impl.h b/dali/internal/system/common/async-task-manager-impl.h
index 7729ff5f0..4edf53830 100644
--- a/dali/internal/system/common/async-task-manager-impl.h
+++ b/dali/internal/system/common/async-task-manager-impl.h
@@ -270,6 +270,7 @@ private:
   Dali::Mutex mWaitingTasksMutex;   ///< Mutex for mWaitingTasks. We can lock mRunningTasksMutex and mCompletedTasksMutex under this scope.
   Dali::Mutex mRunningTasksMutex;   ///< Mutex for mRunningTasks. We can lock mCompletedTasksMutex under this scope.
   Dali::Mutex mCompletedTasksMutex; ///< Mutex for mCompletedTasks. We cannot lock any mutex under this scope.
+  Dali::Mutex mTasksMutex;          ///< Mutex for mTasks.        We cannot lock any mutex under this scope.
 
   std::unique_ptr<EventThreadCallback> mTrigger;