Fix race in events scenarios.

- It could happen that 2 threads try to update the same event within tree
- First thread starts to submit command, it releases cmdToSubmit
- Second thread doesn't see the command and follows
- Second thread thinks that it submitted the command so it follows to
subsequent steps which are child events notification
- We end up with corrupted enqueue sequence as child may submit prior to
parent.
- With this change each submit step is synchronized basing on task count
- When second thread enters submit command without task count being set
it wait for first thread to properly set it.

Change-Id: Ic2ddaea17f9af8cab6781320edae2c268dd0b189
Signed-off-by: Mrozek, Michal <michal.mrozek@intel.com>

unit_tests/command_queue/command_queue_hw_tests.cpp

@@ -753,19 +753,38 @@ HWTEST_F(CommandQueueHwTest, givenCommandQueueThatIsBlockedAndUsesCpuCopyWhenEve
     clReleaseEvent(returnEvent);
 }
 
-HWTEST_F(CommandQueueHwTest, givenEventWithRecordedCommandWhenSubmitCommandIsCalledThenTaskCountIsNotUpdated) {
+HWTEST_F(CommandQueueHwTest, givenEventWithRecordedCommandWhenSubmitCommandIsCalledThenTaskCountMustBeUpdatedFromOtherThread) {
+    std::atomic_bool go{false};
+
     struct mockEvent : public Event {
         using Event::Event;
         using Event::eventWithoutCommand;
         using Event::submitCommand;
+        void synchronizeTaskCount() override {
+            *atomicFence = true;
+            Event::synchronizeTaskCount();
+        }
+        uint32_t synchronizeCallCount = 0u;
+        std::atomic_bool *atomicFence = nullptr;
     };
 
     mockEvent neoEvent(this->pCmdQ, CL_COMMAND_MAP_BUFFER, Event::eventNotReady, Event::eventNotReady);
+    neoEvent.atomicFence = &go;
     EXPECT_TRUE(neoEvent.eventWithoutCommand);
     neoEvent.eventWithoutCommand = false;
 
-    neoEvent.submitCommand(false);
     EXPECT_EQ(Event::eventNotReady, neoEvent.peekTaskCount());
+
+    std::thread t([&]() {
+        while (!go)
+            ;
+        neoEvent.updateTaskCount(77u);
+    });
+
+    neoEvent.submitCommand(false);
+
+    EXPECT_EQ(77u, neoEvent.peekTaskCount());
+    t.join();
 }
 
 HWTEST_F(CommandQueueHwTest, GivenBuiltinKernelWhenBuiltinDispatchInfoBuilderIsProvidedThenThisBuilderIsUsedForCreatingDispatchInfo) {

unit_tests/event/user_events_tests_mt.cpp

@@ -120,6 +120,7 @@ TEST_F(EventTests, givenoneThreadUpdatingUserEventAnotherWaitingOnFinishWhenFini
         cl_event returnedEvent = nullptr;
 
         std::atomic_bool go{false};
+        std::atomic_bool updateEvent{true};
 
         std::thread t([&]() {
             while (!go)
@@ -132,7 +133,9 @@ TEST_F(EventTests, givenoneThreadUpdatingUserEventAnotherWaitingOnFinishWhenFini
         EXPECT_EQ(CL_SUCCESS, retVal);
 
         std::thread t2([&]() {
-            castToObject<Event>(returnedEvent)->updateExecutionStatus();
+            while (updateEvent) {
+                castToObject<Event>(returnedEvent)->updateExecutionStatus();
+            }
         });
 
         go = true;
@@ -141,6 +144,7 @@ TEST_F(EventTests, givenoneThreadUpdatingUserEventAnotherWaitingOnFinishWhenFini
         EXPECT_EQ(pCmdQ->latestTaskCountWaited, i + 1);
 
         t.join();
+        updateEvent = false;
         t2.join();
         clReleaseEvent(returnedEvent);
     }