Add reference on kernel in blocked scenarios.

- Prevents kernel destruction while it may still be in use.

Change-Id: I1f87d09c5cabf29644a1b06b63f1789dbb15985a

Jenkinsfile

@@ -2,4 +2,4 @@
 neoDependenciesRev='726029-739'
 strategy='EQUAL'
 allowedF=49
-allowedCD=375
+allowedCD=374

runtime/helpers/task_information.cpp

@@ -105,6 +105,9 @@ CommandComputeKernel::CommandComputeKernel(CommandQueue &commandQueue, CommandSt
         this->surfaces.push_back(surface);
     }
     this->kernel = kernel;
+    if (kernel) {
+        kernel->incRefInternal();
+    }
     this->kernelCount = kernelCount;
 }
 
@@ -116,6 +119,9 @@ CommandComputeKernel::~CommandComputeKernel() {
     if (kernelOperation->ioh.get() == kernelOperation->dsh.get()) {
         kernelOperation->doNotFreeISH = true;
     }
+    if (kernel) {
+        kernel->decRefInternal();
+    }
 }
 
 CompletionStamp &CommandComputeKernel::submit(uint32_t taskLevel, bool terminated) {

runtime/utilities/reference_tracked_object.h

@@ -145,6 +145,7 @@ class ReferenceTrackedObject {
     unique_ptr_if_unused<DerivedClass> decRefInternal() {
         auto customDeleter = tryGetCustomDeleter();
         bool unused = refInternal.dec();
+        UNRECOVERABLE_IF(refInternal.peek() < 0);
         return unique_ptr_if_unused<DerivedClass>(static_cast<DerivedClass *>(this), unused, customDeleter);
     }
 

unit_tests/command_queue/command_queue_hw_tests.cpp

@@ -412,6 +412,23 @@ HWTEST_F(BlockedCommandQueueTest, givenCommandQueueWhichHasSomeUnusedHeapsWhenBl
     EXPECT_EQ(sshBase, ssh.getBase());
 }
 
+HWTEST_F(BlockedCommandQueueTest, givenEnqueueBlockedByUserEventWhenItIsEnqueuedThenKernelReferenceCountIsIncreased) {
+    UserEvent userEvent(context);
+    MockKernelWithInternals mockKernelWithInternals(*pDevice);
+    auto mockKernel = mockKernelWithInternals.mockKernel;
+
+    size_t offset = 0;
+    size_t size = 1;
+
+    cl_event blockedEvent = &userEvent;
+
+    auto currentRefCount = mockKernel->getRefInternalCount();
+    pCmdQ->enqueueKernel(mockKernel, 1, &offset, &size, &size, 1, &blockedEvent, nullptr);
+    EXPECT_EQ(currentRefCount + 1, mockKernel->getRefInternalCount());
+    userEvent.setStatus(CL_COMPLETE);
+    EXPECT_EQ(currentRefCount, mockKernel->getRefInternalCount());
+}
+
 typedef CommandQueueHwTest CommandQueueHwRefCountTest;
 
 HWTEST_F(CommandQueueHwRefCountTest, givenBlockedCmdQWhenNewBlockedEnqueueReplacesVirtualEventThenPreviousVirtualEventDecrementsCmdQRefCount) {

unit_tests/event/event_tests.cpp

@@ -620,8 +620,8 @@ TEST_F(InternalsEventTest, givenBlockedKernelWithPrintfWhenSubmittedThenPrintOut
 
     delete pPrintfSurface;
     delete pKernelInfo;
-    delete pKernel;
+    pKernel->decRefInternal();
-    delete pProgram;
+    pProgram->decRefInternal();
     delete pCmdQ;
 }
 

unit_tests/mocks/mock_kernel.h

@@ -212,8 +212,8 @@ class MockKernelWithInternals {
         mockKernel->setSshLocal(&sshLocal, sizeof(sshLocal));
     }
     ~MockKernelWithInternals() {
-        delete mockKernel;
+        mockKernel->decRefInternal();
-        delete mockProgram;
+        mockProgram->decRefInternal();
     }
 
     operator MockKernel *() {