[SYCL] Keep CG ownership for run_on_host_intel command nodes

sycl/source/detail/scheduler/commands.hpp

@@ -557,13 +557,6 @@ class ExecCGCommand : public Command {
   // the cleanup process.
   EmptyCommand *MEmptyCmd = nullptr;
 
-  // This function is only usable for native kernel to prevent access to free'd
-  // memory in DispatchNativeKernel.
-  // TODO remove when native kernel support is terminated.
-  void releaseCG() {
-    MCommandGroup.release();
-  }
-
   bool producesPiEvent() const final;
 
   bool supportsPostEnqueueCleanup() const final;

sycl/source/detail/scheduler/scheduler.cpp

@@ -121,9 +121,6 @@ EventImplPtr Scheduler::addCG(std::unique_ptr<detail::CG> CommandGroup,
 
     auto CleanUp = [&]() {
       if (NewCmd && (NewCmd->MDeps.size() == 0 && NewCmd->MUsers.size() == 0)) {
-        if (Type == CG::RunOnHostIntel)
-          static_cast<ExecCGCommand *>(NewCmd)->releaseCG();
-
         NewEvent->setCommand(nullptr);
         delete NewCmd;
       }

sycl/unittests/scheduler/CMakeLists.txt

@@ -21,4 +21,5 @@ add_sycl_unittest(SchedulerTests OBJECT
     utils.cpp
     LeafLimitDiffContexts.cpp
     InOrderQueueSyncCheck.cpp
+    RunOnHostIntelCG.cpp
 )

sycl/unittests/scheduler/RunOnHostIntelCG.cpp

@@ -0,0 +1,45 @@
+//==----------- RunOnHostIntelCG.cpp --- Scheduler unit tests --------------==//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+
+#include "SchedulerTest.hpp"
+#include "SchedulerTestUtils.hpp"
+
+#include <detail/event_impl.hpp>
+
+using namespace sycl;
+
+bool CGDeleted = false;
+class MockCGExecKernel : public detail::CGExecKernel {
+public:
+  MockCGExecKernel(detail::NDRDescT NDRDesc,
+                   std::unique_ptr<detail::HostKernelBase> HostKernel)
+      : CGExecKernel(NDRDesc, std::move(HostKernel), /*SyclKernel*/ nullptr,
+                     /*ArgsStorage*/ {}, /*AccStorage*/ {},
+                     /*SharedPtrStorage*/ {}, /*Requirements*/ {},
+                     /*Events*/ {}, /*Args*/ {}, /*KernelName*/ "",
+                     detail::OSUtil::ExeModuleHandle, /*Streams*/ {},
+                     /*AuxilaryResources*/ {}, detail::CG::RunOnHostIntel) {}
+  ~MockCGExecKernel() override { CGDeleted = true; }
+};
+
+// Check that the command group associated with run_on_host_intel is properly
+// released on command destruction.
+TEST_F(SchedulerTest, RunOnHostIntelCG) {
+  MockScheduler MS;
+  detail::QueueImplPtr QueueImpl = detail::getSyclObjImpl(MQueue);
+
+  detail::NDRDescT NDRDesc;
+  NDRDesc.set(range<1>{1}, id<1>{0});
+  std::unique_ptr<detail::HostKernelBase> HostKernel{
+      new detail::HostKernel<std::function<void()>, void, 1>([]() {})};
+  std::unique_ptr<detail::CG> CommandGroup{
+      new MockCGExecKernel(std::move(NDRDesc), std::move(HostKernel))};
+  MS.addCG(std::move(CommandGroup), QueueImpl);
+  EXPECT_TRUE(CGDeleted);
+}