[SYCL] Allow unittests to use drainThreadPool method on Win (#8006)

Signed-off-by: Tikhomirova, Kseniya <[email protected]>

Author: KseniyaTikhomirova

sycl/source/detail/global_handler.cpp

@@ -52,9 +52,7 @@ class ObjectUsageCounter {
       LockGuard Guard(GlobalHandler::MSyclGlobalHandlerProtector);
       GlobalHandler *RTGlobalObjHandler = GlobalHandler::getInstancePtr();
       if (RTGlobalObjHandler) {
-        RTGlobalObjHandler->drainThreadPool();
-        if (RTGlobalObjHandler->MScheduler.Inst)
-          RTGlobalObjHandler->MScheduler.Inst->releaseResources();
+        RTGlobalObjHandler->prepareSchedulerToRelease();
       }
     }
   }
@@ -93,7 +91,7 @@ void GlobalHandler::attachScheduler(Scheduler *Scheduler) {
   // The method is used in unit tests only. Do not protect with lock since
   // releaseResources will cause dead lock due to host queue release
   if (MScheduler.Inst)
-    MScheduler.Inst->releaseResources();
+    prepareSchedulerToRelease();
   MScheduler.Inst.reset(Scheduler);
 }
 
@@ -201,11 +199,17 @@ void GlobalHandler::unloadPlugins() {
   getPlugins().clear();
 }
 
-void GlobalHandler::drainThreadPool() {
+void GlobalHandler::prepareSchedulerToRelease() {
 #ifndef _WIN32
+  drainThreadPool();
+  if (MScheduler.Inst)
+    MScheduler.Inst->releaseResources();
+#endif
+}
+
+void GlobalHandler::drainThreadPool() {
   if (MHostTaskThreadPool.Inst)
     MHostTaskThreadPool.Inst->drain();
-#endif
 }
 
 void shutdown() {
@@ -216,9 +220,7 @@ void shutdown() {
 
   // Ensure neither host task is working so that no default context is accessed
   // upon its release
-  Handler->drainThreadPool();
-  if (Handler->MScheduler.Inst)
-    Handler->MScheduler.Inst->releaseResources();
+  Handler->prepareSchedulerToRelease();
 
   if (Handler->MHostTaskThreadPool.Inst)
     Handler->MHostTaskThreadPool.Inst->finishAndWait();

sycl/source/detail/global_handler.hpp

@@ -77,6 +77,7 @@ class GlobalHandler {
   void unloadPlugins();
   void releaseDefaultContexts();
   void drainThreadPool();
+  void prepareSchedulerToRelease();
 
   // For testing purposes only
   void attachScheduler(Scheduler *Scheduler);

sycl/source/detail/scheduler/scheduler.cpp

@@ -392,7 +392,6 @@ Scheduler::Scheduler() {
 Scheduler::~Scheduler() { DefaultHostQueue.reset(); }
 
 void Scheduler::releaseResources() {
-#ifndef _WIN32
   //  There might be some commands scheduled for post enqueue cleanup that
   //  haven't been freed because of the graph mutex being locked at the time,
   //  clean them up now.
@@ -408,7 +407,6 @@ void Scheduler::releaseResources() {
   // added to deferred mem obj storage. So we may end up with leak.
   while (!isDeferredMemObjectsEmpty())
     cleanupDeferredMemObjects(BlockingT::BLOCKING);
-#endif
 }
 
 MemObjRecord *Scheduler::getMemObjRecord(const Requirement *const Req) {