[SYCL] Temporarily restore event deps in in-order queues for Level Zero (#3188)

Some of the enqueued operations are implemented directly in the Level
Zero plugin (e.g. map/unmap) and their implementation does not satisfy
in-order queue requirements, leading to incorrect behaviour if the event
dependencies that should be redundant are dropped.

Restore these event dependencies until this is fixed in the Level Zero
plugin.

Author: sergey-semenov

sycl/source/detail/scheduler/commands.cpp

@@ -496,9 +496,14 @@ void Command::processDepEvent(EventImplPtr DepEvent, const DepDesc &Dep) {
   }
 
   // Do not add redundant event dependencies for in-order queues.
-  if (Dep.MDepCommand && Dep.MDepCommand->getWorkerQueue() == WorkerQueue &&
-      WorkerQueue->has_property<property::queue::in_order>())
-    return;
+  // TODO temporarily disabled with Level Zero since the enqueued operations
+  // that are implemented directly in the plugin (e.g. map/unmap) do not satisfy
+  // in-order queue requirements.
+  if (WorkerQueue->is_host() ||
+      WorkerQueue->getPlugin().getBackend() != backend::level_zero)
+    if (Dep.MDepCommand && Dep.MDepCommand->getWorkerQueue() == WorkerQueue &&
+        WorkerQueue->has_property<property::queue::in_order>())
+      return;
 
   ContextImplPtr DepEventContext = DepEvent->getContextImpl();
   // If contexts don't match we'll connect them using host task

sycl/unittests/scheduler/InOrderQueueDeps.cpp

@@ -83,6 +83,13 @@ TEST_F(SchedulerTest, InOrderQueueDeps) {
     std::cout << "Not run due to host-only environment\n";
     return;
   }
+  if (detail::getSyclObjImpl(Plt)->getPlugin().getBackend() ==
+      backend::level_zero) {
+    std::cout << "Removal of redundant dependencies in in-order queues is "
+                 "disabled for Level Zero until it is supported by the plugin"
+              << std::endl;
+    return;
+  }
 
   unittest::PiMock Mock{Plt};
   Mock.redefine<detail::PiApiKind::piMemBufferCreate>(redefinedMemBufferCreate);