[SYCL] Fix handling of interop events for barrier with waitlist

sycl/source/detail/event_impl.hpp

@@ -329,6 +329,14 @@ class event_impl {
 
   bool isProfilingTagEvent() const noexcept { return MProfilingTagEvent; }
 
+  // Check if this event is an interoperability event.
+  bool isInterop() const noexcept {
+    // As an indication of interoperability event, we use the absence of the
+    // queue and command, as well as the fact that it can not be in enqueued
+    // state.
+    return MEvent && MQueue.expired() && !MIsEnqueued && !MCommand;
+  }
+
 protected:
   // When instrumentation is enabled emits trace event for event wait begin and
   // returns the telemetry event generated for the wait

sycl/source/detail/scheduler/commands.cpp

@@ -265,9 +265,12 @@ std::vector<ur_event_handle_t> Command::getUrEventsBlocking(
     if (EventImpl->isDefaultConstructed() || EventImpl->isHost() ||
         EventImpl->isNOP())
       continue;
-    // In this path nullptr native event means that the command has not been
-    // enqueued. It may happen if async enqueue in a host task is involved.
-    if (!EventImpl->isEnqueued()) {
+
+    // If command has not been enqueued then we have to enqueue it.
+    // It may happen if async enqueue in a host task is involved.
+    // Interoperability events are special case and they are not enqueued, as
+    // they don't have associated queue and command.
+    if (!EventImpl->isInterop() && !EventImpl->isEnqueued()) {
       if (!EventImpl->getCommand() ||
           !static_cast<Command *>(EventImpl->getCommand())->producesPiEvent())
         continue;

sycl/test-e2e/Regression/barrier_waitlist_with_interop_event.cpp

@@ -0,0 +1,44 @@
+// REQUIRES: level_zero, level_zero_dev_kit
+// RUN: %{build} %level_zero_options -o %t.out
+// RUN: %{run} %t.out
+// UNSUPPORTED: ze_debug
+
+#include <level_zero/ze_api.h>
+#include <sycl/detail/core.hpp>
+#include <sycl/ext/oneapi/backend/level_zero.hpp>
+#include <sycl/usm.hpp>
+
+// Test checks the case when an interoperability event is passed as a dependency
+// to the barrier. In such case waiting for the even produced by barrier must
+// guarantee completion of the interoperability event.
+
+using namespace sycl;
+
+int main() {
+  sycl::queue Queue;
+  const size_t N = 1024;
+  int *Data = sycl::malloc_shared<int>(N, Queue);
+  auto FillEvent = Queue.fill(Data, 0, N);
+  auto FillZeEvent = get_native<backend::ext_oneapi_level_zero>(FillEvent);
+
+  backend_input_t<backend::ext_oneapi_level_zero, event> EventInteropInput = {
+      FillZeEvent};
+  EventInteropInput.Ownership = sycl::ext::oneapi::level_zero::ownership::keep;
+  auto EventInterop = make_event<backend::ext_oneapi_level_zero>(
+      EventInteropInput, Queue.get_context());
+
+  auto BarrierEvent = Queue.ext_oneapi_submit_barrier({EventInterop});
+  BarrierEvent.wait();
+
+  if (EventInterop.get_info<sycl::info::event::command_execution_status>() !=
+      sycl::info::event_command_status::complete) {
+    Queue.wait();
+    sycl::free(Data, Queue);
+    return -1;
+  }
+
+  // Free the USM memory
+  sycl::free(Data, Queue);
+
+  return 0;
+}