From f1ef5b98bcf40db7621c4fc59cc50519401c65d5 Mon Sep 17 00:00:00 2001
From: Artur Gainullin <artur.gainullin@intel.com>
Date: Thu, 4 Sep 2025 07:41:37 -0700
Subject: [PATCH] [SYCL] Fix barrier on barrier dependency between queues
 (#19970)

Currently for the pattern like this:
```
sycl::event eb1 = q1.ext_oneapi_submit_barrier();
q2.ext_oneapi_submit_barrier({ eb1 });

```
the second barrier ignores `eb1` in the waitlist because it is not
marked as enqueued even though it is supposed to. This PR fixes that.

Fixes https://github.com/intel/llvm/issues/19777
---
 sycl/source/detail/queue_impl.hpp |  1 +
 sycl/unittests/queue/Barrier.cpp  | 22 +++++++++++++++++++++-
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/sycl/source/detail/queue_impl.hpp b/sycl/source/detail/queue_impl.hpp
index 839570553f3ce..86a35e5ffac6c 100644
--- a/sycl/source/detail/queue_impl.hpp
+++ b/sycl/source/detail/queue_impl.hpp
@@ -667,6 +667,7 @@ class queue_impl : public std::enable_shared_from_this<queue_impl> {
     getAdapter().call<UrApiKind::urEnqueueEventsWait>(getHandleRef(), 0,
                                                       nullptr, &UREvent);
     ResEvent->setHandle(UREvent);
+    ResEvent->setEnqueued();
     return ResEvent;
   }
 
diff --git a/sycl/unittests/queue/Barrier.cpp b/sycl/unittests/queue/Barrier.cpp
index b13d703085fc4..c2df018e16de1 100644
--- a/sycl/unittests/queue/Barrier.cpp
+++ b/sycl/unittests/queue/Barrier.cpp
@@ -8,13 +8,19 @@
 
 #include <helpers/TestKernel.hpp>
 #include <helpers/UrMock.hpp>
+#include <sycl/sycl.hpp>
 
 #include <gtest/gtest.h>
 
 static unsigned NumOfEventsWaitWithBarrierCalls = 0;
+static unsigned NumEventsInWaitList = 0;
 
-static ur_result_t redefined_urEnqueueEventsWaitWithBarrierExt(void *) {
+static ur_result_t redefined_urEnqueueEventsWaitWithBarrierExt(void *pParams) {
   NumOfEventsWaitWithBarrierCalls++;
+  // Get the number of events in the wait list
+  auto params =
+      *static_cast<ur_enqueue_events_wait_with_barrier_ext_params_t *>(pParams);
+  NumEventsInWaitList = *params.pnumEventsInWaitList;
 
   return UR_RESULT_SUCCESS;
 }
@@ -94,3 +100,17 @@ TEST(Queue, ExtOneAPISubmitBarrierWithWaitList) {
 
   ASSERT_EQ(NumOfEventsWaitWithBarrierCalls, 1u);
 }
+
+TEST(Queue, BarrierWithBarrierDep) {
+  sycl::unittest::UrMock<> Mock;
+  mock::getCallbacks().set_before_callback(
+      "urEnqueueEventsWaitWithBarrierExt",
+      &redefined_urEnqueueEventsWaitWithBarrierExt);
+  sycl::queue Q1(sycl::property::queue::in_order{});
+  sycl::queue Q2(sycl::property::queue::in_order{});
+  Q1.submit([&](sycl::handler &cgh) { cgh.single_task<TestKernel>([=]() {}); });
+  sycl::event Barrier1 = Q1.ext_oneapi_submit_barrier();
+  NumEventsInWaitList = 0;
+  Q2.ext_oneapi_submit_barrier({Barrier1});
+  ASSERT_EQ(NumEventsInWaitList, 1u);
+}