Fix PR comments

Author: Mikołaj Komar

unified-runtime/source/adapters/level_zero/v2/command_buffer.cpp

@@ -47,32 +47,26 @@ ur_result_t ur_exp_command_buffer_handle_t_::finalizeCommandBuffer() {
   isFinalized = true;
   return UR_RESULT_SUCCESS;
 }
-ur_result_t ur_exp_command_buffer_handle_t_::awaitExecution(
-    locked<ur_command_list_manager> &commandList) {
-  std::ignore = commandList;
+ur_event_handle_t ur_exp_command_buffer_handle_t_::getCurrentExecutionEvent(
+    [[maybe_unused]] locked<ur_command_list_manager> &commandList) {
   assert(
       commandList->getZeCommandList() ==
           commandListManager.get_no_lock()->getZeCommandList() &&
       "Provided command list is not the same as the one in the command buffer");
-  if (currentExecution) {
-    ZE2UR_CALL(zeEventHostSynchronize,
-               (currentExecution->getZeEvent(), UINT64_MAX));
-    UR_CALL(currentExecution->release());
-    currentExecution = nullptr;
-  }
-  return UR_RESULT_SUCCESS;
+  return currentExecution;
 }
 
 ur_result_t ur_exp_command_buffer_handle_t_::registerExecutionEvent(
-    locked<ur_command_list_manager> &commandList,
+    [[maybe_unused]] locked<ur_command_list_manager> &commandList,
     ur_event_handle_t nextExecutionEvent) {
-  std::ignore = commandList;
   assert(
       commandList->getZeCommandList() ==
           commandListManager.get_no_lock()->getZeCommandList() &&
       "Provided command list is not the same as the one in the command buffer");
-  assert(currentExecution == nullptr &&
-         "Current execution event is not null, it should be awaited first");
+  if (currentExecution) {
+    UR_CALL(currentExecution->release());
+    currentExecution = nullptr;
+  }
   if (nextExecutionEvent) {
     currentExecution = nextExecutionEvent;
     UR_CALL(nextExecutionEvent->retain());

unified-runtime/source/adapters/level_zero/v2/command_buffer.hpp

@@ -25,7 +25,8 @@ struct ur_exp_command_buffer_handle_t_ : public _ur_object {
 
   ~ur_exp_command_buffer_handle_t_();
 
-  ur_result_t awaitExecution(locked<ur_command_list_manager> &commandList);
+  ur_event_handle_t
+  getCurrentExecutionEvent(locked<ur_command_list_manager> &commandList);
   ur_result_t
   registerExecutionEvent(locked<ur_command_list_manager> &commandList,
                          ur_event_handle_t nextExecutionEvent);

unified-runtime/source/adapters/level_zero/v2/queue_immediate_in_order.cpp

@@ -932,7 +932,17 @@ ur_result_t ur_queue_immediate_in_order_t::enqueueCommandBufferExp(
   if (phEvent == nullptr) {
     phEvent = &internalEvent;
   }
-  UR_CALL(hCommandBuffer->awaitExecution(commandListLocked));
+  ur_event_handle_t executionEvent =
+      hCommandBuffer->getCurrentExecutionEvent(commandListLocked);
+  std::vector<ur_event_handle_t> extendedWaitList;
+  if (executionEvent != nullptr) {
+    extendedWaitList.resize(numEventsInWaitList + 1);
+    std::copy(phEventWaitList, phEventWaitList + numEventsInWaitList,
+              extendedWaitList.begin());
+    extendedWaitList[numEventsInWaitList] = executionEvent;
+    phEventWaitList = extendedWaitList.data();
+    numEventsInWaitList++;
+  }
   UR_CALL(enqueueGenericCommandListsExp(1, &commandBufferCommandList, phEvent,
                                         numEventsInWaitList, phEventWaitList,
                                         UR_COMMAND_ENQUEUE_COMMAND_BUFFER_EXP));