[SYCL] Fix exception duplication for copy back command

sycl/source/detail/scheduler/commands.cpp

@@ -1722,12 +1722,19 @@ ur_result_t MemCpyCommandHost::enqueueImp() {
   }
 
   flushCrossQueueDeps(EventImpls, MWorkerQueue);
-  MemoryManager::copy(
-      MSrcAllocaCmd->getSYCLMemObj(), MSrcAllocaCmd->getMemAllocation(),
-      MSrcQueue, MSrcReq.MDims, MSrcReq.MMemoryRange, MSrcReq.MAccessRange,
-      MSrcReq.MOffset, MSrcReq.MElemSize, *MDstPtr, MQueue, MDstReq.MDims,
-      MDstReq.MMemoryRange, MDstReq.MAccessRange, MDstReq.MOffset,
-      MDstReq.MElemSize, std::move(RawEvents), MEvent->getHandleRef(), MEvent);
+
+  try {
+    MemoryManager::copy(
+        MSrcAllocaCmd->getSYCLMemObj(), MSrcAllocaCmd->getMemAllocation(),
+        MSrcQueue, MSrcReq.MDims, MSrcReq.MMemoryRange, MSrcReq.MAccessRange,
+        MSrcReq.MOffset, MSrcReq.MElemSize, *MDstPtr, MQueue, MDstReq.MDims,
+        MDstReq.MMemoryRange, MDstReq.MAccessRange, MDstReq.MOffset,
+        MDstReq.MElemSize, std::move(RawEvents), MEvent->getHandleRef(),
+        MEvent);
+  } catch (sycl::exception &e) {
+    return static_cast<ur_result_t>(get_ur_error(e));
+  }
+
   return UR_RESULT_SUCCESS;
 }
 

sycl/source/detail/scheduler/scheduler.cpp

@@ -218,27 +218,40 @@ EventImplPtr Scheduler::addCopyBack(Requirement *Req) {
   }
 
   std::vector<Command *> ToCleanUp;
+  // EnqueueCommand will try to enqueue dependencies (previous operations on the
+  // buffer). If any dep kernel failed it would be reported as sync exception or
+  // async exception on host task completion and enqueue attempt.
+  // No need to report those failures again in copy back submission. So report
+  // only copy back auxiliary and main command failures.
+  bool CopyBackCmdsFailed = false;
   try {
     ReadLockT Lock = acquireReadLock();
     EnqueueResultT Res;
-    bool Enqueued;
+    bool Enqueued = false;
 
     for (Command *Cmd : AuxiliaryCmds) {
       Enqueued = GraphProcessor::enqueueCommand(Cmd, Lock, Res, ToCleanUp, Cmd);
-      if (!Enqueued && EnqueueResultT::SyclEnqueueFailed == Res.MResult)
+      if (!Enqueued && EnqueueResultT::SyclEnqueueFailed == Res.MResult) {
+        CopyBackCmdsFailed |= Res.MCmd == Cmd;
         throw exception(make_error_code(errc::runtime),
                         "Enqueue process failed.");
+      }
     }
 
     Enqueued =
         GraphProcessor::enqueueCommand(NewCmd, Lock, Res, ToCleanUp, NewCmd);
-    if (!Enqueued && EnqueueResultT::SyclEnqueueFailed == Res.MResult)
+    if (!Enqueued && EnqueueResultT::SyclEnqueueFailed == Res.MResult) {
+      CopyBackCmdsFailed |= Res.MCmd == NewCmd;
       throw exception(make_error_code(errc::runtime),
                       "Enqueue process failed.");
+    }
   } catch (...) {
-    auto WorkerQueue = NewCmd->getEvent()->getWorkerQueue();
-    assert(WorkerQueue && "WorkerQueue for CopyBack command must be not null");
-    WorkerQueue->reportAsyncException(std::current_exception());
+    if (CopyBackCmdsFailed) {
+      auto WorkerQueue = NewCmd->getEvent()->getWorkerQueue();
+      assert(WorkerQueue &&
+             "WorkerQueue for CopyBack command must be not null");
+      WorkerQueue->reportAsyncException(std::current_exception());
+    }
   }
   EventImplPtr NewEvent = NewCmd->getEvent();
   cleanupCommands(ToCleanUp);

sycl/unittests/scheduler/FailedCommands.cpp

@@ -9,6 +9,7 @@
 #include "SchedulerTest.hpp"
 #include "SchedulerTestUtils.hpp"
 
+#include <helpers/TestKernel.hpp>
 #include <helpers/UrMock.hpp>
 
 using namespace sycl;
@@ -42,3 +43,46 @@ TEST_F(SchedulerTest, FailedDependency) {
   ASSERT_EQ(MDep.MEnqueueStatus, detail::EnqueueResultT::SyclEnqueueFailed)
       << "MDep should be marked as failed\n";
 }
+
+void RunWithFailedCommandsAndCheck(bool SyncExceptionExpected,
+                                   int AsyncExceptionCountExpected) {
+  platform Plt = sycl::platform();
+  int ExceptionListSize = 0;
+  sycl::async_handler AsyncHandler =
+      [&ExceptionListSize](sycl::exception_list ExceptionList) {
+        ExceptionListSize = ExceptionList.size();
+      };
+  bool ExceptionThrown = false;
+  queue Queue(context(Plt), default_selector_v, AsyncHandler);
+  {
+    int initVal = 0;
+    sycl::buffer<int, 1> Buf(&initVal, 1);
+    try {
+      Queue.submit([&](sycl::handler &CGH) {
+        Buf.get_access<sycl::access::mode::write>(CGH);
+        CGH.single_task<TestKernel<1>>([]() {});
+      });
+    } catch (...) {
+      ExceptionThrown = true;
+    }
+  }
+  EXPECT_EQ(ExceptionThrown, SyncExceptionExpected);
+  Queue.wait_and_throw();
+  EXPECT_EQ(ExceptionListSize, AsyncExceptionCountExpected);
+}
+
+ur_result_t failingUrCall(void *) { return UR_RESULT_ERROR_UNKNOWN; }
+
+TEST_F(SchedulerTest, FailedKernelException) {
+  unittest::UrMock<> Mock;
+  mock::getCallbacks().set_before_callback("urEnqueueKernelLaunch",
+                                           &failingUrCall);
+  RunWithFailedCommandsAndCheck(true, 0);
+}
+
+TEST_F(SchedulerTest, FailedCopyBackException) {
+  unittest::UrMock<> Mock;
+  mock::getCallbacks().set_before_callback("urEnqueueMemBufferRead",
+                                           &failingUrCall);
+  RunWithFailedCommandsAndCheck(false, 1);
+}