llvm · RossBrunton · Aug 22, 2025 · Aug 12, 2025 · Aug 13, 2025 · arsenm
diff --git a/offload/liboffload/API/Event.td b/offload/liboffload/API/Event.td
@@ -48,7 +48,8 @@ def : Enum {
   let desc = "Supported event info.";
   let is_typed = 1;
   let etors = [
-    TaggedEtor<"QUEUE", "ol_queue_handle_t", "The handle of the queue associated with the device.">
+    TaggedEtor<"QUEUE", "ol_queue_handle_t", "The handle of the queue associated with the device.">,
+    TaggedEtor<"IS_COMPLETE", "bool", "True if and only if the event is complete.">,
   ];
 }
 

diff --git a/offload/liboffload/src/OffloadImpl.cpp b/offload/liboffload/src/OffloadImpl.cpp
@@ -553,8 +553,8 @@ Error olGetQueueInfoSize_impl(ol_queue_handle_t Queue, ol_queue_info_t PropName,
 }
 
 Error olSyncEvent_impl(ol_event_handle_t Event) {
+  // No event info means that this event was complete on creation
   if (!Event->EventInfo)
-    // Event always complete
     return Plugin::success();
 
   if (auto Res = Event->Queue->Device->Device->syncEvent(Event->EventInfo))
@@ -575,10 +575,22 @@ Error olGetEventInfoImplDetail(ol_event_handle_t Event,
                                ol_event_info_t PropName, size_t PropSize,
                                void *PropValue, size_t *PropSizeRet) {
   InfoWriter Info(PropSize, PropValue, PropSizeRet);
+  auto Queue = Event->Queue;
 
   switch (PropName) {
   case OL_EVENT_INFO_QUEUE:
-    return Info.write<ol_queue_handle_t>(Event->Queue);
+    return Info.write<ol_queue_handle_t>(Queue);
+  case OL_EVENT_INFO_IS_COMPLETE: {
+    // No event info means that this event was complete on creation
+    if (!Event->EventInfo)
+      return Info.write<bool>(true);
+
+    auto Res = Queue->Device->Device->isEventComplete(Event->EventInfo,
+                                                      Queue->AsyncInfo);
+    if (auto Err = Res.takeError())
+      return Err;
+    return Info.write<bool>(*Res);
+  }
   default:
     return createOffloadError(ErrorCode::INVALID_ENUMERATION,
                               "olGetEventInfo enum '%i' is invalid", PropName);

diff --git a/offload/plugins-nextgen/amdgpu/src/rtl.cpp b/offload/plugins-nextgen/amdgpu/src/rtl.cpp
@@ -1519,6 +1519,9 @@ struct AMDGPUStreamTy {
   /// actions for that and prior events.
   Error synchronizeOn(AMDGPUEventTy &Event);
 
+  /// Return true if the event from this queue is complete
+  Expected<bool> isEventComplete(const AMDGPUEventTy &Event);
+
   /// Query the stream and complete pending post actions if operations finished.
   /// Return whether all the operations completed. This operation does not block
   /// the calling thread.
@@ -1683,6 +1686,18 @@ Error AMDGPUStreamTy::synchronizeOn(AMDGPUEventTy &Event) {
   return completeUntil(Event.RecordedSlot);
 }
 
+Expected<bool> AMDGPUStreamTy::isEventComplete(const AMDGPUEventTy &Event) {
+  std::lock_guard<std::mutex> Lock(Mutex);
+  assert(Event.RecordedStream == this && "event is for a different stream");
+
+  if (Event.RecordedSyncCycle < SyncCycle) {
+    return true;
+  }
+  assert(Event.RecordedSyncCycle == SyncCycle && "event is from the future?");
+
+  return !Slots[Event.RecordedSlot].Signal->load();
+}
+
 struct AMDGPUStreamManagerTy final
     : GenericDeviceResourceManagerTy<AMDGPUResourceRef<AMDGPUStreamTy>> {
   using ResourceRef = AMDGPUResourceRef<AMDGPUStreamTy>;
@@ -2601,6 +2616,13 @@ struct AMDGPUDeviceTy : public GenericDeviceTy, AMDGenericDeviceTy {
     return Query.takeError();
   }
 
+  Expected<bool> isEventCompleteImpl(void *EventPtr,
+                                     AsyncInfoWrapperTy &AsyncInfo) override {
+    AMDGPUEventTy *Event = reinterpret_cast<AMDGPUEventTy *>(EventPtr);
+    auto Stream = AsyncInfo.getQueueAs<AMDGPUStreamTy *>();
+    return Stream && Stream->isEventComplete(*Event);
+  }
+
   /// Synchronize the current thread with the event.
   Error syncEventImpl(void *EventPtr) override {
     AMDGPUEventTy *Event = reinterpret_cast<AMDGPUEventTy *>(EventPtr);

diff --git a/offload/plugins-nextgen/common/include/PluginInterface.h b/offload/plugins-nextgen/common/include/PluginInterface.h
@@ -984,6 +984,11 @@ struct GenericDeviceTy : public DeviceAllocatorTy {
   virtual Error waitEventImpl(void *EventPtr,
                               AsyncInfoWrapperTy &AsyncInfoWrapper) = 0;
 
+  /// Check if the event enqueued to AsyncInfo is complete
+  Expected<bool> isEventComplete(void *Event, __tgt_async_info *AsyncInfo);
+  virtual Expected<bool>
+  isEventCompleteImpl(void *EventPtr, AsyncInfoWrapperTy &AsyncInfoWrapper) = 0;
+
   /// Synchronize the current thread with the event.
   Error syncEvent(void *EventPtr);
   virtual Error syncEventImpl(void *EventPtr) = 0;

diff --git a/offload/plugins-nextgen/common/src/PluginInterface.cpp b/offload/plugins-nextgen/common/src/PluginInterface.cpp
@@ -1648,6 +1648,22 @@ Expected<bool> GenericDeviceTy::hasPendingWork(__tgt_async_info *AsyncInfo) {
   return Res;
 }
 
+Expected<bool> GenericDeviceTy::isEventComplete(void *Event,
+                                                __tgt_async_info *AsyncInfo) {
+  AsyncInfoWrapperTy AsyncInfoWrapper(*this, AsyncInfo);
+  auto Res = isEventCompleteImpl(Event, AsyncInfoWrapper);
+  if (auto Err = Res.takeError()) {
+    AsyncInfoWrapper.finalize(Err);
+    return Err;
+  }
+
+  auto Err = Plugin::success();
+  AsyncInfoWrapper.finalize(Err);
+  if (Err)
+    return Err;
+  return Res;
+}
+
 Error GenericDeviceTy::syncEvent(void *EventPtr) {
   return syncEventImpl(EventPtr);
 }

diff --git a/offload/plugins-nextgen/cuda/dynamic_cuda/cuda.cpp b/offload/plugins-nextgen/cuda/dynamic_cuda/cuda.cpp
@@ -82,6 +82,7 @@ DLWRAP(cuCtxSetLimit, 2)
 
 DLWRAP(cuEventCreate, 2)
 DLWRAP(cuEventRecord, 2)
+DLWRAP(cuEventQuery, 1)
 DLWRAP(cuStreamWaitEvent, 3)
 DLWRAP(cuEventSynchronize, 1)
 DLWRAP(cuEventDestroy, 1)

diff --git a/offload/plugins-nextgen/cuda/dynamic_cuda/cuda.h b/offload/plugins-nextgen/cuda/dynamic_cuda/cuda.h
@@ -352,6 +352,7 @@ CUresult cuCtxSetLimit(CUlimit, size_t);
 
 CUresult cuEventCreate(CUevent *, unsigned int);
 CUresult cuEventRecord(CUevent, CUstream);
+CUresult cuEventQuery(CUevent);
 CUresult cuStreamWaitEvent(CUstream, CUevent, unsigned int);
 CUresult cuEventSynchronize(CUevent);
 CUresult cuEventDestroy(CUevent);

diff --git a/offload/plugins-nextgen/cuda/src/rtl.cpp b/offload/plugins-nextgen/cuda/src/rtl.cpp
@@ -919,6 +919,20 @@ struct CUDADeviceTy : public GenericDeviceTy {
     return true;
   }
 
+  Expected<bool> isEventCompleteImpl(void *EventPtr,
+                                     AsyncInfoWrapperTy &) override {
+    CUevent Event = reinterpret_cast<CUevent>(EventPtr);
+
+    CUresult Ret = cuEventQuery(Event);
+    if (Ret == CUDA_SUCCESS)
+      return true;
+
+    if (Ret == CUDA_ERROR_NOT_READY)
+      return false;
+
+    return Plugin::check(Ret, "error in cuEventQuery: %s");
+  }
+
   /// Synchronize the current thread with the event.
   Error syncEventImpl(void *EventPtr) override {
     CUevent Event = reinterpret_cast<CUevent>(EventPtr);

diff --git a/offload/plugins-nextgen/host/src/rtl.cpp b/offload/plugins-nextgen/host/src/rtl.cpp
@@ -337,6 +337,10 @@ struct GenELF64DeviceTy : public GenericDeviceTy {
   Expected<bool> hasPendingWorkImpl(AsyncInfoWrapperTy &AsyncInfo) override {
     return true;
   }
+  Expected<bool> isEventCompleteImpl(void *Event,
+                                     AsyncInfoWrapperTy &AsyncInfo) override {
+    return true;
+  }
   Error syncEventImpl(void *EventPtr) override { return Plugin::success(); }
 
   /// Print information about the device.

diff --git a/offload/unittests/OffloadAPI/event/olGetEventInfo.cpp b/offload/unittests/OffloadAPI/event/olGetEventInfo.cpp
@@ -13,13 +13,22 @@
 using olGetEventInfoTest = OffloadEventTest;
 OFFLOAD_TESTS_INSTANTIATE_DEVICE_FIXTURE(olGetEventInfoTest);
 
-TEST_P(olGetEventInfoTest, SuccessDevice) {
+TEST_P(olGetEventInfoTest, SuccessQueue) {
   ol_queue_handle_t RetrievedQueue;
   ASSERT_SUCCESS(olGetEventInfo(Event, OL_EVENT_INFO_QUEUE,
                                 sizeof(ol_queue_handle_t), &RetrievedQueue));
   ASSERT_EQ(Queue, RetrievedQueue);
 }
 
+TEST_P(olGetEventInfoTest, SuccessIsComplete) {
+  bool Complete = false;
+  while (!Complete) {
+    ASSERT_SUCCESS(olGetEventInfo(Event, OL_EVENT_INFO_IS_COMPLETE,
+                                  sizeof(Complete), &Complete));
+  }
+  ASSERT_EQ(Complete, true);
+}
+
 TEST_P(olGetEventInfoTest, InvalidNullHandle) {
   ol_queue_handle_t RetrievedQueue;
   ASSERT_ERROR(OL_ERRC_INVALID_NULL_HANDLE,

diff --git a/offload/unittests/OffloadAPI/event/olGetEventInfoSize.cpp b/offload/unittests/OffloadAPI/event/olGetEventInfoSize.cpp
@@ -19,6 +19,12 @@ TEST_P(olGetEventInfoSizeTest, SuccessQueue) {
   ASSERT_EQ(Size, sizeof(ol_queue_handle_t));
 }
 
+TEST_P(olGetEventInfoSizeTest, SuccessIsComplete) {
+  size_t Size = 0;
+  ASSERT_SUCCESS(olGetEventInfoSize(Event, OL_EVENT_INFO_IS_COMPLETE, &Size));
+  ASSERT_EQ(Size, sizeof(bool));
-  ASSERT_EQ(Size, sizeof(bool));
+  EXPECT_EQ(Size, sizeof(bool));
-  ASSERT_EQ(Size, sizeof(bool));
+  EXPECT_EQ(Size, sizeof(bool));
+}
+
 TEST_P(olGetEventInfoSizeTest, InvalidNullHandle) {
   size_t Size = 0;
   ASSERT_ERROR(OL_ERRC_INVALID_NULL_HANDLE,