[Openmp-commits] [PATCH] D144315: [OpenMP] Make isDone lightweight without calling synchronize

Ye Luo via Phabricator via Openmp-commits openmp-commits at lists.llvm.org
Fri Feb 17 18:31:04 PST 2023

ye-luo created this revision.
Herald added subscribers: guansong, yaxunl.
Herald added a project: All.
ye-luo requested review of this revision.
Herald added a reviewer: jdoerfert.
Herald added subscribers: openmp-commits, sstefan1.
Herald added a project: OpenMP.

~TaskAsyncInfoWrapperTy() calls isDone. With synchronize inside isDone, we need to handle the error return from synchronize in the destructor.
The consumers of TaskAsyncInfoWrapperTy, targetDataMapper and targetKernel, both call AsyncInfo.synchronize() before exiting.
For this reason in ~TaskAsyncInfoWrapperTy(), calling synchronize() via isDone() is redundant.
This patch removes synchronize() call inside isDone() and makes it a lightweight check.
__tgt_target_nowait_query needs to call synchronize() before checking isDone().

  rG LLVM Github Monorepo



Index: openmp/libomptarget/src/private.h
--- openmp/libomptarget/src/private.h
+++ openmp/libomptarget/src/private.h
@@ -250,13 +250,9 @@
     if (AsyncInfo == &LocalAsyncInfo)
-    auto DoneOrErr = AsyncInfo->isDone();
-    if (!DoneOrErr)
-      FATAL_MESSAGE0(1,
-                     "Error while querying the async queue for completion.\n");
     // If the are device operations still pending, return immediately without
     // deallocating the handle.
-    if (!*DoneOrErr)
+    if (!AsyncInfo->isDone())
     // Delete the handle and unset it from the OpenMP task data.
Index: openmp/libomptarget/src/omptarget.cpp
--- openmp/libomptarget/src/omptarget.cpp
+++ openmp/libomptarget/src/omptarget.cpp
@@ -51,13 +51,7 @@
   return BufferLocations.back();
-std::optional<bool> AsyncInfoTy::isDone() {
-  if (synchronize() == OFFLOAD_FAIL)
-    return std::nullopt;
-  // The async info operations are completed when the internal queue is empty.
-  return isQueueEmpty();
+bool AsyncInfoTy::isDone() const { return isQueueEmpty(); }
 int32_t AsyncInfoTy::runPostProcessing() {
   size_t Size = PostProcessingFunctions.size();
Index: openmp/libomptarget/src/interface.cpp
--- openmp/libomptarget/src/interface.cpp
+++ openmp/libomptarget/src/interface.cpp
@@ -412,12 +412,11 @@
   if (QueryCounter.isAboveThreshold())
     AsyncInfo->SyncType = AsyncInfoTy::SyncTy::BLOCKING;
-  auto DoneOrErr = AsyncInfo->isDone();
-  if (!DoneOrErr)
+  if (const int Rc = AsyncInfo->synchronize())
     FATAL_MESSAGE0(1, "Error while querying the async queue for completion.\n");
   // If there are device operations still pending, return immediately without
   // deallocating the handle and increase the current thread query count.
-  if (!*DoneOrErr) {
+  if (!AsyncInfo->isDone()) {
Index: openmp/libomptarget/include/omptarget.h
--- openmp/libomptarget/include/omptarget.h
+++ openmp/libomptarget/include/omptarget.h
@@ -17,7 +17,6 @@
 #include <cstdint>
 #include <deque>
 #include <functional>
-#include <optional>
 #include <stddef.h>
 #include <stdint.h>
 #include <type_traits>
@@ -244,12 +243,12 @@
   /// Check if all asynchronous operations are completed.
-  /// \note if the operations are completed, the registered post-processing
-  /// functions will be executed once and unregistered afterwards.
+  /// \note only a lightweight check. If needed, use synchronize() to query the
+  /// status of AsyncInfo before checking.
   /// \returns true if there is no pending asynchronous operations, false
-  /// otherwise. We return a null value in the case of an error from the plugin.
-  std::optional<bool> isDone();
+  /// otherwise.
+  bool isDone() const;
   /// Add a new post-processing function to be executed after synchronization.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D144315.498546.patch
Type: text/x-patch
Size: 3133 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/openmp-commits/attachments/20230218/1d812ff2/attachment-0001.bin>

More information about the Openmp-commits mailing list