[llvm-branch-commits] [mlir] 9edcedf - [mlir] AsyncRuntime: disable threading until test flakiness is fixed

[Eugene Zhulenev via llvm-branch-commits]

Author: Eugene Zhulenev
Date: 2020-12-01T01:12:16-08:00
New Revision: 9edcedf7f222ce7c893d1e3bf19b3a7a1f0f2218

URL: https://github.com/llvm/llvm-project/commit/9edcedf7f222ce7c893d1e3bf19b3a7a1f0f2218
DIFF: https://github.com/llvm/llvm-project/commit/9edcedf7f222ce7c893d1e3bf19b3a7a1f0f2218.diff

LOG: [mlir] AsyncRuntime: disable threading until test flakiness is fixed

ExecutionEngine/LLJIT do not run globals destructors in loaded dynamic libraries when destroyed, and threads managed by ThreadPool can race with program termination, and it leads to segfaults.

TODO: Re-enable threading after fixing a problem with destructors, or removing static globals from dynamic library.

Differential Revision: https://reviews.llvm.org/D92368

Added: 
    

Modified: 
    mlir/lib/ExecutionEngine/AsyncRuntime.cpp

Removed: 
    


################################################################################
diff  --git a/mlir/lib/ExecutionEngine/AsyncRuntime.cpp b/mlir/lib/ExecutionEngine/AsyncRuntime.cpp
index 6bf59f86208d..3b90b9c694f3 100644
--- a/mlir/lib/ExecutionEngine/AsyncRuntime.cpp
+++ b/mlir/lib/ExecutionEngine/AsyncRuntime.cpp
@@ -24,8 +24,6 @@
 #include <thread>
 #include <vector>
 
-#include "llvm/Support/ThreadPool.h"
-
 //===----------------------------------------------------------------------===//
 // Async runtime API.
 //===----------------------------------------------------------------------===//
@@ -45,7 +43,6 @@ class AsyncRuntime {
   AsyncRuntime() : numRefCountedObjects(0) {}
 
   ~AsyncRuntime() {
-    threadPool.wait(); // wait for the completion of all async tasks
     assert(getNumRefCountedObjects() == 0 &&
            "all ref counted objects must be destroyed");
   }
@@ -54,8 +51,6 @@ class AsyncRuntime {
     return numRefCountedObjects.load(std::memory_order_relaxed);
   }
 
-  llvm::ThreadPool &getThreadPool() { return threadPool; }
-
 private:
   friend class RefCounted;
 
@@ -69,8 +64,6 @@ class AsyncRuntime {
   }
 
   std::atomic<int32_t> numRefCountedObjects;
-
-  llvm::ThreadPool threadPool;
 };
 
 // Returns the default per-process instance of an async runtime.
@@ -241,8 +234,7 @@ extern "C" void mlirAsyncRuntimeAwaitAllInGroup(AsyncGroup *group) {
 }
 
 extern "C" void mlirAsyncRuntimeExecute(CoroHandle handle, CoroResume resume) {
-  auto *runtime = getDefaultAsyncRuntimeInstance();
-  runtime->getThreadPool().async([handle, resume]() { (*resume)(handle); });
+  (*resume)(handle);
 }
 
 extern "C" void mlirAsyncRuntimeAwaitTokenAndExecute(AsyncToken *token,