ART: Change ThreadPool::Wait behavior

When a pool is in the stopped state, Wait() will not wait for all
tasks to complete.

Bug: 31385354
Test: m test-art-host-gtest-thread_pool_test
Change-Id: Id0144b685ee2fddf1a1c2c2ca334251130121033

1 files changed, 6 insertions, 1 deletions

diff --git a/runtime/thread_pool.h b/runtime/thread_pool.h
index b6c6f02db8..2ff33a6053 100644
--- a/runtime/thread_pool.h
+++ b/runtime/thread_pool.h
@@ -100,7 +100,8 @@ class ThreadPool {
   ThreadPool(const char* name, size_t num_threads);
   virtual ~ThreadPool();
 
-  // Wait for all tasks currently on queue to get completed.
+  // Wait for all tasks currently on queue to get completed. If the pool has been stopped, only
+  // wait till all already running tasks are done.
   void Wait(Thread* self, bool do_work, bool may_hold_locks) REQUIRES(!task_queue_lock_);
 
   size_t GetTaskCount(Thread* self) REQUIRES(!task_queue_lock_);
@@ -130,6 +131,10 @@ class ThreadPool {
     return shutting_down_;
   }
 
+  bool HasOutstandingTasks() const REQUIRES(task_queue_lock_) {
+    return started_ && !tasks_.empty();
+  }
+
   const std::string name_;
   Mutex task_queue_lock_;
   ConditionVariable task_queue_condition_ GUARDED_BY(task_queue_lock_);