Revert^18 "Thread suspension cleanup and deadlock fix"

This reverts commit 8bc6a58df7046b4d6f4b51eb274c7e60fea396ff.

PS1 is identical to
  https://android-review.git.corp.google.com/c/platform/art/+/2746640

PS2 makes the following changes:
- Remove one DCHECK each from the two WaitForFlipFunction variants.
  The DCHECK could fail if another GC was started in the interim.
- Break up the WaitForSuspendBarrier timeout into shorter ones.
  so we don't time out as easily if our process is frozen.
- Include the thread name for ThreadSuspendByThreadIdWarning, since
  we don't get complete tombstones for some failures.

Test: Treehugger, host tests.
Bug: 240742796
Bug: 203363895
Bug: 238032384
Bug: 253671779
Bug: 276660630
Bug: 295880862
Bug: 294334417
Bug: 301090887
Bug: 313347640
(and more)

Change-Id: I12c5c01b1e006baab4ee4148aadbc721723fb89e

1 files changed, 7 insertions, 1 deletions

diff --git a/runtime/gc/task_processor.h b/runtime/gc/task_processor.h
index 86e36ab6d6..b9e6938b09 100644
--- a/runtime/gc/task_processor.h
+++ b/runtime/gc/task_processor.h
@@ -64,9 +64,15 @@ class TaskProcessor {
   bool IsRunning() const REQUIRES(!lock_);
   void UpdateTargetRunTime(Thread* self, HeapTask* target_time, uint64_t new_target_time)
       REQUIRES(!lock_);
-  Thread* GetRunningThread() const REQUIRES(!lock_);
+  // Is the given thread the task processor thread?
+  // If wait is true, and no thread has been registered via Start(), we briefly
+  // wait for one to be registered. If we time out, we return true.
+  bool IsRunningThread(Thread* t, bool wait = false) REQUIRES(!lock_);
 
  private:
+  // Wait briefly for running_thread_ to become non-null. Return false on timeout.
+  bool WaitForThread(Thread* self) REQUIRES(lock_);
+
   class CompareByTargetRunTime {
    public:
     bool operator()(const HeapTask* a, const HeapTask* b) const {