From 35fd969d663f8f89ecdbdb14e52e4f03e37d3f86 Mon Sep 17 00:00:00 2001
From: Mathieu Chartier <mathieuc@google.com>
Date: Wed, 2 Mar 2016 12:52:37 -0800
Subject: [PATCH] Delete alloc tracking map outside of critical section

There can be lock order violations otherwise due to runtime shutdown
lock that may get acquired in the condition variable destructor.

Bug: 27506909

(cherry picked from commit 0b8b4a609120b90081d898dbf3c26f68fe80de96)

Change-Id: I6972c450db8856e30c13e27aea94b01943618f64
---
 runtime/gc/allocation_record.cc | 5 ++++-
 runtime/gc/heap.cc              | 4 ++++
 runtime/gc/heap.h               | 4 ++++
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/runtime/gc/allocation_record.cc b/runtime/gc/allocation_record.cc
index 4de5388d8..467248330 100644
--- a/runtime/gc/allocation_record.cc
+++ b/runtime/gc/allocation_record.cc
@@ -245,6 +245,9 @@ void AllocRecordObjectMap::SetAllocTrackingEnabled(bool enable) {
       heap->SetAllocTrackingEnabled(true);
     }
   } else {
+    // Delete outside of the critical section to avoid possible lock violations like the runtime
+    // shutdown lock.
+    std::unique_ptr<AllocRecordObjectMap> map;
     {
       MutexLock mu(self, *Locks::alloc_tracker_lock_);
       if (!heap->IsAllocTrackingEnabled()) {
@@ -252,7 +255,7 @@ void AllocRecordObjectMap::SetAllocTrackingEnabled(bool enable) {
       }
       heap->SetAllocTrackingEnabled(false);
       LOG(INFO) << "Disabling alloc tracker";
-      heap->SetAllocationRecords(nullptr);
+      map = heap->ReleaseAllocationRecords();
     }
     // If an allocation comes in before we uninstrument, we will safely drop it on the floor.
     Runtime::Current()->GetInstrumentation()->UninstrumentQuickAllocEntryPoints();
diff --git a/runtime/gc/heap.cc b/runtime/gc/heap.cc
index 836bbf40a..7e242d5bb 100644
--- a/runtime/gc/heap.cc
+++ b/runtime/gc/heap.cc
@@ -3932,6 +3932,10 @@ void Heap::SetAllocationRecords(AllocRecordObjectMap* records) {
   allocation_records_.reset(records);
 }
 
+std::unique_ptr<AllocRecordObjectMap> Heap::ReleaseAllocationRecords() {
+  return std::move(allocation_records_);
+}
+
 void Heap::VisitAllocationRecords(RootVisitor* visitor) const {
   if (IsAllocTrackingEnabled()) {
     MutexLock mu(Thread::Current(), *Locks::alloc_tracker_lock_);
diff --git a/runtime/gc/heap.h b/runtime/gc/heap.h
index 9e1a4077c..37aa82d68 100644
--- a/runtime/gc/heap.h
+++ b/runtime/gc/heap.h
@@ -763,6 +763,10 @@ class Heap {
     return allocation_records_.get();
   }
 
+  // Release ownership of the allocation records.
+  std::unique_ptr<AllocRecordObjectMap> ReleaseAllocationRecords()
+      REQUIRES(Locks::alloc_tracker_lock_);
+
   void SetAllocationRecords(AllocRecordObjectMap* records)
       REQUIRES(Locks::alloc_tracker_lock_);
 
-- 
2.11.0