commit e8649c7f1f1c21fdee1a40068c03d1e294e397ca
author Mathieu Chartier <mathieuc@google.com> Fri Mar 03 18:02:18 2017 -0800
committer Mathieu Chartier <mathieuc@google.com> Fri Mar 03 18:08:34 2017 -0800
tree f1e691e11a9277189d354049be3fab1976d9cca9
parent d9f647ac9a5cb0c6f112332d584756251c2cfb9f

Add GC critical section to GetObjectsAllocated

Prevent GC running during GetObjectsAllocated since we may get a
checkpoint request that tells us to suspend while we are doing
SuspendAll. This can cause a deadlock.

Bug: 35232978

Test: test-art-host

Change-Id: I9c02415df0a0b9fa787d7ce449ec06a40dfaf624

runtime/gc/collector_type.h

diff --git a/runtime/gc/collector_type.h b/runtime/gc/collector_type.h
index eef4fba..f0e1029 100644
--- a/runtime/gc/collector_type.h
+++ b/runtime/gc/collector_type.h
@@ -59,6 +59,8 @@
   kCollectorTypeHprof,
   // Fake collector for installing/removing a system-weak holder.
   kCollectorTypeAddRemoveSystemWeakHolder,
+  // Fake collector type for GetObjectsAllocated
+  kCollectorTypeGetObjectsAllocated,
 };
 std::ostream& operator<<(std::ostream& os, const CollectorType& collector_type);
 

runtime/gc/gc_cause.cc

diff --git a/runtime/gc/gc_cause.cc b/runtime/gc/gc_cause.cc
index 9e34346..c1c1cad 100644
--- a/runtime/gc/gc_cause.cc
+++ b/runtime/gc/gc_cause.cc
@@ -40,6 +40,7 @@
     case kGcCauseJitCodeCache: return "JitCodeCache";
     case kGcCauseAddRemoveSystemWeakHolder: return "SystemWeakHolder";
     case kGcCauseHprof: return "Hprof";
+    case kGcCauseGetObjectsAllocated: return "ObjectsAllocated";
   }
   LOG(FATAL) << "Unreachable";
   UNREACHABLE();

runtime/gc/gc_cause.h

diff --git a/runtime/gc/gc_cause.h b/runtime/gc/gc_cause.h
index 9b285b1..eb27547 100644
--- a/runtime/gc/gc_cause.h
+++ b/runtime/gc/gc_cause.h
@@ -53,8 +53,10 @@
   kGcCauseJitCodeCache,
   // Not a real GC cause, used to add or remove system-weak holders.
   kGcCauseAddRemoveSystemWeakHolder,
-  // Not a real GC cause, used to hprof running in the middle of GC.
+  // Not a real GC cause, used to prevent hprof running in the middle of GC.
   kGcCauseHprof,
+  // Not a real GC cause, used to prevent GetObjectsAllocated running in the middle of GC.
+  kGcCauseGetObjectsAllocated,
 };
 
 const char* PrettyCause(GcCause cause);

runtime/gc/heap.cc

diff --git a/runtime/gc/heap.cc b/runtime/gc/heap.cc
index b857ea3..a769748 100644
--- a/runtime/gc/heap.cc
+++ b/runtime/gc/heap.cc
@@ -1835,6 +1835,11 @@
 size_t Heap::GetObjectsAllocated() const {
   Thread* const self = Thread::Current();
   ScopedThreadStateChange tsc(self, kWaitingForGetObjectsAllocated);
+  // Prevent GC running during GetObjectsALlocated since we may get a checkpoint request that tells
+  // us to suspend while we are doing SuspendAll. b/35232978
+  gc::ScopedGCCriticalSection gcs(Thread::Current(),
+                                  gc::kGcCauseGetObjectsAllocated,
+                                  gc::kCollectorTypeGetObjectsAllocated);
   // Need SuspendAll here to prevent lock violation if RosAlloc does it during InspectAll.
   ScopedSuspendAll ssa(__FUNCTION__);
   ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_);