1 files changed, 22 insertions, 2 deletions
diff --git a/runtime/gc/heap.h b/runtime/gc/heap.h
index 6d70a38765..c9ea03e45c 100644
--- a/runtime/gc/heap.h
+++ b/runtime/gc/heap.h
@@ -769,8 +769,8 @@ class Heap {
   Mutex* heap_trim_request_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
   // When we want to perform the next heap trim (nano seconds).
   uint64_t last_trim_time_ GUARDED_BY(heap_trim_request_lock_);
-  // When we want to perform the next heap transition (nano seconds).
-  uint64_t heap_transition_target_time_ GUARDED_BY(heap_trim_request_lock_);
+  // When we want to perform the next heap transition (nano seconds) or heap trim.
+  uint64_t heap_transition_or_trim_target_time_ GUARDED_BY(heap_trim_request_lock_);
   // If we have a heap trim request pending.
   bool heap_trim_request_pending_ GUARDED_BY(heap_trim_request_lock_);
 
@@ -981,6 +981,7 @@ class Heap {
   friend class VerifyReferenceCardVisitor;
   friend class VerifyReferenceVisitor;
   friend class VerifyObjectVisitor;
+  friend class ScopedHeapFill;
   friend class ScopedHeapLock;
   friend class space::SpaceTest;
 
@@ -997,6 +998,25 @@ class Heap {
   DISALLOW_IMPLICIT_CONSTRUCTORS(Heap);
 };
 
+// ScopedHeapFill changes the bytes allocated counter to be equal to the growth limit. This
+// causes the next allocation to perform a GC and possibly an OOM. It can be used to ensure that a
+// GC happens in specific methods such as ThrowIllegalMonitorStateExceptionF in Monitor::Wait.
+class ScopedHeapFill {
+ public:
+  explicit ScopedHeapFill(Heap* heap)
+      : heap_(heap),
+        delta_(heap_->GetMaxMemory() - heap_->GetBytesAllocated()) {
+    heap_->num_bytes_allocated_.FetchAndAddSequentiallyConsistent(delta_);
+  }
+  ~ScopedHeapFill() {
+    heap_->num_bytes_allocated_.FetchAndSubSequentiallyConsistent(delta_);
+  }
+
+ private:
+  Heap* const heap_;
+  const int64_t delta_;
+};
+
 }  // namespace gc
 }  // namespace art