[heap] pause/resume inline allocation observers around scavenge

src/heap/spaces.cc

Index: src/heap/spaces.cc
diff --git a/src/heap/spaces.cc b/src/heap/spaces.cc
index d2e908bb00e58c0c35e4acfa3688af23923d1cc5..52ebde844f8af97ce6b578381d47569fe0fcc909 100644
--- a/src/heap/spaces.cc
+++ b/src/heap/spaces.cc
@@ -1509,7 +1509,8 @@ void NewSpace::UpdateInlineAllocationLimit(int size_in_bytes) {
     Address high = to_space_.page_high();
     Address new_top = allocation_info_.top() + size_in_bytes;
     allocation_info_.set_limit(Min(new_top, high));
-  } else if (top_on_previous_step_ == 0) {
+  } else if (inline_allocation_observers_paused_ ||
+             top_on_previous_step_ == 0) {
     // Normal limit is the end of the current page.
     allocation_info_.set_limit(to_space_.page_high());
   } else {
@@ -1602,6 +1603,7 @@ bool NewSpace::EnsureAllocation(int size_in_bytes,
 
 
 void NewSpace::StartNextInlineAllocationStep() {
+  DCHECK(!inline_allocation_observers_paused_);
   top_on_previous_step_ =
       inline_allocation_observers_.length() ? allocation_info_.top() : 0;
   UpdateInlineAllocationLimit(0);
@@ -1636,6 +1638,22 @@ void NewSpace::RemoveInlineAllocationObserver(
 }
 
 
+void NewSpace::PauseInlineAllocationObservers() {
+  // Do a step to account for memory allocated so far.
+  InlineAllocationStep(top(), top());
+  inline_allocation_observers_paused_ = true;
+  top_on_previous_step_ = 0;
+  UpdateInlineAllocationLimit(0);
+}
+
+
+void NewSpace::ResumeInlineAllocationObservers() {
+  DCHECK(top_on_previous_step_ == 0);
+  inline_allocation_observers_paused_ = false;
+  StartNextInlineAllocationStep();
+}
+
+
 void NewSpace::InlineAllocationStep(Address top, Address new_top) {
   if (top_on_previous_step_) {
     int bytes_allocated = static_cast<int>(top - top_on_previous_step_);