[heap] inline allocation steps refactor

src/heap/spaces.cc

Index: src/heap/spaces.cc
diff --git a/src/heap/spaces.cc b/src/heap/spaces.cc
index 50a213e8ae4f582a3a684b4639c73894616fb851..ddb1b18458da98f526ae39721625a910872b31b6 100644
--- a/src/heap/spaces.cc
+++ b/src/heap/spaces.cc
@@ -1412,14 +1412,14 @@ 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 (inline_allocation_limit_step_ == 0) {
+  } else if (top_on_previous_step_ == 0) {
     // Normal limit is the end of the current page.
     allocation_info_.set_limit(to_space_.page_high());
   } else {
     // Lower limit during incremental marking.
     Address high = to_space_.page_high();
     Address new_top = allocation_info_.top() + size_in_bytes;
-    Address new_limit = new_top + inline_allocation_limit_step_;
+    Address new_limit = new_top + inline_allocation_limit_step_ - 1;
     allocation_info_.set_limit(Min(new_limit, high));
   }
   DCHECK_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_);
@@ -1504,12 +1504,47 @@ bool NewSpace::EnsureAllocation(int size_in_bytes,
 }
 
 
+void NewSpace::UpdateInlineAllocationLimitStep() {
+  intptr_t step = 0;
+  for (int i = 0; i < inline_allocation_observers_.length(); ++i) {
+    InlineAllocationObserver& observer = inline_allocation_observers_[i];
+    step = step ? Min(step, observer.step_size()) : observer.step_size();
+  }
+  inline_allocation_limit_step_ = step;
+  top_on_previous_step_ = step ? allocation_info_.top() : 0;
+  UpdateInlineAllocationLimit(0);
+}
+
+
+void NewSpace::AddInlineAllocationObserver(
+    intptr_t step_size, InlineAllocationObserver::callback_t callback,
+    void* callback_arg) {
+  DCHECK(callback != nullptr);
+  InlineAllocationObserver observer(step_size, callback, callback_arg);
+  inline_allocation_observers_.Add(observer);
+  UpdateInlineAllocationLimitStep();
+}
+
+
+void NewSpace::RemoveInlineAllocationObserver(
+    InlineAllocationObserver::callback_t callback) {
+  for (int i = 0; i < inline_allocation_observers_.length(); ++i) {
+    if (inline_allocation_observers_[i].callback() == callback) {
+      inline_allocation_observers_.Remove(i);
+      UpdateInlineAllocationLimitStep();
+      return;
+    }
+  }
+  UNREACHABLE();
+}
+
+
 void NewSpace::InlineAllocationStep(Address top, Address new_top) {
   if (top_on_previous_step_) {
     int bytes_allocated = static_cast<int>(top - top_on_previous_step_);
-    heap()->ScheduleIdleScavengeIfNeeded(bytes_allocated);
-    heap()->incremental_marking()->Step(bytes_allocated,
-                                        IncrementalMarking::GC_VIA_STACK_GUARD);
+    for (int i = 0; i < inline_allocation_observers_.length(); ++i) {
+      inline_allocation_observers_[i].step(bytes_allocated);
+    }
     top_on_previous_step_ = new_top;
   }
 }