From 3aca47b7aa4bf2d9156d62b9d6bf27a6761890c9 Mon Sep 17 00:00:00 2001
From: mlippautz <mlippautz@chromium.org>
Date: Thu, 13 Aug 2015 10:22:47 -0700
Subject: [PATCH] [api] Do not force external GCs when only trying to
 synchronously process phantom callbacks

Improves on aec8987b5ee55fa46b90b58927e957a4e5f19c09 by not forcing external GCs
(blink) through the GC epilogue callback.

BUG=chromium:515795
LOG=N

Review URL: https://codereview.chromium.org/1287323002

Cr-Commit-Position: refs/heads/master@{#30164}
---
 include/v8.h          |  4 ++--
 src/api.cc            | 10 ++++++----
 src/global-handles.cc |  4 +++-
 3 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/include/v8.h b/include/v8.h
index 71a1805..fc33810 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -4965,9 +4965,9 @@ enum GCType {
 
 enum GCCallbackFlags {
   kNoGCCallbackFlags = 0,
-  kGCCallbackFlagCompacted = 1 << 0,
   kGCCallbackFlagConstructRetainedObjectInfos = 1 << 1,
-  kGCCallbackFlagForced = 1 << 2
+  kGCCallbackFlagForced = 1 << 2,
+  kGCCallbackFlagSynchronousPhantomCallbackProcessing = 1 << 3
 };
 
 typedef void (*GCPrologueCallback)(GCType type, GCCallbackFlags flags);
diff --git a/src/api.cc b/src/api.cc
index 4f98293..5bb56e6 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -6882,11 +6882,13 @@ void Isolate::CollectAllGarbage(const char* gc_reason) {
   i::Heap* heap = reinterpret_cast<i::Isolate*>(this)->heap();
   if (heap->incremental_marking()->IsStopped()) {
     if (heap->incremental_marking()->CanBeActivated()) {
-      heap->StartIncrementalMarking(i::Heap::kNoGCFlags, kGCCallbackFlagForced,
-                                    gc_reason);
+      heap->StartIncrementalMarking(
+          i::Heap::kNoGCFlags,
+          kGCCallbackFlagSynchronousPhantomCallbackProcessing, gc_reason);
     } else {
-      heap->CollectAllGarbage(i::Heap::kNoGCFlags, gc_reason,
-                              kGCCallbackFlagForced);
+      heap->CollectAllGarbage(
+          i::Heap::kNoGCFlags, gc_reason,
+          kGCCallbackFlagSynchronousPhantomCallbackProcessing);
     }
   } else {
     // Incremental marking is turned on an has already been started.
diff --git a/src/global-handles.cc b/src/global-handles.cc
index 444614c..fcf896f 100644
--- a/src/global-handles.cc
+++ b/src/global-handles.cc
@@ -883,7 +883,9 @@ int GlobalHandles::PostGarbageCollectionProcessing(
   const int initial_post_gc_processing_count = ++post_gc_processing_count_;
   int freed_nodes = 0;
   bool synchronous_second_pass =
-      (gc_callback_flags & kGCCallbackFlagForced) != 0;
+      (gc_callback_flags &
+       (kGCCallbackFlagForced |
+        kGCCallbackFlagSynchronousPhantomCallbackProcessing)) != 0;
   freed_nodes += DispatchPendingPhantomCallbacks(synchronous_second_pass);
   if (initial_post_gc_processing_count != post_gc_processing_count_) {
     // If the callbacks caused a nested GC, then return.  See comment in
-- 
2.7.4