Oilpan: A precise GC should be prioritized than an idle GC

Source/platform/heap/ThreadState.cpp

Index: Source/platform/heap/ThreadState.cpp
diff --git a/Source/platform/heap/ThreadState.cpp b/Source/platform/heap/ThreadState.cpp
index 3971b8206bada4336caa2e1b62f5e4394600ca45..0b06ceacab0bb033d7d863562c7c7acf73d172a3 100644
--- a/Source/platform/heap/ThreadState.cpp
+++ b/Source/platform/heap/ThreadState.cpp
@@ -650,8 +650,6 @@ bool ThreadState::shouldScheduleIdleGC()
 
 bool ThreadState::shouldSchedulePreciseGC()
 {
-    if (gcState() != NoGCScheduled)
-        return false;

[Yuta Kitamura, 2015/08/18 03:06:28]

Let me confirm my understanding of this removal.

* If an idle GC is already scheduled, it's fine to override it
  with a precise GC.
* Sweeping is never scheduled at this point.

Correct?

[haraken, 2015/08/18 03:45:23]

Yes, that is the intention of this CL.
Yes. scheduleGCIfNeeded() should not be called while the lazy sweeping is going
on. Even if it's called for some reason, scheduleGCIfNeeded() returns
immediately if isSweepingInProgress() is true (See line 704).

 #if ENABLE(IDLE_GC)
     return false;

[haraken, 2015/08/18 02:39:53]

yutak@: After landing this change, you just need to change this line to
judgeGCThreshold(1024 * 1024, xxx) to schedule a precise GC with a threshold
xxx.

 #else