Oilpan: Split completeSweep() in idle tasks into chunks

Source/platform/heap/Heap.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 591 matching lines @@
     if (threadState()->isMainThread())
         ScriptForbiddenScope::enter();
 
     Address result = lazySweepPages(allocationSize, gcInfoIndex);
 
     if (threadState()->isMainThread())
         ScriptForbiddenScope::exit();
     return result;
 }
 
+void BaseHeap::sweepUnsweptPage()
+{
+    BasePage* page = m_firstUnsweptPage;
+    if (page->isEmpty()) {
+        page->unlink(&m_firstUnsweptPage);
+        page->removeFromHeap();
+    } else {
+        // Sweep a page and move the page from m_firstUnsweptPages to
+        // m_firstPages.
+        page->sweep();
+        page->unlink(&m_firstUnsweptPage);
+        page->link(&m_firstPage);
+        page->markAsSwept();
+    }
+}
+
+bool BaseHeap::lazySweepWithDeadline(double deadlineSeconds)
+{
+    RELEASE_ASSERT(threadState()->isSweepingInProgress());
+    ASSERT(threadState()->sweepForbidden());
+
+    int pageCount = 1;
+    while (m_firstUnsweptPage) {
+        sweepUnsweptPage();
+        // Check the deadline every time we sweep 10 page.
+        if (pageCount % 10 == 0) {

[kouhei (in TOK), 2015/03/31 11:42:07]

Why 10?

[haraken, 2015/03/31 12:46:58]

I thought it might be heavy to call
Platform::current()->monotonicallyIncreasingTime() at every page sweep (i.e.,
128 KB sweep or one LargeObject sweep). If the performance is OK, we can just
call it per page. Actually I'm not sure.

[Sami, 2015/03/31 12:52:00]

Might want to make this a named constant too. Also, maybe it won't happen in
practice but you could also check m_firstUnsweptPage != nullptr before
scheduling the next sweep (i.e., we ran out of time but also out of pages to
sweep).

[rmcilroy, 2015/03/31 13:01:30]

+1

[haraken, 2015/03/31 13:07:45]

Will fix.

+            if (deadlineSeconds <= Platform::current()->monotonicallyIncreasingTime()) {
+                return false;
+            }
+        }
+        pageCount++;
+    }
+    return true;
+}
+
 void BaseHeap::completeSweep()
 {
     RELEASE_ASSERT(threadState()->isSweepingInProgress());
     ASSERT(threadState()->sweepForbidden());
 
-    if (threadState()->isMainThread())
-        ScriptForbiddenScope::enter();
-
     while (m_firstUnsweptPage) {

[kouhei (in TOK), 2015/03/31 11:42:07]

Nit: Unneeded {}

[haraken, 2015/03/31 12:46:58]

Nit: The coding style guide is updated and it's up to us.

-        BasePage* page = m_firstUnsweptPage;
-        if (page->isEmpty()) {
-            page->unlink(&m_firstUnsweptPage);
-            page->removeFromHeap();
-        } else {
-            // Sweep a page and move the page from m_firstUnsweptPages to
-            // m_firstPages.
-            page->sweep();
-            page->unlink(&m_firstUnsweptPage);
-            page->link(&m_firstPage);
-            page->markAsSwept();
-        }
+        sweepUnsweptPage();
     }
-
-    if (threadState()->isMainThread())
-        ScriptForbiddenScope::exit();
 }
 
 NormalPageHeap::NormalPageHeap(ThreadState* state, int index)
     : BaseHeap(state, index)
     , m_currentAllocationPoint(nullptr)
     , m_remainingAllocationSize(0)
     , m_lastRemainingAllocationSize(0)
     , m_promptlyFreedSize(0)
 #if ENABLE(GC_PROFILING)
     , m_cumulativeAllocationSize(0)
@@ skipping 2198 matching lines @@
 size_t Heap::s_allocatedObjectSize = 0;
 size_t Heap::s_allocatedSpace = 0;
 size_t Heap::s_markedObjectSize = 0;
 
 size_t Heap::s_externallyAllocatedBytes = 0;
 size_t Heap::s_externallyAllocatedBytesAlive = 0;
 unsigned Heap::s_requestedUrgentGC = false;
 double Heap::s_markingTimeInLastGC = 0.0;
 
 } // namespace blink