[oilpan]: Attempt to make allocation faster by only updating the GC stats when needed, rather than …

Source/platform/heap/Heap.cpp

Index: Source/platform/heap/Heap.cpp
diff --git a/Source/platform/heap/Heap.cpp b/Source/platform/heap/Heap.cpp
index 9dddb4a39bcc2d0e7c440d37ba35ea3befd19fbe..4ca81cd8e8265a45822fbcf2bd395784859506ad 100644
--- a/Source/platform/heap/Heap.cpp
+++ b/Source/platform/heap/Heap.cpp
@@ -584,6 +584,7 @@ template<typename Header>
 ThreadHeap<Header>::ThreadHeap(ThreadState* state, int index)
     : m_currentAllocationPoint(0)
     , m_remainingAllocationSize(0)
+    , m_lastRemainingAllocationSize(0)
     , m_firstPage(0)
     , m_firstLargeHeapObject(0)
     , m_firstPageAllocatedDuringSweeping(0)
@@ -625,6 +626,14 @@ template<typename Header>
 Address ThreadHeap<Header>::outOfLineAllocate(size_t size, const GCInfo* gcInfo)
 {
     size_t allocationSize = allocationSizeFromSize(size);
+    ASSERT(allocationSize > remainingAllocationSize());
+    if (allocationSize > HeapPage<Header>::payloadSize() / 2)
+        return allocateLargeObject(allocationSize, gcInfo);
+
+    if (remainingAllocationSize() > 0)
+        addToFreeList(currentAllocationPoint(), remainingAllocationSize());
+    // This also updates the stats.
+    setAllocationPoint(0, 0);
     if (threadState()->shouldGC()) {
         if (threadState()->shouldForceConservativeGC())
             Heap::collectGarbage(ThreadState::HeapPointersOnStack);
@@ -660,13 +669,6 @@ template<typename Header>
 void ThreadHeap<Header>::ensureCurrentAllocation(size_t minSize, const GCInfo* gcInfo)
 {
     ASSERT(minSize >= allocationGranularity);
-    if (remainingAllocationSize() >= minSize)
-        return;
-
-    if (remainingAllocationSize() > 0) {
-        addToFreeList(currentAllocationPoint(), remainingAllocationSize());
-        setAllocationPoint(0, 0);
-    }
     if (allocateFromFreeList(minSize))
         return;
     if (coalesce(minSize) && allocateFromFreeList(minSize))
@@ -856,7 +858,7 @@ bool ThreadHeap<Header>::coalesce(size_t minSize)
             ASSERT(basicHeader->size() < blinkPagePayloadSize());
 
             if (basicHeader->isPromptlyFreed()) {
-                stats().decreaseObjectSpace(reinterpret_cast<Header*>(basicHeader)->payloadSize());
+                stats().decreaseObjectSpace(reinterpret_cast<Header*>(basicHeader)->size());
                 size_t size = basicHeader->size();
                 ASSERT(size >= sizeof(Header));
 #if !ENABLE(ASSERT) && !defined(LEAK_SANITIZER) && !defined(ADDRESS_SANITIZER)
@@ -921,6 +923,12 @@ Address ThreadHeap<Header>::allocateLargeObject(size_t size, const GCInfo* gcInf
 #if defined(ADDRESS_SANITIZER)
     allocationSize += allocationGranularity;
 #endif
+
+    // Update stats before checking if we should GC.
+    if (m_lastRemainingAllocationSize != m_remainingAllocationSize) {
+        stats().increaseObjectSpace(m_lastRemainingAllocationSize-m_remainingAllocationSize);
+        m_lastRemainingAllocationSize = m_remainingAllocationSize;
+    }
     if (threadState()->shouldGC())
         threadState()->setGCRequested();
     Heap::flushHeapDoesNotContainCache();
@@ -938,7 +946,7 @@ Address ThreadHeap<Header>::allocateLargeObject(size_t size, const GCInfo* gcInf
     ASAN_POISON_MEMORY_REGION(largeObject->address() + largeObject->size(), allocationGranularity);
     largeObject->link(&m_firstLargeHeapObject);
     stats().increaseAllocatedSpace(largeObject->size());
-    stats().increaseObjectSpace(largeObject->payloadSize());
+    stats().increaseObjectSpace(largeObject->size());
     return result;
 }
 
@@ -1272,7 +1280,7 @@ void ThreadHeap<Header>::sweepLargePages(HeapStats* stats)
     for (LargeHeapObject<Header>* current = m_firstLargeHeapObject; current;) {
         if (current->isMarked()) {
             stats->increaseAllocatedSpace(current->size());
-            stats->increaseObjectSpace(current->payloadSize());
+            stats->increaseObjectSpace(current->size());
             current->unmark();
             previousNext = &current->m_next;
             current = current->next();
@@ -1423,7 +1431,7 @@ void HeapPage<Header>::getStats(HeapStats& stats)
     do {
         Header* header = reinterpret_cast<Header*>(headerAddress);
         if (!header->isFree())
-            stats.increaseObjectSpace(header->payloadSize());
+            stats.increaseObjectSpace(header->size());
         ASSERT(header->size() < blinkPagePayloadSize());
         headerAddress += header->size();
         ASSERT(headerAddress <= end());
@@ -1487,7 +1495,7 @@ void HeapPage<Header>::sweep(HeapStats* stats, ThreadHeap<Header>* heap)
             heap->addToFreeList(startOfGap, headerAddress - startOfGap);
         header->unmark();
         headerAddress += header->size();
-        stats->increaseObjectSpace(header->payloadSize());
+        stats->increaseObjectSpace(header->size());
         startOfGap = headerAddress;
     }
     if (startOfGap != end())
@@ -1716,7 +1724,7 @@ template<typename Header>
 void LargeHeapObject<Header>::getStats(HeapStats& stats)
 {
     stats.increaseAllocatedSpace(size());
-    stats.increaseObjectSpace(payloadSize());
+    stats.increaseObjectSpace(size());
 }
 
 #if ENABLE(GC_PROFILE_HEAP)