Oilpan: Simplify Heap::allocate

Source/platform/heap/Heap.h

 /*
  * 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 246 matching lines @@
     size_t payloadSize() { return heapObjectHeader()->payloadSize(); }
 
     Header* heapObjectHeader()
     {
         Address headerAddress = address() + sizeof(LargeHeapObject<Header>) + headerPadding<Header>();
         return reinterpret_cast<Header*>(headerAddress);
     }
 
     bool isMarked();
     void unmark();
-    void getStats(HeapStats&);
+    void getStatsForTesting(HeapStats&);
     void mark(Visitor*);
     void finalize();
     void setDeadMark();
     virtual void markOrphaned()
     {
         // Zap the payload with a recognizable value to detect any incorrect
         // cross thread pointer usage.
         memset(payload(), orphanedZapValue, payloadSize());
         BaseHeapPage::markOrphaned();
     }
@@ skipping 250 matching lines @@
         return address() + sizeof(*this) + headerPadding<Header>();
     }
 
     static size_t payloadSize()
     {
         return (blinkPagePayloadSize() - sizeof(HeapPage) - headerPadding<Header>()) & ~allocationMask;
     }
 
     Address end() { return payload() + payloadSize(); }
 
-    void getStats(HeapStats&);
+    void getStatsForTesting(HeapStats&);
     void clearLiveAndMarkDead();
     void sweep(HeapStats*, ThreadHeap<Header>*);
     void clearObjectStartBitMap();
     void finalize(Header*);
     virtual void checkAndMarkPointer(Visitor*, Address) override;
 #if ENABLE(GC_PROFILE_MARKING)
     const GCInfo* findGCInfo(Address) override;
 #endif
 #if ENABLE(GC_PROFILE_HEAP)
     virtual void snapshot(TracedValue*, ThreadState::SnapshotInfo*);
@@ skipping 155 matching lines @@
 
     // Sweep this part of the Blink heap. This finalizes dead objects
     // and builds freelists for all the unused memory.
     virtual void sweep(HeapStats*) = 0;
     virtual void postSweepProcessing() = 0;
 
     virtual void clearFreeLists() = 0;
     virtual void clearLiveAndMarkDead() = 0;
 
     virtual void makeConsistentForSweeping() = 0;
-
 #if ENABLE(ASSERT)
     virtual bool isConsistentForSweeping() = 0;
+#endif
+    virtual void getStatsForTesting(HeapStats&) = 0;
 
-    virtual void getScannedStats(HeapStats&) = 0;
-#endif
+    virtual void updateRemainingAllocationSize() = 0;
 
     virtual void prepareHeapForTermination() = 0;
 
     virtual int normalPageCount() = 0;
 
     virtual BaseHeap* split(int normalPages) = 0;
     virtual void merge(BaseHeap* other) = 0;
 
     // Returns a bucket number for inserting a FreeListEntry of a
     // given size. All FreeListEntries in the given bucket, n, have
@@ skipping 26 matching lines @@
     virtual void snapshot(TracedValue*, ThreadState::SnapshotInfo*);
 #endif
 
     virtual void sweep(HeapStats*);
     virtual void postSweepProcessing();
 
     virtual void clearFreeLists();
     virtual void clearLiveAndMarkDead();
 
     virtual void makeConsistentForSweeping();
-
 #if ENABLE(ASSERT)
     virtual bool isConsistentForSweeping();
+#endif
+    virtual void getStatsForTesting(HeapStats&);
 
-    virtual void getScannedStats(HeapStats&);
-#endif
+    virtual void updateRemainingAllocationSize();
 
     ThreadState* threadState() { return m_threadState; }
     HeapStats& stats() { return m_threadState->stats(); }
 
     inline Address allocate(size_t, const GCInfo*);
     void addToFreeList(Address, size_t);
     inline static size_t roundedAllocationSize(size_t size)
     {
         return allocationSizeFromSize(size) - sizeof(Header);
     }
@@ skipping 14 matching lines @@
     PLATFORM_EXPORT Address outOfLineAllocate(size_t, const GCInfo*);
     static size_t allocationSizeFromSize(size_t);
     PLATFORM_EXPORT Address allocateLargeObject(size_t, const GCInfo*);
     Address currentAllocationPoint() const { return m_currentAllocationPoint; }
     size_t remainingAllocationSize() const { return m_remainingAllocationSize; }
     bool ownsNonEmptyAllocationArea() const { return currentAllocationPoint() && remainingAllocationSize(); }
     void setAllocationPoint(Address point, size_t size)
     {
         ASSERT(!point || heapPageFromAddress(point));
         ASSERT(size <= HeapPage<Header>::payloadSize());
+        updateRemainingAllocationSize();
         m_currentAllocationPoint = point;
-        m_remainingAllocationSize = size;
+        m_lastRemainingAllocationSize = m_remainingAllocationSize = size;
     }
     void ensureCurrentAllocation(size_t, const GCInfo*);
     bool allocateFromFreeList(size_t);
 
     void freeLargeObject(LargeHeapObject<Header>*, LargeHeapObject<Header>**);
     void allocatePage(const GCInfo*);
 
 #if ENABLE(ASSERT)
     bool pagesToBeSweptContains(Address);
     bool pagesAllocatedDuringSweepingContains(Address);
 #endif
 
     void sweepNormalPages(HeapStats*);
     void sweepLargePages(HeapStats*);
     bool coalesce(size_t);
 
     Address m_currentAllocationPoint;
     size_t m_remainingAllocationSize;
+    size_t m_lastRemainingAllocationSize;
 
     HeapPage<Header>* m_firstPage;
     LargeHeapObject<Header>* m_firstLargeHeapObject;
 
     HeapPage<Header>* m_firstPageAllocatedDuringSweeping;
     HeapPage<Header>* m_lastPageAllocatedDuringSweeping;
 
     // Merge point for parallel sweep.
     HeapPage<Header>* m_mergePoint;
 
@@ skipping 104 matching lines @@
     static const GCInfo* findGCInfo(Address);
 
     static String createBacktraceString();
 #endif
 
     // Collect heap stats for all threads attached to the Blink
     // garbage collector. Should only be called during garbage
     // collection where threads are known to be at safe points.
     static void getStats(HeapStats*);
 
+    static void getStatsForTesting(HeapStats*);
+
     static void getHeapSpaceSize(uint64_t*, uint64_t*);
 
     static void makeConsistentForSweeping();
 
 #if ENABLE(ASSERT)
     static bool isConsistentForSweeping();
 #endif
 
     static void flushHeapDoesNotContainCache();
 
@@ skipping 396 matching lines @@
     size_t allocationSize = size + sizeof(Header);
     // Align size with allocation granularity.
     allocationSize = (allocationSize + allocationMask) & ~allocationMask;
     return allocationSize;
 }
 
 template<typename Header>
 Address ThreadHeap<Header>::allocate(size_t size, const GCInfo* gcInfo)
 {
     size_t allocationSize = allocationSizeFromSize(size);
-    bool isLargeObject = allocationSize > blinkPageSize / 2;
-    if (isLargeObject)
-        return allocateLargeObject(allocationSize, gcInfo);
-    if (m_remainingAllocationSize < allocationSize)
-        return outOfLineAllocate(size, gcInfo);
-    Address headerAddress = m_currentAllocationPoint;
-    m_currentAllocationPoint += allocationSize;
-    m_remainingAllocationSize -= allocationSize;
-    Header* header = new (NotNull, headerAddress) Header(allocationSize, gcInfo);
-    size_t payloadSize = allocationSize - sizeof(Header);
-    stats().increaseObjectSpace(payloadSize);
-    Address result = headerAddress + sizeof(*header);
-    ASSERT(!(reinterpret_cast<uintptr_t>(result) & allocationMask));
-    // Unpoison the memory used for the object (payload).
-    ASAN_UNPOISON_MEMORY_REGION(result, payloadSize);
+    if (LIKELY(allocationSize <= m_remainingAllocationSize)) {
+        Address headerAddress = m_currentAllocationPoint;
+        m_currentAllocationPoint += allocationSize;
+        m_remainingAllocationSize -= allocationSize;
+        Header* header = new (NotNull, headerAddress) Header(allocationSize, gcInfo);
+        Address result = headerAddress + sizeof(*header);
+        ASSERT(!(reinterpret_cast<uintptr_t>(result) & allocationMask));
+
+        // Unpoison the memory used for the object (payload).
+        ASAN_UNPOISON_MEMORY_REGION(result, allocationSize - sizeof(Header));
 #if ENABLE(ASSERT) || defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER)
-    memset(result, 0, payloadSize);
+        memset(result, 0, allocationSize - sizeof(Header));
 #endif
-    ASSERT(heapPageFromAddress(headerAddress + allocationSize - 1));
-    return result;
+        ASSERT(heapPageFromAddress(headerAddress + allocationSize - 1));
+        return result;
+    }
+    return outOfLineAllocate(size, gcInfo);
 }
 
 template<typename T, typename HeapTraits>
 Address Heap::allocate(size_t size)
 {
     ThreadState* state = ThreadStateFor<ThreadingTrait<T>::Affinity>::state();
     ASSERT(state->isAllocationAllowed());
     const GCInfo* gcInfo = GCInfoTrait<T>::get();
     int heapIndex = HeapTraits::index(gcInfo->hasFinalizer());
     BaseHeap* heap = state->heap(heapIndex);
@@ skipping 1001 matching lines @@
 };
 
 template<typename T>
 struct IfWeakMember<WeakMember<T> > {
     static bool isDead(Visitor* visitor, const WeakMember<T>& t) { return !visitor->isAlive(t.get()); }
 };
 
 }
 
 #endif // Heap_h