Replace RenderArena with PartitionAlloc.

Source/core/rendering/RenderArena.cpp

-/*
- * Copyright (C) 2003 Apple Computer, Inc.
- * Copyright (C) Research In Motion Limited 2010. All rights reserved.
- *
- * Portions are Copyright (C) 1998 Netscape Communications Corporation.
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
- *
- * Alternatively, the contents of this file may be used under the terms
- * of either the Mozilla Public License Version 1.1, found at
- * http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public
- * License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html
- * (the "GPL"), in which case the provisions of the MPL or the GPL are
- * applicable instead of those above.  If you wish to allow use of your
- * version of this file only under the terms of one of those two
- * licenses (the MPL or the GPL) and not to allow others to use your
- * version of this file under the LGPL, indicate your decision by
- * deletingthe provisions above and replace them with the notice and
- * other provisions required by the MPL or the GPL, as the case may be.
- * If you do not delete the provisions above, a recipient may use your
- * version of this file under any of the LGPL, the MPL or the GPL.
- */
-
-#include "config.h"
-#include "core/rendering/RenderArena.h"
-
-#include <stdlib.h>
-#include <string.h>
-#include <limits>
-#include <wtf/Assertions.h>
-#include <wtf/CryptographicallyRandomNumber.h>
-
-#define ROUNDUP(x, y) ((((x)+((y)-1))/(y))*(y))
-
-#ifdef NDEBUG
-static void* MaskPtr(void* p, uintptr_t mask)
-{
-    return reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(p) ^ mask);
-}
-#endif
-
-namespace WebCore {
-
-#ifndef NDEBUG
-
-const int signature = 0xDBA00AEA;
-const int signatureDead = 0xDBA00AED;
-
-typedef struct {
-    RenderArena* arena;
-    size_t size;
-    int signature;
-} RenderArenaDebugHeader;
-
-static const size_t debugHeaderSize = ARENA_ALIGN(sizeof(RenderArenaDebugHeader));
-
-#endif
-
-RenderArena::RenderArena(unsigned arenaSize)
-    : m_totalSize(0)
-    , m_totalAllocated(0)
-{
-    ASSERT(arenaSize > sizeof(Arena) + ARENA_ALIGN_MASK);
-    // The underlying Arena class allocates some metadata on top of our
-    // requested size. Factor this in so that we can get perfect power-of-two
-    // allocation sizes passed to the underlying malloc() call.
-    arenaSize -= (sizeof(Arena) + ARENA_ALIGN_MASK);
-    // Initialize the arena pool
-    INIT_ARENA_POOL(&m_pool, "RenderArena", arenaSize);
-
-    // Zero out the recyclers array
-    memset(m_recyclers, 0, sizeof(m_recyclers));
-
-    // Mask freelist pointers to detect corruption and stop freelist spraying.
-    // We use an arbitray function and rely on ASLR to randomize it.
-    // The first value in RenderObject (or any class) is a vtable pointer, which
-    // always overlaps with the next pointer. This change guarantees that the
-    // masked vtable/next pointer will never point to valid memory. So, we
-    // should immediately crash on the first invalid vtable access for a stale
-    // RenderObject pointer.
-    // See http://download.crowdstrike.com/papers/hes-exploiting-a-coalmine.pdf.
-    WTF::cryptographicallyRandomValues(&m_mask, sizeof(m_mask));
-    m_mask |= (static_cast<uintptr_t>(3) << (std::numeric_limits<uintptr_t>::digits - 2)) | 1;
-}
-
-RenderArena::~RenderArena()
-{
-    FinishArenaPool(&m_pool);
-}
-
-void* RenderArena::allocate(size_t size)
-{
-    ASSERT(size <= gMaxRecycledSize - 32);
-    m_totalSize += size;
-
-#ifdef ADDRESS_SANITIZER
-    return ::malloc(size);
-#elif !defined(NDEBUG)
-    // Use standard malloc so that memory debugging tools work.
-    ASSERT(this);
-    void* block = ::malloc(debugHeaderSize + size);
-    RenderArenaDebugHeader* header = static_cast<RenderArenaDebugHeader*>(block);
-    header->arena = this;
-    header->size = size;
-    header->signature = signature;
-    return static_cast<char*>(block) + debugHeaderSize;
-#else
-    // Ensure we have correct alignment for pointers.  Important for Tru64
-    size = ROUNDUP(size, sizeof(void*));
-
-    const size_t index = size >> kRecyclerShift;
-
-    void* result = m_recyclers[index];
-    if (result) {
-        // Need to move to the next object
-        void* next = MaskPtr(*((void**)result), m_mask);
-        m_recyclers[index] = next;
-    }
-
-    if (!result) {
-        // Allocate a new chunk from the arena
-        unsigned bytesAllocated = 0;
-        ARENA_ALLOCATE(result, &m_pool, size, &bytesAllocated);
-        m_totalAllocated += bytesAllocated;
-    }
-
-    return result;
-#endif
-}
-
-void RenderArena::free(size_t size, void* ptr)
-{
-    ASSERT(size <= gMaxRecycledSize - 32);
-    m_totalSize -= size;
-
-#ifdef ADDRESS_SANITIZER
-    ::free(ptr);
-#elif !defined(NDEBUG)
-    // Use standard free so that memory debugging tools work.
-    void* block = static_cast<char*>(ptr) - debugHeaderSize;
-    RenderArenaDebugHeader* header = static_cast<RenderArenaDebugHeader*>(block);
-    ASSERT(header->signature == signature);
-    ASSERT_UNUSED(size, header->size == size);
-    ASSERT(header->arena == this);
-    header->signature = signatureDead;
-    ::free(block);
-#else
-    // Ensure we have correct alignment for pointers.  Important for Tru64
-    size = ROUNDUP(size, sizeof(void*));
-
-    const size_t index = size >> kRecyclerShift;
-    void* currentTop = m_recyclers[index];
-    m_recyclers[index] = ptr;
-    *((void**)ptr) = MaskPtr(currentTop, m_mask);
-#endif
-}
-
-} // namespace WebCore