Index: Source/WTF/wtf/BumpPointerAllocator.h |
diff --git a/Source/WTF/wtf/BumpPointerAllocator.h b/Source/WTF/wtf/BumpPointerAllocator.h |
deleted file mode 100644 |
index 3b2cfd974a8d9059043b7252bb2471ef938c7136..0000000000000000000000000000000000000000 |
--- a/Source/WTF/wtf/BumpPointerAllocator.h |
+++ /dev/null |
@@ -1,252 +0,0 @@ |
-/* |
- * Copyright (C) 2010 Apple 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: |
- * 1. Redistributions of source code must retain the above copyright |
- * notice, this list of conditions and the following disclaimer. |
- * 2. Redistributions in binary form must reproduce the above copyright |
- * notice, this list of conditions and the following disclaimer in the |
- * documentation and/or other materials provided with the distribution. |
- * |
- * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY |
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR |
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY |
- * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
- */ |
- |
-#ifndef BumpPointerAllocator_h |
-#define BumpPointerAllocator_h |
- |
-#include <algorithm> |
-#include <wtf/PageAllocation.h> |
-#include <wtf/PageBlock.h> |
- |
-namespace WTF { |
- |
-#define MINIMUM_BUMP_POOL_SIZE 0x1000 |
- |
-class BumpPointerPool { |
-public: |
- // ensureCapacity will check whether the current pool has capacity to |
- // allocate 'size' bytes of memory If it does not, it will attempt to |
- // allocate a new pool (which will be added to this one in a chain). |
- // |
- // If allocation fails (out of memory) this method will return null. |
- // If the return value is non-null, then callers should update any |
- // references they have to this current (possibly full) BumpPointerPool |
- // to instead point to the newly returned BumpPointerPool. |
- BumpPointerPool* ensureCapacity(size_t size) |
- { |
- void* allocationEnd = static_cast<char*>(m_current) + size; |
- ASSERT(allocationEnd > m_current); // check for overflow |
- if (allocationEnd <= static_cast<void*>(this)) |
- return this; |
- return ensureCapacityCrossPool(this, size); |
- } |
- |
- // alloc should only be called after calling ensureCapacity; as such |
- // alloc will never fail. |
- void* alloc(size_t size) |
- { |
- void* current = m_current; |
- void* allocationEnd = static_cast<char*>(current) + size; |
- ASSERT(allocationEnd > current); // check for overflow |
- ASSERT(allocationEnd <= static_cast<void*>(this)); |
- m_current = allocationEnd; |
- return current; |
- } |
- |
- // The dealloc method releases memory allocated using alloc. Memory |
- // must be released in a LIFO fashion, e.g. if the client calls alloc |
- // four times, returning pointer A, B, C, D, then the only valid order |
- // in which these may be deallocaed is D, C, B, A. |
- // |
- // The client may optionally skip some deallocations. In the example |
- // above, it would be valid to only explicitly dealloc C, A (D being |
- // dealloced along with C, B along with A). |
- // |
- // If pointer was not allocated from this pool (or pools) then dealloc |
- // will CRASH(). Callers should update any references they have to |
- // this current BumpPointerPool to instead point to the returned |
- // BumpPointerPool. |
- BumpPointerPool* dealloc(void* position) |
- { |
- if ((position >= m_start) && (position <= static_cast<void*>(this))) { |
- ASSERT(position <= m_current); |
- m_current = position; |
- return this; |
- } |
- return deallocCrossPool(this, position); |
- } |
- |
-private: |
- // Placement operator new, returns the last 'size' bytes of allocation for use as this. |
- void* operator new(size_t size, const PageAllocation& allocation) |
- { |
- ASSERT(size < allocation.size()); |
- return reinterpret_cast<char*>(reinterpret_cast<intptr_t>(allocation.base()) + allocation.size()) - size; |
- } |
- |
- BumpPointerPool(const PageAllocation& allocation) |
- : m_current(allocation.base()) |
- , m_start(allocation.base()) |
- , m_next(0) |
- , m_previous(0) |
- , m_allocation(allocation) |
- { |
- } |
- |
- static BumpPointerPool* create(size_t minimumCapacity = 0) |
- { |
- // Add size of BumpPointerPool object, check for overflow. |
- minimumCapacity += sizeof(BumpPointerPool); |
- if (minimumCapacity < sizeof(BumpPointerPool)) |
- return 0; |
- |
- size_t poolSize = std::max(static_cast<size_t>(MINIMUM_BUMP_POOL_SIZE), WTF::pageSize()); |
- while (poolSize < minimumCapacity) { |
- poolSize <<= 1; |
- // The following if check relies on MINIMUM_BUMP_POOL_SIZE being a power of 2! |
- ASSERT(!(MINIMUM_BUMP_POOL_SIZE & (MINIMUM_BUMP_POOL_SIZE - 1))); |
- if (!poolSize) |
- return 0; |
- } |
- |
- PageAllocation allocation = PageAllocation::allocate(poolSize); |
- if (!!allocation) |
- return new (allocation) BumpPointerPool(allocation); |
- return 0; |
- } |
- |
- void shrink() |
- { |
- ASSERT(!m_previous); |
- m_current = m_start; |
- while (m_next) { |
- BumpPointerPool* nextNext = m_next->m_next; |
- m_next->destroy(); |
- m_next = nextNext; |
- } |
- } |
- |
- void destroy() |
- { |
- m_allocation.deallocate(); |
- } |
- |
- static BumpPointerPool* ensureCapacityCrossPool(BumpPointerPool* previousPool, size_t size) |
- { |
- // The pool passed should not have capacity, so we'll start with the next one. |
- ASSERT(previousPool); |
- ASSERT((static_cast<char*>(previousPool->m_current) + size) > previousPool->m_current); // check for overflow |
- ASSERT((static_cast<char*>(previousPool->m_current) + size) > static_cast<void*>(previousPool)); |
- BumpPointerPool* pool = previousPool->m_next; |
- |
- while (true) { |
- if (!pool) { |
- // We've run to the end; allocate a new pool. |
- pool = BumpPointerPool::create(size); |
- previousPool->m_next = pool; |
- pool->m_previous = previousPool; |
- return pool; |
- } |
- |
- // |
- void* current = pool->m_current; |
- void* allocationEnd = static_cast<char*>(current) + size; |
- ASSERT(allocationEnd > current); // check for overflow |
- if (allocationEnd <= static_cast<void*>(pool)) |
- return pool; |
- } |
- } |
- |
- static BumpPointerPool* deallocCrossPool(BumpPointerPool* pool, void* position) |
- { |
- // Should only be called if position is not in the current pool. |
- ASSERT((position < pool->m_start) || (position > static_cast<void*>(pool))); |
- |
- while (true) { |
- // Unwind the current pool to the start, move back in the chain to the previous pool. |
- pool->m_current = pool->m_start; |
- pool = pool->m_previous; |
- |
- // position was nowhere in the chain! |
- if (!pool) |
- CRASH(); |
- |
- if ((position >= pool->m_start) && (position <= static_cast<void*>(pool))) { |
- ASSERT(position <= pool->m_current); |
- pool->m_current = position; |
- return pool; |
- } |
- } |
- } |
- |
- void* m_current; |
- void* m_start; |
- BumpPointerPool* m_next; |
- BumpPointerPool* m_previous; |
- PageAllocation m_allocation; |
- |
- friend class BumpPointerAllocator; |
-}; |
- |
-// A BumpPointerAllocator manages a set of BumpPointerPool objects, which |
-// can be used for LIFO (stack like) allocation. |
-// |
-// To begin allocating using this class call startAllocator(). The result |
-// of this method will be null if the initial pool allocation fails, or a |
-// pointer to a BumpPointerPool object that can be used to perform |
-// allocations. Whilst running no memory will be released until |
-// stopAllocator() is called. At this point all allocations made through |
-// this allocator will be reaped, and underlying memory may be freed. |
-// |
-// (In practice we will still hold on to the initial pool to allow allocation |
-// to be quickly restared, but aditional pools will be freed). |
-// |
-// This allocator is non-renetrant, it is encumbant on the clients to ensure |
-// startAllocator() is not called again until stopAllocator() has been called. |
-class BumpPointerAllocator { |
-public: |
- BumpPointerAllocator() |
- : m_head(0) |
- { |
- } |
- |
- ~BumpPointerAllocator() |
- { |
- if (m_head) |
- m_head->destroy(); |
- } |
- |
- BumpPointerPool* startAllocator() |
- { |
- if (!m_head) |
- m_head = BumpPointerPool::create(); |
- return m_head; |
- } |
- |
- void stopAllocator() |
- { |
- if (m_head) |
- m_head->shrink(); |
- } |
- |
-private: |
- BumpPointerPool* m_head; |
-}; |
- |
-} |
- |
-using WTF::BumpPointerAllocator; |
- |
-#endif // BumpPointerAllocator_h |