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++ /*
++ * 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. AND ITS CONTRIBUTORS ``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 ITS 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.
++ */
++
++ #include "config.h"
++ #include "PageAllocationAligned.h"
++
++ namespace WTF {
++
++ PageAllocationAligned PageAllocationAligned::allocate(size_t size, size_t alignment, OSAllocator::Usage usage, bool writable)
++ {
++ ASSERT(isPageAligned(size));
++ ASSERT(isPageAligned(alignment));
++ ASSERT(isPowerOfTwo(alignment));
++ ASSERT(size >= alignment);
++ size_t alignmentMask = alignment - 1;
++
++ #if OS(DARWIN)
++ int flags = VM_FLAGS_ANYWHERE;
++ if (usage != OSAllocator::UnknownUsage)
++ flags |= usage;
++ int protection = PROT_READ;
++ if (writable)
++ protection |= PROT_WRITE;
++
++ vm_address_t address = 0;
++ vm_map(current_task(), &address, size, alignmentMask, flags, MEMORY_OBJECT_NULL, 0, FALSE, protection, PROT_READ | PROT_WRITE, VM_INHERIT_DEFAULT);
++ return PageAllocationAligned(reinterpret_cast<void*>(address), size);
++ #else
++ size_t alignmentDelta = alignment - pageSize();
++
++ // Resererve with suffcient additional VM to correctly align.
++ size_t reservationSize = size + alignmentDelta;
++ void* reservationBase = OSAllocator::reserveUncommitted(reservationSize, usage, writable);
++
++ // Select an aligned region within the reservation and commit.
++ void* alignedBase = reinterpret_cast<uintptr_t>(reservationBase) & alignmentMask
++ ? reinterpret_cast<void*>((reinterpret_cast<uintptr_t>(reservationBase) & ~alignmentMask) + alignment)
++ : reservationBase;
++ OSAllocator::commit(alignedBase, size, writable, false);
++
++ return PageAllocationAligned(alignedBase, size, reservationBase, reservationSize);
++ #endif
++ }
++
++ void PageAllocationAligned::deallocate()
++ {
++ // Clear base & size before calling release; if this is *inside* allocation
++ // then we won't be able to clear then after deallocating the memory.
++ PageAllocationAligned tmp;
++ std::swap(tmp, *this);
++
++ ASSERT(tmp);
++ ASSERT(!*this);
++
++ #if OS(DARWIN)
++ vm_deallocate(current_task(), reinterpret_cast<vm_address_t>(tmp.realBase()), tmp.realSize());
++ #else
++ ASSERT(tmp.m_reservation.contains(tmp.realBase(), tmp.realSize()));
++ OSAllocator::decommitAndRelease(tmp.m_reservation.realBase(), tmp.m_reservation.realSize(),
++ tmp.realBase(), tmp.realSize());
++ #endif
++ }
++
++ } // namespace WTF