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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, bool executable)
{
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;
if (executable)
protection |= PROT_EXEC;
vm_address_t address = 0;
vm_map(current_task(), &address, size, alignmentMask, flags, MEMORY_OBJECT_NULL, 0, FALSE, protection, PROT_READ | PROT_WRITE | PROT_EXEC, 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, executable);
// 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, executable);
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.base()), tmp.size());
#else
ASSERT(tmp.m_reservation.contains(tmp.base(), tmp.size()));
OSAllocator::decommitAndRelease(tmp.m_reservation.base(), tmp.m_reservation.size(), tmp.base(), tmp.size());
#endif
}
} // namespace WTF