| /* |
| * 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 |
| ASSERT(alignment >= pageSize()); |
| size_t alignmentDelta = alignment - pageSize(); |
| |
| // Reserve with sufficient 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; |
| // Check that reserveUncommitted always returns aligned blocks if pageSize() == alignment. |
| if (alignmentDelta == 0) { |
| ASSERT(alignedBase == 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 |