1 /* 2 * Copyright (C) 2010 Apple Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' 14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS 17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 23 * THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 #include "config.h" 27 #include "PageAllocationAligned.h" 28 29 namespace WTF { 30 31 PageAllocationAligned PageAllocationAligned::allocate(size_t size, size_t alignment, OSAllocator::Usage usage, bool writable, bool executable) 32 { 33 ASSERT(isPageAligned(size)); 34 ASSERT(isPageAligned(alignment)); 35 ASSERT(isPowerOfTwo(alignment)); 36 ASSERT(size >= alignment); 37 size_t alignmentMask = alignment - 1; 38 39 #if OS(DARWIN) 40 int flags = VM_FLAGS_ANYWHERE; 41 if (usage != OSAllocator::UnknownUsage) 42 flags |= usage; 43 int protection = PROT_READ; 44 if (writable) 45 protection |= PROT_WRITE; 46 if (executable) 47 protection |= PROT_EXEC; 48 49 vm_address_t address = 0; 50 vm_map(current_task(), &address, size, alignmentMask, flags, MEMORY_OBJECT_NULL, 0, FALSE, protection, PROT_READ | PROT_WRITE | PROT_EXEC, VM_INHERIT_DEFAULT); 51 return PageAllocationAligned(reinterpret_cast<void*>(address), size); 52 #else 53 size_t alignmentDelta = alignment - pageSize(); 54 55 // Resererve with suffcient additional VM to correctly align. 56 size_t reservationSize = size + alignmentDelta; 57 void* reservationBase = OSAllocator::reserveUncommitted(reservationSize, usage, writable, executable); 58 59 // Select an aligned region within the reservation and commit. 60 void* alignedBase = reinterpret_cast<uintptr_t>(reservationBase) & alignmentMask 61 ? reinterpret_cast<void*>((reinterpret_cast<uintptr_t>(reservationBase) & ~alignmentMask) + alignment) 62 : reservationBase; 63 OSAllocator::commit(alignedBase, size, writable, executable); 64 65 return PageAllocationAligned(alignedBase, size, reservationBase, reservationSize); 66 #endif 67 } 68 69 void PageAllocationAligned::deallocate() 70 { 71 // Clear base & size before calling release; if this is *inside* allocation 72 // then we won't be able to clear then after deallocating the memory. 73 PageAllocationAligned tmp; 74 std::swap(tmp, *this); 75 76 ASSERT(tmp); 77 ASSERT(!*this); 78 79 #if OS(DARWIN) 80 vm_deallocate(current_task(), reinterpret_cast<vm_address_t>(tmp.base()), tmp.size()); 81 #else 82 ASSERT(tmp.m_reservation.contains(tmp.base(), tmp.size())); 83 OSAllocator::decommitAndRelease(tmp.m_reservation.base(), tmp.m_reservation.size(), tmp.base(), tmp.size()); 84 #endif 85 } 86 87 } // namespace WTF 88
