| /* |
| * 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. |
| */ |
| |
| #ifndef OSAllocator_h |
| #define OSAllocator_h |
| |
| #include <algorithm> |
| #include <wtf/UnusedParam.h> |
| #include <wtf/VMTags.h> |
| |
| namespace WTF { |
| |
| class OSAllocator { |
| public: |
| enum Usage { |
| UnknownUsage = -1, |
| FastMallocPages = VM_TAG_FOR_TCMALLOC_MEMORY, |
| JSGCHeapPages = VM_TAG_FOR_COLLECTOR_MEMORY, |
| JSVMStackPages = VM_TAG_FOR_REGISTERFILE_MEMORY, |
| JSJITCodePages = VM_TAG_FOR_EXECUTABLEALLOCATOR_MEMORY, |
| // Use this flag if we know we don't need page-aligned blocks. |
| JSUnalignedPages = VM_TAG_FOR_UNALIGNED_MEMORY, |
| }; |
| |
| // These methods are symmetric; reserveUncommitted allocates VM in an uncommitted state, |
| // releaseDecommitted should be called on a region of VM allocated by a single reservation, |
| // the memory must all currently be in a decommitted state. |
| static void* reserveUncommitted(size_t, Usage = UnknownUsage, bool writable = true, bool executable = false, bool includesGuardPages = false); |
| WTF_EXPORT_PRIVATE static void releaseDecommitted(void*, size_t); |
| |
| // These methods are symmetric; they commit or decommit a region of VM (uncommitted VM should |
| // never be accessed, since the OS may not have attached physical memory for these regions). |
| // Clients should only call commit on uncommitted regions and decommit on committed regions. |
| static void commit(void*, size_t, bool writable, bool executable); |
| static void decommit(void*, size_t); |
| |
| // These methods are symmetric; reserveAndCommit allocates VM in an committed state, |
| // decommitAndRelease should be called on a region of VM allocated by a single reservation, |
| // the memory must all currently be in a committed state. |
| WTF_EXPORT_PRIVATE static void* reserveAndCommit(size_t, Usage = UnknownUsage, bool writable = true, bool executable = false, bool includesGuardPages = false); |
| static void decommitAndRelease(void* base, size_t size); |
| |
| // These methods are akin to reserveAndCommit/decommitAndRelease, above - however rather than |
| // committing/decommitting the entire region additional parameters allow a subregion to be |
| // specified. |
| static void* reserveAndCommit(size_t reserveSize, size_t commitSize, Usage = UnknownUsage, bool writable = true, bool executable = false); |
| static void decommitAndRelease(void* releaseBase, size_t releaseSize, void* decommitBase, size_t decommitSize); |
| |
| // Reallocate an existing, committed allocation. |
| // The prior allocation must be fully comitted, and the new size will also be fully committed. |
| // This interface is provided since it may be possible to optimize this operation on some platforms. |
| template<typename T> |
| static T* reallocateCommitted(T*, size_t oldSize, size_t newSize, Usage = UnknownUsage, bool writable = true, bool executable = false); |
| |
| #if defined (__LB_SHELL__) || defined(COBALT) |
| WTF_EXPORT static size_t getCurrentBytesAllocated(); |
| #endif |
| }; |
| |
| inline void* OSAllocator::reserveAndCommit(size_t reserveSize, size_t commitSize, Usage usage, bool writable, bool executable) |
| { |
| void* base = reserveUncommitted(reserveSize, usage, writable, executable); |
| commit(base, commitSize, writable, executable); |
| return base; |
| } |
| |
| inline void OSAllocator::decommitAndRelease(void* releaseBase, size_t releaseSize, void* decommitBase, size_t decommitSize) |
| { |
| ASSERT(decommitBase >= releaseBase && (static_cast<char*>(decommitBase) + decommitSize) <= (static_cast<char*>(releaseBase) + releaseSize)); |
| #if OS(WINCE) |
| // On most platforms we can actually skip this final decommit; releasing the VM will |
| // implicitly decommit any physical memory in the region. This is not true on WINCE. |
| decommit(decommitBase, decommitSize); |
| #else |
| UNUSED_PARAM(decommitBase); |
| UNUSED_PARAM(decommitSize); |
| #endif |
| releaseDecommitted(releaseBase, releaseSize); |
| } |
| |
| inline void OSAllocator::decommitAndRelease(void* base, size_t size) |
| { |
| decommitAndRelease(base, size, base, size); |
| } |
| |
| template<typename T> |
| inline T* OSAllocator::reallocateCommitted(T* oldBase, size_t oldSize, size_t newSize, Usage usage, bool writable, bool executable) |
| { |
| void* newBase = reserveAndCommit(newSize, usage, writable, executable); |
| memcpy(newBase, oldBase, std::min(oldSize, newSize)); |
| decommitAndRelease(oldBase, oldSize); |
| return static_cast<T*>(newBase); |
| } |
| |
| } // namespace WTF |
| |
| using WTF::OSAllocator; |
| |
| #endif // OSAllocator_h |