-/*
- * 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 <wtf/UnusedParam.h>
-#include <wtf/VMTags.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,
- };
-
- // 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);
- 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.
- 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);
-};
-
-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) || OS(SYMBIAN)
- // 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.
- // On Symbian, this makes implementation simpler and better aligned with the RChunk API
- 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);
-}
-
-} // namespace WTF
-
-using WTF::OSAllocator;
-
-#endif // OSAllocator_h
projects / apple / javascriptcore.git / blobdiff