1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/src/yarr/OSAllocator.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,103 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
1.5 + * vim: set ts=8 sts=4 et sw=4 tw=99:
1.6 + *
1.7 + * ***** BEGIN LICENSE BLOCK *****
1.8 + * Copyright (C) 2010 Apple Inc. All rights reserved.
1.9 + *
1.10 + * Redistribution and use in source and binary forms, with or without
1.11 + * modification, are permitted provided that the following conditions
1.12 + * are met:
1.13 + * 1. Redistributions of source code must retain the above copyright
1.14 + * notice, this list of conditions and the following disclaimer.
1.15 + * 2. Redistributions in binary form must reproduce the above copyright
1.16 + * notice, this list of conditions and the following disclaimer in the
1.17 + * documentation and/or other materials provided with the distribution.
1.18 + *
1.19 + * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
1.20 + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
1.21 + * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
1.22 + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
1.23 + * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
1.24 + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
1.25 + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
1.26 + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
1.27 + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
1.28 + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
1.29 + * THE POSSIBILITY OF SUCH DAMAGE.
1.30 + *
1.31 + * ***** END LICENSE BLOCK ***** */
1.32 +
1.33 +#ifndef yarr_OSAllocator_h
1.34 +#define yarr_OSAllocator_h
1.35 +
1.36 +#include <stdlib.h>
1.37 +#include "yarr/wtfbridge.h"
1.38 +#include "assembler/wtf/VMTags.h"
1.39 +#include "assembler/wtf/Assertions.h"
1.40 +
1.41 +namespace WTF {
1.42 +
1.43 +class OSAllocator {
1.44 +public:
1.45 + enum Usage {
1.46 + UnknownUsage = -1,
1.47 + FastMallocPages = VM_TAG_FOR_TCMALLOC_MEMORY,
1.48 + JSGCHeapPages = VM_TAG_FOR_COLLECTOR_MEMORY,
1.49 + JSVMStackPages = VM_TAG_FOR_REGISTERFILE_MEMORY,
1.50 + JSJITCodePages = VM_TAG_FOR_EXECUTABLEALLOCATOR_MEMORY
1.51 + };
1.52 +
1.53 + // These methods are symmetric; reserveUncommitted allocates VM in an uncommitted state,
1.54 + // releaseDecommitted should be called on a region of VM allocated by a single reservation,
1.55 + // the memory must all currently be in a decommitted state.
1.56 + static void* reserveUncommitted(size_t, Usage = UnknownUsage, bool writable = true, bool executable = false);
1.57 + static void releaseDecommitted(void*, size_t);
1.58 +
1.59 + // These methods are symmetric; they commit or decommit a region of VM (uncommitted VM should
1.60 + // never be accessed, since the OS may not have attached physical memory for these regions).
1.61 + // Clients should only call commit on uncommitted regions and decommit on committed regions.
1.62 + static void commit(void*, size_t, bool writable, bool executable);
1.63 + static void decommit(void*, size_t);
1.64 +
1.65 + // These methods are symmetric; reserveAndCommit allocates VM in an committed state,
1.66 + // decommitAndRelease should be called on a region of VM allocated by a single reservation,
1.67 + // the memory must all currently be in a committed state.
1.68 + static void* reserveAndCommit(size_t, Usage = UnknownUsage, bool writable = true, bool executable = false);
1.69 + static void decommitAndRelease(void* base, size_t size);
1.70 +
1.71 + // These methods are akin to reserveAndCommit/decommitAndRelease, above - however rather than
1.72 + // committing/decommitting the entire region additional parameters allow a subregion to be
1.73 + // specified.
1.74 + static void* reserveAndCommit(size_t reserveSize, size_t commitSize, Usage = UnknownUsage, bool writable = true, bool executable = false);
1.75 + static void decommitAndRelease(void* releaseBase, size_t releaseSize, void* decommitBase, size_t decommitSize);
1.76 +};
1.77 +
1.78 +inline void* OSAllocator::reserveAndCommit(size_t reserveSize, size_t commitSize, Usage usage, bool writable, bool executable)
1.79 +{
1.80 + void* base = reserveUncommitted(reserveSize, usage, writable, executable);
1.81 + commit(base, commitSize, writable, executable);
1.82 + return base;
1.83 +}
1.84 +
1.85 +inline void OSAllocator::decommitAndRelease(void* releaseBase, size_t releaseSize, void* decommitBase, size_t decommitSize)
1.86 +{
1.87 + ASSERT(decommitBase >= releaseBase && (static_cast<char*>(decommitBase) + decommitSize) <= (static_cast<char*>(releaseBase) + releaseSize));
1.88 +#if WTF_OS_WINCE || WTF_OS_SYMBIAN
1.89 + // On most platforms we can actually skip this final decommit; releasing the VM will
1.90 + // implicitly decommit any physical memory in the region. This is not true on WINCE.
1.91 + // On Symbian, this makes implementation simpler and better aligned with the RChunk API
1.92 + decommit(decommitBase, decommitSize);
1.93 +#endif
1.94 + releaseDecommitted(releaseBase, releaseSize);
1.95 +}
1.96 +
1.97 +inline void OSAllocator::decommitAndRelease(void* base, size_t size)
1.98 +{
1.99 + decommitAndRelease(base, size, base, size);
1.100 +}
1.101 +
1.102 +} // namespace WTF
1.103 +
1.104 +using WTF::OSAllocator;
1.105 +
1.106 +#endif /* yarr_OSAllocator_h */
