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Diffstat (limited to 'src/3rdparty/masm/wtf/PageAllocation.h')
-rw-r--r-- | src/3rdparty/masm/wtf/PageAllocation.h | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/src/3rdparty/masm/wtf/PageAllocation.h b/src/3rdparty/masm/wtf/PageAllocation.h new file mode 100644 index 0000000000..18d31880c0 --- /dev/null +++ b/src/3rdparty/masm/wtf/PageAllocation.h @@ -0,0 +1,120 @@ +/* + * 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. ``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 + * 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 PageAllocation_h +#define PageAllocation_h + +#include <wtf/Assertions.h> +#include <wtf/OSAllocator.h> +#include <wtf/PageBlock.h> +#include <wtf/UnusedParam.h> +#include <wtf/VMTags.h> +#include <algorithm> + +#if OS(DARWIN) +#include <mach/mach_init.h> +#include <mach/vm_map.h> +#endif + +#if OS(WINDOWS) +#include <malloc.h> +#include <windows.h> +#endif + +#if HAVE(ERRNO_H) +#include <errno.h> +#endif + +#if HAVE(MMAP) +#include <sys/mman.h> +#include <unistd.h> +#endif + +namespace WTF { + +/* + PageAllocation + + The PageAllocation class provides a cross-platform memory allocation interface + with similar capabilities to posix mmap/munmap. Memory is allocated by calling + PageAllocation::allocate, and deallocated by calling deallocate on the + PageAllocation object. The PageAllocation holds the allocation's base pointer + and size. + + The allocate method is passed the size required (which must be a multiple of + the system page size, which can be accessed using PageAllocation::pageSize). + Callers may also optinally provide a flag indicating the usage (for use by + system memory usage tracking tools, where implemented), and boolean values + specifying the required protection (defaulting to writable, non-executable). +*/ + +class PageAllocation : private PageBlock { +public: + PageAllocation() + { + } + + using PageBlock::size; + using PageBlock::base; + +#ifndef __clang__ + using PageBlock::operator bool; +#else + // FIXME: This is a workaround for <rdar://problem/8876150>, wherein Clang incorrectly emits an access + // control warning when a client tries to use operator bool exposed above via "using PageBlock::operator bool". + operator bool() const { return PageBlock::operator bool(); } +#endif + + static PageAllocation allocate(size_t size, OSAllocator::Usage usage = OSAllocator::UnknownUsage, bool writable = true, bool executable = false) + { + ASSERT(isPageAligned(size)); + return PageAllocation(OSAllocator::reserveAndCommit(size, usage, writable, executable), size); + } + + void 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. + PageAllocation tmp; + std::swap(tmp, *this); + + ASSERT(tmp); + ASSERT(!*this); + + OSAllocator::decommitAndRelease(tmp.base(), tmp.size()); + } + +private: + PageAllocation(void* base, size_t size) + : PageBlock(base, size, false) + { + } +}; + +} // namespace WTF + +using WTF::PageAllocation; + +#endif // PageAllocation_h |