| /* |
| * 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 |