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michael@0: 
michael@0: #ifndef yarr_PageAllocation_h
michael@0: #define yarr_PageAllocation_h
michael@0: 
michael@0: #include "yarr/wtfbridge.h"
michael@0: #include "yarr/OSAllocator.h"
michael@0: #include "yarr/PageBlock.h"
michael@0: #include "assembler/wtf/VMTags.h"
michael@0: 
michael@0: #if WTF_OS_DARWIN
michael@0: #include <mach/mach_init.h>
michael@0: #include <mach/vm_map.h>
michael@0: #endif
michael@0: 
michael@0: #if WTF_OS_HAIKU
michael@0: #include <OS.h>
michael@0: #endif
michael@0: 
michael@0: #if WTF_OS_WINDOWS
michael@0: #include <malloc.h>
michael@0: #include <windows.h>
michael@0: #endif
michael@0: 
michael@0: #if WTF_OS_SYMBIAN
michael@0: #include <e32hal.h>
michael@0: #include <e32std.h>
michael@0: #endif
michael@0: 
michael@0: #if WTF_HAVE_ERRNO_H
michael@0: #include <errno.h>
michael@0: #endif
michael@0: 
michael@0: #if WTF_HAVE_MMAP
michael@0: #include <sys/mman.h>
michael@0: #include <unistd.h>
michael@0: #endif
michael@0: 
michael@0: namespace WTF {
michael@0: 
michael@0: /*
michael@0:     PageAllocation
michael@0: 
michael@0:     The PageAllocation class provides a cross-platform memory allocation interface
michael@0:     with similar capabilities to posix mmap/munmap.  Memory is allocated by calling
michael@0:     PageAllocation::allocate, and deallocated by calling deallocate on the
michael@0:     PageAllocation object.  The PageAllocation holds the allocation's base pointer
michael@0:     and size.
michael@0: 
michael@0:     The allocate method is passed the size required (which must be a multiple of
michael@0:     the system page size, which can be accessed using PageAllocation::pageSize).
michael@0:     Callers may also optinally provide a flag indicating the usage (for use by
michael@0:     system memory usage tracking tools, where implemented), and boolean values
michael@0:     specifying the required protection (defaulting to writable, non-executable).
michael@0: */
michael@0: 
michael@0: class PageAllocation : private PageBlock {
michael@0: public:
michael@0:     PageAllocation()
michael@0:     {
michael@0:     }
michael@0: 
michael@0:     using PageBlock::size;
michael@0:     using PageBlock::base;
michael@0: 
michael@0: #ifndef __clang__
michael@0:     using PageBlock::operator bool;
michael@0: #else
michael@0:     // FIXME: This is a workaround for <rdar://problem/8876150>, wherein Clang incorrectly emits an access
michael@0:     // control warning when a client tries to use operator bool exposed above via "using PageBlock::operator bool".
michael@0:     operator bool() const { return PageBlock::operator bool(); }
michael@0: #endif
michael@0: 
michael@0:     static PageAllocation allocate(size_t size, OSAllocator::Usage usage = OSAllocator::UnknownUsage, bool writable = true, bool executable = false)
michael@0:     {
michael@0:         ASSERT(isPageAligned(size));
michael@0:         return PageAllocation(OSAllocator::reserveAndCommit(size, usage, writable, executable), size);
michael@0:     }
michael@0: 
michael@0:     void deallocate()
michael@0:     {
michael@0:         // Clear base & size before calling release; if this is *inside* allocation
michael@0:         // then we won't be able to clear then after deallocating the memory.
michael@0:         PageAllocation tmp;
michael@0:         JSC::std::swap(tmp, *this);
michael@0: 
michael@0:         ASSERT(tmp);
michael@0:         ASSERT(!*this);
michael@0: 
michael@0:         OSAllocator::decommitAndRelease(tmp.base(), tmp.size());
michael@0:     }
michael@0: 
michael@0: private:
michael@0:     PageAllocation(void* base, size_t size)
michael@0:         : PageBlock(base, size)
michael@0:     {
michael@0:     }
michael@0: };
michael@0: 
michael@0: } // namespace WTF
michael@0: 
michael@0: using WTF::PageAllocation;
michael@0: 
michael@0: #endif /* yarr_PageAllocation_h */