2 * Copyright (C) 2008 Apple Inc. All rights reserved.
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5 * modification, are permitted provided that the following conditions
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11 * documentation and/or other materials provided with the distribution.
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
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16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
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28 #include "ExecutableAllocator.h"
30 #if ENABLE(EXECUTABLE_ALLOCATOR_DEMAND)
31 #include <wtf/MetaAllocator.h>
32 #include <wtf/PageReservation.h>
33 #include <wtf/VMTags.h>
42 #if ENABLE(EXECUTABLE_ALLOCATOR_DEMAND)
44 class DemandExecutableAllocator: public MetaAllocator {
46 DemandExecutableAllocator()
47 : MetaAllocator(32) // round up all allocations to 32 bytes
49 // Don't preallocate any memory here.
52 virtual ~DemandExecutableAllocator()
54 for (unsigned i = 0; i < reservations.size(); ++i)
55 reservations.at(i).deallocate();
59 virtual void* allocateNewSpace(size_t& numPages)
61 size_t newNumPages = (((numPages * pageSize() + JIT_ALLOCATOR_LARGE_ALLOC_SIZE - 1) / JIT_ALLOCATOR_LARGE_ALLOC_SIZE * JIT_ALLOCATOR_LARGE_ALLOC_SIZE) + pageSize() - 1) / pageSize();
63 ASSERT(newNumPages >= numPages);
65 numPages = newNumPages;
67 PageReservation reservation = PageReservation::reserve(numPages * pageSize(), OSAllocator::JSJITCodePages, EXECUTABLE_POOL_WRITABLE, true);
71 reservations.append(reservation);
73 return reservation.base();
76 virtual void notifyNeedPage(void* page)
78 OSAllocator::commit(page, pageSize(), EXECUTABLE_POOL_WRITABLE, true);
81 virtual void notifyPageIsFree(void* page)
83 OSAllocator::decommit(page, pageSize());
87 Vector<PageReservation, 16> reservations;
90 static DemandExecutableAllocator* allocator;
92 void ExecutableAllocator::initializeAllocator()
95 allocator = new DemandExecutableAllocator();
98 ExecutableAllocator::ExecutableAllocator(JSGlobalData&)
103 bool ExecutableAllocator::isValid() const
108 bool ExecutableAllocator::underMemoryPressure()
113 PassRefPtr<ExecutableMemoryHandle> ExecutableAllocator::allocate(JSGlobalData&, size_t sizeInBytes)
115 RefPtr<ExecutableMemoryHandle> result = allocator->allocate(sizeInBytes);
118 return result.release();
121 size_t ExecutableAllocator::committedByteCount()
123 return allocator->bytesCommitted();
126 #if ENABLE(META_ALLOCATOR_PROFILE)
127 void ExecutableAllocator::dumpProfile()
129 allocator->dumpProfile();
133 #endif // ENABLE(EXECUTABLE_ALLOCATOR_DEMAND)
135 #if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
137 #if OS(WINDOWS) || OS(SYMBIAN)
138 #error "ASSEMBLER_WX_EXCLUSIVE not yet suported on this platform."
141 void ExecutableAllocator::reprotectRegion(void* start, size_t size, ProtectionSetting setting)
143 size_t pageSize = WTF::pageSize();
145 // Calculate the start of the page containing this region,
146 // and account for this extra memory within size.
147 intptr_t startPtr = reinterpret_cast<intptr_t>(start);
148 intptr_t pageStartPtr = startPtr & ~(pageSize - 1);
149 void* pageStart = reinterpret_cast<void*>(pageStartPtr);
150 size += (startPtr - pageStartPtr);
153 size += (pageSize - 1);
154 size &= ~(pageSize - 1);
156 mprotect(pageStart, size, (setting == Writable) ? PROTECTION_FLAGS_RW : PROTECTION_FLAGS_RX);
161 #if CPU(ARM_TRADITIONAL) && OS(LINUX) && COMPILER(RVCT)
163 __asm void ExecutableAllocator::cacheFlush(void* code, size_t size)
180 #endif // HAVE(ASSEMBLER)