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/*
* Copyright (C) 2017-2021 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.
*/
#include "config.h"
#include "StructureAlignedMemoryAllocator.h"
#include "JSCConfig.h"
#include "MarkedBlock.h"
#include "StructureID.h"
#if CPU(ADDRESS64) && !ENABLE(STRUCTURE_ID_WITH_SHIFT)
#include <wtf/NeverDestroyed.h>
#endif
#include <wtf/OSAllocator.h>
#if OS(UNIX) && ASSERT_ENABLED
#include <sys/mman.h>
#endif
namespace JSC {
StructureAlignedMemoryAllocator::StructureAlignedMemoryAllocator(CString name)
: Base(name)
{
}
StructureAlignedMemoryAllocator::~StructureAlignedMemoryAllocator()
{
releaseMemoryFromSubclassDestructor();
}
void StructureAlignedMemoryAllocator::dump(PrintStream& out) const
{
out.print("Structure(", RawPointer(this), ")");
}
void* StructureAlignedMemoryAllocator::tryAllocateMemory(size_t)
{
return nullptr;
}
void StructureAlignedMemoryAllocator::freeMemory(void*)
{
// Structures do not support Precise allocations right now.
RELEASE_ASSERT_NOT_REACHED();
}
void* StructureAlignedMemoryAllocator::tryReallocateMemory(void*, size_t)
{
// Structures do not support Precise allocations right now.
RELEASE_ASSERT_NOT_REACHED();
}
#if CPU(ADDRESS64) && !ENABLE(STRUCTURE_ID_WITH_SHIFT)
class StructureMemoryManager {
public:
StructureMemoryManager()
{
// Don't use the first page because zero is used as the empty StructureID and the first allocation will conflict.
m_usedBlocks.set(0);
uintptr_t mappedHeapSize = structureHeapAddressSize;
for (unsigned i = 0; i < 8; ++i) {
g_jscConfig.startOfStructureHeap = reinterpret_cast<uintptr_t>(OSAllocator::tryReserveUncommittedAligned(mappedHeapSize, structureHeapAddressSize, OSAllocator::FastMallocPages));
if (g_jscConfig.startOfStructureHeap)
break;
mappedHeapSize /= 2;
}
g_jscConfig.sizeOfStructureHeap = mappedHeapSize;
RELEASE_ASSERT(g_jscConfig.startOfStructureHeap && ((g_jscConfig.startOfStructureHeap & ~StructureID::structureIDMask) == g_jscConfig.startOfStructureHeap));
}
void* tryMallocStructureBlock()
{
size_t freeIndex;
{
Locker locker(m_lock);
constexpr size_t startIndex = 0;
freeIndex = m_usedBlocks.findBit(startIndex, 0);
ASSERT(freeIndex <= m_usedBlocks.bitCount());
RELEASE_ASSERT(g_jscConfig.sizeOfStructureHeap <= structureHeapAddressSize);
if (freeIndex * MarkedBlock::blockSize >= g_jscConfig.sizeOfStructureHeap)
return nullptr;
// If we can't find a free block then `freeIndex == m_usedBlocks.bitCount()` and this set will grow the bit vector.
m_usedBlocks.set(freeIndex);
}
WTF_ALLOW_UNSAFE_BUFFER_USAGE_BEGIN
auto* block = reinterpret_cast<uint8_t*>(g_jscConfig.startOfStructureHeap) + freeIndex * MarkedBlock::blockSize;
WTF_ALLOW_UNSAFE_BUFFER_USAGE_END
commitBlock(block);
return block;
}
void freeStructureBlock(void* blockPtr)
{
decommitBlock(blockPtr);
uintptr_t block = reinterpret_cast<uintptr_t>(blockPtr);
RELEASE_ASSERT(g_jscConfig.startOfStructureHeap <= block && block < g_jscConfig.startOfStructureHeap + g_jscConfig.sizeOfStructureHeap);
RELEASE_ASSERT(roundUpToMultipleOf<MarkedBlock::blockSize>(block) == block);
Locker locker(m_lock);
m_usedBlocks.quickClear((block - g_jscConfig.startOfStructureHeap) / MarkedBlock::blockSize);
}
static void commitBlock(void* block)
{
#if OS(UNIX) && !PLATFORM(PLAYSTATION) && ASSERT_ENABLED
constexpr bool readable = true;
constexpr bool writable = true;
OSAllocator::protect(block, MarkedBlock::blockSize, readable, writable);
#else
constexpr bool writable = true;
constexpr bool executable = false;
OSAllocator::commit(block, MarkedBlock::blockSize, writable, executable);
#endif
}
static void decommitBlock(void* block)
{
#if OS(UNIX) && !PLATFORM(PLAYSTATION) && ASSERT_ENABLED
constexpr bool readable = false;
constexpr bool writable = false;
OSAllocator::protect(block, MarkedBlock::blockSize, readable, writable);
#else
OSAllocator::decommit(block, MarkedBlock::blockSize);
#endif
}
private:
Lock m_lock;
BitVector m_usedBlocks;
};
static LazyNeverDestroyed<StructureMemoryManager> s_structureMemoryManager;
void StructureAlignedMemoryAllocator::initializeStructureAddressSpace()
{
static_assert(hasOneBitSet(structureHeapAddressSize));
s_structureMemoryManager.construct();
}
void* StructureAlignedMemoryAllocator::tryMallocBlock()
{
return s_structureMemoryManager->tryMallocStructureBlock();
}
void StructureAlignedMemoryAllocator::freeBlock(void* block)
{
s_structureMemoryManager->freeStructureBlock(block);
}
void StructureAlignedMemoryAllocator::commitBlock(void* block)
{
StructureMemoryManager::commitBlock(block);
}
void StructureAlignedMemoryAllocator::decommitBlock(void* block)
{
StructureMemoryManager::decommitBlock(block);
}
#else // not CPU(ADDRESS64)
// FIXME: This is the same as IsoAlignedMemoryAllocator maybe we should just use that for 32-bit.
void StructureAlignedMemoryAllocator::initializeStructureAddressSpace()
{
g_jscConfig.startOfStructureHeap = 0;
g_jscConfig.sizeOfStructureHeap = UINTPTR_MAX;
}
void* StructureAlignedMemoryAllocator::tryMallocBlock()
{
return tryFastAlignedMalloc(MarkedBlock::blockSize, MarkedBlock::blockSize);
}
void StructureAlignedMemoryAllocator::freeBlock(void* block)
{
fastAlignedFree(block);
}
void StructureAlignedMemoryAllocator::commitBlock(void* block)
{
WTF::fastCommitAlignedMemory(block, MarkedBlock::blockSize);
}
void StructureAlignedMemoryAllocator::decommitBlock(void* block)
{
WTF::fastDecommitAlignedMemory(block, MarkedBlock::blockSize);
}
#endif // CPU(ADDRESS64)
} // namespace JSC
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