mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2026-04-19 02:10:26 +00:00
5af4bc81e1
This allows us to get a correctly aligned allocation with a single syscall, unlike posix_memalign() which makes no such guarantees.
129 lines
3.7 KiB
C++
129 lines
3.7 KiB
C++
/*
|
|
* Copyright (c) 2021-2023, Andreas Kling <andreas@ladybird.org>
|
|
* Copyright (c) 2025, Ryszard Goc <ryszardgoc@gmail.com>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#include <AK/Assertions.h>
|
|
#include <AK/Format.h>
|
|
#include <AK/Platform.h>
|
|
#include <AK/Random.h>
|
|
#include <AK/Vector.h>
|
|
#include <LibGC/BlockAllocator.h>
|
|
#include <LibGC/HeapBlock.h>
|
|
#include <sys/mman.h>
|
|
|
|
#if defined(AK_OS_MACOS)
|
|
# include <mach/mach.h>
|
|
# include <mach/mach_vm.h>
|
|
#endif
|
|
|
|
#ifdef HAS_ADDRESS_SANITIZER
|
|
# include <sanitizer/asan_interface.h>
|
|
# include <sanitizer/lsan_interface.h>
|
|
#endif
|
|
|
|
#if defined(AK_OS_WINDOWS)
|
|
# include <AK/Windows.h>
|
|
# include <memoryapi.h>
|
|
#endif
|
|
|
|
namespace GC {
|
|
|
|
BlockAllocator::~BlockAllocator()
|
|
{
|
|
for (auto* block : m_blocks) {
|
|
ASAN_UNPOISON_MEMORY_REGION(block, HeapBlock::BLOCK_SIZE);
|
|
#if defined(AK_OS_MACOS)
|
|
kern_return_t kr = mach_vm_deallocate(mach_task_self(), reinterpret_cast<mach_vm_address_t>(block), HeapBlock::BLOCK_SIZE);
|
|
VERIFY(kr == KERN_SUCCESS);
|
|
#elif defined(AK_OS_WINDOWS)
|
|
if (!VirtualFree(block, 0, MEM_RELEASE)) {
|
|
warnln("{}", Error::from_windows_error());
|
|
VERIFY_NOT_REACHED();
|
|
}
|
|
#else
|
|
free(block);
|
|
#endif
|
|
}
|
|
}
|
|
|
|
void* BlockAllocator::allocate_block([[maybe_unused]] char const* name)
|
|
{
|
|
if (!m_blocks.is_empty()) {
|
|
// To reduce predictability, take a random block from the cache.
|
|
size_t random_index = get_random_uniform(m_blocks.size());
|
|
auto* block = m_blocks.unstable_take(random_index);
|
|
ASAN_UNPOISON_MEMORY_REGION(block, HeapBlock::BLOCK_SIZE);
|
|
LSAN_REGISTER_ROOT_REGION(block, HeapBlock::BLOCK_SIZE);
|
|
#if defined(MADV_FREE_REUSE) && defined(MADV_FREE_REUSABLE)
|
|
if (madvise(block, HeapBlock::BLOCK_SIZE, MADV_FREE_REUSE) < 0) {
|
|
perror("madvise(MADV_FREE_REUSE)");
|
|
VERIFY_NOT_REACHED();
|
|
}
|
|
#endif
|
|
return block;
|
|
}
|
|
|
|
#if defined(AK_OS_MACOS)
|
|
mach_vm_address_t address = 0;
|
|
kern_return_t kr = mach_vm_map(
|
|
mach_task_self(),
|
|
&address,
|
|
HeapBlock::BLOCK_SIZE,
|
|
HeapBlock::BLOCK_SIZE - 1,
|
|
VM_FLAGS_ANYWHERE,
|
|
MEMORY_OBJECT_NULL,
|
|
0,
|
|
false,
|
|
VM_PROT_READ | VM_PROT_WRITE,
|
|
VM_PROT_READ | VM_PROT_WRITE,
|
|
VM_INHERIT_DEFAULT);
|
|
VERIFY(kr == KERN_SUCCESS);
|
|
auto* block = reinterpret_cast<void*>(address);
|
|
#elif defined(AK_OS_WINDOWS)
|
|
auto* block = VirtualAlloc(NULL, HeapBlock::BLOCK_SIZE, MEM_COMMIT, PAGE_READWRITE);
|
|
VERIFY(block);
|
|
#else
|
|
void* block = nullptr;
|
|
auto rc = posix_memalign(&block, HeapBlock::BLOCK_SIZE, HeapBlock::BLOCK_SIZE);
|
|
VERIFY(rc == 0);
|
|
#endif
|
|
LSAN_REGISTER_ROOT_REGION(block, HeapBlock::BLOCK_SIZE);
|
|
return block;
|
|
}
|
|
|
|
void BlockAllocator::deallocate_block(void* block)
|
|
{
|
|
VERIFY(block);
|
|
|
|
#if defined(AK_OS_WINDOWS)
|
|
DWORD ret = DiscardVirtualMemory(block, HeapBlock::BLOCK_SIZE);
|
|
if (ret != ERROR_SUCCESS) {
|
|
warnln("{}", Error::from_windows_error(ret));
|
|
VERIFY_NOT_REACHED();
|
|
}
|
|
#elif defined(MADV_FREE_REUSE) && defined(MADV_FREE_REUSABLE)
|
|
if (madvise(block, HeapBlock::BLOCK_SIZE, MADV_FREE_REUSABLE) < 0) {
|
|
perror("madvise(MADV_FREE_REUSABLE)");
|
|
VERIFY_NOT_REACHED();
|
|
}
|
|
#elif defined(MADV_FREE)
|
|
if (madvise(block, HeapBlock::BLOCK_SIZE, MADV_FREE) < 0) {
|
|
perror("madvise(MADV_FREE)");
|
|
VERIFY_NOT_REACHED();
|
|
}
|
|
#elif defined(MADV_DONTNEED)
|
|
if (madvise(block, HeapBlock::BLOCK_SIZE, MADV_DONTNEED) < 0) {
|
|
perror("madvise(MADV_DONTNEED)");
|
|
VERIFY_NOT_REACHED();
|
|
}
|
|
#endif
|
|
|
|
ASAN_POISON_MEMORY_REGION(block, HeapBlock::BLOCK_SIZE);
|
|
LSAN_UNREGISTER_ROOT_REGION(block, HeapBlock::BLOCK_SIZE);
|
|
m_blocks.append(block);
|
|
}
|
|
|
|
}
|