101 lines
3.1 KiB
C++
101 lines
3.1 KiB
C++
// Copyright 2022 The Chromium Authors
|
|
// Use of this source code is governed by a BSD-style license that can be
|
|
// found in the LICENSE file.
|
|
|
|
#include "base/allocator/dispatcher/tls.h"
|
|
|
|
#if USE_LOCAL_TLS_EMULATION()
|
|
|
|
#include "base/check.h"
|
|
#include "base/dcheck_is_on.h"
|
|
#include "base/immediate_crash.h"
|
|
#include "build/build_config.h"
|
|
|
|
#include <sys/mman.h>
|
|
|
|
#if BUILDFLAG(IS_ANDROID) || BUILDFLAG(IS_LINUX)
|
|
#include <sys/prctl.h>
|
|
#endif
|
|
|
|
namespace base::allocator::dispatcher::internal {
|
|
|
|
void* MMapAllocator::AllocateMemory(size_t size_in_bytes) {
|
|
void* const mmap_res = mmap(nullptr, size_in_bytes, PROT_READ | PROT_WRITE,
|
|
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
|
|
#if BUILDFLAG(IS_ANDROID) || BUILDFLAG(IS_LINUX)
|
|
#if defined(PR_SET_VMA) && defined(PR_SET_VMA_ANON_NAME)
|
|
if (mmap_res != MAP_FAILED) {
|
|
// Allow the anonymous memory region allocated by mmap(MAP_ANONYMOUS) to
|
|
// be identified in /proc/$PID/smaps. This helps improve visibility into
|
|
// Chromium's memory usage on Android.
|
|
prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, mmap_res, size_in_bytes,
|
|
"tls-mmap-allocator");
|
|
}
|
|
#endif
|
|
#endif
|
|
|
|
return (mmap_res != MAP_FAILED) ? mmap_res : nullptr;
|
|
}
|
|
|
|
bool MMapAllocator::FreeMemoryForTesting(void* pointer_to_allocated,
|
|
size_t size_in_bytes) {
|
|
auto const munmap_res = munmap(pointer_to_allocated, size_in_bytes);
|
|
return (munmap_res == 0);
|
|
}
|
|
|
|
bool PThreadTLSSystem::Setup(
|
|
OnThreadTerminationFunction thread_termination_function) {
|
|
#if DCHECK_IS_ON()
|
|
// Initialize must happen outside of the allocation path. Therefore, it is
|
|
// secure to verify with DCHECK.
|
|
DCHECK(!initialized_.exchange(true, std::memory_order_acq_rel));
|
|
#endif
|
|
|
|
auto const key_create_res =
|
|
pthread_key_create(&data_access_key_, thread_termination_function);
|
|
|
|
// On some platforms creating a new pthread-key requires an allocation when a
|
|
// given number of keys has been created. I.e. in glibc this limit is denoted
|
|
// by PTHREAD_KEY_2NDLEVEL_SIZE. However, this value is neither present on all
|
|
// systems nor accessible from here. Hence, we do not do any checks here.
|
|
// However, we strongly recommend to setup the TLS system as early as possible
|
|
// to avoid exceeding this limit.
|
|
|
|
return (0 == key_create_res);
|
|
}
|
|
|
|
bool PThreadTLSSystem::TearDownForTesting() {
|
|
#if DCHECK_IS_ON()
|
|
// TearDownForTesting must happen outside of the allocation path. Therefore,
|
|
// it is secure to verify with DCHECK.
|
|
DCHECK(initialized_.exchange(false, std::memory_order_acq_rel));
|
|
#endif
|
|
|
|
auto const key_delete_res = pthread_key_delete(data_access_key_);
|
|
return (0 == key_delete_res);
|
|
}
|
|
|
|
void* PThreadTLSSystem::GetThreadSpecificData() {
|
|
#if DCHECK_IS_ON()
|
|
if (!initialized_.load(std::memory_order_acquire)) {
|
|
return nullptr;
|
|
}
|
|
#endif
|
|
|
|
return pthread_getspecific(data_access_key_);
|
|
}
|
|
|
|
bool PThreadTLSSystem::SetThreadSpecificData(void* data) {
|
|
#if DCHECK_IS_ON()
|
|
if (!initialized_.load(std::memory_order_acquire)) {
|
|
return false;
|
|
}
|
|
#endif
|
|
|
|
return (0 == pthread_setspecific(data_access_key_, data));
|
|
}
|
|
|
|
} // namespace base::allocator::dispatcher::internal
|
|
|
|
#endif // USE_LOCAL_TLS_EMULATION()
|