Atmosphere/libraries/libstratosphere/source/fs/fs_memory_management.cpp
2022-02-21 15:17:17 -08:00

119 lines
3.8 KiB
C++

/*
* Copyright (c) Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stratosphere.hpp>
namespace ams::fs {
namespace {
constinit bool g_used_default_allocator = false;
void *DefaultAllocate(size_t size) {
g_used_default_allocator = true;
return ams::Malloc(size);
}
void DefaultDeallocate(void *ptr, size_t size) {
AMS_UNUSED(size);
ams::Free(ptr);
}
constinit os::SdkMutex g_mutex;
constinit AllocateFunction g_allocate_func = DefaultAllocate;
constinit DeallocateFunction g_deallocate_func = DefaultDeallocate;
constexpr size_t RequiredAlignment = alignof(u64);
Result SetAllocatorImpl(AllocateFunction allocator, DeallocateFunction deallocator) {
/* Ensure SetAllocator is used correctly. */
R_UNLESS(g_allocate_func == DefaultAllocate, fs::ResultAllocatorAlreadyRegistered());
R_UNLESS(g_deallocate_func == DefaultDeallocate, fs::ResultAllocatorAlreadyRegistered());
R_UNLESS(allocator != nullptr, fs::ResultNullptrArgument());
R_UNLESS(deallocator != nullptr, fs::ResultNullptrArgument());
R_UNLESS(!g_used_default_allocator, fs::ResultDefaultAllocatorUsed());
/* Set allocators. */
g_allocate_func = allocator;
g_deallocate_func = deallocator;
return ResultSuccess();
}
}
void SetAllocator(AllocateFunction allocator, DeallocateFunction deallocator) {
R_ABORT_UNLESS(SetAllocatorImpl(allocator, deallocator));
}
namespace impl {
void LockAllocatorMutex() {
g_mutex.Lock();
}
void UnlockAllocatorMutex() {
g_mutex.Unlock();
}
void *AllocateUnsafe(size_t size) {
/* Check pre-conditions. */
AMS_ASSERT(g_mutex.IsLockedByCurrentThread());
/* Allocate. */
void * const ptr = g_allocate_func(size);
/* Check alignment. */
if (AMS_UNLIKELY(!util::IsAligned(reinterpret_cast<uintptr_t>(ptr), RequiredAlignment))) {
R_ABORT_UNLESS(fs::ResultAllocatorAlignmentViolation());
}
/* Return allocated pointer. */
return ptr;
}
void DeallocateUnsafe(void *ptr, size_t size) {
/* Check pre-conditions. */
AMS_ASSERT(g_mutex.IsLockedByCurrentThread());
/* Deallocate the pointer. */
g_deallocate_func(ptr, size);
}
void *Allocate(size_t size) {
/* Check pre-conditions. */
AMS_ASSERT(g_allocate_func != nullptr);
/* Lock the allocator. */
std::scoped_lock lk(g_mutex);
return AllocateUnsafe(size);
}
void Deallocate(void *ptr, size_t size) {
/* Check pre-conditions. */
AMS_ASSERT(g_deallocate_func != nullptr);
/* If the pointer is non-null, deallocate it. */
if (ptr != nullptr) {
/* Lock the allocator. */
std::scoped_lock lk(g_mutex);
DeallocateUnsafe(ptr, size);
}
}
}
}