tdlight/tdutils/td/utils/StackAllocator.cpp
2022-01-01 03:35:39 +03:00

81 lines
1.9 KiB
C++

//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2022
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include "td/utils/StackAllocator.h"
#include "td/utils/port/thread_local.h"
#include <array>
#include <cstdlib>
namespace td {
namespace {
class ArrayAllocator final : public StackAllocator::AllocatorImpl {
static const size_t MEM_SIZE = 1024 * 1024;
std::array<char, MEM_SIZE> mem;
size_t pos{0};
MutableSlice allocate(size_t size) final {
if (size > MEM_SIZE) {
std::abort(); // too much memory requested
}
char *res = mem.data() + pos;
pos += (size + 7) & -8;
if (pos > MEM_SIZE) {
std::abort(); // memory is over
}
return {res, size};
}
void free_ptr(char *ptr, size_t size) final {
size = (size + 7) & -8;
if (size > pos || ptr != mem.data() + (pos - size)) {
std::abort(); // shouldn't happen
}
pos -= size;
}
public:
~ArrayAllocator() final {
if (pos != 0) {
std::abort(); // shouldn't happen
}
}
};
class NewAllocator final : public StackAllocator::AllocatorImpl {
MutableSlice allocate(size_t size) final {
return {new char[size], size};
}
void free_ptr(char *ptr, size_t size) final {
delete[] ptr;
}
public:
~NewAllocator() final = default;
};
} // namespace
StackAllocator::Ptr::~Ptr() {
if (!slice_.empty()) {
allocator_->free_ptr(slice_.data(), slice_.size());
}
}
StackAllocator::AllocatorImpl *StackAllocator::impl() {
if (get_thread_id() != 0) {
static TD_THREAD_LOCAL ArrayAllocator *array_allocator; // static zero-initialized
init_thread_local<ArrayAllocator>(array_allocator);
return array_allocator;
} else {
static NewAllocator new_allocator;
return &new_allocator;
}
}
} // namespace td