| /* |
| * Copyright (C) 2015 The Android Open Source Project |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * 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 THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "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 THE |
| * COPYRIGHT OWNER 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. |
| */ |
| |
| #ifndef __LINKER_ALLOCATOR_H |
| #define __LINKER_ALLOCATOR_H |
| |
| #include <errno.h> |
| #include <stdlib.h> |
| #include <sys/cdefs.h> |
| #include <sys/mman.h> |
| #include <stddef.h> |
| #include <unistd.h> |
| |
| #include <vector> |
| |
| #include <async_safe/log.h> |
| |
| #include "private/bionic_prctl.h" |
| |
| const uint32_t kSmallObjectMaxSizeLog2 = 10; |
| const uint32_t kSmallObjectMinSizeLog2 = 4; |
| const uint32_t kSmallObjectAllocatorsCount = kSmallObjectMaxSizeLog2 - kSmallObjectMinSizeLog2 + 1; |
| |
| class LinkerSmallObjectAllocator; |
| |
| // This structure is placed at the beginning of each addressable page |
| // and has all information we need to find the corresponding memory allocator. |
| struct page_info { |
| char signature[4]; |
| uint32_t type; |
| union { |
| // we use allocated_size for large objects allocator |
| size_t allocated_size; |
| // and allocator_addr for small ones. |
| LinkerSmallObjectAllocator* allocator_addr; |
| }; |
| } __attribute__((aligned(16))); |
| |
| struct small_object_page_record { |
| void* page_addr; |
| size_t free_blocks_cnt; |
| size_t allocated_blocks_cnt; |
| }; |
| |
| // for lower_bound... |
| bool operator<(const small_object_page_record& one, const small_object_page_record& two); |
| |
| struct small_object_block_record { |
| small_object_block_record* next; |
| size_t free_blocks_cnt; |
| }; |
| |
| // This is implementation for std::vector allocator |
| template <typename T> |
| class linker_vector_allocator { |
| public: |
| typedef T value_type; |
| typedef T* pointer; |
| typedef const T* const_pointer; |
| typedef T& reference; |
| typedef const T& const_reference; |
| typedef size_t size_type; |
| typedef ptrdiff_t difference_type; |
| |
| T* allocate(size_t n, const T* hint = nullptr) { |
| size_t size = n * sizeof(T); |
| void* ptr = mmap(const_cast<T*>(hint), size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, |
| -1, 0); |
| if (ptr == MAP_FAILED) { |
| // Spec says we need to throw std::bad_alloc here but because our |
| // code does not support exception handling anyways - we are going to abort. |
| async_safe_fatal("mmap failed: %s", strerror(errno)); |
| } |
| |
| prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, ptr, size, "linker_alloc_vector"); |
| |
| return reinterpret_cast<T*>(ptr); |
| } |
| |
| void deallocate(T* ptr, size_t n) { |
| munmap(ptr, n * sizeof(T)); |
| } |
| }; |
| |
| typedef |
| std::vector<small_object_page_record, linker_vector_allocator<small_object_page_record>> |
| linker_vector_t; |
| |
| |
| class LinkerSmallObjectAllocator { |
| public: |
| LinkerSmallObjectAllocator(uint32_t type, size_t block_size); |
| void* alloc(); |
| void free(void* ptr); |
| |
| size_t get_block_size() const { return block_size_; } |
| private: |
| void alloc_page(); |
| void free_page(linker_vector_t::iterator page_record); |
| linker_vector_t::iterator find_page_record(void* ptr); |
| void create_page_record(void* page_addr, size_t free_blocks_cnt); |
| |
| uint32_t type_; |
| size_t block_size_; |
| |
| size_t free_pages_cnt_; |
| small_object_block_record* free_blocks_list_; |
| |
| // sorted vector of page records |
| linker_vector_t page_records_; |
| }; |
| |
| class LinkerMemoryAllocator { |
| public: |
| constexpr LinkerMemoryAllocator() : allocators_(nullptr), allocators_buf_() {} |
| void* alloc(size_t size); |
| |
| // Note that this implementation of realloc never shrinks allocation |
| void* realloc(void* ptr, size_t size); |
| void free(void* ptr); |
| private: |
| void* alloc_mmap(size_t size); |
| page_info* get_page_info(void* ptr); |
| LinkerSmallObjectAllocator* get_small_object_allocator(uint32_t type); |
| void initialize_allocators(); |
| |
| LinkerSmallObjectAllocator* allocators_; |
| uint8_t allocators_buf_[sizeof(LinkerSmallObjectAllocator)*kSmallObjectAllocatorsCount]; |
| }; |
| |
| |
| #endif /* __LINKER_ALLOCATOR_H */ |