/* * Copyright (c) Meta Platforms, Inc. and affiliates. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ // http://www.canonware.com/download/jemalloc/jemalloc-latest/doc/jemalloc.html #pragma once #include <folly/CPortability.h> #include <folly/portability/Config.h> #include <folly/portability/Malloc.h> #if defined(FOLLY_USE_JEMALLOC) && !FOLLY_SANITIZE #include <folly/portability/SysMman.h> #if (JEMALLOC_VERSION_MAJOR > 3) && defined(MADV_DONTDUMP) #define FOLLY_JEMALLOC_NODUMP_ALLOCATOR_SUPPORTED … #if (JEMALLOC_VERSION_MAJOR == 4) #define FOLLY_JEMALLOC_NODUMP_ALLOCATOR_CHUNK #define JEMALLOC_CHUNK_OR_EXTENT … #else #define FOLLY_JEMALLOC_NODUMP_ALLOCATOR_EXTENT #define JEMALLOC_CHUNK_OR_EXTENT … #endif #endif #endif // FOLLY_USE_JEMALLOC #include <cstddef> namespace folly { /** * An allocator which uses Jemalloc to create an dedicated arena to allocate * memory from. The only special property set on the allocated memory is that * the memory is not dump-able. * * This is done by setting MADV_DONTDUMP using the `madvise` system call. A * custom hook installed which is called when allocating a new chunk / extent of * memory. All it does is call the original jemalloc hook to allocate the * memory and then set the advise on it before returning the pointer to the * allocated memory. Jemalloc does not use allocated chunks / extents across * different arenas, without `munmap`-ing them first, and the advises are not * sticky i.e. they are unset if `munmap` is done. Also this arena can't be used * by any other part of the code by just calling `malloc`. * * If target system doesn't support MADV_DONTDUMP or jemalloc doesn't support * custom arena hook, JemallocNodumpAllocator would fall back to using malloc / * free. Such behavior can be identified by using * !defined(FOLLY_JEMALLOC_NODUMP_ALLOCATOR_SUPPORTED). * * Similarly, if binary isn't linked with jemalloc, the logic would fall back to * malloc / free. */ class JemallocNodumpAllocator { … }; /** * JemallocNodumpAllocator singleton. */ JemallocNodumpAllocator& globalJemallocNodumpAllocator(); } // namespace folly
Codebase Browser
folly