diff options
Diffstat (limited to 'absl/base/internal/malloc_hook.h')
| -rw-r--r-- | absl/base/internal/malloc_hook.h | 333 |
1 files changed, 333 insertions, 0 deletions
diff --git a/absl/base/internal/malloc_hook.h b/absl/base/internal/malloc_hook.h new file mode 100644 index 0000000..ed5cf2e --- /dev/null +++ b/absl/base/internal/malloc_hook.h @@ -0,0 +1,333 @@ +// +// Copyright 2017 The Abseil Authors. +// +// 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. +// + +// Some of our malloc implementations can invoke the following hooks whenever +// memory is allocated or deallocated. MallocHook is thread-safe, and things +// you do before calling AddFooHook(MyHook) are visible to any resulting calls +// to MyHook. Hooks must be thread-safe. If you write: +// +// CHECK(MallocHook::AddNewHook(&MyNewHook)); +// +// MyNewHook will be invoked in subsequent calls in the current thread, but +// there are no guarantees on when it might be invoked in other threads. +// +// There are a limited number of slots available for each hook type. Add*Hook +// will return false if there are no slots available. Remove*Hook will return +// false if the given hook was not already installed. +// +// The order in which individual hooks are called in Invoke*Hook is undefined. +// +// It is safe for a hook to remove itself within Invoke*Hook and add other +// hooks. Any hooks added inside a hook invocation (for the same hook type) +// will not be invoked for the current invocation. +// +// One important user of these hooks is the heap profiler. +// +// CAVEAT: If you add new MallocHook::Invoke* calls then those calls must be +// directly in the code of the (de)allocation function that is provided to the +// user and that function must have an ABSL_ATTRIBUTE_SECTION(malloc_hook) +// attribute. +// +// Note: the Invoke*Hook() functions are defined in malloc_hook-inl.h. If you +// need to invoke a hook (which you shouldn't unless you're part of tcmalloc), +// be sure to #include malloc_hook-inl.h in addition to malloc_hook.h. +// +// NOTE FOR C USERS: If you want to use malloc_hook functionality from +// a C program, #include malloc_hook_c.h instead of this file. +// +// IWYU pragma: private, include "base/malloc_hook.h" + +#ifndef ABSL_BASE_INTERNAL_MALLOC_HOOK_H_ +#define ABSL_BASE_INTERNAL_MALLOC_HOOK_H_ + +#include <sys/types.h> +#include <cstddef> + +#include "absl/base/config.h" +#include "absl/base/internal/malloc_hook_c.h" +#include "absl/base/port.h" + +namespace absl { +namespace base_internal { + +// Note: malloc_hook_c.h defines MallocHook_*Hook and +// MallocHook_{Add,Remove}*Hook. The version of these inside the MallocHook +// class are defined in terms of the malloc_hook_c version. See malloc_hook_c.h +// for details of these types/functions. + +class MallocHook { + public: + // The NewHook is invoked whenever an object is being allocated. + // Object pointer and size are passed in. + // It may be passed null pointer if the allocator returned null. + typedef MallocHook_NewHook NewHook; + inline static bool AddNewHook(NewHook hook) { + return MallocHook_AddNewHook(hook); + } + inline static bool RemoveNewHook(NewHook hook) { + return MallocHook_RemoveNewHook(hook); + } + inline static void InvokeNewHook(const void* ptr, size_t size); + + // The DeleteHook is invoked whenever an object is being deallocated. + // Object pointer is passed in. + // It may be passed null pointer if the caller is trying to delete null. + typedef MallocHook_DeleteHook DeleteHook; + inline static bool AddDeleteHook(DeleteHook hook) { + return MallocHook_AddDeleteHook(hook); + } + inline static bool RemoveDeleteHook(DeleteHook hook) { + return MallocHook_RemoveDeleteHook(hook); + } + inline static void InvokeDeleteHook(const void* ptr); + + // The SampledNewHook is invoked for some subset of object allocations + // according to the sampling policy of an allocator such as tcmalloc. + // SampledAlloc has the following fields: + // * AllocHandle handle: to be set to an effectively unique value (in this + // process) by allocator. + // * size_t allocated_size: space actually used by allocator to host + // the object. + // * int stack_depth and const void* stack: invocation stack for + // the allocation. + // The allocator invoking the hook should record the handle value and later + // call InvokeSampledDeleteHook() with that value. + typedef MallocHook_SampledNewHook SampledNewHook; + typedef MallocHook_SampledAlloc SampledAlloc; + inline static bool AddSampledNewHook(SampledNewHook hook) { + return MallocHook_AddSampledNewHook(hook); + } + inline static bool RemoveSampledNewHook(SampledNewHook hook) { + return MallocHook_RemoveSampledNewHook(hook); + } + inline static void InvokeSampledNewHook(const SampledAlloc* sampled_alloc); + + // The SampledDeleteHook is invoked whenever an object previously chosen + // by an allocator for sampling is being deallocated. + // The handle identifying the object --as previously chosen by + // InvokeSampledNewHook()-- is passed in. + typedef MallocHook_SampledDeleteHook SampledDeleteHook; + typedef MallocHook_AllocHandle AllocHandle; + inline static bool AddSampledDeleteHook(SampledDeleteHook hook) { + return MallocHook_AddSampledDeleteHook(hook); + } + inline static bool RemoveSampledDeleteHook(SampledDeleteHook hook) { + return MallocHook_RemoveSampledDeleteHook(hook); + } + inline static void InvokeSampledDeleteHook(AllocHandle handle); + + // The PreMmapHook is invoked with mmap's or mmap64's arguments just + // before the mmap/mmap64 call is actually made. Such a hook may be useful + // in memory limited contexts, to catch allocations that will exceed + // a memory limit, and take outside actions to increase that limit. + typedef MallocHook_PreMmapHook PreMmapHook; + inline static bool AddPreMmapHook(PreMmapHook hook) { + return MallocHook_AddPreMmapHook(hook); + } + inline static bool RemovePreMmapHook(PreMmapHook hook) { + return MallocHook_RemovePreMmapHook(hook); + } + inline static void InvokePreMmapHook(const void* start, + size_t size, + int protection, + int flags, + int fd, + off_t offset); + + // The MmapReplacement is invoked with mmap's arguments and place to put the + // result into after the PreMmapHook but before the mmap/mmap64 call is + // actually made. + // The MmapReplacement should return true if it handled the call, or false + // if it is still necessary to call mmap/mmap64. + // This should be used only by experts, and users must be be + // extremely careful to avoid recursive calls to mmap. The replacement + // should be async signal safe. + // Only one MmapReplacement is supported. After setting an MmapReplacement + // you must call RemoveMmapReplacement before calling SetMmapReplacement + // again. + typedef MallocHook_MmapReplacement MmapReplacement; + inline static bool SetMmapReplacement(MmapReplacement hook) { + return MallocHook_SetMmapReplacement(hook); + } + inline static bool RemoveMmapReplacement(MmapReplacement hook) { + return MallocHook_RemoveMmapReplacement(hook); + } + inline static bool InvokeMmapReplacement(const void* start, + size_t size, + int protection, + int flags, + int fd, + off_t offset, + void** result); + + + // The MmapHook is invoked with mmap's return value and arguments whenever + // a region of memory has been just mapped. + // It may be passed MAP_FAILED if the mmap failed. + typedef MallocHook_MmapHook MmapHook; + inline static bool AddMmapHook(MmapHook hook) { + return MallocHook_AddMmapHook(hook); + } + inline static bool RemoveMmapHook(MmapHook hook) { + return MallocHook_RemoveMmapHook(hook); + } + inline static void InvokeMmapHook(const void* result, + const void* start, + size_t size, + int protection, + int flags, + int fd, + off_t offset); + + // The MunmapReplacement is invoked with munmap's arguments and place to put + // the result into just before the munmap call is actually made. + // The MunmapReplacement should return true if it handled the call, or false + // if it is still necessary to call munmap. + // This should be used only by experts. The replacement should be + // async signal safe. + // Only one MunmapReplacement is supported. After setting an + // MunmapReplacement you must call RemoveMunmapReplacement before + // calling SetMunmapReplacement again. + typedef MallocHook_MunmapReplacement MunmapReplacement; + inline static bool SetMunmapReplacement(MunmapReplacement hook) { + return MallocHook_SetMunmapReplacement(hook); + } + inline static bool RemoveMunmapReplacement(MunmapReplacement hook) { + return MallocHook_RemoveMunmapReplacement(hook); + } + inline static bool InvokeMunmapReplacement(const void* start, + size_t size, + int* result); + + // The MunmapHook is invoked with munmap's arguments just before the munmap + // call is actually made. + // TODO(maxim): Rename this to PreMunmapHook for consistency with PreMmapHook + // and PreSbrkHook. + typedef MallocHook_MunmapHook MunmapHook; + inline static bool AddMunmapHook(MunmapHook hook) { + return MallocHook_AddMunmapHook(hook); + } + inline static bool RemoveMunmapHook(MunmapHook hook) { + return MallocHook_RemoveMunmapHook(hook); + } + inline static void InvokeMunmapHook(const void* start, size_t size); + + // The MremapHook is invoked with mremap's return value and arguments + // whenever a region of memory has been just remapped. + typedef MallocHook_MremapHook MremapHook; + inline static bool AddMremapHook(MremapHook hook) { + return MallocHook_AddMremapHook(hook); + } + inline static bool RemoveMremapHook(MremapHook hook) { + return MallocHook_RemoveMremapHook(hook); + } + inline static void InvokeMremapHook(const void* result, + const void* old_addr, + size_t old_size, + size_t new_size, + int flags, + const void* new_addr); + + // The PreSbrkHook is invoked with sbrk's argument just before sbrk is called + // -- except when the increment is 0. This is because sbrk(0) is often called + // to get the top of the memory stack, and is not actually a + // memory-allocation call. It may be useful in memory-limited contexts, + // to catch allocations that will exceed the limit and take outside + // actions to increase such a limit. + typedef MallocHook_PreSbrkHook PreSbrkHook; + inline static bool AddPreSbrkHook(PreSbrkHook hook) { + return MallocHook_AddPreSbrkHook(hook); + } + inline static bool RemovePreSbrkHook(PreSbrkHook hook) { + return MallocHook_RemovePreSbrkHook(hook); + } + inline static void InvokePreSbrkHook(ptrdiff_t increment); + + // The SbrkHook is invoked with sbrk's result and argument whenever sbrk + // has just executed -- except when the increment is 0. + // This is because sbrk(0) is often called to get the top of the memory stack, + // and is not actually a memory-allocation call. + typedef MallocHook_SbrkHook SbrkHook; + inline static bool AddSbrkHook(SbrkHook hook) { + return MallocHook_AddSbrkHook(hook); + } + inline static bool RemoveSbrkHook(SbrkHook hook) { + return MallocHook_RemoveSbrkHook(hook); + } + inline static void InvokeSbrkHook(const void* result, ptrdiff_t increment); + + // Pointer to a absl::GetStackTrace implementation, following the API in + // base/stacktrace.h. + using GetStackTraceFn = int (*)(void**, int, int); + + // Get the current stack trace. Try to skip all routines up to and + // including the caller of MallocHook::Invoke*. + // Use "skip_count" (similarly to absl::GetStackTrace from stacktrace.h) + // as a hint about how many routines to skip if better information + // is not available. + // Stack trace is filled into *result up to the size of max_depth. + // The actual number of stack frames filled is returned. + inline static int GetCallerStackTrace(void** result, int max_depth, + int skip_count, + GetStackTraceFn get_stack_trace_fn) { + return MallocHook_GetCallerStackTrace(result, max_depth, skip_count, + get_stack_trace_fn); + } + +#if ABSL_HAVE_MMAP + // Unhooked versions of mmap() and munmap(). These should be used + // only by experts, since they bypass heapchecking, etc. + // Note: These do not run hooks, but they still use the MmapReplacement + // and MunmapReplacement. + static void* UnhookedMMap(void* start, size_t size, int protection, int flags, + int fd, off_t offset); + static int UnhookedMUnmap(void* start, size_t size); +#endif + + private: + // Slow path versions of Invoke*Hook. + static void InvokeNewHookSlow(const void* ptr, + size_t size) ABSL_ATTRIBUTE_COLD; + static void InvokeDeleteHookSlow(const void* ptr) ABSL_ATTRIBUTE_COLD; + static void InvokeSampledNewHookSlow(const SampledAlloc* sampled_alloc) + ABSL_ATTRIBUTE_COLD; + static void InvokeSampledDeleteHookSlow(AllocHandle handle) + ABSL_ATTRIBUTE_COLD; + static void InvokePreMmapHookSlow(const void* start, size_t size, + int protection, int flags, int fd, + off_t offset) ABSL_ATTRIBUTE_COLD; + static void InvokeMmapHookSlow(const void* result, const void* start, + size_t size, int protection, int flags, int fd, + off_t offset) ABSL_ATTRIBUTE_COLD; + static bool InvokeMmapReplacementSlow(const void* start, size_t size, + int protection, int flags, int fd, + off_t offset, + void** result) ABSL_ATTRIBUTE_COLD; + static void InvokeMunmapHookSlow(const void* ptr, + size_t size) ABSL_ATTRIBUTE_COLD; + static bool InvokeMunmapReplacementSlow(const void* ptr, size_t size, + int* result) ABSL_ATTRIBUTE_COLD; + static void InvokeMremapHookSlow(const void* result, const void* old_addr, + size_t old_size, size_t new_size, int flags, + const void* new_addr) ABSL_ATTRIBUTE_COLD; + static void InvokePreSbrkHookSlow(ptrdiff_t increment) ABSL_ATTRIBUTE_COLD; + static void InvokeSbrkHookSlow(const void* result, + ptrdiff_t increment) ABSL_ATTRIBUTE_COLD; +}; + +} // namespace base_internal +} // namespace absl +#endif // ABSL_BASE_INTERNAL_MALLOC_HOOK_H_ |