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Diffstat (limited to 'third_party/abseil_cpp/absl/base/internal/low_level_alloc.h')
-rw-r--r-- | third_party/abseil_cpp/absl/base/internal/low_level_alloc.h | 126 |
1 files changed, 0 insertions, 126 deletions
diff --git a/third_party/abseil_cpp/absl/base/internal/low_level_alloc.h b/third_party/abseil_cpp/absl/base/internal/low_level_alloc.h deleted file mode 100644 index db91951c825f..000000000000 --- a/third_party/abseil_cpp/absl/base/internal/low_level_alloc.h +++ /dev/null @@ -1,126 +0,0 @@ -// 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 -// -// https://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. -// - -#ifndef ABSL_BASE_INTERNAL_LOW_LEVEL_ALLOC_H_ -#define ABSL_BASE_INTERNAL_LOW_LEVEL_ALLOC_H_ - -// A simple thread-safe memory allocator that does not depend on -// mutexes or thread-specific data. It is intended to be used -// sparingly, and only when malloc() would introduce an unwanted -// dependency, such as inside the heap-checker, or the Mutex -// implementation. - -// IWYU pragma: private, include "base/low_level_alloc.h" - -#include <sys/types.h> - -#include <cstdint> - -#include "absl/base/attributes.h" -#include "absl/base/config.h" - -// LowLevelAlloc requires that the platform support low-level -// allocation of virtual memory. Platforms lacking this cannot use -// LowLevelAlloc. -#ifdef ABSL_LOW_LEVEL_ALLOC_MISSING -#error ABSL_LOW_LEVEL_ALLOC_MISSING cannot be directly set -#elif !defined(ABSL_HAVE_MMAP) && !defined(_WIN32) -#define ABSL_LOW_LEVEL_ALLOC_MISSING 1 -#endif - -// Using LowLevelAlloc with kAsyncSignalSafe isn't supported on Windows or -// asm.js / WebAssembly. -// See https://kripken.github.io/emscripten-site/docs/porting/pthreads.html -// for more information. -#ifdef ABSL_LOW_LEVEL_ALLOC_ASYNC_SIGNAL_SAFE_MISSING -#error ABSL_LOW_LEVEL_ALLOC_ASYNC_SIGNAL_SAFE_MISSING cannot be directly set -#elif defined(_WIN32) || defined(__asmjs__) || defined(__wasm__) -#define ABSL_LOW_LEVEL_ALLOC_ASYNC_SIGNAL_SAFE_MISSING 1 -#endif - -#include <cstddef> - -#include "absl/base/port.h" - -namespace absl { -ABSL_NAMESPACE_BEGIN -namespace base_internal { - -class LowLevelAlloc { - public: - struct Arena; // an arena from which memory may be allocated - - // Returns a pointer to a block of at least "request" bytes - // that have been newly allocated from the specific arena. - // for Alloc() call the DefaultArena() is used. - // Returns 0 if passed request==0. - // Does not return 0 under other circumstances; it crashes if memory - // is not available. - static void *Alloc(size_t request) ABSL_ATTRIBUTE_SECTION(malloc_hook); - static void *AllocWithArena(size_t request, Arena *arena) - ABSL_ATTRIBUTE_SECTION(malloc_hook); - - // Deallocates a region of memory that was previously allocated with - // Alloc(). Does nothing if passed 0. "s" must be either 0, - // or must have been returned from a call to Alloc() and not yet passed to - // Free() since that call to Alloc(). The space is returned to the arena - // from which it was allocated. - static void Free(void *s) ABSL_ATTRIBUTE_SECTION(malloc_hook); - - // ABSL_ATTRIBUTE_SECTION(malloc_hook) for Alloc* and Free - // are to put all callers of MallocHook::Invoke* in this module - // into special section, - // so that MallocHook::GetCallerStackTrace can function accurately. - - // Create a new arena. - // The root metadata for the new arena is allocated in the - // meta_data_arena; the DefaultArena() can be passed for meta_data_arena. - // These values may be ored into flags: - enum { - // Report calls to Alloc() and Free() via the MallocHook interface. - // Set in the DefaultArena. - kCallMallocHook = 0x0001, - -#ifndef ABSL_LOW_LEVEL_ALLOC_ASYNC_SIGNAL_SAFE_MISSING - // Make calls to Alloc(), Free() be async-signal-safe. Not set in - // DefaultArena(). Not supported on all platforms. - kAsyncSignalSafe = 0x0002, -#endif - }; - // Construct a new arena. The allocation of the underlying metadata honors - // the provided flags. For example, the call NewArena(kAsyncSignalSafe) - // is itself async-signal-safe, as well as generatating an arena that provides - // async-signal-safe Alloc/Free. - static Arena *NewArena(int32_t flags); - - // Destroys an arena allocated by NewArena and returns true, - // provided no allocated blocks remain in the arena. - // If allocated blocks remain in the arena, does nothing and - // returns false. - // It is illegal to attempt to destroy the DefaultArena(). - static bool DeleteArena(Arena *arena); - - // The default arena that always exists. - static Arena *DefaultArena(); - - private: - LowLevelAlloc(); // no instances -}; - -} // namespace base_internal -ABSL_NAMESPACE_END -} // namespace absl - -#endif // ABSL_BASE_INTERNAL_LOW_LEVEL_ALLOC_H_ |