mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-12-05 20:15:58 +00:00
791a4e2b4e
--HG-- extra : rebase_source : f6336b5ba3298bbf9c5418b4e9d993b9173f7926
63 lines
2.3 KiB
C++
63 lines
2.3 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
|
/* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
/*
|
|
* An allocation policy concept, usable for structures and algorithms to
|
|
* control how memory is allocated and how failures are handled.
|
|
*/
|
|
|
|
#ifndef mozilla_AllocPolicy_h_
|
|
#define mozilla_AllocPolicy_h_
|
|
|
|
#include <stddef.h>
|
|
#include <stdlib.h>
|
|
|
|
namespace mozilla {
|
|
|
|
/*
|
|
* Allocation policies are used to implement the standard allocation behaviors
|
|
* in a customizable way. Additionally, custom behaviors may be added to these
|
|
* behaviors, such as additionally reporting an error through an out-of-band
|
|
* mechanism when OOM occurs. The concept modeled here is as follows:
|
|
*
|
|
* - public copy constructor, assignment, destructor
|
|
* - void* malloc_(size_t)
|
|
* Responsible for OOM reporting when null is returned.
|
|
* - void* calloc_(size_t)
|
|
* Responsible for OOM reporting when null is returned.
|
|
* - void* realloc_(void*, size_t, size_t)
|
|
* Responsible for OOM reporting when null is returned. The *used* bytes
|
|
* of the previous buffer is passed in (rather than the old allocation
|
|
* size), in addition to the *new* allocation size requested.
|
|
* - void free_(void*)
|
|
* - void reportAllocOverflow() const
|
|
* Called on allocation overflow (that is, an allocation implicitly tried
|
|
* to allocate more than the available memory space -- think allocating an
|
|
* array of large-size objects, where N * size overflows) before null is
|
|
* returned.
|
|
*
|
|
* mfbt provides (and typically uses by default) only MallocAllocPolicy, which
|
|
* does nothing more than delegate to the malloc/alloc/free functions.
|
|
*/
|
|
|
|
/*
|
|
* A policy that straightforwardly uses malloc/calloc/realloc/free and adds no
|
|
* extra behaviors.
|
|
*/
|
|
class MallocAllocPolicy
|
|
{
|
|
public:
|
|
void* malloc_(size_t bytes) { return malloc(bytes); }
|
|
void* calloc_(size_t bytes) { return calloc(bytes, 1); }
|
|
void* realloc_(void* p, size_t oldBytes, size_t bytes) { return realloc(p, bytes); }
|
|
void free_(void* p) { free(p); }
|
|
void reportAllocOverflow() const {}
|
|
};
|
|
|
|
|
|
} // namespace mozilla
|
|
|
|
#endif // mozilla_AllocPolicy_h_
|