mfbt/AllocPolicy.h@97036ab72558 (annotated)
mfbt/AllocPolicy.h
Tue, 06 Jan 2015 21:39:09 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Tue, 06 Jan 2015 21:39:09 +0100
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
- permissions
- -rw-r--r--
Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.
| michael@0 | 1 | /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ |
| michael@0 | 2 | /* vim: set ts=8 sts=2 et sw=2 tw=80: */ |
| michael@0 | 3 | /* This Source Code Form is subject to the terms of the Mozilla Public |
| michael@0 | 4 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| michael@0 | 5 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| michael@0 | 6 | |
| michael@0 | 7 | /* |
| michael@0 | 8 | * An allocation policy concept, usable for structures and algorithms to |
| michael@0 | 9 | * control how memory is allocated and how failures are handled. |
| michael@0 | 10 | */ |
| michael@0 | 11 | |
| michael@0 | 12 | #ifndef mozilla_AllocPolicy_h |
| michael@0 | 13 | #define mozilla_AllocPolicy_h |
| michael@0 | 14 | |
| michael@0 | 15 | #include <stddef.h> |
| michael@0 | 16 | #include <stdlib.h> |
| michael@0 | 17 | |
| michael@0 | 18 | namespace mozilla { |
| michael@0 | 19 | |
| michael@0 | 20 | /* |
| michael@0 | 21 | * Allocation policies are used to implement the standard allocation behaviors |
| michael@0 | 22 | * in a customizable way. Additionally, custom behaviors may be added to these |
| michael@0 | 23 | * behaviors, such as additionally reporting an error through an out-of-band |
| michael@0 | 24 | * mechanism when OOM occurs. The concept modeled here is as follows: |
| michael@0 | 25 | * |
| michael@0 | 26 | * - public copy constructor, assignment, destructor |
| michael@0 | 27 | * - void* malloc_(size_t) |
| michael@0 | 28 | * Responsible for OOM reporting when null is returned. |
| michael@0 | 29 | * - void* calloc_(size_t) |
| michael@0 | 30 | * Responsible for OOM reporting when null is returned. |
| michael@0 | 31 | * - void* realloc_(void*, size_t, size_t) |
| michael@0 | 32 | * Responsible for OOM reporting when null is returned. The *used* bytes |
| michael@0 | 33 | * of the previous buffer is passed in (rather than the old allocation |
| michael@0 | 34 | * size), in addition to the *new* allocation size requested. |
| michael@0 | 35 | * - void free_(void*) |
| michael@0 | 36 | * - void reportAllocOverflow() const |
| michael@0 | 37 | * Called on allocation overflow (that is, an allocation implicitly tried |
| michael@0 | 38 | * to allocate more than the available memory space -- think allocating an |
| michael@0 | 39 | * array of large-size objects, where N * size overflows) before null is |
| michael@0 | 40 | * returned. |
| michael@0 | 41 | * |
| michael@0 | 42 | * mfbt provides (and typically uses by default) only MallocAllocPolicy, which |
| michael@0 | 43 | * does nothing more than delegate to the malloc/alloc/free functions. |
| michael@0 | 44 | */ |
| michael@0 | 45 | |
| michael@0 | 46 | /* |
| michael@0 | 47 | * A policy that straightforwardly uses malloc/calloc/realloc/free and adds no |
| michael@0 | 48 | * extra behaviors. |
| michael@0 | 49 | */ |
| michael@0 | 50 | class MallocAllocPolicy |
| michael@0 | 51 | { |
| michael@0 | 52 | public: |
| michael@0 | 53 | void* malloc_(size_t bytes) { return malloc(bytes); } |
| michael@0 | 54 | void* calloc_(size_t bytes) { return calloc(bytes, 1); } |
| michael@0 | 55 | void* realloc_(void* p, size_t oldBytes, size_t bytes) { return realloc(p, bytes); } |
| michael@0 | 56 | void free_(void* p) { free(p); } |
| michael@0 | 57 | void reportAllocOverflow() const {} |
| michael@0 | 58 | }; |
| michael@0 | 59 | |
| michael@0 | 60 | |
| michael@0 | 61 | } // namespace mozilla |
| michael@0 | 62 | |
| michael@0 | 63 | #endif /* mozilla_AllocPolicy_h */ |
