1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/src/vm/MallocProvider.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,123 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
1.5 + * vim: set ts=8 sts=4 et sw=4 tw=99:
1.6 + * This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +/*
1.11 + * Hierarchy of SpiderMonkey system memory allocators:
1.12 + *
1.13 + * - System {m,c,re}alloc/new/free: Overridden by jemalloc in most
1.14 + * environments. Do not use these functions directly.
1.15 + *
1.16 + * - js_{m,c,re}alloc/new/free: Wraps the system allocators and adds a
1.17 + * failure injection framework for use by the fuzzers as well as templated,
1.18 + * typesafe variants. See js/public/Utility.h.
1.19 + *
1.20 + * - AllocPolicy: An interface for the js allocators, for use with templates.
1.21 + * These allocators are for system memory whose lifetime is not associated
1.22 + * with a GC thing. See js/src/jsalloc.h.
1.23 + *
1.24 + * - SystemAllocPolicy: No extra functionality over bare allocators.
1.25 + *
1.26 + * - TempAllocPolicy: Adds automatic error reporting to the provided
1.27 + * Context when allocations fail.
1.28 + *
1.29 + * - MallocProvider. A mixin base class that handles automatically updating
1.30 + * the GC's state in response to allocations that are tied to a GC lifetime
1.31 + * or are for a particular GC purpose. These allocators must only be used
1.32 + * for memory that will be freed when a GC thing is swept.
1.33 + *
1.34 + * - gc::Zone: Automatically triggers zone GC.
1.35 + * - JSRuntime: Automatically triggers full GC.
1.36 + * - ThreadsafeContext > ExclusiveContext > JSContext:
1.37 + * Dispatches directly to the runtime.
1.38 + */
1.39 +
1.40 +#ifndef vm_MallocProvider_h
1.41 +#define vm_MallocProvider_h
1.42 +
1.43 +#include "mozilla/Attributes.h"
1.44 +#include "mozilla/Likely.h"
1.45 +
1.46 +#include "js/Utility.h"
1.47 +
1.48 +namespace js {
1.49 +
1.50 +template<class Client>
1.51 +struct MallocProvider
1.52 +{
1.53 + void *malloc_(size_t bytes) {
1.54 + Client *client = static_cast<Client *>(this);
1.55 + client->updateMallocCounter(bytes);
1.56 + void *p = js_malloc(bytes);
1.57 + return MOZ_LIKELY(!!p) ? p : client->onOutOfMemory(nullptr, bytes);
1.58 + }
1.59 +
1.60 + void *calloc_(size_t bytes) {
1.61 + Client *client = static_cast<Client *>(this);
1.62 + client->updateMallocCounter(bytes);
1.63 + void *p = js_calloc(bytes);
1.64 + return MOZ_LIKELY(!!p) ? p : client->onOutOfMemory(reinterpret_cast<void *>(1), bytes);
1.65 + }
1.66 +
1.67 + void *realloc_(void *p, size_t oldBytes, size_t newBytes) {
1.68 + Client *client = static_cast<Client *>(this);
1.69 + /*
1.70 + * For compatibility we do not account for realloc that decreases
1.71 + * previously allocated memory.
1.72 + */
1.73 + if (newBytes > oldBytes)
1.74 + client->updateMallocCounter(newBytes - oldBytes);
1.75 + void *p2 = js_realloc(p, newBytes);
1.76 + return MOZ_LIKELY(!!p2) ? p2 : client->onOutOfMemory(p, newBytes);
1.77 + }
1.78 +
1.79 + void *realloc_(void *p, size_t bytes) {
1.80 + Client *client = static_cast<Client *>(this);
1.81 + /*
1.82 + * For compatibility we do not account for realloc that increases
1.83 + * previously allocated memory.
1.84 + */
1.85 + if (!p)
1.86 + client->updateMallocCounter(bytes);
1.87 + void *p2 = js_realloc(p, bytes);
1.88 + return MOZ_LIKELY(!!p2) ? p2 : client->onOutOfMemory(p, bytes);
1.89 + }
1.90 +
1.91 + template <class T>
1.92 + T *pod_malloc() {
1.93 + return (T *)malloc_(sizeof(T));
1.94 + }
1.95 +
1.96 + template <class T>
1.97 + T *pod_calloc() {
1.98 + return (T *)calloc_(sizeof(T));
1.99 + }
1.100 +
1.101 + template <class T>
1.102 + T *pod_malloc(size_t numElems) {
1.103 + if (numElems & mozilla::tl::MulOverflowMask<sizeof(T)>::value) {
1.104 + Client *client = static_cast<Client *>(this);
1.105 + client->reportAllocationOverflow();
1.106 + return nullptr;
1.107 + }
1.108 + return (T *)malloc_(numElems * sizeof(T));
1.109 + }
1.110 +
1.111 + template <class T>
1.112 + T *pod_calloc(size_t numElems, JSCompartment *comp = nullptr, JSContext *cx = nullptr) {
1.113 + if (numElems & mozilla::tl::MulOverflowMask<sizeof(T)>::value) {
1.114 + Client *client = static_cast<Client *>(this);
1.115 + client->reportAllocationOverflow();
1.116 + return nullptr;
1.117 + }
1.118 + return (T *)calloc_(numElems * sizeof(T));
1.119 + }
1.120 +
1.121 + JS_DECLARE_NEW_METHODS(new_, malloc_, MOZ_ALWAYS_INLINE)
1.122 +};
1.123 +
1.124 +} /* namespace js */
1.125 +
1.126 +#endif /* vm_MallocProvider_h */
