michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
michael@0:  * vim: set ts=8 sts=4 et sw=4 tw=99:
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /*
michael@0:  * Hierarchy of SpiderMonkey system memory allocators:
michael@0:  *
michael@0:  *   - System {m,c,re}alloc/new/free: Overridden by jemalloc in most
michael@0:  *     environments. Do not use these functions directly.
michael@0:  *
michael@0:  *   - js_{m,c,re}alloc/new/free: Wraps the system allocators and adds a
michael@0:  *     failure injection framework for use by the fuzzers as well as templated,
michael@0:  *     typesafe variants. See js/public/Utility.h.
michael@0:  *
michael@0:  *   - AllocPolicy: An interface for the js allocators, for use with templates.
michael@0:  *     These allocators are for system memory whose lifetime is not associated
michael@0:  *     with a GC thing. See js/src/jsalloc.h.
michael@0:  *
michael@0:  *       - SystemAllocPolicy: No extra functionality over bare allocators.
michael@0:  *
michael@0:  *       - TempAllocPolicy: Adds automatic error reporting to the provided
michael@0:  *         Context when allocations fail.
michael@0:  *
michael@0:  *   - MallocProvider. A mixin base class that handles automatically updating
michael@0:  *     the GC's state in response to allocations that are tied to a GC lifetime
michael@0:  *     or are for a particular GC purpose. These allocators must only be used
michael@0:  *     for memory that will be freed when a GC thing is swept.
michael@0:  *
michael@0:  *       - gc::Zone:  Automatically triggers zone GC.
michael@0:  *       - JSRuntime: Automatically triggers full GC.
michael@0:  *       - ThreadsafeContext > ExclusiveContext > JSContext:
michael@0:  *                    Dispatches directly to the runtime.
michael@0:  */
michael@0: 
michael@0: #ifndef vm_MallocProvider_h
michael@0: #define vm_MallocProvider_h
michael@0: 
michael@0: #include "mozilla/Attributes.h"
michael@0: #include "mozilla/Likely.h"
michael@0: 
michael@0: #include "js/Utility.h"
michael@0: 
michael@0: namespace js {
michael@0: 
michael@0: template<class Client>
michael@0: struct MallocProvider
michael@0: {
michael@0:     void *malloc_(size_t bytes) {
michael@0:         Client *client = static_cast<Client *>(this);
michael@0:         client->updateMallocCounter(bytes);
michael@0:         void *p = js_malloc(bytes);
michael@0:         return MOZ_LIKELY(!!p) ? p : client->onOutOfMemory(nullptr, bytes);
michael@0:     }
michael@0: 
michael@0:     void *calloc_(size_t bytes) {
michael@0:         Client *client = static_cast<Client *>(this);
michael@0:         client->updateMallocCounter(bytes);
michael@0:         void *p = js_calloc(bytes);
michael@0:         return MOZ_LIKELY(!!p) ? p : client->onOutOfMemory(reinterpret_cast<void *>(1), bytes);
michael@0:     }
michael@0: 
michael@0:     void *realloc_(void *p, size_t oldBytes, size_t newBytes) {
michael@0:         Client *client = static_cast<Client *>(this);
michael@0:         /*
michael@0:          * For compatibility we do not account for realloc that decreases
michael@0:          * previously allocated memory.
michael@0:          */
michael@0:         if (newBytes > oldBytes)
michael@0:             client->updateMallocCounter(newBytes - oldBytes);
michael@0:         void *p2 = js_realloc(p, newBytes);
michael@0:         return MOZ_LIKELY(!!p2) ? p2 : client->onOutOfMemory(p, newBytes);
michael@0:     }
michael@0: 
michael@0:     void *realloc_(void *p, size_t bytes) {
michael@0:         Client *client = static_cast<Client *>(this);
michael@0:         /*
michael@0:          * For compatibility we do not account for realloc that increases
michael@0:          * previously allocated memory.
michael@0:          */
michael@0:         if (!p)
michael@0:             client->updateMallocCounter(bytes);
michael@0:         void *p2 = js_realloc(p, bytes);
michael@0:         return MOZ_LIKELY(!!p2) ? p2 : client->onOutOfMemory(p, bytes);
michael@0:     }
michael@0: 
michael@0:     template <class T>
michael@0:     T *pod_malloc() {
michael@0:         return (T *)malloc_(sizeof(T));
michael@0:     }
michael@0: 
michael@0:     template <class T>
michael@0:     T *pod_calloc() {
michael@0:         return (T *)calloc_(sizeof(T));
michael@0:     }
michael@0: 
michael@0:     template <class T>
michael@0:     T *pod_malloc(size_t numElems) {
michael@0:         if (numElems & mozilla::tl::MulOverflowMask<sizeof(T)>::value) {
michael@0:             Client *client = static_cast<Client *>(this);
michael@0:             client->reportAllocationOverflow();
michael@0:             return nullptr;
michael@0:         }
michael@0:         return (T *)malloc_(numElems * sizeof(T));
michael@0:     }
michael@0: 
michael@0:     template <class T>
michael@0:     T *pod_calloc(size_t numElems, JSCompartment *comp = nullptr, JSContext *cx = nullptr) {
michael@0:         if (numElems & mozilla::tl::MulOverflowMask<sizeof(T)>::value) {
michael@0:             Client *client = static_cast<Client *>(this);
michael@0:             client->reportAllocationOverflow();
michael@0:             return nullptr;
michael@0:         }
michael@0:         return (T *)calloc_(numElems * sizeof(T));
michael@0:     }
michael@0: 
michael@0:     JS_DECLARE_NEW_METHODS(new_, malloc_, MOZ_ALWAYS_INLINE)
michael@0: };
michael@0: 
michael@0: } /* namespace js */
michael@0: 
michael@0: #endif /* vm_MallocProvider_h */