gecko-dev/js/public/MemoryCallbacks.h

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/* -*- Mode: C++; tab-width: 8; 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/. */
#ifndef js_MemoryCallbacks_h
#define js_MemoryCallbacks_h
#include "jstypes.h"
struct JS_PUBLIC_API JSContext;
namespace JS {
/**
* If a large allocation fails when calling pod_{calloc,realloc}CanGC, the JS
* engine may call the large-allocation-failure callback, if set, to allow the
* embedding to flush caches, possibly perform shrinking GCs, etc. to make some
* room. The allocation will then be retried (and may still fail.) This callback
* can be called on any thread and must be set at most once in a process.
*/
using LargeAllocationFailureCallback = void (*)();
extern JS_PUBLIC_API void SetProcessLargeAllocationFailureCallback(
LargeAllocationFailureCallback afc);
/**
* Unlike the error reporter, which is only called if the exception for an OOM
* bubbles up and is not caught, the OutOfMemoryCallback is called immediately
* at the OOM site to allow the embedding to capture the current state of heap
* allocation before anything is freed. If the large-allocation-failure callback
* is called at all (not all allocation sites call the large-allocation-failure
* callback on failure), it is called before the out-of-memory callback; the
* out-of-memory callback is only called if the allocation still fails after the
* large-allocation-failure callback has returned.
*/
using OutOfMemoryCallback = void (*)(JSContext*, void*);
extern JS_PUBLIC_API void SetOutOfMemoryCallback(JSContext* cx,
OutOfMemoryCallback cb,
void* data);
} // namespace JS
#endif // js_MemoryCallbacks_h