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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* 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 gc_FreeOp_h
#define gc_FreeOp_h
#include "mozilla/Assertions.h" // MOZ_ASSERT
#include "jit/ExecutableAllocator.h" // jit::JitPoisonRangeVector
#include "js/AllocPolicy.h" // SystemAllocPolicy
#include "js/MemoryFunctions.h" // JSFreeOp
#include "js/Utility.h" // AutoEnterOOMUnsafeRegion, js_free
#include "js/Vector.h" // js::Vector
struct JSRuntime;
namespace js {
/*
* A FreeOp can do one thing: free memory. For convenience, it has delete_
* convenience methods that also call destructors.
*
* FreeOp is passed to finalizers and other sweep-phase hooks so that we do not
* need to pass a JSContext to those hooks.
*/
class FreeOp : public JSFreeOp {
Vector<void*, 0, SystemAllocPolicy> freeLaterList;
jit::JitPoisonRangeVector jitPoisonRanges;
public:
static FreeOp* get(JSFreeOp* fop) { return static_cast<FreeOp*>(fop); }
explicit FreeOp(JSRuntime* maybeRuntime);
~FreeOp();
bool onMainThread() const { return runtime_ != nullptr; }
bool maybeOnHelperThread() const {
// Sometimes background finalization happens on the main thread so
// runtime_ being null doesn't always mean we are off thread.
return !runtime_;
}
bool isDefaultFreeOp() const;
void free_(void* p) { js_free(p); }
void freeLater(void* p) {
// FreeOps other than the defaultFreeOp() are constructed on the stack,
// and won't hold onto the pointers to free indefinitely.
MOZ_ASSERT(!isDefaultFreeOp());
AutoEnterOOMUnsafeRegion oomUnsafe;
if (!freeLaterList.append(p)) {
oomUnsafe.crash("FreeOp::freeLater");
}
}
bool appendJitPoisonRange(const jit::JitPoisonRange& range) {
// FreeOps other than the defaultFreeOp() are constructed on the stack,
// and won't hold onto the pointers to free indefinitely.
MOZ_ASSERT(!isDefaultFreeOp());
return jitPoisonRanges.append(range);
}
template <class T>
void delete_(T* p) {
if (p) {
p->~T();
free_(p);
}
}
};
} // namespace js
#endif // gc_FreeOp_h