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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/. */
/*
* JS engine garbage collector API.
*/
#ifndef gc_GC_h
#define gc_GC_h
#include "jsapi.h"
#include "gc/AllocKind.h"
#include "gc/GCEnum.h"
#include "js/TraceKind.h"
class JSExternalString;
class JSFatInlineString;
class JSTracer;
namespace js {
class AccessorShape;
class FatInlineAtom;
class NormalAtom;
class Nursery;
namespace gc {
class Arena;
class TenuredChunk;
struct Cell;
/*
* Map from C++ type to alloc kind for non-object types. JSObject does not have
* a 1:1 mapping, so must use Arena::thingSize.
*
* The AllocKind is available as MapTypeToFinalizeKind<SomeType>::kind.
*/
template <typename T>
struct MapTypeToFinalizeKind {};
#define EXPAND_MAPTYPETOFINALIZEKIND(allocKind, traceKind, type, sizedType, \
bgFinal, nursery, compact) \
template <> \
struct MapTypeToFinalizeKind<type> { \
static const AllocKind kind = AllocKind::allocKind; \
};
FOR_EACH_NONOBJECT_ALLOCKIND(EXPAND_MAPTYPETOFINALIZEKIND)
#undef EXPAND_MAPTYPETOFINALIZEKIND
} /* namespace gc */
extern void TraceRuntime(JSTracer* trc);
// Trace roots but don't evict the nursery first; used from DumpHeap.
extern void TraceRuntimeWithoutEviction(JSTracer* trc);
extern void ReleaseAllJITCode(JSFreeOp* op);
extern void PrepareForDebugGC(JSRuntime* rt);
/* Functions for managing cross compartment gray pointers. */
extern void NotifyGCNukeWrapper(JSObject* o);
extern unsigned NotifyGCPreSwap(JSObject* a, JSObject* b);
extern void NotifyGCPostSwap(JSObject* a, JSObject* b, unsigned preResult);
using IterateChunkCallback = void (*)(JSRuntime*, void*, gc::TenuredChunk*,
const JS::AutoRequireNoGC&);
using IterateZoneCallback = void (*)(JSRuntime*, void*, JS::Zone*,
const JS::AutoRequireNoGC&);
using IterateArenaCallback = void (*)(JSRuntime*, void*, gc::Arena*,
JS::TraceKind, size_t,
const JS::AutoRequireNoGC&);
using IterateCellCallback = void (*)(JSRuntime*, void*, JS::GCCellPtr, size_t,
const JS::AutoRequireNoGC&);
/*
* This function calls |zoneCallback| on every zone, |realmCallback| on
* every realm, |arenaCallback| on every in-use arena, and |cellCallback|
* on every in-use cell in the GC heap.
*
* Note that no read barrier is triggered on the cells passed to cellCallback,
* so no these pointers must not escape the callback.
*/
extern void IterateHeapUnbarriered(JSContext* cx, void* data,
IterateZoneCallback zoneCallback,
JS::IterateRealmCallback realmCallback,
IterateArenaCallback arenaCallback,
IterateCellCallback cellCallback);
/*
* This function is like IterateHeapUnbarriered, but does it for a single zone.
*/
extern void IterateHeapUnbarrieredForZone(
JSContext* cx, JS::Zone* zone, void* data, IterateZoneCallback zoneCallback,
JS::IterateRealmCallback realmCallback, IterateArenaCallback arenaCallback,
IterateCellCallback cellCallback);
/*
* Invoke chunkCallback on every in-use chunk.
*/
extern void IterateChunks(JSContext* cx, void* data,
IterateChunkCallback chunkCallback);
using IterateScriptCallback = void (*)(JSRuntime*, void*, BaseScript*,
const JS::AutoRequireNoGC&);
/*
* Invoke scriptCallback on every in-use script for the given realm or for all
* realms if it is null. The scripts may or may not have bytecode.
*/
extern void IterateScripts(JSContext* cx, JS::Realm* realm, void* data,
IterateScriptCallback scriptCallback);
JS::Realm* NewRealm(JSContext* cx, JSPrincipals* principals,
const JS::RealmOptions& options);
namespace gc {
void FinishGC(JSContext* cx, JS::GCReason = JS::GCReason::FINISH_GC);
void WaitForBackgroundTasks(JSContext* cx);
/*
* Merge all contents of source into target. This can only be used if source is
* the only realm in its zone.
*/
void MergeRealms(JS::Realm* source, JS::Realm* target);
void CollectSelfHostingZone(JSContext* cx);
enum VerifierType { PreBarrierVerifier };
#ifdef JS_GC_ZEAL
extern const char ZealModeHelpText[];
/* Check that write barriers have been used correctly. See gc/Verifier.cpp. */
void VerifyBarriers(JSRuntime* rt, VerifierType type);
void MaybeVerifyBarriers(JSContext* cx, bool always = false);
void DumpArenaInfo();
#else
static inline void VerifyBarriers(JSRuntime* rt, VerifierType type) {}
static inline void MaybeVerifyBarriers(JSContext* cx, bool always = false) {}
#endif
/*
* Instances of this class prevent GC from happening while they are live. If an
* allocation causes a heap threshold to be exceeded, no GC will be performed
* and the allocation will succeed. Allocation may still fail for other reasons.
*
* Use of this class is highly discouraged, since without GC system memory can
* become exhausted and this can cause crashes at places where we can't handle
* allocation failure.
*
* Use of this is permissible in situations where it would be impossible (or at
* least very difficult) to tolerate GC and where only a fixed number of objects
* are allocated, such as:
*
* - error reporting
* - JIT bailout handling
* - brain transplants (JSObject::swap)
* - debugging utilities not exposed to the browser
*
* This works by updating the |JSContext::suppressGC| counter which is checked
* at the start of GC.
*/
class MOZ_RAII JS_HAZ_GC_SUPPRESSED AutoSuppressGC {
int32_t& suppressGC_;
public:
explicit AutoSuppressGC(JSContext* cx);
~AutoSuppressGC() { suppressGC_--; }
};
const char* StateName(State state);
} /* namespace gc */
/* Use this to avoid assertions when manipulating the wrapper map. */
class MOZ_RAII AutoDisableProxyCheck {
public:
#ifdef DEBUG
AutoDisableProxyCheck();
~AutoDisableProxyCheck();
#else
AutoDisableProxyCheck() {}
#endif
};
struct MOZ_RAII AutoDisableCompactingGC {
explicit AutoDisableCompactingGC(JSContext* cx);
~AutoDisableCompactingGC();
private:
JSContext* cx;
};
} /* namespace js */
#endif /* gc_GC_h */
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