gecko/xpcom/base/CycleCollectedJSRuntime.h

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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 mozilla_CycleCollectedJSRuntime_h__
#define mozilla_CycleCollectedJSRuntime_h__
#include "mozilla/MemoryReporting.h"
#include "jsapi.h"
#include "nsCycleCollector.h"
#include "nsCycleCollectionParticipant.h"
#include "nsDataHashtable.h"
#include "nsHashKeys.h"
#include "nsTArray.h"
class nsCycleCollectionNoteRootCallback;
class nsIException;
namespace js {
class Class;
}
namespace mozilla {
class JSGCThingParticipant: public nsCycleCollectionParticipant
{
public:
NS_IMETHOD_(void) Root(void *n)
{
}
NS_IMETHOD_(void) Unlink(void *n)
{
}
NS_IMETHOD_(void) Unroot(void *n)
{
}
NS_IMETHOD_(void) DeleteCycleCollectable(void *n)
{
}
NS_IMETHOD Traverse(void *n, nsCycleCollectionTraversalCallback &cb);
};
class JSZoneParticipant : public nsCycleCollectionParticipant
{
public:
MOZ_CONSTEXPR JSZoneParticipant(): nsCycleCollectionParticipant() {}
NS_IMETHOD_(void) Root(void *p)
{
}
NS_IMETHOD_(void) Unlink(void *p)
{
}
NS_IMETHOD_(void) Unroot(void *p)
{
}
NS_IMETHOD_(void) DeleteCycleCollectable(void *n)
{
}
NS_IMETHOD Traverse(void *p, nsCycleCollectionTraversalCallback &cb);
};
class IncrementalFinalizeRunnable;
// Contains various stats about the cycle collection.
struct CycleCollectorResults
{
CycleCollectorResults()
{
// Initialize here so when we increment mNumSlices the first time we're
// not using uninitialized memory.
Init();
}
void Init()
{
mForcedGC = false;
mMergedZones = false;
mVisitedRefCounted = 0;
mVisitedGCed = 0;
mFreedRefCounted = 0;
mFreedGCed = 0;
mNumSlices = 1;
// mNumSlices is initialized to one, because we call Init() after the
// per-slice increment of mNumSlices has already occurred.
}
bool mForcedGC;
bool mMergedZones;
uint32_t mVisitedRefCounted;
uint32_t mVisitedGCed;
uint32_t mFreedRefCounted;
uint32_t mFreedGCed;
uint32_t mNumSlices;
};
class CycleCollectedJSRuntime
{
friend class JSGCThingParticipant;
friend class JSZoneParticipant;
friend class IncrementalFinalizeRunnable;
protected:
CycleCollectedJSRuntime(JSRuntime* aParentRuntime,
uint32_t aMaxbytes,
JSUseHelperThreads aUseHelperThreads);
virtual ~CycleCollectedJSRuntime();
size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
void UnmarkSkippableJSHolders();
virtual void TraverseAdditionalNativeRoots(nsCycleCollectionNoteRootCallback& aCb) {}
virtual void TraceAdditionalNativeGrayRoots(JSTracer* aTracer) {}
virtual void CustomGCCallback(JSGCStatus aStatus) {}
virtual bool CustomContextCallback(JSContext* aCx, unsigned aOperation)
{
return true; // Don't block context creation.
}
private:
void
DescribeGCThing(bool aIsMarked, void* aThing, JSGCTraceKind aTraceKind,
nsCycleCollectionTraversalCallback& aCb) const;
virtual bool
DescribeCustomObjects(JSObject* aObject, const js::Class* aClasp,
char (&aName)[72]) const
{
return false; // We did nothing.
}
void
NoteGCThingJSChildren(void* aThing, JSGCTraceKind aTraceKind,
nsCycleCollectionTraversalCallback& aCb) const;
void
NoteGCThingXPCOMChildren(const js::Class* aClasp, JSObject* aObj,
nsCycleCollectionTraversalCallback& aCb) const;
virtual bool
NoteCustomGCThingXPCOMChildren(const js::Class* aClasp, JSObject* aObj,
nsCycleCollectionTraversalCallback& aCb) const
{
return false; // We did nothing.
}
enum TraverseSelect {
TRAVERSE_CPP,
TRAVERSE_FULL
};
void
TraverseGCThing(TraverseSelect aTs, void* aThing,
JSGCTraceKind aTraceKind,
nsCycleCollectionTraversalCallback& aCb);
void
TraverseZone(JS::Zone* aZone, nsCycleCollectionTraversalCallback& aCb);
static void
TraverseObjectShim(void* aData, void* aThing);
void TraverseNativeRoots(nsCycleCollectionNoteRootCallback& aCb);
static void TraceBlackJS(JSTracer* aTracer, void* aData);
static void TraceGrayJS(JSTracer* aTracer, void* aData);
static void GCCallback(JSRuntime* aRuntime, JSGCStatus aStatus, void* aData);
static bool ContextCallback(JSContext* aCx, unsigned aOperation,
void* aData);
virtual void TraceNativeBlackRoots(JSTracer* aTracer) { };
void TraceNativeGrayRoots(JSTracer* aTracer);
enum DeferredFinalizeType {
FinalizeIncrementally,
FinalizeNow,
};
void FinalizeDeferredThings(DeferredFinalizeType aType);
void OnGC(JSGCStatus aStatus);
public:
void AddJSHolder(void* aHolder, nsScriptObjectTracer* aTracer);
void RemoveJSHolder(void* aHolder);
#ifdef DEBUG
bool IsJSHolder(void* aHolder);
void AssertNoObjectsToTrace(void* aPossibleJSHolder);
#endif
already_AddRefed<nsIException> GetPendingException() const;
void SetPendingException(nsIException* aException);
nsCycleCollectionParticipant* GCThingParticipant();
nsCycleCollectionParticipant* ZoneParticipant();
nsresult TraverseRoots(nsCycleCollectionNoteRootCallback &aCb);
bool UsefulToMergeZones() const;
void FixWeakMappingGrayBits() const;
bool AreGCGrayBitsValid() const;
void GarbageCollect(uint32_t reason) const;
void DeferredFinalize(DeferredFinalizeAppendFunction aAppendFunc,
DeferredFinalizeFunction aFunc,
void* aThing);
void DeferredFinalize(nsISupports* aSupports);
void DumpJSHeap(FILE* aFile);
virtual void PrepareForForgetSkippable() = 0;
virtual void BeginCycleCollectionCallback() = 0;
virtual void EndCycleCollectionCallback(CycleCollectorResults &aResults) = 0;
virtual void DispatchDeferredDeletion(bool aContinuation) = 0;
JSRuntime* Runtime() const
{
MOZ_ASSERT(mJSRuntime);
return mJSRuntime;
}
// Get the current thread's CycleCollectedJSRuntime. Returns null if there
// isn't one.
static CycleCollectedJSRuntime* Get();
private:
JSGCThingParticipant mGCThingCycleCollectorGlobal;
JSZoneParticipant mJSZoneCycleCollectorGlobal;
JSRuntime* mJSRuntime;
nsDataHashtable<nsPtrHashKey<void>, nsScriptObjectTracer*> mJSHolders;
nsTArray<nsISupports*> mDeferredSupports;
typedef nsDataHashtable<nsFuncPtrHashKey<DeferredFinalizeFunction>, void*>
DeferredFinalizerTable;
DeferredFinalizerTable mDeferredFinalizerTable;
nsRefPtr<IncrementalFinalizeRunnable> mFinalizeRunnable;
nsCOMPtr<nsIException> mPendingException;
};
} // namespace mozilla
#endif // mozilla_CycleCollectedJSRuntime_h__