gecko-dev/xpcom/base/nsCycleCollector.h
2012-06-30 14:16:32 -07:00

103 lines
3.2 KiB
C++

/* -*- Mode: C++; tab-width: 2; 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 nsCycleCollector_h__
#define nsCycleCollector_h__
//#define DEBUG_CC
class nsISupports;
class nsICycleCollectorListener;
class nsCycleCollectionParticipant;
class nsCycleCollectionTraversalCallback;
// Contains various stats about the cycle collection.
class nsCycleCollectorResults
{
public:
nsCycleCollectorResults() :
mForcedGC(false), mVisitedRefCounted(0), mVisitedGCed(0),
mFreedRefCounted(0), mFreedGCed(0) {}
bool mForcedGC;
PRUint32 mVisitedRefCounted;
PRUint32 mVisitedGCed;
PRUint32 mFreedRefCounted;
PRUint32 mFreedGCed;
};
nsresult nsCycleCollector_startup();
typedef void (*CC_BeforeUnlinkCallback)(void);
void nsCycleCollector_setBeforeUnlinkCallback(CC_BeforeUnlinkCallback aCB);
typedef void (*CC_ForgetSkippableCallback)(void);
void nsCycleCollector_setForgetSkippableCallback(CC_ForgetSkippableCallback aCB);
void nsCycleCollector_forgetSkippable(bool aRemoveChildlessNodes = false);
#ifdef DEBUG_CC
void nsCycleCollector_logPurpleRemoval(void* aObject);
#endif
void nsCycleCollector_collect(bool aMergeCompartments,
nsCycleCollectorResults *aResults,
nsICycleCollectorListener *aListener);
PRUint32 nsCycleCollector_suspectedCount();
void nsCycleCollector_shutdownThreads();
void nsCycleCollector_shutdown();
// Various methods the cycle collector needs to deal with Javascript.
struct nsCycleCollectionJSRuntime
{
virtual nsresult BeginCycleCollection(nsCycleCollectionTraversalCallback &cb) = 0;
virtual nsresult FinishTraverse() = 0;
/**
* Called before/after transitioning to/from the main thread.
*
* NotifyLeaveMainThread may return 'false' to prevent the cycle collector
* from leaving the main thread.
*/
virtual bool NotifyLeaveMainThread() = 0;
virtual void NotifyEnterCycleCollectionThread() = 0;
virtual void NotifyLeaveCycleCollectionThread() = 0;
virtual void NotifyEnterMainThread() = 0;
/**
* Should we force a JavaScript GC before a CC?
*/
virtual bool NeedCollect() = 0;
/**
* Runs the JavaScript GC. |reason| is a gcreason::Reason from jsfriendapi.h.
*/
virtual void Collect(PRUint32 reason) = 0;
/**
* Get the JS cycle collection participant.
*/
virtual nsCycleCollectionParticipant *GetParticipant() = 0;
};
// Helpers for interacting with JS
void nsCycleCollector_registerJSRuntime(nsCycleCollectionJSRuntime *rt);
void nsCycleCollector_forgetJSRuntime();
#ifdef DEBUG
void nsCycleCollector_DEBUG_shouldBeFreed(nsISupports *n);
void nsCycleCollector_DEBUG_wasFreed(nsISupports *n);
#endif
#define NS_CYCLE_COLLECTOR_LOGGER_CID \
{ 0x58be81b4, 0x39d2, 0x437c, \
{ 0x94, 0xea, 0xae, 0xde, 0x2c, 0x62, 0x08, 0xd3 } }
extern nsresult
nsCycleCollectorLoggerConstructor(nsISupports* outer,
const nsIID& aIID,
void* *aInstancePtr);
#endif // nsCycleCollector_h__