gecko-dev/xpcom/base/nsAgg.h
Andrew McCreight 76b4feac36 Bug 937818, part 1 - Add objects to the purple buffer on AddRef. r=smaug
ICC uses this to track objects that have been AddRef'd during ICC graph building.
For those objects, we may not have the proper information for them, so treat them
as live.
2013-12-17 19:29:57 -08:00

332 lines
21 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* 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 nsAgg_h___
#define nsAgg_h___
#include "nsISupports.h"
#include "nsCycleCollectionParticipant.h"
////////////////////////////////////////////////////////////////////////////////
// Put NS_DECL_AGGREGATED or NS_DECL_CYCLE_COLLECTING_AGGREGATED in your class's
// declaration.
#define NS_DECL_AGGREGATED \
NS_DECL_ISUPPORTS \
NS_DECL_AGGREGATED_HELPER
#define NS_DECL_CYCLE_COLLECTING_AGGREGATED \
NS_DECL_CYCLE_COLLECTING_ISUPPORTS \
NS_DECL_AGGREGATED_HELPER
#define NS_DECL_AGGREGATED_HELPER \
public: \
\
/** \
* Returns the nsISupports pointer of the inner object (aka the \
* aggregatee). This pointer is really only useful to the outer object \
* (aka the aggregator), which can use it to hold on to the inner \
* object. Anything else wants the nsISupports pointer of the outer \
* object (gotten by QI'ing inner or outer to nsISupports). This method \
* returns a non-addrefed pointer. \
* @return the nsISupports pointer of the inner object \
*/ \
nsISupports* InnerObject(void) { return &fAggregated; } \
\
/** \
* Returns true if this object is part of an aggregated object. \
*/ \
bool IsPartOfAggregated(void) { return fOuter != InnerObject(); } \
\
private: \
\
/* You must implement this operation instead of the nsISupports */ \
/* methods. */ \
nsresult \
AggregatedQueryInterface(const nsIID& aIID, void** aInstancePtr); \
\
class Internal : public nsISupports { \
public: \
\
Internal() {} \
\
NS_IMETHOD QueryInterface(const nsIID& aIID, void** aInstancePtr); \
NS_IMETHOD_(nsrefcnt) AddRef(void); \
NS_IMETHOD_(nsrefcnt) Release(void); \
\
NS_DECL_OWNINGTHREAD \
}; \
\
friend class Internal; \
\
nsISupports* fOuter; \
Internal fAggregated; \
\
public: \
#define NS_DECL_AGGREGATED_CYCLE_COLLECTION_CLASS(_class) \
class NS_CYCLE_COLLECTION_INNERCLASS \
: public nsXPCOMCycleCollectionParticipant \
{ \
public: \
NS_IMETHOD_(void) Unlink(void *p); \
NS_IMETHOD Traverse(void *p, nsCycleCollectionTraversalCallback &cb); \
NS_IMETHOD_(void) DeleteCycleCollectable(void* p) \
{ \
NS_CYCLE_COLLECTION_CLASSNAME(_class):: \
Downcast(static_cast<nsISupports*>(p))->DeleteCycleCollectable(); \
} \
static _class* Downcast(nsISupports* s) \
{ \
return (_class*)((char*)(s) - offsetof(_class, fAggregated)); \
} \
static nsISupports* Upcast(_class *p) \
{ \
return p->InnerObject(); \
} \
static nsXPCOMCycleCollectionParticipant* GetParticipant() \
{ \
return &_class::NS_CYCLE_COLLECTION_INNERNAME; \
} \
}; \
NS_CHECK_FOR_RIGHT_PARTICIPANT_IMPL(_class); \
static NS_CYCLE_COLLECTION_INNERCLASS NS_CYCLE_COLLECTION_INNERNAME;
// Put this in your class's constructor:
#define NS_INIT_AGGREGATED(outer) \
PR_BEGIN_MACRO \
fOuter = outer ? outer : &fAggregated; \
PR_END_MACRO
// Put this in your class's implementation file:
#define NS_IMPL_AGGREGATED(_class) \
\
NS_IMPL_AGGREGATED_HELPER(_class) \
\
NS_IMETHODIMP_(nsrefcnt) \
_class::Internal::AddRef(void) \
{ \
_class* agg = (_class*)((char*)(this) - offsetof(_class, fAggregated)); \
MOZ_ASSERT(int32_t(agg->mRefCnt) >= 0, "illegal refcnt"); \
NS_ASSERT_OWNINGTHREAD(_class); \
++agg->mRefCnt; \
NS_LOG_ADDREF(this, agg->mRefCnt, #_class, sizeof(*this)); \
return agg->mRefCnt; \
} \
\
NS_IMETHODIMP_(nsrefcnt) \
_class::Internal::Release(void) \
{ \
_class* agg = (_class*)((char*)(this) - offsetof(_class, fAggregated)); \
MOZ_ASSERT(int32_t(agg->mRefCnt) > 0, "dup release"); \
NS_ASSERT_OWNINGTHREAD(_class); \
--agg->mRefCnt; \
NS_LOG_RELEASE(this, agg->mRefCnt, #_class); \
if (agg->mRefCnt == 0) { \
agg->mRefCnt = 1; /* stabilize */ \
delete agg; \
return 0; \
} \
return agg->mRefCnt; \
} \
#define NS_IMPL_CYCLE_COLLECTING_AGGREGATED(_class) \
\
NS_IMPL_AGGREGATED_HELPER(_class) \
\
NS_IMETHODIMP_(nsrefcnt) \
_class::Internal::AddRef(void) \
{ \
_class* agg = NS_CYCLE_COLLECTION_CLASSNAME(_class)::Downcast(this); \
MOZ_ASSERT(int32_t(agg->mRefCnt) >= 0, "illegal refcnt"); \
NS_ASSERT_OWNINGTHREAD_AGGREGATE(agg, _class); \
nsrefcnt count = agg->mRefCnt.incr(this); \
NS_LOG_ADDREF(this, count, #_class, sizeof(*agg)); \
return count; \
} \
NS_IMETHODIMP_(nsrefcnt) \
_class::Internal::Release(void) \
{ \
_class* agg = NS_CYCLE_COLLECTION_CLASSNAME(_class)::Downcast(this); \
MOZ_ASSERT(int32_t(agg->mRefCnt) > 0, "dup release"); \
NS_ASSERT_OWNINGTHREAD_AGGREGATE(agg, _class); \
nsrefcnt count = agg->mRefCnt.decr(this); \
NS_LOG_RELEASE(this, count, #_class); \
return count; \
} \
NS_IMETHODIMP_(void) \
_class::DeleteCycleCollectable(void) \
{ \
delete this; \
}
#define NS_IMPL_AGGREGATED_HELPER(_class) \
NS_IMETHODIMP \
_class::QueryInterface(const nsIID& aIID, void** aInstancePtr) \
{ \
return fOuter->QueryInterface(aIID, aInstancePtr); \
} \
\
NS_IMETHODIMP_(nsrefcnt) \
_class::AddRef(void) \
{ \
return fOuter->AddRef(); \
} \
\
NS_IMETHODIMP_(nsrefcnt) \
_class::Release(void) \
{ \
return fOuter->Release(); \
} \
\
NS_IMETHODIMP \
_class::Internal::QueryInterface(const nsIID& aIID, void** aInstancePtr) \
{ \
_class* agg = (_class*)((char*)(this) - offsetof(_class, fAggregated)); \
return agg->AggregatedQueryInterface(aIID, aInstancePtr); \
} \
/**
* To make aggregated objects participate in cycle collection we need to enable
* the outer object (aggregator) to traverse/unlink the objects held by the
* inner object (the aggregatee). We can't just make the inner object QI'able to
* NS_CYCLECOLLECTIONPARTICIPANT_IID, we don't want to return the inner object's
* nsCycleCollectionParticipant for the outer object (which will happen if the
* outer object doesn't participate in cycle collection itself).
* NS_AGGREGATED_CYCLECOLLECTIONPARTICIPANT_IID enables the outer object to get
* the inner objects nsCycleCollectionParticipant.
*
* There are three cases:
* - No aggregation
* QI'ing to NS_CYCLECOLLECTIONPARTICIPANT_IID will return the inner
* object's nsCycleCollectionParticipant.
*
* - Aggregation and outer object does not participate in cycle collection
* QI'ing to NS_CYCLECOLLECTIONPARTICIPANT_IID will not return anything.
*
* - Aggregation and outer object does participate in cycle collection
* QI'ing to NS_CYCLECOLLECTIONPARTICIPANT_IID will return the outer
* object's nsCycleCollectionParticipant. The outer object's
* nsCycleCollectionParticipant can then QI the inner object to
* NS_AGGREGATED_CYCLECOLLECTIONPARTICIPANT_IID to get the inner object's
* nsCycleCollectionParticipant, which it can use to traverse/unlink the
* objects reachable from the inner object.
*/
#define NS_AGGREGATED_CYCLECOLLECTIONPARTICIPANT_IID \
{ \
0x32889b7e, \
0xe4fe, \
0x43f4, \
{ 0x85, 0x31, 0xb5, 0x28, 0x23, 0xa2, 0xe9, 0xfc } \
}
/**
* Just holds the IID so NS_GET_IID works.
*/
class nsAggregatedCycleCollectionParticipant
{
public:
NS_DECLARE_STATIC_IID_ACCESSOR(NS_AGGREGATED_CYCLECOLLECTIONPARTICIPANT_IID)
};
NS_DEFINE_STATIC_IID_ACCESSOR(nsAggregatedCycleCollectionParticipant,
NS_AGGREGATED_CYCLECOLLECTIONPARTICIPANT_IID)
// for use with QI macros in nsISupportsUtils.h:
#define NS_INTERFACE_MAP_BEGIN_AGGREGATED(_class) \
NS_IMPL_AGGREGATED_QUERY_HEAD(_class)
#define NS_INTERFACE_MAP_ENTRY_CYCLE_COLLECTION_AGGREGATED(_class) \
NS_IMPL_QUERY_CYCLE_COLLECTION(_class)
#define NS_INTERFACE_MAP_ENTRIES_CYCLE_COLLECTION_AGGREGATED(_class) \
NS_INTERFACE_MAP_ENTRY_CYCLE_COLLECTION_AGGREGATED(_class) \
NS_INTERFACE_MAP_ENTRY_CYCLE_COLLECTION_ISUPPORTS(_class)
#define NS_IMPL_AGGREGATED_QUERY_HEAD(_class) \
nsresult \
_class::AggregatedQueryInterface(REFNSIID aIID, void** aInstancePtr) \
{ \
NS_ASSERTION(aInstancePtr, \
"AggregatedQueryInterface requires a non-NULL result ptr!"); \
if ( !aInstancePtr ) \
return NS_ERROR_NULL_POINTER; \
nsISupports* foundInterface; \
if ( aIID.Equals(NS_GET_IID(nsISupports)) ) \
foundInterface = InnerObject(); \
else
#define NS_IMPL_AGGREGATED_QUERY_CYCLE_COLLECTION(_class) \
if (aIID.Equals(IsPartOfAggregated() ? \
NS_GET_IID(nsCycleCollectionParticipant) : \
NS_GET_IID(nsAggregatedCycleCollectionParticipant))) \
foundInterface = NS_CYCLE_COLLECTION_PARTICIPANT(_class); \
else
#define NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_AGGREGATED(_class) \
NS_IMETHODIMP \
NS_CYCLE_COLLECTION_CLASSNAME(_class)::Traverse \
(void *p, nsCycleCollectionTraversalCallback &cb) \
{ \
nsISupports *s = static_cast<nsISupports*>(p); \
MOZ_ASSERT(CheckForRightISupports(s), \
"not the nsISupports pointer we expect"); \
_class *tmp = static_cast<_class*>(Downcast(s)); \
if (!tmp->IsPartOfAggregated()) \
NS_IMPL_CYCLE_COLLECTION_DESCRIBE(_class, tmp->mRefCnt.get())
#define NS_GENERIC_AGGREGATED_CONSTRUCTOR(_InstanceClass) \
static nsresult \
_InstanceClass##Constructor(nsISupports *aOuter, REFNSIID aIID, \
void **aResult) \
{ \
*aResult = nullptr; \
if (NS_WARN_IF(aOuter && !aIID.Equals(NS_GET_IID(nsISupports)))) \
return NS_ERROR_INVALID_ARG; \
\
_InstanceClass* inst = new _InstanceClass(aOuter); \
if (!inst) { \
return NS_ERROR_OUT_OF_MEMORY; \
} \
\
nsISupports* inner = inst->InnerObject(); \
nsresult rv = inner->QueryInterface(aIID, aResult); \
if (NS_FAILED(rv)) { \
delete inst; \
} \
\
return rv; \
} \
#define NS_GENERIC_AGGREGATED_CONSTRUCTOR_INIT(_InstanceClass, _InitMethod) \
static nsresult \
_InstanceClass##Constructor(nsISupports *aOuter, REFNSIID aIID, \
void **aResult) \
{ \
*aResult = nullptr; \
if (NS_WARN_IF(aOuter && !aIID.Equals(NS_GET_IID(nsISupports)))) \
return NS_ERROR_INVALID_ARG; \
\
_InstanceClass* inst = new _InstanceClass(aOuter); \
if (!inst) { \
return NS_ERROR_OUT_OF_MEMORY; \
} \
\
nsISupports* inner = inst->InnerObject(); \
NS_ADDREF(inner); \
nsresult rv = inst->_InitMethod(); \
if (NS_SUCCEEDED(rv)) { \
rv = inner->QueryInterface(aIID, aResult); \
} \
NS_RELEASE(inner); \
\
return rv; \
} \
#endif /* nsAgg_h___ */