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Diffstat (limited to 'xpcom/glue/nsCycleCollectionParticipant.h')
| -rw-r--r-- | xpcom/glue/nsCycleCollectionParticipant.h | 852 |
1 files changed, 852 insertions, 0 deletions
diff --git a/xpcom/glue/nsCycleCollectionParticipant.h b/xpcom/glue/nsCycleCollectionParticipant.h new file mode 100644 index 000000000..2dfbb6750 --- /dev/null +++ b/xpcom/glue/nsCycleCollectionParticipant.h @@ -0,0 +1,852 @@ +/* -*- 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 nsCycleCollectionParticipant_h__ +#define nsCycleCollectionParticipant_h__ + +#include "mozilla/MacroArgs.h" +#include "mozilla/MacroForEach.h" +#include "nsCycleCollectionNoteChild.h" +#include "js/RootingAPI.h" + +#define NS_XPCOMCYCLECOLLECTIONPARTICIPANT_IID \ +{ \ + 0x9674489b, \ + 0x1f6f, \ + 0x4550, \ + { 0xa7, 0x30, 0xcc, 0xae, 0xdd, 0x10, 0x4c, 0xf9 } \ +} + +/** + * Special IID to get at the base nsISupports for a class. Usually this is the + * canonical nsISupports pointer, but in the case of tearoffs for example it is + * the base nsISupports pointer of the tearoff. This allow the cycle collector + * to have separate nsCycleCollectionParticipant's for tearoffs or aggregated + * classes. + */ +#define NS_CYCLECOLLECTIONISUPPORTS_IID \ +{ \ + 0xc61eac14, \ + 0x5f7a, \ + 0x4481, \ + { 0x96, 0x5e, 0x7e, 0xaa, 0x6e, 0xff, 0xa8, 0x5f } \ +} + +/** + * Just holds the IID so NS_GET_IID works. + */ +class nsCycleCollectionISupports +{ +public: + NS_DECLARE_STATIC_IID_ACCESSOR(NS_CYCLECOLLECTIONISUPPORTS_IID) +}; + +NS_DEFINE_STATIC_IID_ACCESSOR(nsCycleCollectionISupports, + NS_CYCLECOLLECTIONISUPPORTS_IID) + +namespace JS { +template<class T> class Heap; +} /* namespace JS */ + +/* + * A struct defining pure virtual methods which are called when tracing cycle + * collection paticipants. The appropriate method is called depending on the + * type of JS GC thing. + */ +struct TraceCallbacks +{ + virtual void Trace(JS::Heap<JS::Value>* aPtr, const char* aName, + void* aClosure) const = 0; + virtual void Trace(JS::Heap<jsid>* aPtr, const char* aName, + void* aClosure) const = 0; + virtual void Trace(JS::Heap<JSObject*>* aPtr, const char* aName, + void* aClosure) const = 0; + virtual void Trace(JSObject** aPtr, const char* aName, + void* aClosure) const = 0; + virtual void Trace(JS::TenuredHeap<JSObject*>* aPtr, const char* aName, + void* aClosure) const = 0; + virtual void Trace(JS::Heap<JSString*>* aPtr, const char* aName, + void* aClosure) const = 0; + virtual void Trace(JS::Heap<JSScript*>* aPtr, const char* aName, + void* aClosure) const = 0; + virtual void Trace(JS::Heap<JSFunction*>* aPtr, const char* aName, + void* aClosure) const = 0; +}; + +/* + * An implementation of TraceCallbacks that calls a single function for all JS + * GC thing types encountered. Implemented in nsCycleCollectorTraceJSHelpers.cpp. + */ +struct TraceCallbackFunc : public TraceCallbacks +{ + typedef void (*Func)(JS::GCCellPtr aPtr, const char* aName, void* aClosure); + + explicit TraceCallbackFunc(Func aCb) : mCallback(aCb) {} + + virtual void Trace(JS::Heap<JS::Value>* aPtr, const char* aName, + void* aClosure) const override; + virtual void Trace(JS::Heap<jsid>* aPtr, const char* aName, + void* aClosure) const override; + virtual void Trace(JS::Heap<JSObject*>* aPtr, const char* aName, + void* aClosure) const override; + virtual void Trace(JSObject** aPtr, const char* aName, + void* aClosure) const override; + virtual void Trace(JS::TenuredHeap<JSObject*>* aPtr, const char* aName, + void* aClosure) const override; + virtual void Trace(JS::Heap<JSString*>* aPtr, const char* aName, + void* aClosure) const override; + virtual void Trace(JS::Heap<JSScript*>* aPtr, const char* aName, + void* aClosure) const override; + virtual void Trace(JS::Heap<JSFunction*>* aPtr, const char* aName, + void* aClosure) const override; + +private: + Func mCallback; +}; + +/** + * Participant implementation classes + */ +class NS_NO_VTABLE nsCycleCollectionParticipant +{ +public: + constexpr nsCycleCollectionParticipant() : mMightSkip(false) {} + constexpr explicit nsCycleCollectionParticipant(bool aSkip) : mMightSkip(aSkip) {} + + NS_IMETHOD Traverse(void* aPtr, nsCycleCollectionTraversalCallback& aCb) = 0; + + NS_IMETHOD_(void) Root(void* aPtr) = 0; + NS_IMETHOD_(void) Unlink(void* aPtr) = 0; + NS_IMETHOD_(void) Unroot(void* aPtr) = 0; + NS_IMETHOD_(const char*) ClassName() = 0; + + NS_IMETHOD_(void) Trace(void* aPtr, const TraceCallbacks& aCb, + void* aClosure) {} + + // If CanSkip returns true, p is removed from the purple buffer during + // a call to nsCycleCollector_forgetSkippable(). + // Note, calling CanSkip may remove objects from the purple buffer! + // If aRemovingAllowed is true, p can be removed from the purple buffer. + bool CanSkip(void* aPtr, bool aRemovingAllowed) + { + return mMightSkip ? CanSkipReal(aPtr, aRemovingAllowed) : false; + } + + // If CanSkipInCC returns true, p is skipped when selecting roots for the + // cycle collector graph. + // Note, calling CanSkipInCC may remove other objects from the purple buffer! + bool CanSkipInCC(void* aPtr) + { + return mMightSkip ? CanSkipInCCReal(aPtr) : false; + } + + // If CanSkipThis returns true, p is not added to the graph. + // This method is called during cycle collection, so don't + // change the state of any objects! + bool CanSkipThis(void* aPtr) + { + return mMightSkip ? CanSkipThisReal(aPtr) : false; + } + + NS_IMETHOD_(void) DeleteCycleCollectable(void* aPtr) = 0; + +protected: + NS_IMETHOD_(bool) CanSkipReal(void* aPtr, bool aRemovingAllowed) + { + NS_ASSERTION(false, "Forgot to implement CanSkipReal?"); + return false; + } + NS_IMETHOD_(bool) CanSkipInCCReal(void* aPtr) + { + NS_ASSERTION(false, "Forgot to implement CanSkipInCCReal?"); + return false; + } + NS_IMETHOD_(bool) CanSkipThisReal(void* aPtr) + { + NS_ASSERTION(false, "Forgot to implement CanSkipThisReal?"); + return false; + } + +private: + const bool mMightSkip; +}; + +class NS_NO_VTABLE nsScriptObjectTracer : public nsCycleCollectionParticipant +{ +public: + constexpr nsScriptObjectTracer() + : nsCycleCollectionParticipant(false) + { + } + constexpr explicit nsScriptObjectTracer(bool aSkip) + : nsCycleCollectionParticipant(aSkip) + { + } + + NS_IMETHOD_(void) Trace(void* aPtr, const TraceCallbacks& aCb, + void* aClosure) override = 0; + + // Implemented in nsCycleCollectorTraceJSHelpers.cpp. + static void NoteJSChild(JS::GCCellPtr aGCThing, const char* aName, + void* aClosure); +}; + +class NS_NO_VTABLE nsXPCOMCycleCollectionParticipant : public nsScriptObjectTracer +{ +public: + constexpr nsXPCOMCycleCollectionParticipant() + : nsScriptObjectTracer(false) + { + } + constexpr explicit nsXPCOMCycleCollectionParticipant(bool aSkip) + : nsScriptObjectTracer(aSkip) + { + } + + NS_DECLARE_STATIC_IID_ACCESSOR(NS_XPCOMCYCLECOLLECTIONPARTICIPANT_IID) + + NS_IMETHOD_(void) Root(void* aPtr) override; + NS_IMETHOD_(void) Unroot(void* aPtr) override; + + NS_IMETHOD_(void) Trace(void* aPtr, const TraceCallbacks& aCb, + void* aClosure) override; + + static bool CheckForRightISupports(nsISupports* aSupports); +}; + +NS_DEFINE_STATIC_IID_ACCESSOR(nsXPCOMCycleCollectionParticipant, + NS_XPCOMCYCLECOLLECTIONPARTICIPANT_IID) + +/////////////////////////////////////////////////////////////////////////////// +// Helpers for implementing a QI to nsXPCOMCycleCollectionParticipant +/////////////////////////////////////////////////////////////////////////////// + +#define NS_CYCLE_COLLECTION_CLASSNAME(_class) \ + _class::NS_CYCLE_COLLECTION_INNERCLASS + +#define NS_IMPL_QUERY_CYCLE_COLLECTION(_class) \ + if ( aIID.Equals(NS_GET_IID(nsXPCOMCycleCollectionParticipant)) ) { \ + *aInstancePtr = NS_CYCLE_COLLECTION_PARTICIPANT(_class); \ + return NS_OK; \ + } else + +#define NS_IMPL_QUERY_CYCLE_COLLECTION_ISUPPORTS(_class) \ + if ( aIID.Equals(NS_GET_IID(nsCycleCollectionISupports)) ) { \ + *aInstancePtr = NS_CYCLE_COLLECTION_CLASSNAME(_class)::Upcast(this); \ + return NS_OK; \ + } else + +#define NS_INTERFACE_MAP_ENTRY_CYCLE_COLLECTION(_class) \ + NS_IMPL_QUERY_CYCLE_COLLECTION(_class) + +#define NS_INTERFACE_MAP_ENTRY_CYCLE_COLLECTION_ISUPPORTS(_class) \ + NS_IMPL_QUERY_CYCLE_COLLECTION_ISUPPORTS(_class) + +#define NS_INTERFACE_MAP_ENTRIES_CYCLE_COLLECTION(_class) \ + NS_INTERFACE_MAP_ENTRY_CYCLE_COLLECTION(_class) \ + NS_INTERFACE_MAP_ENTRY_CYCLE_COLLECTION_ISUPPORTS(_class) + +#define NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(_class) \ + NS_INTERFACE_MAP_BEGIN(_class) \ + NS_INTERFACE_MAP_ENTRIES_CYCLE_COLLECTION(_class) + +#define NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(_class) \ + NS_INTERFACE_MAP_BEGIN(_class) \ + NS_INTERFACE_MAP_ENTRY_CYCLE_COLLECTION(_class) + +#define NS_INTERFACE_TABLE_TO_MAP_SEGUE_CYCLE_COLLECTION(_class) \ + if (rv == NS_OK) return rv; \ + nsISupports* foundInterface; \ + NS_INTERFACE_MAP_ENTRIES_CYCLE_COLLECTION(_class) + +#define NS_INTERFACE_TABLE_HEAD_CYCLE_COLLECTION_INHERITED(_class) \ + NS_IMETHODIMP _class::QueryInterface(REFNSIID aIID, void** aInstancePtr) \ + { \ + NS_PRECONDITION(aInstancePtr, "null out param"); \ + \ + if ( aIID.Equals(NS_GET_IID(nsXPCOMCycleCollectionParticipant)) ) { \ + *aInstancePtr = NS_CYCLE_COLLECTION_PARTICIPANT(_class); \ + return NS_OK; \ + } \ + nsresult rv; + +#define NS_CYCLE_COLLECTION_UPCAST(obj, clazz) \ + NS_CYCLE_COLLECTION_CLASSNAME(clazz)::Upcast(obj) + +#ifdef DEBUG +#define NS_CHECK_FOR_RIGHT_PARTICIPANT(_ptr) _ptr->CheckForRightParticipant() +#else +#define NS_CHECK_FOR_RIGHT_PARTICIPANT(_ptr) +#endif + +// The default implementation of this class template is empty, because it +// should never be used: see the partial specializations below. +template<typename T, + bool IsXPCOM = mozilla::IsBaseOf<nsISupports, T>::value> +struct DowncastCCParticipantImpl +{ +}; + +// Specialization for XPCOM CC participants +template<typename T> +struct DowncastCCParticipantImpl<T, true> +{ + static T* Run(void* aPtr) + { + nsISupports* s = static_cast<nsISupports*>(aPtr); + MOZ_ASSERT(NS_CYCLE_COLLECTION_CLASSNAME(T)::CheckForRightISupports(s), + "not the nsISupports pointer we expect"); + T* rval = NS_CYCLE_COLLECTION_CLASSNAME(T)::Downcast(s); + NS_CHECK_FOR_RIGHT_PARTICIPANT(rval); + return rval; + } +}; + +// Specialization for native CC participants +template<typename T> +struct DowncastCCParticipantImpl<T, false> +{ + static T* Run(void* aPtr) { return static_cast<T*>(aPtr); } +}; + +template<typename T> +T* +DowncastCCParticipant(void* aPtr) +{ + return DowncastCCParticipantImpl<T>::Run(aPtr); +} + +/////////////////////////////////////////////////////////////////////////////// +// Helpers for implementing CanSkip methods +/////////////////////////////////////////////////////////////////////////////// + +#define NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_BEGIN(_class) \ + NS_IMETHODIMP_(bool) \ + NS_CYCLE_COLLECTION_CLASSNAME(_class)::CanSkipReal(void *p, \ + bool aRemovingAllowed) \ + { \ + _class *tmp = DowncastCCParticipant<_class >(p); + +#define NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_END \ + (void)tmp; \ + return false; \ + } + +#define NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_BEGIN(_class) \ + NS_IMETHODIMP_(bool) \ + NS_CYCLE_COLLECTION_CLASSNAME(_class)::CanSkipInCCReal(void *p) \ + { \ + _class *tmp = DowncastCCParticipant<_class >(p); + +#define NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_END \ + (void)tmp; \ + return false; \ + } + +#define NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_BEGIN(_class) \ + NS_IMETHODIMP_(bool) \ + NS_CYCLE_COLLECTION_CLASSNAME(_class)::CanSkipThisReal(void *p) \ + { \ + _class *tmp = DowncastCCParticipant<_class >(p); + +#define NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_END \ + (void)tmp; \ + return false; \ + } + +/////////////////////////////////////////////////////////////////////////////// +// Helpers for implementing nsCycleCollectionParticipant::Unlink +// +// You need to use NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED if you want +// the base class Unlink version to be called before your own implementation. +// You can use NS_IMPL_CYCLE_COLLECTION_UNLINK_END_INHERITED if you want the +// base class Unlink to get called after your own implementation. You should +// never use them together. +/////////////////////////////////////////////////////////////////////////////// + +#define NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(_class) \ + NS_IMETHODIMP_(void) \ + NS_CYCLE_COLLECTION_CLASSNAME(_class)::Unlink(void *p) \ + { \ + _class *tmp = DowncastCCParticipant<_class >(p); + +#define NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(_class, _base_class) \ + NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(_class) \ + nsISupports *s = static_cast<nsISupports*>(p); \ + NS_CYCLE_COLLECTION_CLASSNAME(_base_class)::Unlink(s); + +#define NS_IMPL_CYCLE_COLLECTION_UNLINK_HELPER(_field) \ + ImplCycleCollectionUnlink(tmp->_field); + +#define NS_IMPL_CYCLE_COLLECTION_UNLINK(...) \ + MOZ_STATIC_ASSERT_VALID_ARG_COUNT(__VA_ARGS__); \ + MOZ_FOR_EACH(NS_IMPL_CYCLE_COLLECTION_UNLINK_HELPER, (), (__VA_ARGS__)) + +#define NS_IMPL_CYCLE_COLLECTION_UNLINK_END \ + (void)tmp; \ + } + +#define NS_IMPL_CYCLE_COLLECTION_UNLINK_END_INHERITED(_base_class) \ + nsISupports *s = static_cast<nsISupports*>(p); \ + NS_CYCLE_COLLECTION_CLASSNAME(_base_class)::Unlink(s); \ + (void)tmp; \ + } + +#define NS_IMPL_CYCLE_COLLECTION_UNLINK_0(_class) \ + NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(_class) \ + NS_IMPL_CYCLE_COLLECTION_UNLINK_END + + +/////////////////////////////////////////////////////////////////////////////// +// Helpers for implementing nsCycleCollectionParticipant::Traverse +/////////////////////////////////////////////////////////////////////////////// + +#define NS_IMPL_CYCLE_COLLECTION_DESCRIBE(_class, _refcnt) \ + cb.DescribeRefCountedNode(_refcnt, #_class); + +#define NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INTERNAL(_class) \ + NS_IMETHODIMP \ + NS_CYCLE_COLLECTION_CLASSNAME(_class)::Traverse \ + (void *p, nsCycleCollectionTraversalCallback &cb) \ + { \ + _class *tmp = DowncastCCParticipant<_class >(p); + +#define NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(_class) \ + NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INTERNAL(_class) \ + NS_IMPL_CYCLE_COLLECTION_DESCRIBE(_class, tmp->mRefCnt.get()) + +// Base class' CC participant should return NS_SUCCESS_INTERRUPTED_TRAVERSE +// from Traverse if it wants derived classes to not traverse anything from +// their CC participant. + +#define NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(_class, _base_class) \ + NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INTERNAL(_class) \ + nsISupports *s = static_cast<nsISupports*>(p); \ + if (NS_CYCLE_COLLECTION_CLASSNAME(_base_class)::Traverse(s, cb) \ + == NS_SUCCESS_INTERRUPTED_TRAVERSE) { \ + return NS_SUCCESS_INTERRUPTED_TRAVERSE; \ + } + +#define NS_IMPL_CYCLE_COLLECTION_TRAVERSE_HELPER(_field) \ + ImplCycleCollectionTraverse(cb, tmp->_field, #_field, 0); + +#define NS_IMPL_CYCLE_COLLECTION_TRAVERSE(...) \ + MOZ_STATIC_ASSERT_VALID_ARG_COUNT(__VA_ARGS__); \ + MOZ_FOR_EACH(NS_IMPL_CYCLE_COLLECTION_TRAVERSE_HELPER, (), (__VA_ARGS__)) + +#define NS_IMPL_CYCLE_COLLECTION_TRAVERSE_RAWPTR(_field) \ + CycleCollectionNoteChild(cb, tmp->_field, #_field); + +#define NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS \ + { \ + TraceCallbackFunc noteJsChild(&nsScriptObjectTracer::NoteJSChild); \ + Trace(p, noteJsChild, &cb); \ + } + +#define NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END \ + (void)tmp; \ + return NS_OK; \ + } + +/////////////////////////////////////////////////////////////////////////////// +// Helpers for implementing nsScriptObjectTracer::Trace +/////////////////////////////////////////////////////////////////////////////// + +#define NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(_class) \ + void \ + NS_CYCLE_COLLECTION_CLASSNAME(_class)::Trace(void *p, \ + const TraceCallbacks &aCallbacks, \ + void *aClosure) \ + { \ + _class *tmp = DowncastCCParticipant<_class >(p); + +#define NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN_INHERITED(_class, _base_class) \ + NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(_class) \ + nsISupports *s = static_cast<nsISupports*>(p); \ + NS_CYCLE_COLLECTION_CLASSNAME(_base_class)::Trace(s, aCallbacks, aClosure); + +#define NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(_field) \ + aCallbacks.Trace(&tmp->_field, #_field, aClosure); + +// NB: The (void)tmp; hack in the TRACE_END macro exists to support +// implementations that don't need to do anything in their Trace method. +// Without this hack, some compilers warn about the unused tmp local. +#define NS_IMPL_CYCLE_COLLECTION_TRACE_END \ + (void)tmp; \ + } + +/////////////////////////////////////////////////////////////////////////////// +// Helpers for implementing a concrete nsCycleCollectionParticipant +/////////////////////////////////////////////////////////////////////////////// + +// If a class defines a participant, then QIing an instance of that class to +// nsXPCOMCycleCollectionParticipant should produce that participant. +#ifdef DEBUG +#define NS_CHECK_FOR_RIGHT_PARTICIPANT_BASE \ + virtual void CheckForRightParticipant() +#define NS_CHECK_FOR_RIGHT_PARTICIPANT_DERIVED \ + virtual void CheckForRightParticipant() override +#define NS_CHECK_FOR_RIGHT_PARTICIPANT_BODY(_class) \ + { \ + nsXPCOMCycleCollectionParticipant *p; \ + CallQueryInterface(this, &p); \ + MOZ_ASSERT(p == &NS_CYCLE_COLLECTION_INNERNAME, \ + #_class " should QI to its own CC participant"); \ + } +#define NS_CHECK_FOR_RIGHT_PARTICIPANT_IMPL(_class) \ + NS_CHECK_FOR_RIGHT_PARTICIPANT_BASE \ + NS_CHECK_FOR_RIGHT_PARTICIPANT_BODY(_class) +#define NS_CHECK_FOR_RIGHT_PARTICIPANT_IMPL_INHERITED(_class) \ + NS_CHECK_FOR_RIGHT_PARTICIPANT_DERIVED \ + NS_CHECK_FOR_RIGHT_PARTICIPANT_BODY(_class) +#else +#define NS_CHECK_FOR_RIGHT_PARTICIPANT_IMPL(_class) +#define NS_CHECK_FOR_RIGHT_PARTICIPANT_IMPL_INHERITED(_class) +#endif + +#define NS_DECL_CYCLE_COLLECTION_CLASS_NAME_METHOD(_class) \ + NS_IMETHOD_(const char*) ClassName() override { return #_class; }; + + +#define NS_DECL_CYCLE_COLLECTION_CLASS_BODY_NO_UNLINK(_class, _base) \ +public: \ + NS_IMETHOD Traverse(void *p, nsCycleCollectionTraversalCallback &cb) \ + override; \ + NS_DECL_CYCLE_COLLECTION_CLASS_NAME_METHOD(_class) \ + NS_IMETHOD_(void) DeleteCycleCollectable(void *p) override \ + { \ + DowncastCCParticipant<_class>(p)->DeleteCycleCollectable(); \ + } \ + static _class* Downcast(nsISupports* s) \ + { \ + return static_cast<_class*>(static_cast<_base*>(s)); \ + } \ + static nsISupports* Upcast(_class *p) \ + { \ + return NS_ISUPPORTS_CAST(_base*, p); \ + } \ + template<typename T> \ + friend nsISupports* \ + ToSupports(T* p, NS_CYCLE_COLLECTION_INNERCLASS* dummy); + +#define NS_DECL_CYCLE_COLLECTION_CLASS_BODY(_class, _base) \ + NS_DECL_CYCLE_COLLECTION_CLASS_BODY_NO_UNLINK(_class, _base) \ + NS_IMETHOD_(void) Unlink(void *p) override; + +#define NS_PARTICIPANT_AS(type, participant) \ + const_cast<type*>(reinterpret_cast<const type*>(participant)) + +#define NS_IMPL_GET_XPCOM_CYCLE_COLLECTION_PARTICIPANT(_class) \ + static constexpr nsXPCOMCycleCollectionParticipant* GetParticipant() \ + { \ + return &_class::NS_CYCLE_COLLECTION_INNERNAME; \ + } + +/** + * We use this macro to force that classes that inherit from a ccable class and + * declare their own participant declare themselves as inherited cc classes. + * To avoid possibly unnecessary vtables we only do this checking in debug + * builds. + */ +#ifdef DEBUG +#define NOT_INHERITED_CANT_OVERRIDE virtual void BaseCycleCollectable() final {} +#else +#define NOT_INHERITED_CANT_OVERRIDE +#endif + +#define NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(_class, _base) \ +class NS_CYCLE_COLLECTION_INNERCLASS \ + : public nsXPCOMCycleCollectionParticipant \ +{ \ + NS_DECL_CYCLE_COLLECTION_CLASS_BODY(_class, _base) \ + NS_IMPL_GET_XPCOM_CYCLE_COLLECTION_PARTICIPANT(_class) \ +}; \ +NS_CHECK_FOR_RIGHT_PARTICIPANT_IMPL(_class) \ +static NS_CYCLE_COLLECTION_INNERCLASS NS_CYCLE_COLLECTION_INNERNAME; \ + NOT_INHERITED_CANT_OVERRIDE + +#define NS_DECL_CYCLE_COLLECTION_CLASS(_class) \ + NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(_class, _class) + +// Cycle collector helper for ambiguous classes that can sometimes be skipped. +#define NS_DECL_CYCLE_COLLECTION_SKIPPABLE_CLASS_AMBIGUOUS(_class, _base) \ +class NS_CYCLE_COLLECTION_INNERCLASS \ + : public nsXPCOMCycleCollectionParticipant \ +{ \ +public: \ + constexpr NS_CYCLE_COLLECTION_INNERCLASS () \ + : nsXPCOMCycleCollectionParticipant(true) {} \ +private: \ + NS_DECL_CYCLE_COLLECTION_CLASS_BODY(_class, _base) \ + NS_IMETHOD_(bool) CanSkipReal(void *p, bool aRemovingAllowed) override; \ + NS_IMETHOD_(bool) CanSkipInCCReal(void *p) override; \ + NS_IMETHOD_(bool) CanSkipThisReal(void *p) override; \ + NS_IMPL_GET_XPCOM_CYCLE_COLLECTION_PARTICIPANT(_class) \ +}; \ +NS_CHECK_FOR_RIGHT_PARTICIPANT_IMPL(_class) \ +static NS_CYCLE_COLLECTION_INNERCLASS NS_CYCLE_COLLECTION_INNERNAME; \ +NOT_INHERITED_CANT_OVERRIDE + +#define NS_DECL_CYCLE_COLLECTION_SKIPPABLE_CLASS(_class) \ + NS_DECL_CYCLE_COLLECTION_SKIPPABLE_CLASS_AMBIGUOUS(_class, _class) + +#define NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_AMBIGUOUS(_class, _base) \ +class NS_CYCLE_COLLECTION_INNERCLASS \ + : public nsXPCOMCycleCollectionParticipant \ +{ \ + NS_DECL_CYCLE_COLLECTION_CLASS_BODY(_class, _base) \ + NS_IMETHOD_(void) Trace(void *p, const TraceCallbacks &cb, void *closure) override; \ + NS_IMPL_GET_XPCOM_CYCLE_COLLECTION_PARTICIPANT(_class) \ +}; \ +NS_CHECK_FOR_RIGHT_PARTICIPANT_IMPL(_class) \ +static NS_CYCLE_COLLECTION_INNERCLASS NS_CYCLE_COLLECTION_INNERNAME; \ +NOT_INHERITED_CANT_OVERRIDE + +#define NS_DECL_CYCLE_COLLECTION_SKIPPABLE_SCRIPT_HOLDER_CLASS_AMBIGUOUS(_class, _base) \ +class NS_CYCLE_COLLECTION_INNERCLASS \ + : public nsXPCOMCycleCollectionParticipant \ +{ \ +public: \ + constexpr NS_CYCLE_COLLECTION_INNERCLASS () \ + : nsXPCOMCycleCollectionParticipant(true) {} \ +private: \ + NS_DECL_CYCLE_COLLECTION_CLASS_BODY(_class, _base) \ + NS_IMETHOD_(void) Trace(void *p, const TraceCallbacks &cb, void *closure) override; \ + NS_IMETHOD_(bool) CanSkipReal(void *p, bool aRemovingAllowed) override; \ + NS_IMETHOD_(bool) CanSkipInCCReal(void *p) override; \ + NS_IMETHOD_(bool) CanSkipThisReal(void *p) override; \ + NS_IMPL_GET_XPCOM_CYCLE_COLLECTION_PARTICIPANT(_class) \ +}; \ +NS_CHECK_FOR_RIGHT_PARTICIPANT_IMPL(_class) \ +static NS_CYCLE_COLLECTION_INNERCLASS NS_CYCLE_COLLECTION_INNERNAME; \ +NOT_INHERITED_CANT_OVERRIDE + +#define NS_DECL_CYCLE_COLLECTION_SKIPPABLE_SCRIPT_HOLDER_CLASS(_class) \ + NS_DECL_CYCLE_COLLECTION_SKIPPABLE_SCRIPT_HOLDER_CLASS_AMBIGUOUS(_class, _class) + +#define NS_DECL_CYCLE_COLLECTION_SKIPPABLE_SCRIPT_HOLDER_CLASS_INHERITED(_class, \ + _base_class) \ +class NS_CYCLE_COLLECTION_INNERCLASS \ + : public NS_CYCLE_COLLECTION_CLASSNAME(_base_class) \ +{ \ + NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED_BODY(_class, _base_class) \ + NS_IMETHOD_(void) Trace(void *p, const TraceCallbacks &cb, void *closure) override; \ + NS_IMETHOD_(bool) CanSkipReal(void *p, bool aRemovingAllowed) override; \ + NS_IMETHOD_(bool) CanSkipInCCReal(void *p) override; \ + NS_IMETHOD_(bool) CanSkipThisReal(void *p) override; \ + NS_IMPL_GET_XPCOM_CYCLE_COLLECTION_PARTICIPANT(_class) \ +}; \ +NS_CHECK_FOR_RIGHT_PARTICIPANT_IMPL_INHERITED(_class) \ +static NS_CYCLE_COLLECTION_INNERCLASS NS_CYCLE_COLLECTION_INNERNAME; + +#define NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(_class) \ + NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_AMBIGUOUS(_class, _class) + +#define NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED_BODY_NO_UNLINK(_class, \ + _base_class) \ +public: \ + NS_IMETHOD Traverse(void *p, nsCycleCollectionTraversalCallback &cb) \ + override; \ + NS_DECL_CYCLE_COLLECTION_CLASS_NAME_METHOD(_class) \ + static _class* Downcast(nsISupports* s) \ + { \ + return static_cast<_class*>(static_cast<_base_class*>( \ + NS_CYCLE_COLLECTION_CLASSNAME(_base_class)::Downcast(s))); \ + } + +#define NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED_BODY(_class, _base_class) \ + NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED_BODY_NO_UNLINK(_class, _base_class) \ + NS_IMETHOD_(void) Unlink(void *p) override; + +#define NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(_class, _base_class) \ +class NS_CYCLE_COLLECTION_INNERCLASS \ + : public NS_CYCLE_COLLECTION_CLASSNAME(_base_class) \ +{ \ +public: \ + NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED_BODY(_class, _base_class) \ + NS_IMPL_GET_XPCOM_CYCLE_COLLECTION_PARTICIPANT(_class) \ +}; \ +NS_CHECK_FOR_RIGHT_PARTICIPANT_IMPL_INHERITED(_class) \ +static NS_CYCLE_COLLECTION_INNERCLASS NS_CYCLE_COLLECTION_INNERNAME; + +#define NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED_NO_UNLINK(_class, \ + _base_class) \ +class NS_CYCLE_COLLECTION_INNERCLASS \ + : public NS_CYCLE_COLLECTION_CLASSNAME(_base_class) \ +{ \ +public: \ + NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED_BODY_NO_UNLINK(_class, _base_class) \ + NS_IMPL_GET_XPCOM_CYCLE_COLLECTION_PARTICIPANT(_class) \ +}; \ +NS_CHECK_FOR_RIGHT_PARTICIPANT_IMPL_INHERITED(_class) \ +static NS_CYCLE_COLLECTION_INNERCLASS NS_CYCLE_COLLECTION_INNERNAME; + +#define NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(_class, \ + _base_class) \ +class NS_CYCLE_COLLECTION_INNERCLASS \ + : public NS_CYCLE_COLLECTION_CLASSNAME(_base_class) \ +{ \ + NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED_BODY(_class, _base_class) \ + NS_IMETHOD_(void) Trace(void *p, const TraceCallbacks &cb, void *closure) \ + override; \ + NS_IMPL_GET_XPCOM_CYCLE_COLLECTION_PARTICIPANT(_class) \ +}; \ +NS_CHECK_FOR_RIGHT_PARTICIPANT_IMPL_INHERITED(_class) \ +static NS_CYCLE_COLLECTION_INNERCLASS NS_CYCLE_COLLECTION_INNERNAME; + +// Cycle collector participant declarations. + +#define NS_DECL_CYCLE_COLLECTION_NATIVE_CLASS_BODY(_class) \ + public: \ + NS_IMETHOD_(void) Root(void *n) override; \ + NS_IMETHOD_(void) Unlink(void *n) override; \ + NS_IMETHOD_(void) Unroot(void *n) override; \ + NS_IMETHOD Traverse(void *n, nsCycleCollectionTraversalCallback &cb) \ + override; \ + NS_DECL_CYCLE_COLLECTION_CLASS_NAME_METHOD(_class) \ + NS_IMETHOD_(void) DeleteCycleCollectable(void *n) override \ + { \ + DowncastCCParticipant<_class>(n)->DeleteCycleCollectable(); \ + } \ + static _class* Downcast(void* s) \ + { \ + return DowncastCCParticipant<_class>(s); \ + } \ + static void* Upcast(_class *p) \ + { \ + return static_cast<void*>(p); \ + } + +#define NS_DECL_CYCLE_COLLECTION_NATIVE_CLASS(_class) \ + void DeleteCycleCollectable(void) \ + { \ + delete this; \ + } \ + class NS_CYCLE_COLLECTION_INNERCLASS \ + : public nsCycleCollectionParticipant \ + { \ + NS_DECL_CYCLE_COLLECTION_NATIVE_CLASS_BODY(_class) \ + static constexpr nsCycleCollectionParticipant* GetParticipant() \ + { \ + return &_class::NS_CYCLE_COLLECTION_INNERNAME; \ + } \ + }; \ + static NS_CYCLE_COLLECTION_INNERCLASS NS_CYCLE_COLLECTION_INNERNAME; + +#define NS_DECL_CYCLE_COLLECTION_SKIPPABLE_NATIVE_CLASS(_class) \ + void DeleteCycleCollectable(void) \ + { \ + delete this; \ + } \ + class NS_CYCLE_COLLECTION_INNERCLASS \ + : public nsCycleCollectionParticipant \ + { \ + public: \ + constexpr NS_CYCLE_COLLECTION_INNERCLASS () \ + : nsCycleCollectionParticipant(true) {} \ + private: \ + NS_DECL_CYCLE_COLLECTION_NATIVE_CLASS_BODY(_class) \ + NS_IMETHOD_(bool) CanSkipReal(void *p, bool aRemovingAllowed) override; \ + NS_IMETHOD_(bool) CanSkipInCCReal(void *p) override; \ + NS_IMETHOD_(bool) CanSkipThisReal(void *p) override; \ + static nsCycleCollectionParticipant* GetParticipant() \ + { \ + return &_class::NS_CYCLE_COLLECTION_INNERNAME; \ + } \ + }; \ + static NS_CYCLE_COLLECTION_INNERCLASS NS_CYCLE_COLLECTION_INNERNAME; + +#define NS_DECL_CYCLE_COLLECTION_SKIPPABLE_NATIVE_CLASS_WITH_CUSTOM_DELETE(_class) \ +class NS_CYCLE_COLLECTION_INNERCLASS \ + : public nsCycleCollectionParticipant \ +{ \ +public: \ + constexpr NS_CYCLE_COLLECTION_INNERCLASS () \ + : nsCycleCollectionParticipant(true) {} \ +private: \ + NS_DECL_CYCLE_COLLECTION_NATIVE_CLASS_BODY(_class) \ + NS_IMETHOD_(bool) CanSkipReal(void *p, bool aRemovingAllowed) override; \ + NS_IMETHOD_(bool) CanSkipInCCReal(void *p) override; \ + NS_IMETHOD_(bool) CanSkipThisReal(void *p) override; \ + static nsCycleCollectionParticipant* GetParticipant() \ + { \ + return &_class::NS_CYCLE_COLLECTION_INNERNAME; \ + } \ +}; \ +static NS_CYCLE_COLLECTION_INNERCLASS NS_CYCLE_COLLECTION_INNERNAME; + +#define NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(_class) \ + void DeleteCycleCollectable(void) \ + { \ + delete this; \ + } \ + class NS_CYCLE_COLLECTION_INNERCLASS \ + : public nsScriptObjectTracer \ + { \ + NS_DECL_CYCLE_COLLECTION_NATIVE_CLASS_BODY(_class) \ + NS_IMETHOD_(void) Trace(void *p, const TraceCallbacks &cb, void *closure) \ + override; \ + static constexpr nsScriptObjectTracer* GetParticipant() \ + { \ + return &_class::NS_CYCLE_COLLECTION_INNERNAME; \ + } \ + }; \ + static NS_CYCLE_COLLECTION_INNERCLASS NS_CYCLE_COLLECTION_INNERNAME; + +#define NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(_class, _root_function) \ + NS_IMETHODIMP_(void) \ + NS_CYCLE_COLLECTION_CLASSNAME(_class)::Root(void *p) \ + { \ + _class *tmp = static_cast<_class*>(p); \ + tmp->_root_function(); \ + } + +#define NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(_class, _unroot_function) \ + NS_IMETHODIMP_(void) \ + NS_CYCLE_COLLECTION_CLASSNAME(_class)::Unroot(void *p) \ + { \ + _class *tmp = static_cast<_class*>(p); \ + tmp->_unroot_function(); \ + } + +#define NS_IMPL_CYCLE_COLLECTION_CLASS(_class) \ + _class::NS_CYCLE_COLLECTION_INNERCLASS _class::NS_CYCLE_COLLECTION_INNERNAME; + +// NB: This is not something you usually want to use. It is here to allow +// adding things to the CC graph to help debugging via CC logs, but it does not +// traverse or unlink anything, so it is useless for anything else. +#define NS_IMPL_CYCLE_COLLECTION_0(_class) \ + NS_IMPL_CYCLE_COLLECTION_CLASS(_class) \ + NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(_class) \ + NS_IMPL_CYCLE_COLLECTION_UNLINK_END \ + NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(_class) \ + NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END + +#define NS_IMPL_CYCLE_COLLECTION(_class, ...) \ + NS_IMPL_CYCLE_COLLECTION_CLASS(_class) \ + NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(_class) \ + NS_IMPL_CYCLE_COLLECTION_UNLINK(__VA_ARGS__) \ + NS_IMPL_CYCLE_COLLECTION_UNLINK_END \ + NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(_class) \ + NS_IMPL_CYCLE_COLLECTION_TRAVERSE(__VA_ARGS__) \ + NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END + +// If you are looking for NS_IMPL_CYCLE_COLLECTION_INHERITED_0(_class, _base) +// you should instead not declare any cycle collected stuff in _class, so it +// will just inherit the CC declarations from _base. + +#define NS_IMPL_CYCLE_COLLECTION_INHERITED(_class, _base, ...) \ + NS_IMPL_CYCLE_COLLECTION_CLASS(_class) \ + NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(_class, _base) \ + NS_IMPL_CYCLE_COLLECTION_UNLINK(__VA_ARGS__) \ + NS_IMPL_CYCLE_COLLECTION_UNLINK_END \ + NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(_class, _base) \ + NS_IMPL_CYCLE_COLLECTION_TRAVERSE(__VA_ARGS__) \ + NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END + +#define NS_CYCLE_COLLECTION_NOTE_EDGE_NAME CycleCollectionNoteEdgeName + +#endif // nsCycleCollectionParticipant_h__ |