/** @file * VirtualBox COM base classes definition */ /* * Copyright (C) 2006-2010 Oracle Corporation * * This file is part of VirtualBox Open Source Edition (OSE), as * available from http://www.virtualbox.org. This file is free software; * you can redistribute it and/or modify it under the terms of the GNU * General Public License (GPL) as published by the Free Software * Foundation, in version 2 as it comes in the "COPYING" file of the * VirtualBox OSE distribution. VirtualBox OSE is distributed in the * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. */ #ifndef ____H_VIRTUALBOXBASEIMPL #define ____H_VIRTUALBOXBASEIMPL #include #include #include #include #include "VBox/com/AutoLock.h" #include "VBox/com/string.h" #include "VBox/com/Guid.h" #include "VBox/com/VirtualBox.h" // avoid including VBox/settings.h and VBox/xml.h; // only declare the classes namespace xml { class File; } using namespace com; using namespace util; class AutoInitSpan; class AutoUninitSpan; class VirtualBox; class Machine; class Medium; class Host; typedef std::list< ComObjPtr > MediaList; //////////////////////////////////////////////////////////////////////////////// // // COM helpers // //////////////////////////////////////////////////////////////////////////////// #if !defined (VBOX_WITH_XPCOM) #include /* use a special version of the singleton class factory, * see KB811591 in msdn for more info. */ #undef DECLARE_CLASSFACTORY_SINGLETON #define DECLARE_CLASSFACTORY_SINGLETON(obj) DECLARE_CLASSFACTORY_EX(CMyComClassFactorySingleton) template class CMyComClassFactorySingleton : public CComClassFactory { public: CMyComClassFactorySingleton() : m_hrCreate(S_OK){} virtual ~CMyComClassFactorySingleton(){} // IClassFactory STDMETHOD(CreateInstance)(LPUNKNOWN pUnkOuter, REFIID riid, void** ppvObj) { HRESULT hRes = E_POINTER; if (ppvObj != NULL) { *ppvObj = NULL; // Aggregation is not supported in singleton objects. ATLASSERT(pUnkOuter == NULL); if (pUnkOuter != NULL) hRes = CLASS_E_NOAGGREGATION; else { if (m_hrCreate == S_OK && m_spObj == NULL) { Lock(); __try { // Fix: The following If statement was moved inside the __try statement. // Did another thread arrive here first? if (m_hrCreate == S_OK && m_spObj == NULL) { // lock the module to indicate activity // (necessary for the monitor shutdown thread to correctly // terminate the module in case when CreateInstance() fails) _pAtlModule->Lock(); CComObjectCached *p; m_hrCreate = CComObjectCached::CreateInstance(&p); if (SUCCEEDED(m_hrCreate)) { m_hrCreate = p->QueryInterface(IID_IUnknown, (void**)&m_spObj); if (FAILED(m_hrCreate)) { delete p; } } _pAtlModule->Unlock(); } } __finally { Unlock(); } } if (m_hrCreate == S_OK) { hRes = m_spObj->QueryInterface(riid, ppvObj); } else { hRes = m_hrCreate; } } } return hRes; } HRESULT m_hrCreate; CComPtr m_spObj; }; #endif /* !defined (VBOX_WITH_XPCOM) */ //////////////////////////////////////////////////////////////////////////////// // // Macros // //////////////////////////////////////////////////////////////////////////////// /** * Special version of the Assert macro to be used within VirtualBoxBase * subclasses that also inherit the VirtualBoxSupportErrorInfoImpl template. * * In the debug build, this macro is equivalent to Assert. * In the release build, this macro uses |setError(E_FAIL, ...)| to set the * error info from the asserted expression. * * @see VirtualBoxSupportErrorInfoImpl::setError * * @param expr Expression which should be true. */ #if defined (DEBUG) #define ComAssert(expr) Assert(expr) #else #define ComAssert(expr) \ do { \ if (RT_UNLIKELY(!(expr))) \ setError(E_FAIL, \ "Assertion failed: [%s] at '%s' (%d) in %s.\nPlease contact the product vendor!", \ #expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \ } while (0) #endif /** * Special version of the AssertMsg macro to be used within VirtualBoxBase * subclasses that also inherit the VirtualBoxSupportErrorInfoImpl template. * * See ComAssert for more info. * * @param expr Expression which should be true. * @param a printf argument list (in parenthesis). */ #if defined (DEBUG) #define ComAssertMsg(expr, a) AssertMsg(expr, a) #else #define ComAssertMsg(expr, a) \ do { \ if (RT_UNLIKELY(!(expr))) \ setError(E_FAIL, \ "Assertion failed: [%s] at '%s' (%d) in %s.\n%s.\nPlease contact the product vendor!", \ #expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \ } while (0) #endif /** * Special version of the AssertRC macro to be used within VirtualBoxBase * subclasses that also inherit the VirtualBoxSupportErrorInfoImpl template. * * See ComAssert for more info. * * @param vrc VBox status code. */ #if defined (DEBUG) #define ComAssertRC(vrc) AssertRC(vrc) #else #define ComAssertRC(vrc) ComAssertMsgRC(vrc, ("%Rra", vrc)) #endif /** * Special version of the AssertMsgRC macro to be used within VirtualBoxBase * subclasses that also inherit the VirtualBoxSupportErrorInfoImpl template. * * See ComAssert for more info. * * @param vrc VBox status code. * @param msg printf argument list (in parenthesis). */ #if defined (DEBUG) #define ComAssertMsgRC(vrc, msg) AssertMsgRC(vrc, msg) #else #define ComAssertMsgRC(vrc, msg) ComAssertMsg(RT_SUCCESS(vrc), msg) #endif /** * Special version of the AssertComRC macro to be used within VirtualBoxBase * subclasses that also inherit the VirtualBoxSupportErrorInfoImpl template. * * See ComAssert for more info. * * @param rc COM result code */ #if defined (DEBUG) #define ComAssertComRC(rc) AssertComRC(rc) #else #define ComAssertComRC(rc) ComAssertMsg(SUCCEEDED(rc), ("COM RC = %Rhrc (0x%08X)", (rc), (rc))) #endif /** Special version of ComAssert that returns ret if expr fails */ #define ComAssertRet(expr, ret) \ do { ComAssert(expr); if (!(expr)) return (ret); } while (0) /** Special version of ComAssertMsg that returns ret if expr fails */ #define ComAssertMsgRet(expr, a, ret) \ do { ComAssertMsg(expr, a); if (!(expr)) return (ret); } while (0) /** Special version of ComAssertRC that returns ret if vrc does not succeed */ #define ComAssertRCRet(vrc, ret) \ do { ComAssertRC(vrc); if (!RT_SUCCESS(vrc)) return (ret); } while (0) /** Special version of ComAssertComRC that returns ret if rc does not succeed */ #define ComAssertComRCRet(rc, ret) \ do { ComAssertComRC(rc); if (!SUCCEEDED(rc)) return (ret); } while (0) /** Special version of ComAssertComRC that returns rc if rc does not succeed */ #define ComAssertComRCRetRC(rc) \ do { ComAssertComRC(rc); if (!SUCCEEDED(rc)) return (rc); } while (0) /** Special version of ComAssert that evaluates eval and breaks if expr fails */ #define ComAssertBreak(expr, eval) \ if (1) { ComAssert(expr); if (!(expr)) { eval; break; } } else do {} while (0) /** Special version of ComAssertMsg that evaluates eval and breaks if expr fails */ #define ComAssertMsgBreak(expr, a, eval) \ if (1) { ComAssertMsg(expr, a); if (!(expr)) { eval; break; } } else do {} while (0) /** Special version of ComAssertRC that evaluates eval and breaks if vrc does not succeed */ #define ComAssertRCBreak(vrc, eval) \ if (1) { ComAssertRC(vrc); if (!RT_SUCCESS(vrc)) { eval; break; } } else do {} while (0) /** Special version of ComAssertFailed that evaluates eval and breaks */ #define ComAssertFailedBreak(eval) \ if (1) { ComAssertFailed(); { eval; break; } } else do {} while (0) /** Special version of ComAssertMsgFailed that evaluates eval and breaks */ #define ComAssertMsgFailedBreak(msg, eval) \ if (1) { ComAssertMsgFailed (msg); { eval; break; } } else do {} while (0) /** Special version of ComAssertComRC that evaluates eval and breaks if rc does not succeed */ #define ComAssertComRCBreak(rc, eval) \ if (1) { ComAssertComRC(rc); if (!SUCCEEDED(rc)) { eval; break; } } else do {} while (0) /** Special version of ComAssertComRC that just breaks if rc does not succeed */ #define ComAssertComRCBreakRC(rc) \ if (1) { ComAssertComRC(rc); if (!SUCCEEDED(rc)) { break; } } else do {} while (0) /** Special version of ComAssert that evaluates eval and throws it if expr fails */ #define ComAssertThrow(expr, eval) \ if (1) { ComAssert(expr); if (!(expr)) { throw (eval); } } else do {} while (0) /** Special version of ComAssertRC that evaluates eval and throws it if vrc does not succeed */ #define ComAssertRCThrow(vrc, eval) \ if (1) { ComAssertRC(vrc); if (!RT_SUCCESS(vrc)) { throw (eval); } } else do {} while (0) /** Special version of ComAssertComRC that evaluates eval and throws it if rc does not succeed */ #define ComAssertComRCThrow(rc, eval) \ if (1) { ComAssertComRC(rc); if (!SUCCEEDED(rc)) { throw (eval); } } else do {} while (0) /** Special version of ComAssertComRC that just throws rc if rc does not succeed */ #define ComAssertComRCThrowRC(rc) \ if (1) { ComAssertComRC(rc); if (!SUCCEEDED(rc)) { throw rc; } } else do {} while (0) //////////////////////////////////////////////////////////////////////////////// /** * Checks that the pointer argument is not NULL and returns E_INVALIDARG + * extended error info on failure. * @param arg Input pointer-type argument (strings, interface pointers...) */ #define CheckComArgNotNull(arg) \ do { \ if (RT_UNLIKELY((arg) == NULL)) \ return setError(E_INVALIDARG, tr("Argument %s is NULL"), #arg); \ } while (0) /** * Checks that safe array argument is not NULL and returns E_INVALIDARG + * extended error info on failure. * @param arg Input safe array argument (strings, interface pointers...) */ #define CheckComArgSafeArrayNotNull(arg) \ do { \ if (RT_UNLIKELY(ComSafeArrayInIsNull(arg))) \ return setError(E_INVALIDARG, tr("Argument %s is NULL"), #arg); \ } while (0) /** * Checks that the string argument is not a NULL or empty string and returns * E_INVALIDARG + extended error info on failure. * @param arg Input string argument (BSTR etc.). */ #define CheckComArgStrNotEmptyOrNull(arg) \ do { \ if (RT_UNLIKELY((arg) == NULL || *(arg) == '\0')) \ return setError(E_INVALIDARG, \ tr("Argument %s is empty or NULL"), #arg); \ } while (0) /** * Checks that the given expression (that must involve the argument) is true and * returns E_INVALIDARG + extended error info on failure. * @param arg Argument. * @param expr Expression to evaluate. */ #define CheckComArgExpr(arg, expr) \ do { \ if (RT_UNLIKELY(!(expr))) \ return setError(E_INVALIDARG, \ tr("Argument %s is invalid (must be %s)"), #arg, #expr); \ } while (0) /** * Checks that the given expression (that must involve the argument) is true and * returns E_INVALIDARG + extended error info on failure. The error message must * be customized. * @param arg Argument. * @param expr Expression to evaluate. * @param msg Parenthesized printf-like expression (must start with a verb, * like "must be one of...", "is not within..."). */ #define CheckComArgExprMsg(arg, expr, msg) \ do { \ if (RT_UNLIKELY(!(expr))) \ return setError(E_INVALIDARG, tr ("Argument %s %s"), \ #arg, Utf8StrFmt msg .c_str()); \ } while (0) /** * Checks that the given pointer to an output argument is valid and returns * E_POINTER + extended error info otherwise. * @param arg Pointer argument. */ #define CheckComArgOutPointerValid(arg) \ do { \ if (RT_UNLIKELY(!VALID_PTR(arg))) \ return setError(E_POINTER, \ tr("Output argument %s points to invalid memory location (%p)"), \ #arg, (void *) (arg)); \ } while (0) /** * Checks that the given pointer to an output safe array argument is valid and * returns E_POINTER + extended error info otherwise. * @param arg Safe array argument. */ #define CheckComArgOutSafeArrayPointerValid(arg) \ do { \ if (RT_UNLIKELY(ComSafeArrayOutIsNull(arg))) \ return setError(E_POINTER, \ tr("Output argument %s points to invalid memory location (%p)"), \ #arg, (void*)(arg)); \ } while (0) /** * Sets the extended error info and returns E_NOTIMPL. */ #define ReturnComNotImplemented() \ do { \ return setError(E_NOTIMPL, tr("Method %s is not implemented"), __FUNCTION__); \ } while (0) /** * Declares an empty constructor and destructor for the given class. * This is useful to prevent the compiler from generating the default * ctor and dtor, which in turn allows to use forward class statements * (instead of including their header files) when declaring data members of * non-fundamental types with constructors (which are always called implicitly * by constructors and by the destructor of the class). * * This macro is to be placed within (the public section of) the class * declaration. Its counterpart, DEFINE_EMPTY_CTOR_DTOR, must be placed * somewhere in one of the translation units (usually .cpp source files). * * @param cls class to declare a ctor and dtor for */ #define DECLARE_EMPTY_CTOR_DTOR(cls) cls(); ~cls(); /** * Defines an empty constructor and destructor for the given class. * See DECLARE_EMPTY_CTOR_DTOR for more info. */ #define DEFINE_EMPTY_CTOR_DTOR(cls) \ cls::cls() { /*empty*/ } \ cls::~cls() { /*empty*/ } /** * A variant of 'throw' that hits a debug breakpoint first to make * finding the actual thrower possible. */ #ifdef DEBUG #define DebugBreakThrow(a) \ do { \ RTAssertDebugBreak(); \ throw (a); \ } while (0) #else #define DebugBreakThrow(a) throw (a) #endif /** * Parent class of VirtualBoxBase which enables translation support (which * Main doesn't have yet, but this provides the tr() function which will one * day provide translations). * * This class sits in between Lockable and VirtualBoxBase only for the one * reason that the USBProxyService wants translation support but is not * implemented as a COM object, which VirtualBoxBase implies. */ class ATL_NO_VTABLE VirtualBoxTranslatable : public Lockable { public: /** * Placeholder method with which translations can one day be implemented * in Main. This gets called by the tr() function. * @param context * @param pcszSourceText * @param comment * @return */ static const char *translate(const char *context, const char *pcszSourceText, const char *comment = 0) { NOREF(context); NOREF(comment); return pcszSourceText; } /** * Translates the given text string by calling translate() and passing * the name of the C class as the first argument ("context of * translation"). See VirtualBoxBase::translate() for more info. * * @param aSourceText String to translate. * @param aComment Comment to the string to resolve possible * ambiguities (NULL means no comment). * * @return Translated version of the source string in UTF-8 encoding, or * the source string itself if the translation is not found in the * specified context. */ inline static const char *tr(const char *pcszSourceText, const char *aComment = NULL) { return VirtualBoxTranslatable::translate(NULL, // getComponentName(), eventually pcszSourceText, aComment); } }; //////////////////////////////////////////////////////////////////////////////// // // VirtualBoxBase // //////////////////////////////////////////////////////////////////////////////// #define VIRTUALBOXBASE_ADD_VIRTUAL_COMPONENT_METHODS(cls, iface) \ virtual const IID& getClassIID() const \ { \ return cls::getStaticClassIID(); \ } \ static const IID& getStaticClassIID() \ { \ return COM_IIDOF(iface); \ } \ virtual const char* getComponentName() const \ { \ return cls::getStaticComponentName(); \ } \ static const char* getStaticComponentName() \ { \ return #cls; \ } /** * VIRTUALBOXBASE_ADD_ERRORINFO_SUPPORT: * This macro must be used once in the declaration of any class derived * from VirtualBoxBase. It implements the pure virtual getClassIID() and * getComponentName() methods. If this macro is not present, instances * of a class derived from VirtualBoxBase cannot be instantiated. * * @param X The class name, e.g. "Class". * @param IX The interface name which this class implements, e.g. "IClass". */ #ifdef VBOX_WITH_XPCOM #define VIRTUALBOXBASE_ADD_ERRORINFO_SUPPORT(cls, iface) \ VIRTUALBOXBASE_ADD_VIRTUAL_COMPONENT_METHODS(cls, iface) #else // #ifdef VBOX_WITH_XPCOM #define VIRTUALBOXBASE_ADD_ERRORINFO_SUPPORT(cls, iface) \ VIRTUALBOXBASE_ADD_VIRTUAL_COMPONENT_METHODS(cls, iface) \ STDMETHOD(InterfaceSupportsErrorInfo)(REFIID riid) \ { \ const _ATL_INTMAP_ENTRY* pEntries = cls::_GetEntries(); \ Assert(pEntries); \ if (!pEntries) \ return S_FALSE; \ BOOL bSupports = FALSE; \ BOOL bISupportErrorInfoFound = FALSE; \ while (pEntries->pFunc != NULL && !bSupports) \ { \ if (!bISupportErrorInfoFound) \ bISupportErrorInfoFound = InlineIsEqualGUID(*(pEntries->piid), IID_ISupportErrorInfo); \ else \ bSupports = InlineIsEqualGUID(*(pEntries->piid), riid); \ pEntries++; \ } \ Assert(bISupportErrorInfoFound); \ return bSupports ? S_OK : S_FALSE; \ } #endif // #ifdef VBOX_WITH_XPCOM /** * Abstract base class for all component classes implementing COM * interfaces of the VirtualBox COM library. * * Declares functionality that should be available in all components. * * Among the basic functionality implemented by this class is the primary object * state that indicates if the object is ready to serve the calls, and if not, * what stage it is currently at. Here is the primary state diagram: * * +-------------------------------------------------------+ * | | * | (InitFailed) -----------------------+ | * | ^ | | * v | v | * [*] ---> NotReady ----> (InInit) -----> Ready -----> (InUninit) ----+ * ^ | * | v * | Limited * | | * +-------+ * * The object is fully operational only when its state is Ready. The Limited * state means that only some vital part of the object is operational, and it * requires some sort of reinitialization to become fully operational. The * NotReady state means the object is basically dead: it either was not yet * initialized after creation at all, or was uninitialized and is waiting to be * destroyed when the last reference to it is released. All other states are * transitional. * * The NotReady->InInit->Ready, NotReady->InInit->Limited and * NotReady->InInit->InitFailed transition is done by the AutoInitSpan smart * class. * * The Limited->InInit->Ready, Limited->InInit->Limited and * Limited->InInit->InitFailed transition is done by the AutoReinitSpan smart * class. * * The Ready->InUninit->NotReady and InitFailed->InUninit->NotReady * transitions are done by the AutoUninitSpan smart class. * * In order to maintain the primary state integrity and declared functionality * all subclasses must: * * 1) Use the above Auto*Span classes to perform state transitions. See the * individual class descriptions for details. * * 2) All public methods of subclasses (i.e. all methods that can be called * directly, not only from within other methods of the subclass) must have a * standard prolog as described in the AutoCaller and AutoLimitedCaller * documentation. Alternatively, they must use addCaller()/releaseCaller() * directly (and therefore have both the prolog and the epilog), but this is * not recommended. */ class ATL_NO_VTABLE VirtualBoxBase : public VirtualBoxTranslatable, public CComObjectRootEx #if !defined (VBOX_WITH_XPCOM) , public ISupportErrorInfo #endif { public: enum State { NotReady, Ready, InInit, InUninit, InitFailed, Limited }; VirtualBoxBase(); virtual ~VirtualBoxBase(); /** * Unintialization method. * * Must be called by all final implementations (component classes) when the * last reference to the object is released, before calling the destructor. * * This method is also automatically called by the uninit() method of this * object's parent if this object is a dependent child of a class derived * from VirtualBoxBaseWithChildren (see * VirtualBoxBaseWithChildren::addDependentChild). * * @note Never call this method the AutoCaller scope or after the * #addCaller() call not paired by #releaseCaller() because it is a * guaranteed deadlock. See AutoUninitSpan for details. */ virtual void uninit() { } virtual HRESULT addCaller(State *aState = NULL, bool aLimited = false); virtual void releaseCaller(); /** * Adds a limited caller. This method is equivalent to doing * addCaller (aState, true), but it is preferred because provides * better self-descriptiveness. See #addCaller() for more info. */ HRESULT addLimitedCaller(State *aState = NULL) { return addCaller(aState, true /* aLimited */); } /** * Pure virtual method for simple run-time type identification without * having to enable C++ RTTI. * * This *must* be implemented by every subclass deriving from VirtualBoxBase; * use the VIRTUALBOXBASE_ADD_ERRORINFO_SUPPORT macro to do that most easily. */ virtual const IID& getClassIID() const = 0; /** * Pure virtual method for simple run-time type identification without * having to enable C++ RTTI. * * This *must* be implemented by every subclass deriving from VirtualBoxBase; * use the VIRTUALBOXBASE_ADD_ERRORINFO_SUPPORT macro to do that most easily. */ virtual const char* getComponentName() const = 0; /** * Virtual method which determins the locking class to be used for validating * lock order with the standard member lock handle. This method is overridden * in a number of subclasses. */ virtual VBoxLockingClass getLockingClass() const { return LOCKCLASS_OTHEROBJECT; } virtual RWLockHandle *lockHandle() const; /** * Returns a lock handle used to protect the primary state fields (used by * #addCaller(), AutoInitSpan, AutoUninitSpan, etc.). Only intended to be * used for similar purposes in subclasses. WARNING: NO any other locks may * be requested while holding this lock! */ WriteLockHandle *stateLockHandle() { return &mStateLock; } static HRESULT setErrorInternal(HRESULT aResultCode, const GUID &aIID, const char *aComponent, const Utf8Str &aText, bool aWarning, bool aLogIt); HRESULT setError(HRESULT aResultCode, const char *pcsz, ...); HRESULT setWarning(HRESULT aResultCode, const char *pcsz, ...); HRESULT setErrorNoLog(HRESULT aResultCode, const char *pcsz, ...); private: void setState(State aState) { Assert(mState != aState); mState = aState; mStateChangeThread = RTThreadSelf(); } /** Primary state of this object */ State mState; /** Thread that caused the last state change */ RTTHREAD mStateChangeThread; /** Total number of active calls to this object */ unsigned mCallers; /** Posted when the number of callers drops to zero */ RTSEMEVENT mZeroCallersSem; /** Posted when the object goes from InInit/InUninit to some other state */ RTSEMEVENTMULTI mInitUninitSem; /** Number of threads waiting for mInitUninitDoneSem */ unsigned mInitUninitWaiters; /** Protects access to state related data members */ WriteLockHandle mStateLock; /** User-level object lock for subclasses */ mutable RWLockHandle *mObjectLock; friend class AutoInitSpan; friend class AutoReinitSpan; friend class AutoUninitSpan; }; /** * Dummy macro that is used to shut down Qt's lupdate tool warnings in some * situations. This macro needs to be present inside (better at the very * beginning) of the declaration of the class that inherits from * VirtualBoxSupportTranslation template, to make lupdate happy. */ #define Q_OBJECT //////////////////////////////////////////////////////////////////////////////// /** * Base class to track VirtualBoxBaseNEXT chlidren of the component. * * This class is a preferrable VirtualBoxBase replacement for components that * operate with collections of child components. It gives two useful * possibilities: * *
  1. * Given an IUnknown instance, it's possible to quickly determine * whether this instance represents a child object that belongs to the * given component, and if so, get a valid VirtualBoxBase pointer to the * child object. The returned pointer can be then safely casted to the * actual class of the child object (to get access to its "internal" * non-interface methods) provided that no other child components implement * the same original COM interface IUnknown is queried from. *
  2. * When the parent object uninitializes itself, it can easily unintialize * all its VirtualBoxBase derived children (using their * VirtualBoxBase::uninit() implementations). This is done simply by * calling the #uninitDependentChildren() method. *
* * In order to let the above work, the following must be done: *
  1. * When a child object is initialized, it calls #addDependentChild() of * its parent to register itself within the list of dependent children. *
  2. * When the child object it is uninitialized, it calls * #removeDependentChild() to unregister itself. *
* * Note that if the parent object does not call #uninitDependentChildren() when * it gets uninitialized, it must call uninit() methods of individual children * manually to disconnect them; a failure to do so will cause crashes in these * methods when children get destroyed. The same applies to children not calling * #removeDependentChild() when getting destroyed. * * Note that children added by #addDependentChild() are weakly referenced * (i.e. AddRef() is not called), so when a child object is deleted externally * (because it's reference count goes to zero), it will automatically remove * itself from the map of dependent children provided that it follows the rules * described here. * * Access to the child list is serialized using the #childrenLock() lock handle * (which defaults to the general object lock handle (see * VirtualBoxBase::lockHandle()). This lock is used by all add/remove methods of * this class so be aware of the need to preserve the {parent, child} lock order * when calling these methods. * * Read individual method descriptions to get further information. * * @todo This is a VirtualBoxBaseWithChildren equivalent that uses the * VirtualBoxBaseNEXT implementation. Will completely supersede * VirtualBoxBaseWithChildren after the old VirtualBoxBase implementation * has gone. */ class VirtualBoxBaseWithChildrenNEXT : public VirtualBoxBase { public: VirtualBoxBaseWithChildrenNEXT() {} virtual ~VirtualBoxBaseWithChildrenNEXT() {} /** * Lock handle to use when adding/removing child objects from the list of * children. It is guaranteed that no any other lock is requested in methods * of this class while holding this lock. * * @warning By default, this simply returns the general object's lock handle * (see VirtualBoxBase::lockHandle()) which is sufficient for most * cases. */ virtual RWLockHandle *childrenLock() { return lockHandle(); } /** * Adds the given child to the list of dependent children. * * Usually gets called from the child's init() method. * * @note @a aChild (unless it is in InInit state) must be protected by * VirtualBoxBase::AutoCaller to make sure it is not uninitialized on * another thread during this method's call. * * @note When #childrenLock() is not overloaded (returns the general object * lock) and this method is called from under the child's read or * write lock, make sure the {parent, child} locking order is * preserved by locking the callee (this object) for writing before * the child's lock. * * @param aChild Child object to add (must inherit VirtualBoxBase AND * implement some interface). * * @note Locks #childrenLock() for writing. */ template void addDependentChild(C *aChild) { AssertReturnVoid(aChild != NULL); doAddDependentChild(ComPtr(aChild), aChild); } /** * Equivalent to template void addDependentChild (C *aChild) * but takes a ComObjPtr argument. */ template void addDependentChild(const ComObjPtr &aChild) { AssertReturnVoid(!aChild.isNull()); doAddDependentChild(ComPtr(static_cast(aChild)), aChild); } /** * Removes the given child from the list of dependent children. * * Usually gets called from the child's uninit() method. * * Keep in mind that the called (parent) object may be no longer available * (i.e. may be deleted deleted) after this method returns, so you must not * call any other parent's methods after that! * * @note Locks #childrenLock() for writing. * * @note @a aChild (unless it is in InUninit state) must be protected by * VirtualBoxBase::AutoCaller to make sure it is not uninitialized on * another thread during this method's call. * * @note When #childrenLock() is not overloaded (returns the general object * lock) and this method is called from under the child's read or * write lock, make sure the {parent, child} locking order is * preserved by locking the callee (this object) for writing before * the child's lock. This is irrelevant when the method is called from * under this object's VirtualBoxBaseProto::AutoUninitSpan (i.e. in * InUninit state) since in this case no locking is done. * * @param aChild Child object to remove. * * @note Locks #childrenLock() for writing. */ template void removeDependentChild(C *aChild) { AssertReturnVoid(aChild != NULL); doRemoveDependentChild(ComPtr(aChild)); } /** * Equivalent to template void removeDependentChild (C *aChild) * but takes a ComObjPtr argument. */ template void removeDependentChild(const ComObjPtr &aChild) { AssertReturnVoid(!aChild.isNull()); doRemoveDependentChild(ComPtr(static_cast(aChild))); } protected: void uninitDependentChildren(); VirtualBoxBase *getDependentChild(const ComPtr &aUnk); private: void doAddDependentChild(IUnknown *aUnk, VirtualBoxBase *aChild); void doRemoveDependentChild(IUnknown *aUnk); typedef std::map DependentChildren; DependentChildren mDependentChildren; }; //////////////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////////////// /** * Simple template that manages data structure allocation/deallocation * and supports data pointer sharing (the instance that shares the pointer is * not responsible for memory deallocation as opposed to the instance that * owns it). */ template class Shareable { public: Shareable() : mData (NULL), mIsShared(FALSE) {} ~Shareable() { free(); } void allocate() { attach(new D); } virtual void free() { if (mData) { if (!mIsShared) delete mData; mData = NULL; mIsShared = false; } } void attach(D *d) { AssertMsg(d, ("new data must not be NULL")); if (d && mData != d) { if (mData && !mIsShared) delete mData; mData = d; mIsShared = false; } } void attach(Shareable &d) { AssertMsg( d.mData == mData || !d.mIsShared, ("new data must not be shared") ); if (this != &d && !d.mIsShared) { attach(d.mData); d.mIsShared = true; } } void share(D *d) { AssertMsg(d, ("new data must not be NULL")); if (mData != d) { if (mData && !mIsShared) delete mData; mData = d; mIsShared = true; } } void share(const Shareable &d) { share(d.mData); } void attachCopy(const D *d) { AssertMsg(d, ("data to copy must not be NULL")); if (d) attach(new D(*d)); } void attachCopy(const Shareable &d) { attachCopy(d.mData); } virtual D *detach() { D *d = mData; mData = NULL; mIsShared = false; return d; } D *data() const { return mData; } D *operator->() const { AssertMsg(mData, ("data must not be NULL")); return mData; } bool isNull() const { return mData == NULL; } bool operator!() const { return isNull(); } bool isShared() const { return mIsShared; } protected: D *mData; bool mIsShared; }; /// @todo (dmik) remove after we switch to VirtualBoxBaseNEXT completely /** * Simple template that enhances Shareable<> and supports data * backup/rollback/commit (using the copy constructor of the managed data * structure). */ template class Backupable : public Shareable { public: Backupable() : Shareable (), mBackupData(NULL) {} void free() { AssertMsg(this->mData || !mBackupData, ("backup must be NULL if data is NULL")); rollback(); Shareable::free(); } D *detach() { AssertMsg(this->mData || !mBackupData, ("backup must be NULL if data is NULL")); rollback(); return Shareable::detach(); } void share(const Backupable &d) { AssertMsg(!d.isBackedUp(), ("data to share must not be backed up")); if (!d.isBackedUp()) Shareable::share(d.mData); } /** * Stores the current data pointer in the backup area, allocates new data * using the copy constructor on current data and makes new data active. */ void backup() { AssertMsg(this->mData, ("data must not be NULL")); if (this->mData && !mBackupData) { D *pNewData = new D(*this->mData); mBackupData = this->mData; this->mData = pNewData; } } /** * Deletes new data created by #backup() and restores previous data pointer * stored in the backup area, making it active again. */ void rollback() { if (this->mData && mBackupData) { delete this->mData; this->mData = mBackupData; mBackupData = NULL; } } /** * Commits current changes by deleting backed up data and clearing up the * backup area. The new data pointer created by #backup() remains active * and becomes the only managed pointer. * * This method is much faster than #commitCopy() (just a single pointer * assignment operation), but makes the previous data pointer invalid * (because it is freed). For this reason, this method must not be * used if it's possible that data managed by this instance is shared with * some other Shareable instance. See #commitCopy(). */ void commit() { if (this->mData && mBackupData) { if (!this->mIsShared) delete mBackupData; mBackupData = NULL; this->mIsShared = false; } } /** * Commits current changes by assigning new data to the previous data * pointer stored in the backup area using the assignment operator. * New data is deleted, the backup area is cleared and the previous data * pointer becomes active and the only managed pointer. * * This method is slower than #commit(), but it keeps the previous data * pointer valid (i.e. new data is copied to the same memory location). * For that reason it's safe to use this method on instances that share * managed data with other Shareable instances. */ void commitCopy() { if (this->mData && mBackupData) { *mBackupData = *(this->mData); delete this->mData; this->mData = mBackupData; mBackupData = NULL; } } void assignCopy(const D *pData) { AssertMsg(this->mData, ("data must not be NULL")); AssertMsg(pData, ("data to copy must not be NULL")); if (this->mData && pData) { if (!mBackupData) { D *pNewData = new D(*pData); mBackupData = this->mData; this->mData = pNewData; } else *this->mData = *pData; } } void assignCopy(const Backupable &d) { assignCopy(d.mData); } bool isBackedUp() const { return mBackupData != NULL; } D *backedUpData() const { return mBackupData; } protected: D *mBackupData; }; #endif // !____H_VIRTUALBOXBASEIMPL