/** @file * * VirtualBox COM base classes definition */ /* * Copyright (C) 2006-2007 innotek GmbH * * 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 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. * * If you received this file as part of a commercial VirtualBox * distribution, then only the terms of your commercial VirtualBox * license agreement apply instead of the previous paragraph. */ #ifndef ____H_VIRTUALBOXBASEIMPL #define ____H_VIRTUALBOXBASEIMPL #include "VBox/com/string.h" #include "VBox/com/Guid.h" #include "VBox/com/ptr.h" #include "VBox/com/ErrorInfo.h" #include "VBox/com/VirtualBox.h" #include "AutoLock.h" using namespace com; using util::AutoLock; using util::AutoReaderLock; using util::AutoMultiLock; #include #include #include #include #if defined (__WIN__) #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 (__WIN__) // macros //////////////////////////////////////////////////////////////////////////////// /** * A 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 (!(expr)) \ setError (E_FAIL, "Assertion failed: [%s] at '%s' (%d) in %s.\n" \ "Please contact the product vendor!", \ #expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \ } while (0) #endif /** * A 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 (!(expr)) \ setError (E_FAIL, "Assertion failed: [%s] at '%s' (%d) in %s.\n" \ "%s.\n" \ "Please contact the product vendor!", \ #expr, __FILE__, __LINE__, __PRETTY_FUNCTION__, Utf8StrFmt a .raw()); \ } while (0) #endif /** * A 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, ("%Vra", vrc)) #endif /** * A 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 (VBOX_SUCCESS (vrc), msg) #endif /** * A special version of the AssertFailed macro to be used within VirtualBoxBase * subclasses that also inherit the VirtualBoxSupportErrorInfoImpl template. * * See ComAssert for more info. */ #if defined (DEBUG) #define ComAssertFailed() AssertFailed() #else #define ComAssertFailed() \ do { \ setError (E_FAIL, "Assertion failed at '%s' (%d) in %s.\n" \ "Please contact the product vendor!", \ __FILE__, __LINE__, __PRETTY_FUNCTION__); \ } while (0) #endif /** * A special version of the AssertMsgFailed macro to be used within VirtualBoxBase * subclasses that also inherit the VirtualBoxSupportErrorInfoImpl template. * * See ComAssert for more info. * * @param a printf argument list (in parenthesis). */ #if defined (DEBUG) #define ComAssertMsgFailed(a) AssertMsgFailed(a) #else #define ComAssertMsgFailed(a) \ do { \ setError (E_FAIL, "Assertion failed at '%s' (%d) in %s.\n" \ "%s.\n" \ "Please contact the product vendor!", \ __FILE__, __LINE__, __PRETTY_FUNCTION__, Utf8StrFmt a .raw()); \ } while (0) #endif /** * A 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 = 0x%08X\n", 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 (!VBOX_SUCCESS (vrc)) return (ret); } while (0) /** Special version of ComAssertMsgRC that returns ret if vrc does not succeed */ #define ComAssertMsgRCRet(vrc, msg, ret) \ do { ComAssertMsgRC (vrc, msg); if (!VBOX_SUCCESS (vrc)) return (ret); } while (0) /** Special version of ComAssertFailed that returns ret */ #define ComAssertFailedRet(ret) \ do { ComAssertFailed(); return (ret); } while (0) /** Special version of ComAssertMsgFailed that returns ret */ #define ComAssertMsgFailedRet(msg, ret) \ do { ComAssertMsgFailed (msg); 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 evaulates 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 evaulates 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 evaulates eval and breaks if vrc does not succeed */ #define ComAssertRCBreak(vrc, eval) \ if (1) { ComAssertRC (vrc); if (!VBOX_SUCCESS (vrc)) { eval; break; } } else do {} while (0) /** Special version of ComAssertMsgRC that evaulates eval and breaks if vrc does not succeed */ #define ComAssertMsgRCBreak(vrc, msg, eval) \ if (1) { ComAssertMsgRC (vrc, msg); if (!VBOX_SUCCESS (vrc)) { eval; break; } } else do {} while (0) /** Special version of ComAssertFailed that evaulates eval and breaks */ #define ComAssertFailedBreak(eval) \ if (1) { ComAssertFailed(); { eval; break; } } else do {} while (0) /** Special version of ComAssertMsgFailed that evaulates eval and breaks */ #define ComAssertMsgFailedBreak(msg, eval) \ if (1) { ComAssertMsgFailed (msg); { eval; break; } } else do {} while (0) /** Special version of ComAssertComRC that evaulates 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) /// @todo (dmik) remove after we switch to VirtualBoxBaseNEXT completely /** * Checks whether this object is ready or not. Objects are typically ready * after they are successfully created by their parent objects and become * not ready when the respective parent itsef becomes not ready or gets * destroyed while a reference to the child is still held by the caller * (which prevents it from destruction). * * When this object is not ready, the macro sets error info and returns * E_UNEXPECTED (the translatable error message is defined in null context). * Otherwise, the macro does nothing. * * This macro must be used at the beginning of all interface methods * (right after entering the class lock) in classes derived from both * VirtualBoxBase and VirtualBoxSupportErrorInfoImpl. */ #define CHECK_READY() \ do { \ if (!isReady()) \ return setError (E_UNEXPECTED, tr ("The object is not ready")); \ } while (0) /** * Declares an empty construtor 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 palced 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 construtor and destructor for the given class. * See DECLARE_EMPTY_CTOR_DTOR for more info. */ #define DEFINE_EMPTY_CTOR_DTOR(cls) \ cls::cls () {}; cls::~cls () {}; //////////////////////////////////////////////////////////////////////////////// namespace stdx { /** * A wrapper around the container that owns pointers it stores. * * @note * Ownership is recognized only when destructing the container! * Pointers are not deleted when erased using erase() etc. * * @param container * class that meets Container requirements (for example, an instance of * std::list<>, std::vector<> etc.). The given class must store * pointers (for example, std::list ). */ template class ptr_container : public container { public: ~ptr_container() { for (typename container::iterator it = container::begin(); it != container::end(); ++ it) delete (*it); } }; }; //////////////////////////////////////////////////////////////////////////////// class ATL_NO_VTABLE VirtualBoxBaseNEXT_base #ifdef __WIN__ : public CComObjectRootEx #else : public CComObjectRootEx #endif , public AutoLock::Lockable { public: enum State { NotReady, Ready, InInit, InUninit, InitFailed, Limited }; protected: VirtualBoxBaseNEXT_base(); virtual ~VirtualBoxBaseNEXT_base(); public: // AutoLock::Lockable interface virtual AutoLock::Handle *lockHandle() const; /** * Virtual unintialization method. * Must be called by all implementations (COM classes) when the last * reference to the object is released, before calling the destructor. * Also, this method is called automatically by the uninit() method of the * parent of this object, when this object is a dependent child of a class * derived from VirtualBoxBaseWithChildren (@sa * VirtualBoxBaseWithChildren::addDependentChild). */ 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 */); } /** * Smart class that automatically increases the number of callers of the * given VirtualBoxBase object when an instance is constructed and decreases * it back when the created instance goes out of scope (i.e. gets destroyed). * * If #rc() returns a failure after the instance creation, it means that * the managed VirtualBoxBase object is not Ready, or in any other invalid * state, so that the caller must not use the object and can return this * failed result code to the upper level. * * See VirtualBoxBase::addCaller(), VirtualBoxBase::addLimitedCaller() and * VirtualBoxBase::releaseCaller() for more details about object callers. * * @param aLimited |false| if this template should use * VirtualiBoxBase::addCaller() calls to add callers, or * |true| if VirtualiBoxBase::addLimitedCaller() should be * used. * * @note It is preferrable to use the AutoCaller and AutoLimitedCaller * classes than specify the @a aLimited argument, for better * self-descriptiveness. */ template class AutoCallerBase { public: /** * Increases the number of callers of the given object * by calling VirtualBoxBase::addCaller(). * * @param aObj Object to add a caller to. If NULL, this * instance is effectively turned to no-op (where * rc() will return S_OK and state() will be * NotReady). */ AutoCallerBase (VirtualBoxBaseNEXT_base *aObj) : mObj (aObj) , mRC (S_OK) , mState (NotReady) { if (mObj) mRC = mObj->addCaller (&mState, aLimited); } /** * If the number of callers was successfully increased, * decreases it using VirtualBoxBase::releaseCaller(), otherwise * does nothing. */ ~AutoCallerBase() { if (mObj && SUCCEEDED (mRC)) mObj->releaseCaller(); } /** * Stores the result code returned by VirtualBoxBase::addCaller() * after instance creation or after the last #add() call. A successful * result code means the number of callers was successfully increased. */ HRESULT rc() const { return mRC; } /** * Returns |true| if |SUCCEEDED (rc())| is |true|, for convenience. * |true| means the number of callers was successfully increased. */ bool isOk() const { return SUCCEEDED (mRC); } /** * Stores the object state returned by VirtualBoxBase::addCaller() * after instance creation or after the last #add() call. */ State state() const { return mState; } /** * Temporarily decreases the number of callers of the managed object. * May only be called if #isOk() returns |true|. Note that #rc() will * return E_FAIL after this method succeeds. */ void release() { Assert (SUCCEEDED (mRC)); if (SUCCEEDED (mRC)) { if (mObj) mObj->releaseCaller(); mRC = E_FAIL; } } /** * Restores the number of callers decreased by #release(). May only * be called after #release(). */ void add() { Assert (!SUCCEEDED (mRC)); if (mObj && !SUCCEEDED (mRC)) mRC = mObj->addCaller (&mState, aLimited); } private: DECLARE_CLS_COPY_CTOR_ASSIGN_NOOP (AutoCallerBase) DECLARE_CLS_NEW_DELETE_NOOP (AutoCallerBase) VirtualBoxBaseNEXT_base *mObj; HRESULT mRC; State mState; }; /** * Smart class that automatically increases the number of normal * (non-limited) callers of the given VirtualBoxBase object when an * instance is constructed and decreases it back when the created instance * goes out of scope (i.e. gets destroyed). * * A typical usage pattern to declare a normal method of some object * (i.e. a method that is valid only when the object provides its * full functionality) is: * * STDMETHODIMP Component::Foo() * { * AutoCaller autoCaller (this); * CheckComRCReturnRC (autoCaller.rc()); * ... * * * Using this class is equivalent to using the AutoCallerBase template * with the @a aLimited argument set to |false|, but this class is * preferred because provides better self-descriptiveness. * * See AutoCallerBase for more information about auto caller functionality. */ typedef AutoCallerBase AutoCaller; /** * Smart class that automatically increases the number of limited callers * of the given VirtualBoxBase object when an instance is constructed and * decreases it back when the created instance goes out of scope (i.e. * gets destroyed). * * A typical usage pattern to declare a limited method of some object * (i.e. a method that is valid even if the object doesn't provide its * full functionality) is: * * STDMETHODIMP Component::Bar() * { * AutoLimitedCaller autoCaller (this); * CheckComRCReturnRC (autoCaller.rc()); * ... * * * Using this class is equivalent to using the AutoCallerBase template * with the @a aLimited argument set to |true|, but this class is * preferred because provides better self-descriptiveness. * * See AutoCallerBase for more information about auto caller functionality. */ typedef AutoCallerBase AutoLimitedCaller; protected: /** * Smart class to enclose the state transition NotReady->InInit->Ready. * * Instances must be created at the beginning of init() methods of * VirtualBoxBase subclasses as a stack-based variable using |this| pointer * as the argument. When this variable is created it automatically places * the object to the InInit state. * * When the created variable goes out of scope (i.e. gets destroyed), * depending on the success status of this initialization span, it either * places the object to the Ready state or calls the object's * VirtualBoxBase::uninit() method which is supposed to place the object * back to the NotReady state using the AutoUninitSpan class. * * The initial success status of the initialization span is determined by * the @a aSuccess argument of the AutoInitSpan constructor (|false| by * default). Inside the initialization span, the success status can be set * to |true| using #setSucceeded() or to |false| using #setFailed(). Please * don't forget to set the correct success status before letting the * AutoInitSpan variable go out of scope (for example, by performing an * early return from the init() method)! * * Note that if an instance of this class gets constructed when the * object is in the state other than NotReady, #isOk() returns |false| and * methods of this class do nothing: the state transition is not performed. * * A typical usage pattern is: * * HRESULT Component::init() * { * AutoInitSpan autoInitSpan (this); * AssertReturn (autoInitSpan.isOk(), E_UNEXPECTED); * ... * if (FAILED (rc)) * return rc; * ... * if (SUCCEEDED (rc)) * autoInitSpan.setSucceeded(); * return rc; * } * * * @note Never create instances of this class outside init() methods of * VirtualBoxBase subclasses and never pass anything other than |this| as * the argument to the constructor! */ class AutoInitSpan { public: enum Status { Failed = 0x0, Succeeded = 0x1, Limited = 0x2 }; AutoInitSpan (VirtualBoxBaseNEXT_base *aObj, Status aStatus = Failed); ~AutoInitSpan(); /** * Returns |true| if this instance has been created at the right moment * (when the object was in the NotReady state) and |false| otherwise. */ bool isOk() const { return mOk; } /** * Sets the initialization status to Succeeded to indicates successful * initialization. The AutoInitSpan destructor will place the managed * VirtualBoxBase object to the Ready state. */ void setSucceeded() { mStatus = Succeeded; } /** * Sets the initialization status to Succeeded to indicate limited * (partly successful) initialization. The AutoInitSpan destructor will * place the managed VirtualBoxBase object to the Limited state. */ void setLimited() { mStatus = Limited; } /** * Sets the initialization status to Failure to indicates failed * initialization. The AutoInitSpan destructor will place the managed * VirtualBoxBase object to the InitFailed state and will automatically * call its uninit() method which is supposed to place the object back * to the NotReady state using AutoUninitSpan. */ void setFailed() { mStatus = Failed; } /** Returns the current initialization status. */ Status status() { return mStatus; } private: DECLARE_CLS_COPY_CTOR_ASSIGN_NOOP (AutoInitSpan) DECLARE_CLS_NEW_DELETE_NOOP (AutoInitSpan) VirtualBoxBaseNEXT_base *mObj; Status mStatus : 3; // must be at least total number of bits + 1 (sign) bool mOk : 1; }; /** * Smart class to enclose the state transition Limited->InInit->Ready. * * Instances must be created at the beginning of methods of VirtualBoxBase * subclasses that try to re-initialize the object to bring it to the * Ready state (full functionality) after partial initialization * (limited functionality)>, as a stack-based variable using |this| pointer * as the argument. When this variable is created it automatically places * the object to the InInit state. * * When the created variable goes out of scope (i.e. gets destroyed), * depending on the success status of this initialization span, it either * places the object to the Ready state or brings it back to the Limited * state. * * The initial success status of the re-initialization span is |false|. * In order to make it successful, #setSucceeded() must be called before * the instance is destroyed. * * Note that if an instance of this class gets constructed when the * object is in the state other than Limited, #isOk() returns |false| and * methods of this class do nothing: the state transition is not performed. * * A typical usage pattern is: * * HRESULT Component::reinit() * { * AutoReadySpan autoReadySpan (this); * AssertReturn (autoReadySpan.isOk(), E_UNEXPECTED); * ... * if (FAILED (rc)) * return rc; * ... * if (SUCCEEDED (rc)) * autoReadySpan.setSucceeded(); * return rc; * } * * * @note Never create instances of this class outside re-initialization * methods of VirtualBoxBase subclasses and never pass anything other than * |this| as the argument to the constructor! */ class AutoReadySpan { public: AutoReadySpan (VirtualBoxBaseNEXT_base *aObj); ~AutoReadySpan(); /** * Returns |true| if this instance has been created at the right moment * (when the object was in the Limited state) and |false| otherwise. */ bool isOk() const { return mOk; } /** * Sets the re-initialization status to Succeeded to indicates * successful re-initialization. The AutoReadySpan destructor will * place the managed VirtualBoxBase object to the Ready state. */ void setSucceeded() { mSucceeded = true; } private: DECLARE_CLS_COPY_CTOR_ASSIGN_NOOP (AutoReadySpan) DECLARE_CLS_NEW_DELETE_NOOP (AutoReadySpan) VirtualBoxBaseNEXT_base *mObj; bool mSucceeded : 1; bool mOk : 1; }; /** * Smart class to enclose the state transition Ready->InUnnit->NotReady or * InitFailed->InUnnit->NotReady. * * Must be created at the beginning of uninit() methods of VirtualBoxBase * subclasses as a stack-based variable using |this| pointer as the argument. * When this variable is created it automatically places the object to the * InUninit state, unless it is already in the NotReady state as indicated * by #uninitDone() returning |true|. In the latter case, the uninit() * method must immediately return because there should be nothing to * uninitialize. * * When this variable goes out of scope (i.e. gets destroyed), it places * the object to the NotReady state. * * A typical usage pattern is: * * void Component::uninit() * { * AutoUninitSpan autoUninitSpan (this); * if (autoUninitSpan.uninitDone()) * retrun; * ... * * * @note Never create instances of this class outside uninit() methods and * never pass anything other than |this| as the argument to the constructor! */ class AutoUninitSpan { public: AutoUninitSpan (VirtualBoxBaseNEXT_base *aObj); ~AutoUninitSpan(); /** |true| when uninit() is called as a result of init() failure */ bool initFailed() { return mInitFailed; } /** |true| when uninit() has already been called (so the object is NotReady) */ bool uninitDone() { return mUninitDone; } private: DECLARE_CLS_COPY_CTOR_ASSIGN_NOOP (AutoUninitSpan) DECLARE_CLS_NEW_DELETE_NOOP (AutoUninitSpan) VirtualBoxBaseNEXT_base *mObj; bool mInitFailed : 1; bool mUninitDone : 1; }; 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; /** Semaphore posted when the number of callers drops to zero */ RTSEMEVENT mZeroCallersSem; /** Semaphore posted when the object goes from InInit some other state */ RTSEMEVENTMULTI mInitDoneSem; /** Number of threads waiting for mInitDoneSem */ unsigned mInitDoneSemUsers; /** Protects access to state related data members */ RTCRITSECT mStateLock; /** User-level object lock for subclasses */ mutable AutoLock::Handle *mObjectLock; }; /** * This macro adds the error info support to methods of the VirtualBoxBase * class (by overriding them). Place it to the public section of the * VirtualBoxBase subclass and the following methods will set the extended * error info in case of failure instead of just returning the result code: * *
    *
  • VirtualBoxBase::addCaller() *
* * @note The given VirtualBoxBase subclass must also inherit from both * VirtualBoxSupportErrorInfoImpl and VirtualBoxSupportTranslation templates! * * @param C VirtualBoxBase subclass to add the error info support to */ #define VIRTUALBOXBASE_ADD_ERRORINFO_SUPPORT(C) \ virtual HRESULT addCaller (VirtualBoxBaseNEXT_base::State *aState = NULL, \ bool aLimited = false) \ { \ VirtualBoxBaseNEXT_base::State state; \ HRESULT rc = VirtualBoxBaseNEXT_base::addCaller (&state, aLimited); \ if (FAILED (rc)) \ { \ if (state == VirtualBoxBaseNEXT_base::Limited) \ rc = setError (rc, tr ("The object functonality is limited")); \ else \ rc = setError (rc, tr ("The object is not ready")); \ } \ if (aState) \ *aState = state; \ return rc; \ } \ //////////////////////////////////////////////////////////////////////////////// /// @todo (dmik) remove after we switch to VirtualBoxBaseNEXT completely class ATL_NO_VTABLE VirtualBoxBase : public VirtualBoxBaseNEXT_base //#ifdef __WIN__ // : public CComObjectRootEx //#else // : public CComObjectRootEx //#endif { public: VirtualBoxBase() { mReady = false; } virtual ~VirtualBoxBase() { } /** * Virtual unintialization method. Called during parent object's * uninitialization, if the given subclass instance is a dependent child of * a class dervived from VirtualBoxBaseWithChildren (@sa * VirtualBoxBaseWithChildren::addDependentChild). In this case, this * method's impelemtation must call setReady (false), */ virtual void uninit() {} // sets the ready state of the object void setReady(bool isReady) { mReady = isReady; } // get the ready state of the object bool isReady() { return mReady; } static const char *translate (const char *context, const char *sourceText, const char *comment = 0); private: // flag determining whether an object is ready // for usage, i.e. methods may be called bool mReady; // mutex semaphore to lock the object }; /** * Temporary class to disable deprecated methods of VirtualBoxBase. * Can be used as a base for components that are completely switched to * the new locking scheme (VirtualBoxBaseNEXT_base). * * @todo remove after we switch to VirtualBoxBaseNEXT completely. */ class VirtualBoxBaseNEXT : public VirtualBoxBase { private: void lock(); void unlock(); void setReady (bool isReady); bool isReady(); }; //////////////////////////////////////////////////////////////////////////////// /** Helper for VirtualBoxSupportTranslation */ class VirtualBoxSupportTranslationBase { protected: static bool cutClassNameFrom__PRETTY_FUNCTION__ (char *prettyFunctionName); }; /** * This template implements the NLS string translation support for the * given class by providing a #tr() function. * * @param C class that needs to support the string translation * * @note * Every class that wants to use the #tr() function in its own methods must * inherit from this template, regardless of whether its base class (if any) * inherits from it or not! Otherwise, the translation service will not * work correctly. However, the declaration of the resulting class must * contain the VIRTUALBOXSUPPORTTRANSLATION_OVERRIDE() macro * if one of its base classes also inherits from this template (to resolve * the ambiguity of the #tr() function). */ template class VirtualBoxSupportTranslation : virtual protected VirtualBoxSupportTranslationBase { public: /** * Translates the given text string according to the currently installed * translation table and current context, which is determined by the * class name. See VirtualBoxBase::translate() for more info. * * @param sourceText the string to translate * @param comment the comment to the string (NULL means no comment) * * @return * the translated version of the source string in UTF-8 encoding, * or the source string itself if the translation is not found in * the current context. */ inline static const char *tr (const char *sourceText, const char *comment = 0) { return VirtualBoxBase::translate (getClassName(), sourceText, comment); } protected: static const char *getClassName() { static char fn [sizeof (__PRETTY_FUNCTION__) + 1]; if (!className) { strcpy (fn, __PRETTY_FUNCTION__); cutClassNameFrom__PRETTY_FUNCTION__ (fn); className = fn; } return className; } private: static const char *className; }; template const char *VirtualBoxSupportTranslation ::className = NULL; /** * This macro must be invoked inside the public section of the declaration of * the class inherited from the VirtualBoxSupportTranslation template, in case * when one of its other base classes also inherits from that template. This is * necessary to resolve the ambiguity of the #tr() function. * * @param C class that inherits from the VirtualBoxSupportTranslation template * more than once (through its other base clases) */ #define VIRTUALBOXSUPPORTTRANSLATION_OVERRIDE(C) \ inline static const char *tr (const char *sourceText, const char *comment = 0) \ { \ return VirtualBoxSupportTranslation ::tr (sourceText, comment); \ } /** * A 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 //////////////////////////////////////////////////////////////////////////////// /** * Helper for the VirtualBoxSupportErrorInfoImpl template. */ class VirtualBoxSupportErrorInfoImplBase { static HRESULT setErrorInternal (HRESULT aResultCode, const GUID &aIID, const Bstr &aComponent, const Bstr &aText, bool aPreserve); protected: inline static HRESULT setError (HRESULT aResultCode, const GUID &aIID, const Bstr &aComponent, const Bstr &aText) { return setErrorInternal (aResultCode, aIID, aComponent, aText, false /* aPreserve */); } inline static HRESULT addError (HRESULT aResultCode, const GUID &aIID, const Bstr &aComponent, const Bstr &aText) { return setErrorInternal (aResultCode, aIID, aComponent, aText, true /* aPreserve */); } static HRESULT setError (HRESULT aResultCode, const GUID &aIID, const Bstr &aComponent, const char *aText, va_list aArgs) { return setErrorInternal (aResultCode, aIID, aComponent, Utf8StrFmt (aText, aArgs), false /* aPreserve */); } static HRESULT addError (HRESULT aResultCode, const GUID &aIID, const Bstr &aComponent, const char *aText, va_list aArgs) { return setErrorInternal (aResultCode, aIID, aComponent, Utf8StrFmt (aText, aArgs), true /* aPreserve */); } }; /** * This template implements ISupportErrorInfo for the given component class * and provides the #setError() method to conveniently set the error information * from within interface methods' implementations. * * On Windows, the template argument must define a COM interface map using * BEGIN_COM_MAP / END_COM_MAP macros and this map must contain a * COM_INTERFACE_ENTRY(ISupportErrorInfo) definition. All interface entries * that follow it will be considered to support IErrorInfo, i.e. the * InterfaceSupportsErrorInfo() implementation will return S_OK for the * corresponding IID. * * On all platforms, the template argument must also define the following * method: |public static const wchar_t *C::getComponentName()|. See * #setError (HRESULT, const char *, ...) for a description on how it is * used. * * @param C * component class that implements one or more COM interfaces * @param I * default interface for the component. This interface's IID is used * by the shortest form of #setError, for convenience. */ template class ATL_NO_VTABLE VirtualBoxSupportErrorInfoImpl : protected VirtualBoxSupportErrorInfoImplBase #if defined (__WIN__) , public ISupportErrorInfo #else #endif { public: #if defined (__WIN__) STDMETHOD(InterfaceSupportsErrorInfo) (REFIID riid) { const _ATL_INTMAP_ENTRY* pEntries = C::_GetEntries(); Assert (pEntries); if (!pEntries) return S_FALSE; BOOL bSupports = FALSE; BOOL bISupportErrorInfoFound = FALSE; while (pEntries->pFunc != NULL && !bSupports) { if (!bISupportErrorInfoFound) { // skip the com map entries until ISupportErrorInfo is found bISupportErrorInfoFound = InlineIsEqualGUID (*(pEntries->piid), IID_ISupportErrorInfo); } else { // look for the requested interface in the rest of the com map bSupports = InlineIsEqualGUID (*(pEntries->piid), riid); } pEntries++; } Assert (bISupportErrorInfoFound); return bSupports ? S_OK : S_FALSE; } #endif // defined (__WIN__) protected: /** * Sets the error information for the current thread. * This information can be retrieved by a caller of an interface method * using IErrorInfo on Windows or nsIException on Linux, or the cross-platform * IVirtualBoxErrorInfo interface that provides extended error info (only * for components from the VirtualBox COM library). Alternatively, the * platform-independent class com::ErrorInfo (defined in VBox[XP]COM.lib) * can be used to retrieve error info in a convenient way. * * It is assumed that the interface method that uses this function returns * an unsuccessful result code to the caller (otherwise, there is no reason * for the caller to try to retrieve error info after method invocation). * * Here is a table of correspondence between this method's arguments * and IErrorInfo/nsIException/IVirtualBoxErrorInfo attributes/methods: * * argument IErrorInfo nsIException IVirtualBoxErrorInfo * ---------------------------------------------------------------- * resultCode -- result resultCode * iid GetGUID -- interfaceID * component GetSource -- component * text GetDescription message text * * This method is rarely needs to be used though. There are more convenient * overloaded versions, that automatically substitute some arguments * taking their values from the template parameters. See * #setError (HRESULT, const char *, ...) for an example. * * @param aResultCode result (error) code, must not be S_OK * @param aIID IID of the intrface that defines the error * @param aComponent name of the component that generates the error * @param aText error message (must not be null), an RTStrPrintf-like * format string in UTF-8 encoding * @param ... list of arguments for the format string * * @return * the error argument, for convenience, If an error occures while * creating error info itself, that error is returned instead of the * error argument. */ inline static HRESULT setError (HRESULT aResultCode, const GUID &aIID, const wchar_t *aComponent, const char *aText, ...) { va_list args; va_start (args, aText); HRESULT rc = VirtualBoxSupportErrorInfoImplBase::setError (aResultCode, aIID, aComponent, aText, args); va_end (args); return rc; } /** * This method is the same as #setError() except that it preserves the * error info object (if any) set for the current thread before this * method is called by storing it in the IVirtualBoxErrorInfo::next * attribute of the new error info object. */ inline static HRESULT addError (HRESULT aResultCode, const GUID &aIID, const wchar_t *aComponent, const char *aText, ...) { va_list args; va_start (args, aText); HRESULT rc = VirtualBoxSupportErrorInfoImplBase::addError (aResultCode, aIID, aComponent, aText, args); va_end (args); return rc; } /** * Sets the error information for the current thread. * A convenience method that automatically sets the default interface * ID (taken from the I template argument) and the component name * (a value of C::getComponentName()). * * See #setError (HRESULT, const GUID &, const wchar_t *, const char *text, ...) * for details. * * This method is the most common (and convenient) way to set error * information from within interface methods. A typical pattern of usage * is looks like this: * * * return setError (E_FAIL, "Terrible Error"); * * or * * HRESULT rc = setError (E_FAIL, "Terrible Error"); * ... * return rc; * */ inline static HRESULT setError (HRESULT aResultCode, const char *aText, ...) { va_list args; va_start (args, aText); HRESULT rc = VirtualBoxSupportErrorInfoImplBase::setError (aResultCode, COM_IIDOF(I), C::getComponentName(), aText, args); va_end (args); return rc; } /** * This method is the same as #setError() except that it preserves the * error info object (if any) set for the current thread before this * method is called by storing it in the IVirtualBoxErrorInfo::next * attribute of the new error info object. */ inline static HRESULT addError (HRESULT aResultCode, const char *aText, ...) { va_list args; va_start (args, aText); HRESULT rc = VirtualBoxSupportErrorInfoImplBase::addError (aResultCode, COM_IIDOF(I), C::getComponentName(), aText, args); va_end (args); return rc; } /** * Sets the error information for the current thread, va_list variant. * A convenience method that automatically sets the default interface * ID (taken from the I template argument) and the component name * (a value of C::getComponentName()). * * See #setError (HRESULT, const GUID &, const wchar_t *, const char *text, ...) * and #setError (HRESULT, const char *, ...) for details. */ inline static HRESULT setErrorV (HRESULT aResultCode, const char *aText, va_list aArgs) { HRESULT rc = VirtualBoxSupportErrorInfoImplBase::setError (aResultCode, COM_IIDOF(I), C::getComponentName(), aText, aArgs); return rc; } /** * This method is the same as #setErrorV() except that it preserves the * error info object (if any) set for the current thread before this * method is called by storing it in the IVirtualBoxErrorInfo::next * attribute of the new error info object. */ inline static HRESULT addErrorV (HRESULT aResultCode, const char *aText, va_list aArgs) { HRESULT rc = VirtualBoxSupportErrorInfoImplBase::addError (aResultCode, COM_IIDOF(I), C::getComponentName(), aText, aArgs); return rc; } /** * Sets the error information for the current thread, BStr variant. * A convenience method that automatically sets the default interface * ID (taken from the I template argument) and the component name * (a value of C::getComponentName()). * * This method is preferred iy you have a ready (translated and formatted) * Bstr string, because it omits an extra conversion Utf8Str -> Bstr. * * See #setError (HRESULT, const GUID &, const wchar_t *, const char *text, ...) * and #setError (HRESULT, const char *, ...) for details. */ inline static HRESULT setErrorBstr (HRESULT aResultCode, const Bstr &aText) { HRESULT rc = VirtualBoxSupportErrorInfoImplBase::setError (aResultCode, COM_IIDOF(I), C::getComponentName(), aText); return rc; } /** * This method is the same as #setErrorBstr() except that it preserves the * error info object (if any) set for the current thread before this * method is called by storing it in the IVirtualBoxErrorInfo::next * attribute of the new error info object. */ inline static HRESULT addErrorBstr (HRESULT aResultCode, const Bstr &aText) { HRESULT rc = VirtualBoxSupportErrorInfoImplBase::addError (aResultCode, COM_IIDOF(I), C::getComponentName(), aText); return rc; } /** * Sets the error information for the current thread. * A convenience method that automatically sets the component name * (a value of C::getComponentName()), but allows to specify the interface * id manually. * * See #setError (HRESULT, const GUID &, const wchar_t *, const char *text, ...) * for details. */ inline static HRESULT setError (HRESULT aResultCode, const GUID &aIID, const char *aText, ...) { va_list args; va_start (args, aText); HRESULT rc = VirtualBoxSupportErrorInfoImplBase::setError (aResultCode, aIID, C::getComponentName(), aText, args); va_end (args); return rc; } /** * This method is the same as #setError() except that it preserves the * error info object (if any) set for the current thread before this * method is called by storing it in the IVirtualBoxErrorInfo::next * attribute of the new error info object. */ inline static HRESULT addError (HRESULT aResultCode, const GUID &aIID, const char *aText, ...) { va_list args; va_start (args, aText); HRESULT rc = VirtualBoxSupportErrorInfoImplBase::addError (aResultCode, aIID, C::getComponentName(), aText, args); va_end (args); return rc; } private: }; //////////////////////////////////////////////////////////////////////////////// /** * Base class to track VirtualBoxBase 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 created by 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 initial 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. *
      3. * * 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 a child object it is uninitialized, it calls #removeDependentChild() * to unregister itself. This must be done after the child has called * setReady(false) to indicate it is no more valid, and not from under * the child object's lock. Note also, that the first action the child's * uninit() implementation must do is to check for readiness after acquiring * the object's lock and return immediately if not ready. *
          3. * * Children added by #addDependentChild() are weakly referenced * (i.e. AddRef() is not called), so when a child is externally destructed * (i.e. its reference count goes to zero), it will automatically remove * itself from a map of dependent children, provided that it follows the * rules described here. * * @note * Because of weak referencing, deadlocks and assertions are very likely * if #addDependentChild() or #removeDependentChild() are used incorrectly * (called at inappropriate times). Check the above rules once more. */ class VirtualBoxBaseWithChildren : public VirtualBoxBase { public: VirtualBoxBaseWithChildren() : mUninitDoneSem (NIL_RTSEMEVENT), mChildrenLeft (0) { RTCritSectInit (&mMapLock); } virtual ~VirtualBoxBaseWithChildren() { RTCritSectDelete (&mMapLock); } /** * Adds the given child to the map of dependent children. * Intended to be called from the child's init() method, * from under the child's lock. * * @param C the child object to add (must inherit VirtualBoxBase AND * implement some interface) */ template void addDependentChild (C *child) { AssertReturn (child, (void) 0); addDependentChild (child, child); } /** * Removes the given child from the map of dependent children. * Must be called after the child has called setReady(false), and * not from under the child object's lock. * * @param C the child object to remove (must inherit VirtualBoxBase AND * implement some interface) */ template void removeDependentChild (C *child) { AssertReturn (child, (void) 0); /// @todo (r=dmik) the below check (and the relevant comment above) // seems to be not necessary any more once we completely switch to // the NEXT locking scheme. This requires altering removeDependentChild() // and uninitDependentChildren() as well (due to the new state scheme, // there is a separate mutex for state transition, so calling the // child's uninit() from under the children map lock should not produce // dead-locks any more). Assert (!child->isLockedOnCurrentThread()); removeDependentChild (ComPtr (child)); } protected: void uninitDependentChildren(); VirtualBoxBase *getDependentChild (const ComPtr &unk); private: void addDependentChild (const ComPtr &unk, VirtualBoxBase *child); void removeDependentChild (const ComPtr &unk); typedef std::map DependentChildren; DependentChildren mDependentChildren; RTCRITSECT mMapLock; RTSEMEVENT mUninitDoneSem; unsigned mChildrenLeft; }; /** * Temporary class to disable deprecated methods of VirtualBoxBase. * Can be used as a base for components that are completely switched to * the new locking scheme (VirtualBoxBaseNEXT_base). * * @todo remove after we switch to VirtualBoxBaseNEXT completely. */ class VirtualBoxBaseWithChildrenNEXT : public VirtualBoxBaseWithChildren { private: void lock(); void unlock(); void setReady (bool isReady); bool isReady(); }; //////////////////////////////////////////////////////////////////////////////// /** * Base class to track component's chlidren of some particular type. * * This class is similar to VirtualBoxBaseWithChildren, with the exception * that all children must be of the same type. For this reason, it's not * necessary to use a map to store children, so a list is used instead. * * As opposed to VirtualBoxBaseWithChildren, children added by * #addDependentChild() are strongly referenced, so that they cannot * be externally destructed until #removeDependentChild() is called. * For this reason, strict rules of calling #removeDependentChild() don't * apply to instances of this class -- it can be called anywhere in the * child's uninit() implementation. * * @param C type of child objects (must inherit VirtualBoxBase AND * implement some interface) */ template class VirtualBoxBaseWithTypedChildren : public VirtualBoxBase { public: typedef std::list > DependentChildren; VirtualBoxBaseWithTypedChildren() : mInUninit (false) {} virtual ~VirtualBoxBaseWithTypedChildren() {} /** * Adds the given child to the list of dependent children. * Must be called from the child's init() method, * from under the child's lock. * * @param C the child object to add (must inherit VirtualBoxBase AND * implement some interface) */ void addDependentChild (C *child) { AssertReturn (child, (void) 0); AutoLock alock (mMapLock); if (mInUninit) return; mDependentChildren.push_back (child); } /** * Removes the given child from the list of dependent children. * Must be called from the child's uninit() method, * under the child's lock. * * @param C the child object to remove (must inherit VirtualBoxBase AND * implement some interface) */ void removeDependentChild (C *child) { AssertReturn (child, (void) 0); AutoLock alock (mMapLock); if (mInUninit) return; mDependentChildren.remove (child); } protected: /** * Returns an internal lock handle to lock the list of children * returned by #dependentChildren() using AutoLock: * * AutoLock alock (dependentChildrenLock()); * */ AutoLock::Handle &dependentChildrenLock() const { return mMapLock; } /** * Returns the read-only list of all dependent children. * @note * Access the returned list (iterate, get size etc.) only after * doing |AutoLock alock (dependentChildrenLock());|! */ const DependentChildren &dependentChildren() const { return mDependentChildren; } /** * Uninitializes all dependent children registered with #addDependentChild(). * * @note * This method will call uninit() methods of children. If these methods * access the parent object, uninitDependentChildren() must be called * either at the beginning of the parent uninitialization sequence (when * it is still operational) or after setReady(false) is called to * indicate the parent is out of action. */ void uninitDependentChildren() { AutoLock alock (this); AutoLock mapLock (mMapLock); if (mDependentChildren.size()) { // set flag to ignore #removeDependentChild() called from child->uninit() mInUninit = true; // leave the locks to let children waiting for #removeDependentChild() run mapLock.leave(); alock.leave(); for (typename DependentChildren::iterator it = mDependentChildren.begin(); it != mDependentChildren.end(); ++ it) { C *child = (*it); Assert (child); if (child) child->uninit(); } mDependentChildren.clear(); alock.enter(); mapLock.enter(); mInUninit = false; } } /** * Removes (detaches) all dependent children registered with * #addDependentChild(), without uninitializing them. * * @note This method must be called from under the main object's lock */ void removeDependentChildren() { AutoLock alock (mMapLock); mDependentChildren.clear(); } private: DependentChildren mDependentChildren; bool mInUninit; mutable AutoLock::Handle mMapLock; }; /** * Temporary class to disable deprecated methods of VirtualBoxBase. * Can be used as a base for components that are completely switched to * the new locking scheme (VirtualBoxBaseNEXT_base). * * @todo remove after we switch to VirtualBoxBaseNEXT completely. */ template class VirtualBoxBaseWithTypedChildrenNEXT : public VirtualBoxBaseWithTypedChildren { public: typedef util::AutoLock AutoLock; private: void lock(); void unlock(); bool isLockedOnCurrentThread(); void setReady (bool isReady); bool isReady(); }; //////////////////////////////////////////////////////////////////////////////// /// @todo (dmik) remove after we switch to VirtualBoxBaseNEXT completely /** * 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 *data) { AssertMsg (data, ("new data must not be NULL")); if (data && mData != data) { if (mData && !mIsShared) delete mData; mData = data; mIsShared = false; } } void attach (Shareable &data) { AssertMsg ( data.mData == mData || !data.mIsShared, ("new data must not be shared") ); if (this != &data && !data.mIsShared) { attach (data.mData); data.mIsShared = true; } } void share (D *data) { AssertMsg (data, ("new data must not be NULL")); if (mData != data) { if (mData && !mIsShared) delete mData; mData = data; mIsShared = true; } } void share (const Shareable &data) { share (data.mData); } void attachCopy (const D *data) { AssertMsg (data, ("data to copy must not be NULL")); if (data) attach (new D (*data)); } void attachCopy (const Shareable &data) { attachCopy (data.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 &data) { AssertMsg (!data.isBackedUp(), ("data to share must not be backed up")); if (!data.isBackedUp()) Shareable ::share (data.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) { mBackupData = this->mData; this->mData = new D (*mBackupData); } } /** * 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 *data) { AssertMsg (this->mData, ("data must not be NULL")); AssertMsg (data, ("data to copy must not be NULL")); if (this->mData && data) { if (!mBackupData) { mBackupData = this->mData; this->mData = new D (*data); } else *this->mData = *data; } } void assignCopy (const Backupable &data) { assignCopy (data.mData); } bool isBackedUp() const { return mBackupData != NULL; } bool hasActualChanges() const { AssertMsg (this->mData, ("data must not be NULL")); return this->mData != NULL && mBackupData != NULL && !(*this->mData == *mBackupData); } D *backedUpData() const { return mBackupData; } protected: D *mBackupData; }; #endif // ____H_VIRTUALBOXBASEIMPL