/** @file * * VBox frontends: Basic Frontend (BFE): * Declarations of the BFE base classes */ /* * 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. */ #ifndef ____H_VIRTUALBOXBASEIMPL #define ____H_VIRTUALBOXBASEIMPL #ifdef VBOXBFE_WITHOUT_COM # include "COMDefs.h" // Our wrapper for COM definitions left in the code #else # include #endif #include // For the AssertComRC macro #include #include #include #include #include // for ASMReturnAddress #include #include // macros and inlines //////////////////////////////////////////////////////////////////////////////// /** * A lightweight replacement for the COM setError function. I am * assuming that this is only called in circumstances justifying * an assertion. * * @returns error number * @param iNum error number - this is simply returned * @param pszFormat formatted error message */ static inline int setError(int iNum, const char *pszFormat, ...) { va_list args; va_start(args, pszFormat); AssertMsgFailed((pszFormat, args)); va_end(args); return iNum; } /** * Translate an error string. We do not do translation. */ #define tr(a) a /** * 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 { } 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 { } 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 { } 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 { } 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 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 vaulates eval and breaks */ #define ComAssertFailedBreak(eval) \ if (1) { ComAssertFailed(); { eval; break; } } else do {} while (0) /** Special version of ComAssertMsgFailed that vaulates eval and breaks */ #define ComAssertMsgFailedBreak(msg, eval) \ if (1) { ComAssertMsgFailed (msg); { eval; break; } } else do {} while (0) /** Special version of ComAssertComRC that vaulates 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) /** * 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 VirtualBoxBase { public: VirtualBoxBase() { mReady = false; RTCritSectInit(&mCritSec); } virtual ~VirtualBoxBase() { RTCritSectDelete(&mCritSec); } /** * 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() {} // lock the object void lock() { RTCritSectEnter(&mCritSec); } // unlock the object void unlock() { RTCritSectLeave(&mCritSec); } /** Returns true when the current thread owns this object's lock. */ bool isLockedOnCurrentThread() { return RTCritSectIsOwner (&mCritSec); } /** * Helper class to make safe locking / unlocking. * The constructor, given the VirtualBoxBase pointer, safely acquires the * lock protecting its data. This lock will be released automatically * when the instance goes out of scope (block, funciton etc.). * * @note * An instance of this class must be declared as a local variable, * otherwise the optimizer will most likely destruct it right after * creation (but not at the end of the block), so the lock will be * released immediately. */ class AutoLock { public: #if defined(DEBUG) # define ___CritSectEnter(cs) \ RTCritSectEnterDebug ((cs), \ "AutoLock::lock()/enter() return address >>>", 0, \ (RTUINTPTR) ASMReturnAddress()) #else # define ___CritSectEnter(cs) RTCritSectEnter ((cs)) #endif /** Internal lock handle */ class Handle { public: Handle (RTCRITSECT &critSect) : lock (critSect) {} private: RTCRITSECT &lock; friend class AutoLock; }; AutoLock() : mLock (NULL), mLevel (0), mLeftLevel (0) {} AutoLock (VirtualBoxBase *that) : mLock (that ? &that->mCritSec : NULL) , mLevel (0), mLeftLevel (0) { if (mLock) { ___CritSectEnter (mLock); ++ mLevel; } } AutoLock (RTCRITSECT &critSect) : mLock (&critSect), mLevel (0), mLeftLevel (0) { if (mLock) { ___CritSectEnter (mLock); ++ mLevel; } } AutoLock (const Handle &handle) : mLock (&handle.lock), mLevel (0), mLeftLevel (0) { if (mLock) { ___CritSectEnter (mLock); ++ mLevel; } } ~AutoLock() { if (mLock) { if (mLeftLevel) { mLeftLevel -= mLevel; mLevel = 0; for (; mLeftLevel; -- mLeftLevel) RTCritSectEnter (mLock); } AssertMsg (mLevel <= 1, ("Lock level > 1: %d\n", mLevel)); for (; mLevel; -- mLevel) RTCritSectLeave (mLock); } } /** * Tries to acquire the lock or increases the lock level * if the lock is already owned by this thread. */ void lock() { if (mLock) { AssertMsgReturn (mLeftLevel == 0, ("lock() after leave()\n"), (void) 0); ___CritSectEnter (mLock); ++ mLevel; } } /** * Decreases the lock level. If the level goes to zero, the lock * is released by the current thread. */ void unlock() { if (mLock) { AssertMsgReturn (mLevel > 0, ("Lock level is zero\n"), (void) 0); AssertMsgReturn (mLeftLevel == 0, ("lock() after leave()\n"), (void) 0); -- mLevel; RTCritSectLeave (mLock); } } /** * Causes the current thread to completely release the lock * (including locks acquired by all other instances of this class * referring to the same object or handle). #enter() must be called * to acquire the lock back and restore all lock levels. */ void leave() { if (mLock) { AssertMsg (mLevel > 0, ("Lock level is zero\n")); AssertMsgReturn (mLeftLevel == 0, ("leave() w/o enter()\n"), (void) 0); mLeftLevel = RTCritSectGetRecursion (mLock); for (uint32_t left = mLeftLevel; left; -- left) RTCritSectLeave (mLock); Assert (mLeftLevel >= mLevel); } } /** * Causes the current thread to acquire the lock again and restore * all lock levels after calling #leave(). */ void enter() { if (mLock) { AssertMsg (mLevel > 0, ("Lock level is zero\n")); AssertMsgReturn (mLeftLevel > 0, ("enter() w/o leave()\n"), (void) 0); for (; mLeftLevel; -- mLeftLevel) ___CritSectEnter (mLock); } } uint32_t level() const { return mLevel; } bool isNull() const { return mLock == NULL; } bool operator !() const { return isNull(); } bool belongsTo (VirtualBoxBase *that) const { return that && &that->mCritSec == mLock; } private: AutoLock (const AutoLock &that); // disabled AutoLock &operator = (const AutoLock &that); // disabled RTCRITSECT *mLock; uint32_t mLevel; uint32_t mLeftLevel; #undef ___CritSectEnter }; // sets the ready state of the object void setReady(bool isReady) { mReady = isReady; } // get the ready state of the object bool isReady() { return mReady; } /** * Translates the given text string according to the currently installed * translation table and current context. The current context is determined * by the context parameter. Additionally, a comment to the source text * string text can be given. This comment (which is NULL by default) * is helpful in sutuations where it is necessary to distinguish between * two or more semantically different roles of the same source text in the * same context. * * @param context the context of the the translation * @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 given context. */ 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 RTCRITSECT mCritSec; }; //////////////////////////////////////////////////////////////////////////////// /** * 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; }; /** * 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