//////////////////////////////////////////////////////////////////////////////// // The Loki Library // Copyright (c) 2001 by Andrei Alexandrescu // This code accompanies the book: // Alexandrescu, Andrei. "Modern C++ Design: Generic Programming and Design // Patterns Applied". Copyright (c) 2001. Addison-Wesley. // Permission to use, copy, modify, distribute and sell this software for any // purpose is hereby granted without fee, provided that the above copyright // notice appear in all copies and that both that copyright notice and this // permission notice appear in supporting documentation. // The author or Addison-Wesley Longman make no representations about the // suitability of this software for any purpose. It is provided "as is" // without express or implied warranty. //////////////////////////////////////////////////////////////////////////////// #ifndef LOKI_THREADS_INC_ #define LOKI_THREADS_INC_ // $Id$ /// @defgroup ThreadingGroup Threading /// Policies to for the threading model: /// /// - SingleThreaded /// - ObjectLevelLockable /// - ClassLevelLockable /// /// All classes in Loki have configurable threading model. /// /// The macro LOKI_DEFAULT_THREADING selects the default /// threading model for certain components of Loki /// (it affects only default template arguments) /// /// \par Usage: /// /// To use a specific threading model define /// /// - nothing, single-theading is default /// - LOKI_OBJECT_LEVEL_THREADING for object-level-threading /// - LOKI_CLASS_LEVEL_THREADING for class-level-threading /// /// \par Supported platfroms: /// /// - Windows (windows.h) /// - POSIX (pthread.h): /// No recursive mutex support with pthread. /// This means: calling Lock() on a Loki::Mutex twice from the /// same thread before unlocking the mutex deadlocks the system. /// To avoid this redesign your synchronization. See also: /// http://sourceforge.net/tracker/index.php?func=detail&aid=1516182&group_id=29557&atid=396647 #include #if defined(LOKI_CLASS_LEVEL_THREADING) || defined(LOKI_OBJECT_LEVEL_THREADING) #define LOKI_DEFAULT_THREADING_NO_OBJ_LEVEL ::Loki::ClassLevelLockable #if defined(LOKI_CLASS_LEVEL_THREADING) && !defined(LOKI_OBJECT_LEVEL_THREADING) #define LOKI_DEFAULT_THREADING ::Loki::ClassLevelLockable #else #define LOKI_DEFAULT_THREADING ::Loki::ObjectLevelLockable #endif #if defined(_WIN32) || defined(_WIN64) #include #define LOKI_WINDOWS_H #else #include #define LOKI_PTHREAD_H #endif #else #define LOKI_DEFAULT_THREADING ::Loki::SingleThreaded #define LOKI_DEFAULT_THREADING_NO_OBJ_LEVEL ::Loki::SingleThreaded #endif #ifndef LOKI_DEFAULT_MUTEX #define LOKI_DEFAULT_MUTEX ::Loki::Mutex #endif #ifdef LOKI_WINDOWS_H #define LOKI_THREADS_MUTEX(x) CRITICAL_SECTION (x); #define LOKI_THREADS_MUTEX_INIT(x) ::InitializeCriticalSection (x) #define LOKI_THREADS_MUTEX_DELETE(x) ::DeleteCriticalSection (x) #define LOKI_THREADS_MUTEX_LOCK(x) ::EnterCriticalSection (x) #define LOKI_THREADS_MUTEX_UNLOCK(x) ::LeaveCriticalSection (x) #define LOKI_THREADS_LONG LONG #define LOKI_THREADS_MUTEX_CTOR(x) #define LOKI_THREADS_ATOMIC_FUNCTIONS \ static IntType AtomicMultiply(volatile IntType& lval, const IntType val) \ { \ ::EnterCriticalSection( &atomic_mutex_ ); \ lval *= val; \ ::LeaveCriticalSection( &atomic_mutex_ ); \ return lval; \ } \ \ static IntType AtomicDivide(volatile IntType& lval, const IntType val) \ { \ ::EnterCriticalSection( &atomic_mutex_ ); \ lval /= val; \ ::LeaveCriticalSection( &atomic_mutex_ ); \ return lval; \ } \ \ static IntType AtomicIncrement(volatile IntType& lval) \ { \ ::EnterCriticalSection( &atomic_mutex_ ); \ ++lval; \ ::LeaveCriticalSection( &atomic_mutex_ ); \ return lval; \ } \ \ static IntType AtomicDecrement(volatile IntType& lval) \ { \ ::EnterCriticalSection( &atomic_mutex_ ); \ --lval; \ ::LeaveCriticalSection( &atomic_mutex_ ); \ return lval; \ } \ \ static void AtomicAssign(volatile IntType& lval, const IntType val) \ { InterlockedExchange(&const_cast(lval), val); } \ \ static void AtomicAssign(IntType& lval, volatile const IntType& val) \ { InterlockedExchange(&lval, val); } \ \ static IntType AtomicIncrement(volatile IntType& lval, const IntType compare, bool & matches ) \ { \ ::EnterCriticalSection( &atomic_mutex_ ); \ ++lval; \ matches = ( lval == compare ); \ ::LeaveCriticalSection( &atomic_mutex_ ); \ return lval; \ } \ \ static IntType AtomicDecrement(volatile IntType& lval, const IntType compare, bool & matches ) \ { \ ::EnterCriticalSection( &atomic_mutex_ ); \ --lval; \ matches = ( lval == compare ); \ ::LeaveCriticalSection( &atomic_mutex_ ); \ return lval; \ } \ \ static IntType AtomicAdd(volatile IntType& lval, const IntType val, const IntType compare, bool & matches ) \ { \ ::EnterCriticalSection( &atomic_mutex_ ); \ lval += val; \ matches = ( lval == compare ); \ ::LeaveCriticalSection( &atomic_mutex_ ); \ return lval; \ } \ \ static IntType AtomicSubtract(volatile IntType& lval, const IntType val, const IntType compare, bool & matches ) \ { \ ::EnterCriticalSection( &atomic_mutex_ ); \ lval -= val; \ matches = ( lval == compare ); \ ::LeaveCriticalSection( &atomic_mutex_ ); \ return lval; \ } \ \ static IntType AtomicMultiply(volatile IntType& lval, const IntType val, const IntType compare, bool & matches ) \ { \ ::EnterCriticalSection( &atomic_mutex_ ); \ lval *= val; \ matches = ( lval == compare ); \ ::LeaveCriticalSection( &atomic_mutex_ ); \ return lval; \ } \ \ static IntType AtomicDivide(volatile IntType& lval, const IntType val, const IntType compare, bool & matches ) \ { \ ::EnterCriticalSection( &atomic_mutex_ ); \ lval /= val; \ matches = ( lval == compare ); \ ::LeaveCriticalSection( &atomic_mutex_ ); \ return lval; \ } #elif defined(LOKI_PTHREAD_H) #define LOKI_THREADS_MUTEX(x) pthread_mutex_t (x); #define LOKI_THREADS_MUTEX_INIT(x) ::pthread_mutex_init(x, 0) // define to 1 to enable recursive mutex support #if 0 // experimental recursive mutex support #define LOKI_THREADS_MUTEX_CTOR(x) : x(PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP) #else // no recursive mutex support #define LOKI_THREADS_MUTEX_CTOR(x) #endif #define LOKI_THREADS_MUTEX_DELETE(x) ::pthread_mutex_destroy (x) #define LOKI_THREADS_MUTEX_LOCK(x) ::pthread_mutex_lock (x) #define LOKI_THREADS_MUTEX_UNLOCK(x) ::pthread_mutex_unlock (x) #define LOKI_THREADS_LONG long #define LOKI_THREADS_ATOMIC(x) \ pthread_mutex_lock(&atomic_mutex_); \ x; \ pthread_mutex_unlock(&atomic_mutex_) #define LOKI_THREADS_ATOMIC_FUNCTIONS \ private: \ static pthread_mutex_t atomic_mutex_; \ public: \ static IntType AtomicMultiply(volatile IntType& lval, const IntType val) \ { \ ::pthread_mutex_lock( &atomic_mutex_ ); \ lval *= val; \ ::pthread_mutex_unlock( &atomic_mutex_ ); \ return lval; \ } \ \ static IntType AtomicDivide(volatile IntType& lval, const IntType val) \ { \ ::pthread_mutex_lock( &atomic_mutex_ ); \ lval /= val; \ ::pthread_mutex_unlock( &atomic_mutex_ ); \ return lval; \ } \ \ static IntType AtomicIncrement(volatile IntType& lval) \ { \ ::pthread_mutex_lock( &atomic_mutex_ ); \ ++lval; \ ::pthread_mutex_unlock( &atomic_mutex_ ); \ return lval; \ } \ \ static IntType AtomicDecrement(volatile IntType& lval) \ { \ ::pthread_mutex_lock( &atomic_mutex_ ); \ --lval; \ ::pthread_mutex_unlock( &atomic_mutex_ ); \ return lval; \ } \ \ static void AtomicAssign(volatile IntType& lval, const IntType val) \ { \ ::pthread_mutex_lock( &atomic_mutex_ ); \ lval = val; \ ::pthread_mutex_unlock( &atomic_mutex_ ); \ return lval; \ } \ \ static void AtomicAssign(IntType& lval, volatile const IntType& val) \ { \ ::pthread_mutex_lock( &atomic_mutex_ ); \ lval = val; \ ::pthread_mutex_unlock( &atomic_mutex_ ); \ return lval; \ } \ \ static IntType AtomicIncrement(volatile IntType& lval, const IntType compare, bool & matches ) \ { \ ::pthread_mutex_lock( &atomic_mutex_ ); \ ++lval; \ matches = ( compare == lval ); \ ::pthread_mutex_unlock( &atomic_mutex_ ); \ return lval; \ } \ \ static IntType AtomicDecrement(volatile IntType& lval, const IntType compare, bool & matches ) \ { \ ::pthread_mutex_lock( &atomic_mutex_ ); \ --lval; \ matches = ( compare == lval ); \ ::pthread_mutex_unlock( &atomic_mutex_ ); \ return lval; \ } \ static IntType AtomicMultiply(volatile IntType& lval, const IntType val, const IntType compare, bool & matches ) \ { \ ::pthread_mutex_lock( &atomic_mutex_ ); \ lval *= val; \ matches = ( lval == compare ); \ ::pthread_mutex_unlock( &atomic_mutex_ ); \ return lval; \ } \ \ static IntType AtomicDivide(volatile IntType& lval, const IntType val, const IntType compare, bool & matches ) \ { \ ::pthread_mutex_lock( &atomic_mutex_ ); \ lval /= val; \ matches = ( lval == compare ); \ ::pthread_mutex_unlock( &atomic_mutex_ ); \ return lval; \ } #else // single threaded #define LOKI_THREADS_MUTEX(x) #define LOKI_THREADS_MUTEX_INIT(x) #define LOKI_THREADS_MUTEX_DELETE(x) #define LOKI_THREADS_MUTEX_LOCK(x) #define LOKI_THREADS_MUTEX_UNLOCK(x) #define LOKI_THREADS_LONG #define LOKI_THREADS_MUTEX_CTOR(x) #endif namespace Loki { //////////////////////////////////////////////////////////////////////////////// /// \class Mutex // /// \ingroup ThreadingGroup /// A simple and portable Mutex. A default policy class for locking objects. //////////////////////////////////////////////////////////////////////////////// class Mutex { public: Mutex() LOKI_THREADS_MUTEX_CTOR(mtx_) { LOKI_THREADS_MUTEX_INIT(&mtx_); } ~Mutex() { LOKI_THREADS_MUTEX_DELETE(&mtx_); } void Lock() { LOKI_THREADS_MUTEX_LOCK(&mtx_); } void Unlock() { LOKI_THREADS_MUTEX_UNLOCK(&mtx_); } private: /// Copy-constructor not implemented. Mutex(const Mutex &); /// Copy-assignement operator not implemented. Mutex & operator = (const Mutex &); LOKI_THREADS_MUTEX(mtx_) }; //////////////////////////////////////////////////////////////////////////////// /// \class SingleThreaded /// /// \ingroup ThreadingGroup /// Implementation of the ThreadingModel policy used by various classes /// Implements a single-threaded model; no synchronization //////////////////////////////////////////////////////////////////////////////// template class SingleThreaded { public: /// \struct Lock /// Dummy Lock class struct Lock { Lock() {} explicit Lock(const SingleThreaded&) {} explicit Lock(const SingleThreaded*) {} }; typedef Host VolatileType; typedef int IntType; static IntType AtomicAdd(volatile IntType& lval, const IntType val) { return lval += val; } static IntType AtomicSubtract(volatile IntType& lval, const IntType val) { return lval -= val; } static IntType AtomicMultiply(volatile IntType& lval, const IntType val) { return lval *= val; } static IntType AtomicDivide(volatile IntType& lval, const IntType val) { return lval /= val; } static IntType AtomicIncrement(volatile IntType& lval) { return ++lval; } static IntType AtomicDecrement(volatile IntType& lval) { return --lval; } static void AtomicAssign(volatile IntType & lval, const IntType val) { lval = val; } static void AtomicAssign(IntType & lval, volatile IntType & val) { lval = val; } static IntType AtomicAdd(volatile IntType& lval, const IntType val, const IntType compare, bool & matches ) { lval += val; matches = ( lval == compare ); return lval; } static IntType AtomicSubtract(volatile IntType& lval, const IntType val, const IntType compare, bool & matches ) { lval -= val; matches = ( lval == compare ); return lval; } static IntType AtomicMultiply(volatile IntType& lval, const IntType val, const IntType compare, bool & matches ) { lval *= val; matches = ( lval == compare ); return lval; } static IntType AtomicDivide(volatile IntType& lval, const IntType val, const IntType compare, bool & matches ) { lval /= val; matches = ( lval == compare ); return lval; } static IntType AtomicIncrement(volatile IntType& lval, const IntType compare, bool & matches ) { ++lval; matches = ( lval == compare ); return lval; } static IntType AtomicDecrement(volatile IntType& lval, const IntType compare, bool & matches ) { --lval; matches = ( lval == compare ); return lval; } }; #if defined(LOKI_WINDOWS_H) || defined(LOKI_PTHREAD_H) //////////////////////////////////////////////////////////////////////////////// /// \class ObjectLevelLockable /// /// \ingroup ThreadingGroup /// Implementation of the ThreadingModel policy used by various classes /// Implements a object-level locking scheme //////////////////////////////////////////////////////////////////////////////// template < class Host, class MutexPolicy = LOKI_DEFAULT_MUTEX > class ObjectLevelLockable { mutable MutexPolicy mtx_; public: ObjectLevelLockable() : mtx_() {} ObjectLevelLockable(const ObjectLevelLockable&) : mtx_() {} ~ObjectLevelLockable() {} class Lock; friend class Lock; /// \struct Lock /// Lock class to lock on object level class Lock { public: /// Lock object explicit Lock(const ObjectLevelLockable& host) : host_(host) { host_.mtx_.Lock(); } /// Lock object explicit Lock(const ObjectLevelLockable* host) : host_(*host) { host_.mtx_.Lock(); } /// Unlock object ~Lock() { host_.mtx_.Unlock(); } private: /// private by design of the object level threading Lock(); Lock(const Lock&); Lock& operator=(const Lock&); const ObjectLevelLockable& host_; }; typedef volatile Host VolatileType; typedef LOKI_THREADS_LONG IntType; LOKI_THREADS_ATOMIC_FUNCTIONS }; #ifdef LOKI_PTHREAD_H template pthread_mutex_t ObjectLevelLockable::atomic_mutex_ = PTHREAD_MUTEX_INITIALIZER; #endif //////////////////////////////////////////////////////////////////////////////// /// \class ClassLevelLockable /// /// \ingroup ThreadingGroup /// Implementation of the ThreadingModel policy used by various classes /// Implements a class-level locking scheme //////////////////////////////////////////////////////////////////////////////// template class ClassLevelLockable { struct Initializer { /// This function provides a Scott-Meyers type of Singleton as the initializer /// for the shared mutex. static Initializer & GetIt( void ) { static Initializer initializer_; return initializer_; } inline bool IsInit( void ) { return init_; } inline MutexPolicy & GetMutex( void ) { return mtx_; } private: bool init_; MutexPolicy mtx_; Initializer() : init_(false), mtx_() { init_ = true; } ~Initializer() { assert(init_); } Initializer( const Initializer & ); Initializer & operator = ( const Initializer & ); }; public: class Lock; friend class Lock; /// \struct Lock /// Lock class to lock on class level class Lock { public: /// Lock class Lock() { Initializer & initializer = Initializer::GetIt(); assert( initializer.IsInit() ); initializer.GetMutex().Lock(); } /// Lock class explicit Lock(const ClassLevelLockable&) { Initializer & initializer = Initializer::GetIt(); assert( initializer.IsInit() ); initializer.GetMutex().Lock(); } /// Lock class explicit Lock(const ClassLevelLockable*) { Initializer & initializer = Initializer::GetIt(); assert( initializer.IsInit() ); initializer.GetMutex().Lock(); } /// Unlock class ~Lock() { Initializer & initializer = Initializer::GetIt(); assert( initializer.IsInit() ); initializer.GetMutex().Unlock(); } private: Lock(const Lock&); Lock& operator=(const Lock&); }; typedef volatile Host VolatileType; typedef LOKI_THREADS_LONG IntType; LOKI_THREADS_ATOMIC_FUNCTIONS }; #ifdef LOKI_PTHREAD_H template pthread_mutex_t ClassLevelLockable::atomic_mutex_ = PTHREAD_MUTEX_INITIALIZER; #endif #endif // #if defined(LOKI_WINDOWS_H) || defined(LOKI_PTHREAD_H) } // namespace Loki #endif // end file guardian