X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/6fe7378863be6febaaab0e8aa855b51781351ac5..ccdcde00d9ae27ca20ff6c3c9495918a0ec725aa:/include/wx/thread.h diff --git a/include/wx/thread.h b/include/wx/thread.h index c4f09dc254..60f5c7c5c4 100644 --- a/include/wx/thread.h +++ b/include/wx/thread.h @@ -80,6 +80,7 @@ enum // you should consider wxMutexLocker whenever possible instead of directly // working with wxMutex class - it is safer +class WXDLLEXPORT wxConditionInternal; class WXDLLEXPORT wxMutexInternal; class WXDLLEXPORT wxMutex { @@ -99,14 +100,14 @@ public: bool IsLocked() const { return (m_locked > 0); } protected: - friend class wxCondition; - // no assignment operator nor copy ctor wxMutex(const wxMutex&); wxMutex& operator=(const wxMutex&); int m_locked; wxMutexInternal *m_internal; + + friend class wxConditionInternal; }; // a helper class which locks the mutex in the ctor and unlocks it in the dtor: @@ -213,28 +214,53 @@ private: }; // ---------------------------------------------------------------------------- -// Condition variable: allows to block the thread execution until something -// happens (== condition is signaled) +// wxCondition models a POSIX condition variable which allows one (or more) +// thread(s) to wait until some condition is fulfilled // ---------------------------------------------------------------------------- -class wxConditionInternal; class WXDLLEXPORT wxCondition { public: - // constructor & destructor - wxCondition(); + // constructor and destructor + + // Each wxCondition object is associated with with a wxMutex object The + // mutex object MUST be locked before calling Wait() + wxCondition(wxMutex& mutex); + + // dtor is not virtual, don't use this class polymorphically ~wxCondition(); - // wait until the condition is signaled - // waits indefinitely. + // NB: the associated mutex MUST be locked beforehand by the calling thread + // + // it atomically releases the lock on the associated mutex + // and starts waiting to be woken up by a Signal()/Broadcast() + // once its signaled, then it will wait until it can reacquire + // the lock on the associated mutex object, before returning. void Wait(); - // waits until a signal is raised or the timeout elapses - bool Wait(unsigned long sec, unsigned long nsec); - // signal the condition - // wakes up one (and only one) of the waiting threads + // exactly as Wait() except that it may also return if the specified + // timeout ellapses even if the condition hasn't been signalled: in this + // case, the return value is FALSE, otherwise (i.e. in case of a normal + // return) it is TRUE + // + // the timeeout parameter specifies a interval that needs to be waited in + // milliseconds + bool Wait( unsigned long timeout_millis ); + + // NB: the associated mutex may or may not be locked by the calling thread + // + // this method unblocks one thread if any are blocking on the condition. + // if no thread is blocking in Wait(), then the signal is NOT remembered + // The thread which was blocking on Wait(), will then reacquire the lock + // on the associated mutex object before returning void Signal(); - // wakes up all threads waiting onthis condition + + // NB: the associated mutex may or may not be locked by the calling thread + // + // this method unblocks all threads if any are blocking on the condition. + // if no thread is blocking in Wait(), then the signal is NOT remembered + // The threads which were blocking on Wait(), will then reacquire the lock + // on the associated mutex object before returning. void Broadcast(); private: @@ -242,7 +268,43 @@ private: }; // ---------------------------------------------------------------------------- -// Thread class +// wxSemaphore: a counter limiting the number of threads concurrently accessing +// a shared resource +// ---------------------------------------------------------------------------- + +class WXDLLEXPORT wxSemaphoreInternal; +class WXDLLEXPORT wxSemaphore +{ +public: + // specifying a maxcount of 0 actually makes wxSemaphore behave as if there + // is no upper limit, if maxcount is 1 the semaphore behaves as a mutex + wxSemaphore( int initialcount = 0, int maxcount = 0 ); + + // dtor is not virtual, don't use this class polymorphically + ~wxSemaphore(); + + // wait indefinitely, until the semaphore count goes beyond 0 + // and then decrement it and return (this method might have been called + // Acquire()) + void Wait(); + + // same as Wait(), but does not block, returns TRUE if successful and + // FALSE if the count is zero + bool TryWait(); + + // same as Wait(), but as a timeout limit, returns TRUE if the semaphore + // was acquired and FALSE if the timeout has ellapsed + bool Wait( unsigned long timeout_millis ); + + // increments the semaphore count and signals one of the waiting threads + void Post(); + +private: + wxSemaphoreInternal *m_internal; +}; + +// ---------------------------------------------------------------------------- +// wxThread: class encpasulating a thread of execution // ---------------------------------------------------------------------------- // there are two different kinds of threads: joinable and detached (default) @@ -254,6 +316,13 @@ private: // created by the wxThread object while "main thread" is the thread created // during the process initialization (a.k.a. the GUI thread) +// On VMS thread pointers are 64 bits (also needed for other systems??? +#ifdef __VMS + typedef unsigned long long wxThreadIdType; +#else + typedef unsigned long wxThreadIdType; +#endif + class wxThreadInternal; class WXDLLEXPORT wxThread { @@ -286,6 +355,11 @@ public: // Returns -1 if unknown, number of CPUs otherwise static int GetCPUCount(); + // Get the platform specific thread ID and return as a long. This + // can be used to uniquely identify threads, even if they are not + // wxThreads. This is used by wxPython. + static wxThreadIdType GetCurrentId(); + // sets the concurrency level: this is, roughly, the number of threads // the system tries to schedule to run in parallel. 0 means the // default value (usually acceptable, but may not yield the best @@ -307,11 +381,7 @@ public: // platforms that support that - call Run() to start it // (special cased for watcom which won't accept 0 default) -#ifdef __WATCOMC__ - wxThreadError Create(unsigned int stackSize = 10240); -#else wxThreadError Create(unsigned int stackSize = 0); -#endif // starts execution of the thread - from the moment Run() is called // the execution of wxThread::Entry() may start at any moment, caller @@ -375,12 +445,8 @@ public: // Get the thread ID - a platform dependent number which uniquely // identifies a thread inside a process -#ifdef __VMS - unsigned long long GetId() const; -#else - unsigned long GetId() const; -#endif - + wxThreadIdType GetId() const; + // called when the thread exits - in the context of this thread // // NB: this function will not be called if the thread is Kill()ed @@ -533,4 +599,3 @@ public: #endif // __THREADH__ -// vi:sts=4:sw=4:et