// 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
{
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:
{
public:
// lock the mutex in the ctor
- wxMutexLocker(wxMutex& mutex) : m_mutex(mutex)
- { m_isOk = m_mutex.Lock() == wxMUTEX_NO_ERROR; }
+ wxMutexLocker(wxMutex& mutex)
+ : m_isOk(FALSE), m_mutex(mutex)
+ { m_isOk = ( m_mutex.Lock() == wxMUTEX_NO_ERROR ); }
// returns TRUE if mutex was successfully locked in ctor
bool IsOk() const
// in order to avoid any overhead under platforms where critical sections are
// just mutexes make all wxCriticalSection class functions inline
-#if !defined(__WXMSW__) && !defined(__WXPM__) && !defined(__WXMAC__)
+#if !defined(__WXMSW__) && !defined(__WXPM__)
#define WXCRITICAL_INLINE inline
#define wxCRITSECT_IS_MUTEX 1
-#else // MSW || Mac || OS2
+#else // MSW || OS2
#define WXCRITICAL_INLINE
#define wxCRITSECT_IS_MUTEX 0
};
// ----------------------------------------------------------------------------
-// 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
{
+ DECLARE_NO_COPY_CLASS(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:
};
// ----------------------------------------------------------------------------
-// Thread class
+// wxSemaphore: a counter limiting the number of threads concurrently accessing
+// a shared resource
+// ----------------------------------------------------------------------------
+
+class WXDLLEXPORT wxSemaphoreInternal;
+class WXDLLEXPORT wxSemaphore
+{
+ DECLARE_NO_COPY_CLASS(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)
// 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
{
// NB: at least under MSW worker threads can not call ::wxSleep()!
static void Sleep(unsigned long milliseconds);
+ // get the number of system CPUs - useful with SetConcurrency()
+ // (the "best" value for it is usually number of CPUs + 1)
+ //
+ // 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
+ // performance for this process)
+ //
+ // Returns TRUE on success, FALSE otherwise (if not implemented, for
+ // example)
+ static bool SetConcurrency(size_t level);
+
// constructor only creates the C++ thread object and doesn't create (or
// start) the real thread
wxThread(wxThreadKind kind = wxTHREAD_DETACHED);
// from _another_ thread (typically the thread that created this one, e.g.
// the main thread), not from the thread itself
- // create a new thread - call Run() to start it
- wxThreadError Create();
+ // create a new thread and optionally set the stack size on
+ // platforms that support that - call Run() to start it
+ // (special cased for watcom which won't accept 0 default)
+
+ wxThreadError Create(unsigned int stackSize = 0);
// starts execution of the thread - from the moment Run() is called
// the execution of wxThread::Entry() may start at any moment, caller
// Get the thread ID - a platform dependent number which uniquely
// identifies a thread inside a process
- unsigned long GetId() const;
+ wxThreadIdType GetId() const;
// called when the thread exits - in the context of this thread
//
// having to take them inside "#if wxUSE_THREADS"
#define wxENTER_CRIT_SECT(cs) (cs).Enter()
#define wxLEAVE_CRIT_SECT(cs) (cs).Leave()
+#define wxCRIT_SECT_DECLARE(cs) static wxCriticalSection cs
#define wxCRIT_SECT_LOCKER(name, cs) wxCriticalSectionLocker name(cs)
#else // !wxUSE_THREADS
// having to take them inside "#if wxUSE_THREADS"
#define wxENTER_CRIT_SECT(cs)
#define wxLEAVE_CRIT_SECT(cs)
+#define wxCRIT_SECT_DECLARE(cs)
#define wxCRIT_SECT_LOCKER(name, cs)
#endif // wxUSE_THREADS
// return TRUE if the main thread is waiting for some other to terminate:
// wxApp then should block all "dangerous" messages
extern bool WXDLLEXPORT wxIsWaitingForThread();
+
+ // implement wxCriticalSection using mutexes
+ inline wxCriticalSection::wxCriticalSection() : m_mutex() { }
+ inline wxCriticalSection::~wxCriticalSection() { }
+
+ inline void wxCriticalSection::Enter() { (void)m_mutex.Lock(); }
+ inline void wxCriticalSection::Leave() { (void)m_mutex.Unlock(); }
#elif defined(__WXPM__)
// unlock GUI if there are threads waiting for and lock it back when
// there are no more of them - should be called periodically by the main
#endif // wxUSE_THREADS
#endif // __THREADH__
+
projects / wxWidgets.git / blobdiff