#include "wx/setup.h"
#if wxUSE_THREADS
-/* otherwise we get undefined references for non-thread case (KB)*/
+
+// only for wxUSE_THREADS - otherwise we'd get undefined symbols
#ifdef __GNUG__
#pragma interface "thread.h"
#endif
// constants
// ----------------------------------------------------------------------------
-typedef enum
+enum wxMutexError
{
- wxMUTEX_NO_ERROR = 0,
- wxMUTEX_DEAD_LOCK, // Mutex has been already locked by THE CALLING thread
- wxMUTEX_BUSY, // Mutex has been already locked by ONE thread
- wxMUTEX_UNLOCKED,
- wxMUTEX_MISC_ERROR
-} wxMutexError;
-
-typedef enum
+ wxMUTEX_NO_ERROR = 0,
+ wxMUTEX_DEAD_LOCK, // Mutex has been already locked by THE CALLING thread
+ wxMUTEX_BUSY, // Mutex has been already locked by ONE thread
+ wxMUTEX_UNLOCKED,
+ wxMUTEX_MISC_ERROR
+};
+
+enum wxThreadError
+{
+ wxTHREAD_NO_ERROR = 0, // No error
+ wxTHREAD_NO_RESOURCE, // No resource left to create a new thread
+ wxTHREAD_RUNNING, // The thread is already running
+ wxTHREAD_NOT_RUNNING, // The thread isn't running
+ wxTHREAD_KILLED, // Thread we waited for had to be killed
+ wxTHREAD_MISC_ERROR // Some other error
+};
+
+enum wxThreadKind
{
- wxTHREAD_NO_ERROR = 0, // No error
- wxTHREAD_NO_RESOURCE, // No resource left to create a new thread
- wxTHREAD_RUNNING, // The thread is already running
- wxTHREAD_NOT_RUNNING, // The thread isn't running
- wxTHREAD_MISC_ERROR // Some other error
-} wxThreadError;
+ wxTHREAD_DETACHED,
+ wxTHREAD_JOINABLE
+};
// defines the interval of priority
-#define WXTHREAD_MIN_PRIORITY 0u
-#define WXTHREAD_DEFAULT_PRIORITY 50u
-#define WXTHREAD_MAX_PRIORITY 100u
+enum
+{
+ WXTHREAD_MIN_PRIORITY = 0u,
+ WXTHREAD_DEFAULT_PRIORITY = 50u,
+ WXTHREAD_MAX_PRIORITY = 100u
+};
// ----------------------------------------------------------------------------
// A mutex object is a synchronization object whose state is set to signaled
// 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 *p_internal;
+ 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
// Critical section: this is the same as mutex but is only visible to the
// threads of the same process. For the platforms which don't have native
// support for critical sections, they're implemented entirely in terms of
-// mutexes
+// mutexes.
+//
+// NB: wxCriticalSection object does not allocate any memory in its ctor
+// which makes it possible to have static globals of this class
// ----------------------------------------------------------------------------
-// in order to avoid any overhead under !MSW make all wxCriticalSection class
-// functions inline - but this can't be done under MSW
-#if defined(__WXMSW__) || defined(__WXPM__)
- class WXDLLEXPORT wxCriticalSectionInternal;
- #define WXCRITICAL_INLINE
-#elif defined(__WXMAC__)
- class WXDLLEXPORT wxCriticalSectionInternal;
- #define WXCRITICAL_INLINE
-#else // !MSW && !PM
+class WXDLLEXPORT wxCriticalSectionInternal;
+
+// 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__)
#define WXCRITICAL_INLINE inline
+
+ #define wxCRITSECT_IS_MUTEX 1
+#else // MSW || OS2
+ #define WXCRITICAL_INLINE
+
+ #define wxCRITSECT_IS_MUTEX 0
#endif // MSW/!MSW
// you should consider wxCriticalSectionLocker whenever possible instead of
wxCriticalSection(const wxCriticalSection&);
wxCriticalSection& operator=(const wxCriticalSection&);
-#if defined(__WXMSW__) || defined(__WXPM__) || defined(__WXMAC__)
- wxCriticalSectionInternal *m_critsect;
-#else // !MSW
+#if wxCRITSECT_IS_MUTEX
wxMutex m_mutex;
-#endif // MSW/!MSW
+#elif defined(__WXMSW__)
+ // we can't allocate any memory in the ctor, so use placement new -
+ // unfortunately, we have to hardcode the sizeof() here because we can't
+ // include windows.h from this public header
+ char m_buffer[24];
+#elif !defined(__WXPM__)
+ wxCriticalSectionInternal *m_critsect;
+#else
+ // nothing for OS/2
+#endif // !Unix/Unix
};
// keep your preprocessor name space clean
};
// ----------------------------------------------------------------------------
-// Condition handler.
+// 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();
- ~wxCondition();
-
- // Waits indefinitely.
- void Wait(wxMutex& mutex);
- // Waits until a signal is raised or the timeout is elapsed.
- bool Wait(wxMutex& mutex, unsigned long sec, unsigned long nsec);
- // Raises a signal: only one "Waiter" is released.
- void Signal();
- // Broadcasts to all "Waiters".
- void Broadcast();
+ // 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();
+
+ // 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();
+
+ // 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();
+
+ // 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:
+ wxConditionInternal *m_internal;
+};
+
+// ----------------------------------------------------------------------------
+// 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:
- wxConditionInternal *p_internal;
+ wxSemaphoreInternal *m_internal;
};
// ----------------------------------------------------------------------------
-// Thread management class
+// wxThread: class encpasulating a thread of execution
// ----------------------------------------------------------------------------
-// FIXME Thread termination model is still unclear. Delete() should probably
-// have a timeout after which the thread must be Kill()ed.
+// there are two different kinds of threads: joinable and detached (default)
+// ones. Only joinable threads can return a return code and only detached
+// threads auto-delete themselves - the user should delete the joinable
+// threads manually.
// NB: in the function descriptions the words "this thread" mean the thread
// 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);
- // default constructor
- wxThread();
+ // 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);
+
+ // functions that change the thread state: all these can only be called
+ // from _another_ thread (typically the thread that created this one, e.g.
+ // the main thread), not from the thread itself
+
+ // 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)
- // function that change the thread state
- // create a new thread - call Run() to start it
- wxThreadError Create();
+ 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
+ // starts execution of the thread - from the moment Run() is called
+ // the execution of wxThread::Entry() may start at any moment, caller
// shouldn't suppose that it starts after (or before) Run() returns.
wxThreadError Run();
- // stops the thread if it's running and deletes the wxThread object
- // freeing its memory. This function should also be called if the
- // Create() or Run() fails to free memory (otherwise it will be done by
- // the thread itself when it terminates). The return value is the
- // thread exit code if the thread was gracefully terminated, 0 if it
- // wasn't running and -1 if an error occured.
- ExitCode Delete();
+ // stops the thread if it's running and deletes the wxThread object if
+ // this is a detached thread freeing its memory - otherwise (for
+ // joinable threads) you still need to delete wxThread object
+ // yourself.
+ //
+ // this function only works if the thread calls TestDestroy()
+ // periodically - the thread will only be deleted the next time it
+ // does it!
+ //
+ // will fill the rc pointer with the thread exit code if it's !NULL
+ wxThreadError Delete(ExitCode *rc = (ExitCode *)NULL);
+
+ // waits for a joinable thread to finish and returns its exit code
+ //
+ // Returns (ExitCode)-1 on error (for example, if the thread is not
+ // joinable)
+ ExitCode Wait();
// kills the thread without giving it any chance to clean up - should
// not be used in normal circumstances, use Delete() instead. It is a
// dangerous function that should only be used in the most extreme
- // cases! The wxThread object is deleted by Kill() if thread was
- // killed (i.e. no errors occured).
+ // cases!
+ //
+ // The wxThread object is deleted by Kill() if the thread is
+ // detachable, but you still have to delete it manually for joinable
+ // threads.
wxThreadError Kill();
- // pause a running thread
+ // pause a running thread: as Delete(), this only works if the thread
+ // calls TestDestroy() regularly
wxThreadError Pause();
// resume a paused thread
// Get the current priority.
unsigned int GetPriority() const;
- // Get the thread ID - a platform dependent number which uniquely
- // identifies a thread inside a process
- unsigned long GetID() const;
-
// thread status inquiries
// Returns true if the thread is alive: i.e. running or suspended
bool IsAlive() const;
// Returns true if the thread is suspended
bool IsPaused() const;
+ // is the thread of detached kind?
+ bool IsDetached() const { return m_isDetached; }
+
+ // Get the thread ID - a platform dependent number which uniquely
+ // identifies a thread inside a process
+ 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
virtual void OnExit() { }
+ // dtor is public, but the detached threads should never be deleted - use
+ // Delete() instead (or leave the thread terminate by itself)
+ virtual ~wxThread();
+
protected:
// Returns TRUE if the thread was asked to terminate: this function should
// be called by the thread from time to time, otherwise the main thread
bool TestDestroy();
// exits from the current thread - can be called only from this thread
- void Exit(void *exitcode = 0);
-
- // destructor is private - user code can't delete thread objects, they will
- // auto-delete themselves (and thus must be always allocated on the heap).
- // Use Delete() or Kill() instead.
- //
- // NB: derived classes dtors shouldn't be public neither!
- virtual ~wxThread();
+ void Exit(ExitCode exitcode = 0);
// entry point for the thread - called by Run() and executes in the context
// of this thread.
friend class wxThreadInternal;
// the (platform-dependent) thread class implementation
- wxThreadInternal *p_internal;
+ wxThreadInternal *m_internal;
// protects access to any methods of wxThreadInternal object
wxCriticalSection m_critsect;
+
+ // true if the thread is detached, false if it is joinable
+ bool m_isDetached;
};
// ----------------------------------------------------------------------------
// macros for entering/leaving critical sections which may be used without
// 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_LOCKER(name, cs) wxCriticalSectionLocker name(*cs)
+#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
// returns TRUE if the main thread has GUI lock
extern bool WXDLLEXPORT wxGuiOwnedByMainThread();
+
+ // return TRUE if the main thread is waiting for some other to terminate:
+ // wxApp then should block all "dangerous" messages
+ extern bool WXDLLEXPORT wxIsWaitingForThread();
+
#else // !MSW && !PM
// implement wxCriticalSection using mutexes
inline wxCriticalSection::wxCriticalSection() { }
#endif // wxUSE_THREADS
#endif // __THREADH__
+
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