/////////////////////////////////////////////////////////////////////////////
-// Name: thread.h
+// Name: wx/thread.h
// Purpose: Thread API
// Author: Guilhem Lavaux
// Modified by: Vadim Zeitlin (modifications partly inspired by omnithreads
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
-#ifndef __THREADH__
-#define __THREADH__
+#ifndef _WX_THREAD_H_
+#define _WX_THREAD_H_
// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------
// get the value of wxUSE_THREADS configuration flag
-#include "wx/setup.h"
+#include "wx/defs.h"
#if wxUSE_THREADS
-/* otherwise we get undefined references for non-thread case (KB)*/
-#ifdef __GNUG__
- #pragma interface "thread.h"
-#endif
-
-// Windows headers define it
-#ifdef Yield
- #undef Yield
-#endif
-
-#include "wx/module.h"
// ----------------------------------------------------------------------------
// constants
// ----------------------------------------------------------------------------
-typedef enum
+enum wxMutexError
+{
+ wxMUTEX_NO_ERROR = 0, // operation completed successfully
+ wxMUTEX_INVALID, // mutex hasn't been initialized
+ wxMUTEX_DEAD_LOCK, // mutex is already locked by the calling thread
+ wxMUTEX_BUSY, // mutex is already locked by another thread
+ wxMUTEX_UNLOCKED, // attempt to unlock a mutex which is not locked
+ wxMUTEX_TIMEOUT, // LockTimeout() has timed out
+ wxMUTEX_MISC_ERROR // any other error
+};
+
+enum wxCondError
{
- 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
+ wxCOND_NO_ERROR = 0,
+ wxCOND_INVALID,
+ wxCOND_TIMEOUT, // WaitTimeout() has timed out
+ wxCOND_MISC_ERROR
+};
+
+enum wxSemaError
{
- 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;
+ wxSEMA_NO_ERROR = 0,
+ wxSEMA_INVALID, // semaphore hasn't been initialized successfully
+ wxSEMA_BUSY, // returned by TryWait() if Wait() would block
+ wxSEMA_TIMEOUT, // returned by WaitTimeout()
+ wxSEMA_OVERFLOW, // Post() would increase counter past the max
+ wxSEMA_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_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
+};
+
+// There are 2 types of mutexes: normal mutexes and recursive ones. The attempt
+// to lock a normal mutex by a thread which already owns it results in
+// undefined behaviour (it always works under Windows, it will almost always
+// result in a deadlock under Unix). Locking a recursive mutex in such
+// situation always succeeds and it must be unlocked as many times as it has
+// been locked.
+//
+// However recursive mutexes have several important drawbacks: first, in the
+// POSIX implementation, they're less efficient. Second, and more importantly,
+// they CAN NOT BE USED WITH CONDITION VARIABLES under Unix! Using them with
+// wxCondition will work under Windows and some Unices (notably Linux) but will
+// deadlock under other Unix versions (e.g. Solaris). As it might be difficult
+// to ensure that a recursive mutex is not used with wxCondition, it is a good
+// idea to avoid using recursive mutexes at all. Also, the last problem with
+// them is that some (older) Unix versions don't support this at all -- which
+// results in a configure warning when building and a deadlock when using them.
+enum wxMutexType
+{
+ // normal mutex: try to always use this one
+ wxMUTEX_DEFAULT,
+
+ // recursive mutex: don't use these ones with wxCondition
+ wxMUTEX_RECURSIVE
+};
+
+// forward declarations
+class WXDLLIMPEXP_FWD_BASE wxThreadHelper;
+class WXDLLIMPEXP_FWD_BASE wxConditionInternal;
+class WXDLLIMPEXP_FWD_BASE wxMutexInternal;
+class WXDLLIMPEXP_FWD_BASE wxSemaphoreInternal;
+class WXDLLIMPEXP_FWD_BASE wxThreadInternal;
// ----------------------------------------------------------------------------
// 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 wxMutexInternal;
-class WXDLLEXPORT wxMutex
+class WXDLLIMPEXP_BASE wxMutex
{
public:
// constructor & destructor
- wxMutex();
+ // ------------------------
+
+ // create either default (always safe) or recursive mutex
+ wxMutex(wxMutexType mutexType = wxMUTEX_DEFAULT);
+
+ // destroys the mutex kernel object
~wxMutex();
- // Lock the mutex.
+ // test if the mutex has been created successfully
+ bool IsOk() const;
+
+ // mutex operations
+ // ----------------
+
+ // Lock the mutex, blocking on it until it is unlocked by the other thread.
+ // The result of locking a mutex already locked by the current thread
+ // depend on the mutex type.
+ //
+ // The caller must call Unlock() later if Lock() returned wxMUTEX_NO_ERROR.
wxMutexError Lock();
- // Try to lock the mutex: if it can't, returns immediately with an error.
+
+ // Same as Lock() but return wxMUTEX_TIMEOUT if the mutex can't be locked
+ // during the given number of milliseconds
+ wxMutexError LockTimeout(unsigned long ms);
+
+ // Try to lock the mutex: if it is currently locked, return immediately
+ // with an error. Otherwise the caller must call Unlock().
wxMutexError TryLock();
- // Unlock the mutex.
- wxMutexError Unlock();
- // Returns true if the mutex is locked.
- bool IsLocked() const { return (m_locked > 0); }
+ // Unlock the mutex. It is an error to unlock an already unlocked mutex
+ wxMutexError Unlock();
protected:
- friend class wxCondition;
+ wxMutexInternal *m_internal;
- // no assignment operator nor copy ctor
- wxMutex(const wxMutex&);
- wxMutex& operator=(const wxMutex&);
+ friend class wxConditionInternal;
- int m_locked;
- wxMutexInternal *p_internal;
+ wxDECLARE_NO_COPY_CLASS(wxMutex);
};
// a helper class which locks the mutex in the ctor and unlocks it in the dtor:
// this ensures that mutex is always unlocked, even if the function returns or
// throws an exception before it reaches the end
-class WXDLLEXPORT wxMutexLocker
+class WXDLLIMPEXP_BASE wxMutexLocker
{
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
+ // returns true if mutex was successfully locked in ctor
bool IsOk() const
{ return m_isOk; }
// 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
-#ifdef __WXMSW__
- class WXDLLEXPORT wxCriticalSectionInternal;
- #define WXCRITICAL_INLINE
-#else // !MSW
- #define WXCRITICAL_INLINE inline
+// in order to avoid any overhead under platforms where critical sections are
+// just mutexes make all wxCriticalSection class functions inline
+#if !defined(__WXMSW__)
+ #define wxCRITSECT_IS_MUTEX 1
+
+ #define wxCRITSECT_INLINE WXEXPORT inline
+#else // MSW
+ #define wxCRITSECT_IS_MUTEX 0
+
+ #define wxCRITSECT_INLINE
#endif // MSW/!MSW
+enum wxCriticalSectionType
+{
+ // recursive critical section
+ wxCRITSEC_DEFAULT,
+
+ // non-recursive critical section
+ wxCRITSEC_NON_RECURSIVE
+};
+
// you should consider wxCriticalSectionLocker whenever possible instead of
// directly working with wxCriticalSection class - it is safer
-class WXDLLEXPORT wxCriticalSection
+class WXDLLIMPEXP_BASE wxCriticalSection
{
public:
// ctor & dtor
- WXCRITICAL_INLINE wxCriticalSection();
- WXCRITICAL_INLINE ~wxCriticalSection();
-
+ wxCRITSECT_INLINE wxCriticalSection( wxCriticalSectionType critSecType = wxCRITSEC_DEFAULT );
+ wxCRITSECT_INLINE ~wxCriticalSection();
// enter the section (the same as locking a mutex)
- WXCRITICAL_INLINE void Enter();
+ wxCRITSECT_INLINE void Enter();
+
// leave the critical section (same as unlocking a mutex)
- WXCRITICAL_INLINE void Leave();
+ wxCRITSECT_INLINE void Leave();
private:
- // no assignment operator nor copy ctor
- wxCriticalSection(const wxCriticalSection&);
- wxCriticalSection& operator=(const wxCriticalSection&);
-
-#ifdef __WXMSW__
- 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 and we also have to use the
+ // union to force the correct (i.e. maximal) alignment
+ //
+ // if CRITICAL_SECTION size changes in Windows, you'll get an assert from
+ // thread.cpp and will need to increase the buffer size
+ //
+ // finally, we need this typedef instead of declaring m_buffer directly
+ // because otherwise the assert mentioned above wouldn't compile with some
+ // compilers (notably CodeWarrior 8)
+#ifdef __WIN64__
+ typedef char wxCritSectBuffer[40];
+#else // __WIN32__
+ typedef char wxCritSectBuffer[24];
+#endif
+ union
+ {
+ unsigned long m_dummy1;
+ void *m_dummy2;
+
+ wxCritSectBuffer m_buffer;
+ };
+#endif // Unix&OS2/Win32
+
+ wxDECLARE_NO_COPY_CLASS(wxCriticalSection);
};
-// keep your preprocessor name space clean
-#undef WXCRITICAL_INLINE
+#if wxCRITSECT_IS_MUTEX
+ // implement wxCriticalSection using mutexes
+ inline wxCriticalSection::wxCriticalSection( wxCriticalSectionType critSecType )
+ : m_mutex( critSecType == wxCRITSEC_DEFAULT ? wxMUTEX_RECURSIVE : wxMUTEX_DEFAULT ) { }
+ inline wxCriticalSection::~wxCriticalSection() { }
+
+ inline void wxCriticalSection::Enter() { (void)m_mutex.Lock(); }
+ inline void wxCriticalSection::Leave() { (void)m_mutex.Unlock(); }
+#endif // wxCRITSECT_IS_MUTEX
+
+#undef wxCRITSECT_INLINE
+#undef wxCRITSECT_IS_MUTEX
// wxCriticalSectionLocker is the same to critical sections as wxMutexLocker is
-// to th mutexes
-class WXDLLEXPORT wxCriticalSectionLocker
+// to mutexes
+class WXDLLIMPEXP_BASE wxCriticalSectionLocker
{
public:
- wxCriticalSectionLocker(wxCriticalSection& critsect) : m_critsect(critsect)
- { m_critsect.Enter(); }
+ wxCriticalSectionLocker(wxCriticalSection& cs)
+ : m_critsect(cs)
+ {
+ m_critsect.Enter();
+ }
+
~wxCriticalSectionLocker()
- { m_critsect.Leave(); }
+ {
+ m_critsect.Leave();
+ }
private:
- // no assignment operator nor copy ctor
- wxCriticalSectionLocker(const wxCriticalSectionLocker&);
- wxCriticalSectionLocker& operator=(const wxCriticalSectionLocker&);
-
wxCriticalSection& m_critsect;
+
+ wxDECLARE_NO_COPY_CLASS(wxCriticalSectionLocker);
+};
+
+// ----------------------------------------------------------------------------
+// wxCondition models a POSIX condition variable which allows one (or more)
+// thread(s) to wait until some condition is fulfilled
+// ----------------------------------------------------------------------------
+
+class WXDLLIMPEXP_BASE wxCondition
+{
+public:
+ // Each wxCondition object is associated with a (single) 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();
+
+ // return true if the condition has been created successfully
+ bool IsOk() const;
+
+ // 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.
+ wxCondError Wait();
+
+ // exactly as Wait() except that it may also return if the specified
+ // timeout elapses 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 timeout parameter specifies an interval that needs to be waited for
+ // in milliseconds
+ wxCondError WaitTimeout(unsigned long milliseconds);
+
+ // 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
+ wxCondError 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.
+ wxCondError Broadcast();
+
+
+#if WXWIN_COMPATIBILITY_2_6
+ // deprecated version, don't use
+ wxDEPRECATED( bool Wait(unsigned long milliseconds) );
+#endif // WXWIN_COMPATIBILITY_2_6
+
+private:
+ wxConditionInternal *m_internal;
+
+ wxDECLARE_NO_COPY_CLASS(wxCondition);
};
+#if WXWIN_COMPATIBILITY_2_6
+ inline bool wxCondition::Wait(unsigned long milliseconds)
+ { return WaitTimeout(milliseconds) == wxCOND_NO_ERROR; }
+#endif // WXWIN_COMPATIBILITY_2_6
+
// ----------------------------------------------------------------------------
-// Condition handler.
+// wxSemaphore: a counter limiting the number of threads concurrently accessing
+// a shared resource
// ----------------------------------------------------------------------------
-class wxConditionInternal;
-class WXDLLEXPORT wxCondition
+class WXDLLIMPEXP_BASE wxSemaphore
{
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();
+ // 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();
+
+ // return true if the semaphore has been created successfully
+ bool IsOk() const;
+
+ // wait indefinitely, until the semaphore count goes beyond 0
+ // and then decrement it and return (this method might have been called
+ // Acquire())
+ wxSemaError Wait();
+
+ // same as Wait(), but does not block, returns wxSEMA_NO_ERROR if
+ // successful and wxSEMA_BUSY if the count is currently zero
+ wxSemaError TryWait();
+
+ // same as Wait(), but as a timeout limit, returns wxSEMA_NO_ERROR if the
+ // semaphore was acquired and wxSEMA_TIMEOUT if the timeout has elapsed
+ wxSemaError WaitTimeout(unsigned long milliseconds);
+
+ // increments the semaphore count and signals one of the waiting threads
+ wxSemaError Post();
private:
- wxConditionInternal *p_internal;
+ wxSemaphoreInternal *m_internal;
+
+ wxDECLARE_NO_COPY_CLASS(wxSemaphore);
};
// ----------------------------------------------------------------------------
-// Thread management class
+// wxThread: class encapsulating 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)
-class wxThreadInternal;
-class WXDLLEXPORT wxThread
+
+// 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 WXDLLIMPEXP_BASE wxThread
{
public:
// the return type for the thread function
// Returns true if current thread is the main thread.
static bool IsMain();
- // Release the rest of our time slice leting the other threads run
+ // Release the rest of our time slice letting the other threads run
static void Yield();
// Sleep during the specified period of time in milliseconds
//
- // NB: at least under MSW worker threads can not call ::wxSleep()!
+ // This is the same as wxMilliSleep().
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
- // function that change the thread state
- // 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)
- // starts execution of the thread - from the moment Run() is called the
- // execution of wxThread::Entry() may start at any moment, caller
+ 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
// 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 = 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).
+ // not be used under 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 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;
- // 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() { }
+ // is the thread of detached kind?
+ bool IsDetached() const { return m_isDetached; }
-protected:
- // Returns TRUE if the thread was asked to terminate: this function should
+ // Get the thread ID - a platform dependent number which uniquely
+ // identifies a thread inside a process
+ wxThreadIdType GetId() const;
+
+ wxThreadKind GetKind() const
+ { return m_isDetached ? wxTHREAD_DETACHED : wxTHREAD_JOINABLE; }
+
+ // 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
// will be left forever in Delete()!
- bool TestDestroy();
-
- // exits from the current thread - can be called only from this thread
- void Exit(void *exitcode = 0);
+ virtual bool TestDestroy();
- // 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!
+ // dtor is public, but the detached threads should never be deleted - use
+ // Delete() instead (or leave the thread terminate by itself)
virtual ~wxThread();
+protected:
+ // exits from the current thread - can be called only from this thread
+ void Exit(ExitCode exitcode = 0);
+
// entry point for the thread - called by Run() and executes in the context
// of this thread.
virtual void *Entry() = 0;
wxThread(const wxThread&);
wxThread& operator=(const wxThread&);
+ // 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() { }
+
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;
+};
+
+// wxThreadHelperThread class
+// --------------------------
+
+class WXDLLIMPEXP_BASE wxThreadHelperThread : public wxThread
+{
+public:
+ // constructor only creates the C++ thread object and doesn't create (or
+ // start) the real thread
+ wxThreadHelperThread(wxThreadHelper& owner, wxThreadKind kind)
+ : wxThread(kind), m_owner(owner)
+ { }
+
+protected:
+ // entry point for the thread -- calls Entry() in owner.
+ virtual void *Entry();
+
+private:
+ // the owner of the thread
+ wxThreadHelper& m_owner;
+
+ // no copy ctor/assignment operator
+ wxThreadHelperThread(const wxThreadHelperThread&);
+ wxThreadHelperThread& operator=(const wxThreadHelperThread&);
+};
+
+// ----------------------------------------------------------------------------
+// wxThreadHelper: this class implements the threading logic to run a
+// background task in another object (such as a window). It is a mix-in: just
+// derive from it to implement a threading background task in your class.
+// ----------------------------------------------------------------------------
+
+class WXDLLIMPEXP_BASE wxThreadHelper
+{
+private:
+ void KillThread()
+ {
+ // If wxThreadHelperThread is detached and is about to finish, it will
+ // set m_thread to NULL so don't delete it then.
+ // But if KillThread is called before wxThreadHelperThread (in detached mode)
+ // sets it to NULL, then the thread object still exists and can be killed
+ wxCriticalSectionLocker locker(m_critSection);
+
+ if ( m_thread )
+ {
+ m_thread->Kill();
+
+ if ( m_kind == wxTHREAD_JOINABLE )
+ delete m_thread;
+
+ m_thread = NULL;
+ }
+ }
+
+public:
+ // constructor only initializes m_thread to NULL
+ wxThreadHelper(wxThreadKind kind = wxTHREAD_JOINABLE)
+ : m_thread(NULL), m_kind(kind) { }
+
+ // destructor deletes m_thread
+ virtual ~wxThreadHelper() { KillThread(); }
+
+#if WXWIN_COMPATIBILITY_2_8
+ wxDEPRECATED( wxThreadError Create(unsigned int stackSize = 0) );
+#endif
+
+ // create a new thread (and optionally set the stack size on platforms that
+ // support/need that), call Run() to start it
+ wxThreadError CreateThread(wxThreadKind kind = wxTHREAD_JOINABLE,
+ unsigned int stackSize = 0)
+ {
+ KillThread();
+
+ m_kind = kind;
+ m_thread = new wxThreadHelperThread(*this, m_kind);
+
+ return m_thread->Create(stackSize);
+ }
+
+ // entry point for the thread - called by Run() and executes in the context
+ // of this thread.
+ virtual void *Entry() = 0;
+
+ // returns a pointer to the thread which can be used to call Run()
+ wxThread *GetThread() const
+ {
+ wxCriticalSectionLocker locker((wxCriticalSection&)m_critSection);
+
+ wxThread* thread = m_thread;
+
+ return thread;
+ }
+
+protected:
+ wxThread *m_thread;
+ wxThreadKind m_kind;
+ wxCriticalSection m_critSection; // To guard the m_thread variable
+
+ friend class wxThreadHelperThread;
};
+#if WXWIN_COMPATIBILITY_2_8
+inline wxThreadError wxThreadHelper::Create(unsigned int stackSize)
+{ return CreateThread(m_kind, stackSize); }
+#endif
+
+// call Entry() in owner, put it down here to avoid circular declarations
+inline void *wxThreadHelperThread::Entry()
+{
+ void * const result = m_owner.Entry();
+
+ wxCriticalSectionLocker locker(m_owner.m_critSection);
+
+ // Detached thread will be deleted after returning, so make sure
+ // wxThreadHelper::GetThread will not return an invalid pointer.
+ // And that wxThreadHelper::KillThread will not try to kill
+ // an already deleted thread
+ if ( m_owner.m_kind == wxTHREAD_DETACHED )
+ m_owner.m_thread = NULL;
+
+ return result;
+}
+
// ----------------------------------------------------------------------------
// Automatic initialization
// ----------------------------------------------------------------------------
// GUI mutex handling.
-void WXDLLEXPORT wxMutexGuiEnter();
-void WXDLLEXPORT wxMutexGuiLeave();
+void WXDLLIMPEXP_BASE wxMutexGuiEnter();
+void WXDLLIMPEXP_BASE wxMutexGuiLeave();
-#else // !wxUSE_THREADS
+// 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_DECLARE(cs) static wxCriticalSection cs
+#define wxCRIT_SECT_DECLARE_MEMBER(cs) wxCriticalSection cs
+#define wxCRIT_SECT_LOCKER(name, cs) wxCriticalSectionLocker name(cs)
-#include <wx/defs.h> // for WXDLLEXPORT
+// function for checking if we're in the main thread which may be used whether
+// wxUSE_THREADS is 0 or 1
+inline bool wxIsMainThread() { return wxThread::IsMain(); }
-// no thread support
-inline void WXDLLEXPORT wxMutexGuiEnter() { }
-inline void WXDLLEXPORT wxMutexGuiLeave() { }
-
-#endif // wxUSE_THREADS
+#else // !wxUSE_THREADS
-// automatically unlock GUI mutex in dtor
-class WXDLLEXPORT wxMutexGuiLocker
+// no thread support
+inline void wxMutexGuiEnter() { }
+inline void wxMutexGuiLeave() { }
+
+// macros for entering/leaving critical sections which may be used without
+// having to take them inside "#if wxUSE_THREADS"
+// (the implementation uses dummy structs to force semicolon after the macro)
+#define wxENTER_CRIT_SECT(cs) do {} while (0)
+#define wxLEAVE_CRIT_SECT(cs) do {} while (0)
+#define wxCRIT_SECT_DECLARE(cs) struct wxDummyCS##cs
+#define wxCRIT_SECT_DECLARE_MEMBER(cs) struct wxDummyCSMember##cs
+#define wxCRIT_SECT_LOCKER(name, cs) struct wxDummyCSLocker##name
+
+// if there is only one thread, it is always the main one
+inline bool wxIsMainThread() { return true; }
+
+#endif // wxUSE_THREADS/!wxUSE_THREADS
+
+// mark part of code as being a critical section: this macro declares a
+// critical section with the given name and enters it immediately and leaves
+// it at the end of the current scope
+//
+// example:
+//
+// int Count()
+// {
+// static int s_counter = 0;
+//
+// wxCRITICAL_SECTION(counter);
+//
+// return ++s_counter;
+// }
+//
+// this function is MT-safe in presence of the threads but there is no
+// overhead when the library is compiled without threads
+#define wxCRITICAL_SECTION(name) \
+ wxCRIT_SECT_DECLARE(s_cs##name); \
+ wxCRIT_SECT_LOCKER(cs##name##Locker, s_cs##name)
+
+// automatically lock GUI mutex in ctor and unlock it in dtor
+class WXDLLIMPEXP_BASE wxMutexGuiLocker
{
public:
wxMutexGuiLocker() { wxMutexGuiEnter(); }
// -----------------------------------------------------------------------------
// implementation only until the end of file
// -----------------------------------------------------------------------------
+
#if wxUSE_THREADS
-#ifdef __WXMSW__
+
+#if defined(__WXMSW__) || defined(__OS2__) || defined(__EMX__)
// 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
// thread
- extern void WXDLLEXPORT wxMutexGuiLeaveOrEnter();
+ extern void WXDLLIMPEXP_BASE wxMutexGuiLeaveOrEnter();
- // returns TRUE if the main thread has GUI lock
- extern bool WXDLLEXPORT wxGuiOwnedByMainThread();
+ // returns true if the main thread has GUI lock
+ extern bool WXDLLIMPEXP_BASE wxGuiOwnedByMainThread();
// wakes up the main thread if it's sleeping inside ::GetMessage()
- extern void WXDLLEXPORT wxWakeUpMainThread();
+ extern void WXDLLIMPEXP_BASE wxWakeUpMainThread();
- // return TRUE if the main thread is waiting for some other to terminate:
+ // 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
- // implement wxCriticalSection using mutexes
- inline wxCriticalSection::wxCriticalSection() { }
- inline wxCriticalSection::~wxCriticalSection() { }
+ extern bool WXDLLIMPEXP_BASE wxIsWaitingForThread();
+#endif // MSW, OS/2
- inline void wxCriticalSection::Enter() { (void)m_mutex.Lock(); }
- inline void wxCriticalSection::Leave() { (void)m_mutex.Unlock(); }
-#endif // MSW/!MSW
#endif // wxUSE_THREADS
-#endif // __THREADH__
+#endif // _WX_THREAD_H_
projects / wxWidgets.git / blobdiff