/////////////////////////////////////////////////////////////////////////////
-// Name: thread.h
+// Name: wx/thread.h
// Purpose: Thread API
// Author: Guilhem Lavaux
-// Modified by:
+// Modified by: Vadim Zeitlin (modifications partly inspired by omnithreads
+// package from Olivetti & Oracle Research Laboratory)
// Created: 04/13/98
// RCS-ID: $Id$
// Copyright: (c) Guilhem Lavaux
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
-#ifndef __THREADH__
-#define __THREADH__
+#ifndef _WX_THREAD_H_
+#define _WX_THREAD_H_
-#ifdef __GNUG__
-#pragma interface "thread.h"
-#endif
+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------
+
+// get the value of wxUSE_THREADS configuration flag
+#include "wx/defs.h"
-#include "wx/object.h"
-#include "wx/setup.h"
-#include "wx/module.h"
+#if wxUSE_THREADS
// ----------------------------------------------------------------------------
// 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;
+ wxCOND_NO_ERROR = 0,
+ wxCOND_INVALID,
+ wxCOND_TIMEOUT, // WaitTimeout() has timed out
+ wxCOND_MISC_ERROR
+};
-typedef enum
+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
+};
-/* defines the interval of priority. */
-#define WXTHREAD_MIN_PRIORITY 0
-#define WXTHREAD_DEFAULT_PRIORITY 50
-#define WXTHREAD_MAX_PRIORITY 100
+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
+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;
// ----------------------------------------------------------------------------
-// GUI mutex handling.
+// A mutex object is a synchronization object whose state is set to signaled
+// when it is not owned by any thread, and nonsignaled when it is owned. Its
+// name comes from its usefulness in coordinating mutually-exclusive access to
+// a shared resource. Only one thread at a time can own a mutex object.
// ----------------------------------------------------------------------------
-void WXDLLEXPORT wxMutexGuiEnter();
-void WXDLLEXPORT wxMutexGuiLeave();
+// you should consider wxMutexLocker whenever possible instead of directly
+// working with wxMutex class - it is safer
+class WXDLLIMPEXP_BASE wxMutex
+{
+public:
+ // constructor & destructor
+ // ------------------------
+
+ // create either default (always safe) or recursive mutex
+ wxMutex(wxMutexType mutexType = wxMUTEX_DEFAULT);
+
+ // destroys the mutex kernel object
+ ~wxMutex();
+
+ // 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();
+
+ // 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. It is an error to unlock an already unlocked mutex
+ wxMutexError Unlock();
+
+protected:
+ wxMutexInternal *m_internal;
+
+ friend class wxConditionInternal;
+
+ DECLARE_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 WXDLLIMPEXP_BASE wxMutexLocker
+{
+public:
+ // lock the mutex in the ctor
+ 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
+ { return m_isOk; }
+
+ // unlock the mutex in dtor
+ ~wxMutexLocker()
+ { if ( IsOk() ) m_mutex.Unlock(); }
+
+private:
+ // no assignment operator nor copy ctor
+ wxMutexLocker(const wxMutexLocker&);
+ wxMutexLocker& operator=(const wxMutexLocker&);
+
+ bool m_isOk;
+ wxMutex& m_mutex;
+};
// ----------------------------------------------------------------------------
-// Mutex handler
+// 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.
+//
+// NB: wxCriticalSection object does not allocate any memory in its ctor
+// which makes it possible to have static globals of this class
// ----------------------------------------------------------------------------
-class WXDLLEXPORT wxMutexInternal;
-class WXDLLEXPORT wxMutex
+// in order to avoid any overhead under platforms where critical sections are
+// just mutexes make all wxCriticalSection class functions inline
+#if !defined(__WXMSW__) && !defined(__WXMAC__)
+ #define wxCRITSECT_IS_MUTEX 1
+
+ #define wxCRITSECT_INLINE inline
+#else // MSW
+ #define wxCRITSECT_IS_MUTEX 0
+
+ #define wxCRITSECT_INLINE
+#endif // MSW/!MSW
+
+// you should consider wxCriticalSectionLocker whenever possible instead of
+// directly working with wxCriticalSection class - it is safer
+class WXDLLIMPEXP_BASE wxCriticalSection
{
public:
- // constructor & destructor
- wxMutex();
- ~wxMutex();
+ // ctor & dtor
+ wxCRITSECT_INLINE wxCriticalSection();
+ wxCRITSECT_INLINE ~wxCriticalSection();
- // Lock the mutex.
- wxMutexError Lock();
- // Try to lock the mutex: if it can't, returns immediately with an error.
- wxMutexError TryLock();
- // Unlock the mutex.
- wxMutexError Unlock();
+ // enter the section (the same as locking a mutex)
+ wxCRITSECT_INLINE void Enter();
- // Returns true if the mutex is locked.
- bool IsLocked() const { return (m_locked > 0); }
+ // leave the critical section (same as unlocking a mutex)
+ wxCRITSECT_INLINE void Leave();
-protected:
- friend class wxCondition;
+private:
+#if wxCRITSECT_IS_MUTEX
+ wxMutex m_mutex;
+#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;
+ };
+#elif defined(__WXMAC__)
+ void *m_critRegion ;
+#endif // Unix&OS2/Win32
+
+ DECLARE_NO_COPY_CLASS(wxCriticalSection)
+};
+
+#if wxCRITSECT_IS_MUTEX
+ // implement wxCriticalSection using mutexes
+ inline wxCriticalSection::wxCriticalSection() { }
+ 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 mutexes
+class WXDLLIMPEXP_BASE wxCriticalSectionLocker
+{
+public:
+ wxCriticalSectionLocker(wxCriticalSection& cs)
+ : m_critsect(cs)
+ {
+ m_critsect.Enter();
+ }
- int m_locked;
- wxMutexInternal *p_internal;
+ ~wxCriticalSectionLocker()
+ {
+ m_critsect.Leave();
+ }
+
+private:
+ wxCriticalSection& m_critsect;
+
+ DECLARE_NO_COPY_CLASS(wxCriticalSectionLocker)
};
// ----------------------------------------------------------------------------
-// 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
+class WXDLLIMPEXP_BASE 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();
+ // 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 *p_internal;
+ wxConditionInternal *m_internal;
+
+ DECLARE_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
+
// ----------------------------------------------------------------------------
-// Thread management class
+// wxSemaphore: a counter limiting the number of threads concurrently accessing
+// a shared resource
// ----------------------------------------------------------------------------
-class wxThreadInternal;
-class WXDLLEXPORT wxThread
+class WXDLLIMPEXP_BASE wxSemaphore
{
public:
- // constructor & destructor.
- wxThread();
- virtual ~wxThread();
+ // 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 );
- // Create a new thread, this method should check there is only one thread
- // running by object.
- wxThreadError Create();
+ // dtor is not virtual, don't use this class polymorphically
+ ~wxSemaphore();
- // Destroys the thread immediately if the defer flag isn't true.
- wxThreadError Destroy();
+ // return true if the semaphore has been created successfully
+ bool IsOk() const;
- // Pause a running thread
- wxThreadError Pause();
+ // wait indefinitely, until the semaphore count goes beyond 0
+ // and then decrement it and return (this method might have been called
+ // Acquire())
+ wxSemaError Wait();
- // Resume a paused thread
- wxThreadError Resume();
+ // same as Wait(), but does not block, returns wxSEMA_NO_ERROR if
+ // successful and wxSEMA_BUSY if the count is currently zero
+ wxSemaError TryWait();
- // Switches on the defer flag.
- void DeferDestroy(bool on);
+ // 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);
- // Waits for the termination of the thread.
- void *Join();
+ // increments the semaphore count and signals one of the waiting threads
+ wxSemaError Post();
- // Sets the priority to "prio". (Warning: The priority can only be set before
- // the thread is created)
- void SetPriority(int prio);
- // Get the current priority.
- int GetPriority() const;
+private:
+ wxSemaphoreInternal *m_internal;
- // Get the thread ID
- unsigned long GetID() const;
+ DECLARE_NO_COPY_CLASS(wxSemaphore)
+};
- // Returns true if the thread is alive.
- bool IsAlive() const;
- // Returns true if the thread is running (not paused, not killed).
- bool IsRunning() const;
- // Returns true if the thread is suspended
- bool IsPaused() const { return IsAlive() && !IsRunning(); }
+// ----------------------------------------------------------------------------
+// wxThread: class encapsulating a thread of execution
+// ----------------------------------------------------------------------------
- // Returns true if the thread is the main thread (aka the GUI thread).
- static bool IsMain();
+// 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.
- // Called when thread exits.
- virtual void OnExit();
+// 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 WXDLLIMPEXP_BASE wxThread
+{
+public:
+ // the return type for the thread function
+ typedef void *ExitCode;
+
+ // static functions
+ // Returns the wxThread object for the calling thread. NULL is returned
+ // if the caller is the main thread (but it's recommended to use
+ // IsMain() and only call This() for threads other than the main one
+ // because NULL is also returned on error). If the thread wasn't
+ // created with wxThread class, the returned value is undefined.
+ static wxThread *This();
+
+ // Returns true if current thread is the main thread.
+ static bool IsMain();
+
+ // Release the rest of our time slice letting the other threads run
+ static void Yield();
+
+ // Sleep during the specified period of time in milliseconds
+ //
+ // This is the same as wxMilliSleep().
+ 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);
+
+ // 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)
+
+ 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 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 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: as Delete(), this only works if the thread
+ // calls TestDestroy() regularly
+ wxThreadError Pause();
+
+ // resume a paused thread
+ wxThreadError Resume();
+
+ // priority
+ // Sets the priority to "prio": see WXTHREAD_XXX_PRIORITY constants
+ //
+ // NB: the priority can only be set before the thread is created
+ void SetPriority(unsigned int prio);
+
+ // Get the current priority.
+ unsigned int GetPriority() 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 running (not paused, not killed).
+ bool IsRunning() 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() { }
+
+ // 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()!
+ virtual bool TestDestroy();
+
+ // dtor is public, but the detached threads should never be deleted - use
+ // Delete() instead (or leave the thread terminate by itself)
+ virtual ~wxThread();
protected:
- // In case, the DIFFER flag is true, enables another thread to kill this one.
- void TestDestroy();
- // Exits from the current thread.
- void Exit(void *status = NULL);
+ // 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;
private:
- // Entry point for the thread.
- virtual void *Entry() = 0;
+ // no copy ctor/assignment operator
+ wxThread(const wxThread&);
+ wxThread& operator=(const wxThread&);
+
+ friend class wxThreadInternal;
+
+ // the (platform-dependent) thread class implementation
+ 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:
- friend class wxThreadInternal;
+ // the owner of the thread
+ wxThreadHelper& m_owner;
- wxThreadInternal *p_internal;
+ // no copy ctor/assignment operator
+ wxThreadHelperThread(const wxThreadHelperThread&);
+ wxThreadHelperThread& operator=(const wxThreadHelperThread&);
};
// ----------------------------------------------------------------------------
-// Automatic initialization
+// 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 wxThreadModule : public wxModule
+class WXDLLIMPEXP_BASE wxThreadHelper
{
- DECLARE_DYNAMIC_CLASS(wxThreadModule)
-
+private:
+ void KillThread()
+ {
+ // If detached thread is about to finish, it will set
+ // m_thread to NULL so don't delete it then
+ // But if KillThread is called before detached thread
+ // 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:
- wxThreadModule() {}
+ // 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(); }
+
+ // create a new thread (and optionally set the stack size on platforms that
+ // support/need that), call Run() to start it
+ wxThreadError Create(unsigned int stackSize = 0)
+ {
+ KillThread();
+
+ 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;
+};
+
+// 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;
+}
- virtual bool OnInit();
- virtual void OnExit();
+// ----------------------------------------------------------------------------
+// Automatic initialization
+// ----------------------------------------------------------------------------
+
+// GUI mutex handling.
+void WXDLLIMPEXP_BASE wxMutexGuiEnter();
+void WXDLLIMPEXP_BASE wxMutexGuiLeave();
+
+// 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)
+
+// 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(); }
+
+#else // !wxUSE_THREADS
+
+// 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(); }
+ ~wxMutexGuiLocker() { wxMutexGuiLeave(); }
};
+// -----------------------------------------------------------------------------
+// implementation only until the end of file
+// -----------------------------------------------------------------------------
+
+#if wxUSE_THREADS
+
+#if defined(__WXMSW__) || defined(__WXMAC__) || 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 WXDLLIMPEXP_BASE wxMutexGuiLeaveOrEnter();
+
+ // 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 WXDLLIMPEXP_BASE wxWakeUpMainThread();
+
+ // return true if the main thread is waiting for some other to terminate:
+ // wxApp then should block all "dangerous" messages
+ extern bool WXDLLIMPEXP_BASE wxIsWaitingForThread();
+#endif // MSW, Mac, OS/2
+#endif // wxUSE_THREADS
-#endif // __THREADH__
+#endif // _WX_THREAD_H_
projects / wxWidgets.git / blobdiff