869 lines
30 KiB
C++
869 lines
30 KiB
C++
/////////////////////////////////////////////////////////////////////////////
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// Name: wx/thread.h
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// Purpose: Thread API
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// Author: Guilhem Lavaux
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// Modified by: Vadim Zeitlin (modifications partly inspired by omnithreads
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// package from Olivetti & Oracle Research Laboratory)
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// Created: 04/13/98
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// RCS-ID: $Id: thread.h 70796 2012-03-04 00:29:31Z VZ $
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// Copyright: (c) Guilhem Lavaux
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// Licence: wxWindows licence
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/////////////////////////////////////////////////////////////////////////////
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#ifndef _WX_THREAD_H_
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#define _WX_THREAD_H_
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// ----------------------------------------------------------------------------
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// headers
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// ----------------------------------------------------------------------------
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// get the value of wxUSE_THREADS configuration flag
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#include "wx/defs.h"
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#if wxUSE_THREADS
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// ----------------------------------------------------------------------------
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// constants
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// ----------------------------------------------------------------------------
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enum wxMutexError
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{
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wxMUTEX_NO_ERROR = 0, // operation completed successfully
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wxMUTEX_INVALID, // mutex hasn't been initialized
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wxMUTEX_DEAD_LOCK, // mutex is already locked by the calling thread
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wxMUTEX_BUSY, // mutex is already locked by another thread
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wxMUTEX_UNLOCKED, // attempt to unlock a mutex which is not locked
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wxMUTEX_TIMEOUT, // LockTimeout() has timed out
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wxMUTEX_MISC_ERROR // any other error
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};
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enum wxCondError
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{
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wxCOND_NO_ERROR = 0,
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wxCOND_INVALID,
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wxCOND_TIMEOUT, // WaitTimeout() has timed out
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wxCOND_MISC_ERROR
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};
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enum wxSemaError
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{
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wxSEMA_NO_ERROR = 0,
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wxSEMA_INVALID, // semaphore hasn't been initialized successfully
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wxSEMA_BUSY, // returned by TryWait() if Wait() would block
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wxSEMA_TIMEOUT, // returned by WaitTimeout()
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wxSEMA_OVERFLOW, // Post() would increase counter past the max
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wxSEMA_MISC_ERROR
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};
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enum wxThreadError
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{
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wxTHREAD_NO_ERROR = 0, // No error
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wxTHREAD_NO_RESOURCE, // No resource left to create a new thread
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wxTHREAD_RUNNING, // The thread is already running
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wxTHREAD_NOT_RUNNING, // The thread isn't running
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wxTHREAD_KILLED, // Thread we waited for had to be killed
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wxTHREAD_MISC_ERROR // Some other error
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};
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enum wxThreadKind
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{
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wxTHREAD_DETACHED,
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wxTHREAD_JOINABLE
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};
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enum wxThreadWait
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{
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wxTHREAD_WAIT_BLOCK,
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wxTHREAD_WAIT_YIELD, // process events while waiting; MSW only
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// For compatibility reasons we use wxTHREAD_WAIT_YIELD by default as this
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// was the default behaviour of wxMSW 2.8 but it should be avoided as it's
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// dangerous and not portable.
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#if WXWIN_COMPATIBILITY_2_8
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wxTHREAD_WAIT_DEFAULT = wxTHREAD_WAIT_YIELD
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#else
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wxTHREAD_WAIT_DEFAULT = wxTHREAD_WAIT_BLOCK
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#endif
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};
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// defines the interval of priority
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enum
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{
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WXTHREAD_MIN_PRIORITY = 0u,
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WXTHREAD_DEFAULT_PRIORITY = 50u,
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WXTHREAD_MAX_PRIORITY = 100u
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};
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// There are 2 types of mutexes: normal mutexes and recursive ones. The attempt
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// to lock a normal mutex by a thread which already owns it results in
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// undefined behaviour (it always works under Windows, it will almost always
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// result in a deadlock under Unix). Locking a recursive mutex in such
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// situation always succeeds and it must be unlocked as many times as it has
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// been locked.
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//
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// However recursive mutexes have several important drawbacks: first, in the
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// POSIX implementation, they're less efficient. Second, and more importantly,
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// they CAN NOT BE USED WITH CONDITION VARIABLES under Unix! Using them with
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// wxCondition will work under Windows and some Unices (notably Linux) but will
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// deadlock under other Unix versions (e.g. Solaris). As it might be difficult
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// to ensure that a recursive mutex is not used with wxCondition, it is a good
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// idea to avoid using recursive mutexes at all. Also, the last problem with
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// them is that some (older) Unix versions don't support this at all -- which
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// results in a configure warning when building and a deadlock when using them.
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enum wxMutexType
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{
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// normal mutex: try to always use this one
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wxMUTEX_DEFAULT,
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// recursive mutex: don't use these ones with wxCondition
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wxMUTEX_RECURSIVE
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};
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// forward declarations
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class WXDLLIMPEXP_FWD_BASE wxThreadHelper;
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class WXDLLIMPEXP_FWD_BASE wxConditionInternal;
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class WXDLLIMPEXP_FWD_BASE wxMutexInternal;
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class WXDLLIMPEXP_FWD_BASE wxSemaphoreInternal;
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class WXDLLIMPEXP_FWD_BASE wxThreadInternal;
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// ----------------------------------------------------------------------------
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// A mutex object is a synchronization object whose state is set to signaled
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// when it is not owned by any thread, and nonsignaled when it is owned. Its
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// name comes from its usefulness in coordinating mutually-exclusive access to
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// a shared resource. Only one thread at a time can own a mutex object.
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// ----------------------------------------------------------------------------
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// you should consider wxMutexLocker whenever possible instead of directly
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// working with wxMutex class - it is safer
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class WXDLLIMPEXP_BASE wxMutex
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{
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public:
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// constructor & destructor
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// ------------------------
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// create either default (always safe) or recursive mutex
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wxMutex(wxMutexType mutexType = wxMUTEX_DEFAULT);
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// destroys the mutex kernel object
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~wxMutex();
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// test if the mutex has been created successfully
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bool IsOk() const;
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// mutex operations
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// ----------------
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// Lock the mutex, blocking on it until it is unlocked by the other thread.
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// The result of locking a mutex already locked by the current thread
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// depend on the mutex type.
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//
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// The caller must call Unlock() later if Lock() returned wxMUTEX_NO_ERROR.
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wxMutexError Lock();
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// Same as Lock() but return wxMUTEX_TIMEOUT if the mutex can't be locked
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// during the given number of milliseconds
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wxMutexError LockTimeout(unsigned long ms);
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// Try to lock the mutex: if it is currently locked, return immediately
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// with an error. Otherwise the caller must call Unlock().
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wxMutexError TryLock();
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// Unlock the mutex. It is an error to unlock an already unlocked mutex
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wxMutexError Unlock();
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protected:
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wxMutexInternal *m_internal;
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friend class wxConditionInternal;
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wxDECLARE_NO_COPY_CLASS(wxMutex);
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};
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// a helper class which locks the mutex in the ctor and unlocks it in the dtor:
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// this ensures that mutex is always unlocked, even if the function returns or
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// throws an exception before it reaches the end
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class WXDLLIMPEXP_BASE wxMutexLocker
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{
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public:
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// lock the mutex in the ctor
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wxMutexLocker(wxMutex& mutex)
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: m_isOk(false), m_mutex(mutex)
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{ m_isOk = ( m_mutex.Lock() == wxMUTEX_NO_ERROR ); }
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// returns true if mutex was successfully locked in ctor
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bool IsOk() const
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{ return m_isOk; }
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// unlock the mutex in dtor
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~wxMutexLocker()
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{ if ( IsOk() ) m_mutex.Unlock(); }
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private:
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// no assignment operator nor copy ctor
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wxMutexLocker(const wxMutexLocker&);
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wxMutexLocker& operator=(const wxMutexLocker&);
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bool m_isOk;
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wxMutex& m_mutex;
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};
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// ----------------------------------------------------------------------------
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// Critical section: this is the same as mutex but is only visible to the
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// threads of the same process. For the platforms which don't have native
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// support for critical sections, they're implemented entirely in terms of
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// mutexes.
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//
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// NB: wxCriticalSection object does not allocate any memory in its ctor
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// which makes it possible to have static globals of this class
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// ----------------------------------------------------------------------------
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// in order to avoid any overhead under platforms where critical sections are
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// just mutexes make all wxCriticalSection class functions inline
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#if !defined(__WINDOWS__)
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#define wxCRITSECT_IS_MUTEX 1
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#define wxCRITSECT_INLINE WXEXPORT inline
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#else // MSW
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#define wxCRITSECT_IS_MUTEX 0
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#define wxCRITSECT_INLINE
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#endif // MSW/!MSW
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enum wxCriticalSectionType
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{
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// recursive critical section
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wxCRITSEC_DEFAULT,
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// non-recursive critical section
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wxCRITSEC_NON_RECURSIVE
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};
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// you should consider wxCriticalSectionLocker whenever possible instead of
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// directly working with wxCriticalSection class - it is safer
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class WXDLLIMPEXP_BASE wxCriticalSection
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{
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public:
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// ctor & dtor
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wxCRITSECT_INLINE wxCriticalSection( wxCriticalSectionType critSecType = wxCRITSEC_DEFAULT );
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wxCRITSECT_INLINE ~wxCriticalSection();
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// enter the section (the same as locking a mutex)
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wxCRITSECT_INLINE void Enter();
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// try to enter the section (the same as trying to lock a mutex)
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wxCRITSECT_INLINE bool TryEnter();
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// leave the critical section (same as unlocking a mutex)
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wxCRITSECT_INLINE void Leave();
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private:
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#if wxCRITSECT_IS_MUTEX
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wxMutex m_mutex;
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#elif defined(__WINDOWS__)
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// we can't allocate any memory in the ctor, so use placement new -
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// unfortunately, we have to hardcode the sizeof() here because we can't
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// include windows.h from this public header and we also have to use the
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// union to force the correct (i.e. maximal) alignment
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//
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// if CRITICAL_SECTION size changes in Windows, you'll get an assert from
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// thread.cpp and will need to increase the buffer size
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//
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// finally, we need this typedef instead of declaring m_buffer directly
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// because otherwise the assert mentioned above wouldn't compile with some
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// compilers (notably CodeWarrior 8)
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#ifdef __WIN64__
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typedef char wxCritSectBuffer[40];
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#else // __WIN32__
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typedef char wxCritSectBuffer[24];
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#endif
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union
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{
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unsigned long m_dummy1;
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void *m_dummy2;
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wxCritSectBuffer m_buffer;
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};
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#endif // Unix&OS2/Win32
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wxDECLARE_NO_COPY_CLASS(wxCriticalSection);
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};
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#if wxCRITSECT_IS_MUTEX
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// implement wxCriticalSection using mutexes
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inline wxCriticalSection::wxCriticalSection( wxCriticalSectionType critSecType )
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: m_mutex( critSecType == wxCRITSEC_DEFAULT ? wxMUTEX_RECURSIVE : wxMUTEX_DEFAULT ) { }
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inline wxCriticalSection::~wxCriticalSection() { }
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inline void wxCriticalSection::Enter() { (void)m_mutex.Lock(); }
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inline bool wxCriticalSection::TryEnter() { return m_mutex.TryLock() == wxMUTEX_NO_ERROR; }
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inline void wxCriticalSection::Leave() { (void)m_mutex.Unlock(); }
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#endif // wxCRITSECT_IS_MUTEX
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#undef wxCRITSECT_INLINE
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#undef wxCRITSECT_IS_MUTEX
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// wxCriticalSectionLocker is the same to critical sections as wxMutexLocker is
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// to mutexes
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class WXDLLIMPEXP_BASE wxCriticalSectionLocker
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{
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public:
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wxCriticalSectionLocker(wxCriticalSection& cs)
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: m_critsect(cs)
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{
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m_critsect.Enter();
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}
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~wxCriticalSectionLocker()
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{
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m_critsect.Leave();
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}
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private:
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wxCriticalSection& m_critsect;
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wxDECLARE_NO_COPY_CLASS(wxCriticalSectionLocker);
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};
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// ----------------------------------------------------------------------------
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// wxCondition models a POSIX condition variable which allows one (or more)
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// thread(s) to wait until some condition is fulfilled
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// ----------------------------------------------------------------------------
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class WXDLLIMPEXP_BASE wxCondition
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{
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public:
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// Each wxCondition object is associated with a (single) wxMutex object.
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// The mutex object MUST be locked before calling Wait()
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wxCondition(wxMutex& mutex);
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// dtor is not virtual, don't use this class polymorphically
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~wxCondition();
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// return true if the condition has been created successfully
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bool IsOk() const;
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// NB: the associated mutex MUST be locked beforehand by the calling thread
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//
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// it atomically releases the lock on the associated mutex
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// and starts waiting to be woken up by a Signal()/Broadcast()
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// once its signaled, then it will wait until it can reacquire
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// the lock on the associated mutex object, before returning.
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wxCondError Wait();
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// exactly as Wait() except that it may also return if the specified
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// timeout elapses even if the condition hasn't been signalled: in this
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// case, the return value is false, otherwise (i.e. in case of a normal
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// return) it is true
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//
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// the timeout parameter specifies an interval that needs to be waited for
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// in milliseconds
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wxCondError WaitTimeout(unsigned long milliseconds);
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// NB: the associated mutex may or may not be locked by the calling thread
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//
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// this method unblocks one thread if any are blocking on the condition.
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// if no thread is blocking in Wait(), then the signal is NOT remembered
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// The thread which was blocking on Wait() will then reacquire the lock
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// on the associated mutex object before returning
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wxCondError Signal();
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// NB: the associated mutex may or may not be locked by the calling thread
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//
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// this method unblocks all threads if any are blocking on the condition.
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// if no thread is blocking in Wait(), then the signal is NOT remembered
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// The threads which were blocking on Wait() will then reacquire the lock
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// on the associated mutex object before returning.
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wxCondError Broadcast();
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#if WXWIN_COMPATIBILITY_2_6
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// deprecated version, don't use
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wxDEPRECATED( bool Wait(unsigned long milliseconds) );
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#endif // WXWIN_COMPATIBILITY_2_6
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private:
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wxConditionInternal *m_internal;
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wxDECLARE_NO_COPY_CLASS(wxCondition);
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};
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#if WXWIN_COMPATIBILITY_2_6
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inline bool wxCondition::Wait(unsigned long milliseconds)
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{ return WaitTimeout(milliseconds) == wxCOND_NO_ERROR; }
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#endif // WXWIN_COMPATIBILITY_2_6
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// ----------------------------------------------------------------------------
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// wxSemaphore: a counter limiting the number of threads concurrently accessing
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// a shared resource
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// ----------------------------------------------------------------------------
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class WXDLLIMPEXP_BASE wxSemaphore
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{
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public:
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// specifying a maxcount of 0 actually makes wxSemaphore behave as if there
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// is no upper limit, if maxcount is 1 the semaphore behaves as a mutex
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wxSemaphore( int initialcount = 0, int maxcount = 0 );
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// dtor is not virtual, don't use this class polymorphically
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~wxSemaphore();
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// return true if the semaphore has been created successfully
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bool IsOk() const;
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// wait indefinitely, until the semaphore count goes beyond 0
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// and then decrement it and return (this method might have been called
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// Acquire())
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wxSemaError Wait();
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// same as Wait(), but does not block, returns wxSEMA_NO_ERROR if
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// successful and wxSEMA_BUSY if the count is currently zero
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wxSemaError TryWait();
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// same as Wait(), but as a timeout limit, returns wxSEMA_NO_ERROR if the
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// semaphore was acquired and wxSEMA_TIMEOUT if the timeout has elapsed
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wxSemaError WaitTimeout(unsigned long milliseconds);
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// increments the semaphore count and signals one of the waiting threads
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wxSemaError Post();
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private:
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wxSemaphoreInternal *m_internal;
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wxDECLARE_NO_COPY_CLASS(wxSemaphore);
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};
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// ----------------------------------------------------------------------------
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// wxThread: class encapsulating a thread of execution
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// ----------------------------------------------------------------------------
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// there are two different kinds of threads: joinable and detached (default)
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// ones. Only joinable threads can return a return code and only detached
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// threads auto-delete themselves - the user should delete the joinable
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// threads manually.
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// NB: in the function descriptions the words "this thread" mean the thread
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// created by the wxThread object while "main thread" is the thread created
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// during the process initialization (a.k.a. the GUI thread)
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// On VMS thread pointers are 64 bits (also needed for other systems???
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#ifdef __VMS
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typedef unsigned long long wxThreadIdType;
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#else
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typedef unsigned long wxThreadIdType;
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#endif
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class WXDLLIMPEXP_BASE wxThread
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{
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public:
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// the return type for the thread function
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typedef void *ExitCode;
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// static functions
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// Returns the wxThread object for the calling thread. NULL is returned
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// if the caller is the main thread (but it's recommended to use
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// IsMain() and only call This() for threads other than the main one
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// because NULL is also returned on error). If the thread wasn't
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// created with wxThread class, the returned value is undefined.
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static wxThread *This();
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// Returns true if current thread is the main thread.
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//
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// Notice that it also returns true if main thread id hadn't been
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// initialized yet on the assumption that it's too early in wx startup
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// process for any other threads to have been created in this case.
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static bool IsMain()
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{
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return !ms_idMainThread || GetCurrentId() == ms_idMainThread;
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}
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// Return the main thread id
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static wxThreadIdType GetMainId() { return ms_idMainThread; }
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// Release the rest of our time slice letting the other threads run
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static void Yield();
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// Sleep during the specified period of time in milliseconds
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//
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// This is the same as wxMilliSleep().
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static void Sleep(unsigned long milliseconds);
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// get the number of system CPUs - useful with SetConcurrency()
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// (the "best" value for it is usually number of CPUs + 1)
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//
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// Returns -1 if unknown, number of CPUs otherwise
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static int GetCPUCount();
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// Get the platform specific thread ID and return as a long. This
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// can be used to uniquely identify threads, even if they are not
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// wxThreads. This is used by wxPython.
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static wxThreadIdType GetCurrentId();
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// sets the concurrency level: this is, roughly, the number of threads
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// the system tries to schedule to run in parallel. 0 means the
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// default value (usually acceptable, but may not yield the best
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// performance for this process)
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//
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// Returns true on success, false otherwise (if not implemented, for
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// example)
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static bool SetConcurrency(size_t level);
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// constructor only creates the C++ thread object and doesn't create (or
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// start) the real thread
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wxThread(wxThreadKind kind = wxTHREAD_DETACHED);
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// functions that change the thread state: all these can only be called
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// from _another_ thread (typically the thread that created this one, e.g.
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// the main thread), not from the thread itself
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// create a new thread and optionally set the stack size on
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|
// 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 = NULL,
|
|
wxThreadWait waitMode = wxTHREAD_WAIT_DEFAULT);
|
|
|
|
// 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(wxThreadWait waitMode = wxTHREAD_WAIT_DEFAULT);
|
|
|
|
// 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;
|
|
|
|
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()!
|
|
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:
|
|
// 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;
|
|
|
|
|
|
// Callbacks which may be overridden by the derived class to perform some
|
|
// specific actions when the thread is deleted or killed. By default they
|
|
// do nothing.
|
|
|
|
// This one is called by Delete() before actually deleting the thread and
|
|
// is executed in the context of the thread that called Delete().
|
|
virtual void OnDelete() {}
|
|
|
|
// This one is called by Kill() before killing the thread and is executed
|
|
// in the context of the thread that called Kill().
|
|
virtual void OnKill() {}
|
|
|
|
private:
|
|
// no copy ctor/assignment operator
|
|
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;
|
|
friend class wxThreadModule;
|
|
|
|
|
|
// the main thread identifier, should be set on startup
|
|
static wxThreadIdType ms_idMainThread;
|
|
|
|
// 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:
|
|
// 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 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;
|
|
// also notice that Watcom doesn't like declaring a struct as a member so we
|
|
// need to actually define it in wxCRIT_SECT_DECLARE_MEMBER)
|
|
#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(__WINDOWS__) || defined(__OS2__) || defined(__EMX__) || defined(__WXOSX__)
|
|
// 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();
|
|
|
|
#ifndef __WXOSX__
|
|
// 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
|
|
#endif // MSW, OS/2
|
|
|
|
#endif // wxUSE_THREADS
|
|
|
|
#endif // _WX_THREAD_H_
|