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/////////////////////////////////////////////////////////////////////////////
// Name: wx/thread.h
// Purpose: Thread API
// Author: Guilhem Lavaux
// Modified by: Vadim Zeitlin (modifications partly inspired by omnithreads
// package from Olivetti & Oracle Research Laboratory)
// Created: 04/13/98
// RCS-ID: $Id: thread.h 67185 2011-03-14 11:54:32Z VZ $
// Copyright: (c) Guilhem Lavaux
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#ifndef _WX_THREAD_H_
#define _WX_THREAD_H_
// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------
// get the value of wxUSE_THREADS configuration flag
#include "wx/defs.h"
#if wxUSE_THREADS
// ----------------------------------------------------------------------------
// constants
// ----------------------------------------------------------------------------
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
{
wxCOND_NO_ERROR = 0,
wxCOND_INVALID,
wxCOND_TIMEOUT, // WaitTimeout() has timed out
wxCOND_MISC_ERROR
};
enum wxSemaError
{
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
};
enum wxThreadWait
{
wxTHREAD_WAIT_BLOCK,
wxTHREAD_WAIT_YIELD, // process events while waiting; MSW only
// For compatibility reasons we use wxTHREAD_WAIT_YIELD by default as this
// was the default behaviour of wxMSW 2.8 but it should be avoided as it's
// dangerous and not portable.
#if WXWIN_COMPATIBILITY_2_8
wxTHREAD_WAIT_DEFAULT = wxTHREAD_WAIT_YIELD
#else
wxTHREAD_WAIT_DEFAULT = wxTHREAD_WAIT_BLOCK
#endif
};
// 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;
// ----------------------------------------------------------------------------
// 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.
// ----------------------------------------------------------------------------
// 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;
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 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;
};
// ----------------------------------------------------------------------------
// 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
// ----------------------------------------------------------------------------
// 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 WXDLLIMPEXP_BASE wxCriticalSection
{
public:
// ctor & dtor
wxCRITSECT_INLINE wxCriticalSection( wxCriticalSectionType critSecType = wxCRITSEC_DEFAULT );
wxCRITSECT_INLINE ~wxCriticalSection();
// enter the section (the same as locking a mutex)
wxCRITSECT_INLINE void Enter();
// leave the critical section (same as unlocking a mutex)
wxCRITSECT_INLINE void Leave();
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;
};
#endif // Unix&OS2/Win32
wxDECLARE_NO_COPY_CLASS(wxCriticalSection);
};
#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 mutexes
class WXDLLIMPEXP_BASE wxCriticalSectionLocker
{
public:
wxCriticalSectionLocker(wxCriticalSection& cs)
: m_critsect(cs)
{
m_critsect.Enter();
}
~wxCriticalSectionLocker()
{
m_critsect.Leave();
}
private:
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
// ----------------------------------------------------------------------------
// wxSemaphore: a counter limiting the number of threads concurrently accessing
// a shared resource
// ----------------------------------------------------------------------------
class WXDLLIMPEXP_BASE wxSemaphore
{
public:
// specifying a maxcount of 0 actually makes wxSemaphore behave as if there
// is no upper limit, if maxcount is 1 the semaphore behaves as a mutex
wxSemaphore( int initialcount = 0, int maxcount = 0 );
// dtor is not virtual, don't use this class polymorphically
~wxSemaphore();
// 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:
wxSemaphoreInternal *m_internal;
wxDECLARE_NO_COPY_CLASS(wxSemaphore);
};
// ----------------------------------------------------------------------------
// wxThread: class encapsulating a thread of execution
// ----------------------------------------------------------------------------
// there are two different kinds of threads: joinable and detached (default)
// ones. Only joinable threads can return a return code and only detached
// threads auto-delete themselves - the user should delete the joinable
// threads manually.
// NB: in the function descriptions the words "this thread" mean the thread
// created by the wxThread object while "main thread" is the thread created
// during the process initialization (a.k.a. the GUI thread)
// On VMS thread pointers are 64 bits (also needed for other systems???
#ifdef __VMS
typedef unsigned long long wxThreadIdType;
#else
typedef unsigned long wxThreadIdType;
#endif
class 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.
//
// Notice that it also returns true if main thread id hadn't been
// initialized yet on the assumption that it's too early in wx startup
// process for any other threads to have been created in this case.
static bool IsMain()
{
return !ms_idMainThread || GetCurrentId() == ms_idMainThread;
}
// Return the main thread id
static wxThreadIdType GetMainId() { return ms_idMainThread; }
// 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 = 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(__WXMSW__) || 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_
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