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thread fixes for MSW (samples doesn't compile currently under !MSW, will

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be fixed a.s.a.p.)


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@1351 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
This commit is contained in:
Vadim Zeitlin
1999-01-09 00:28:27 +00:00
parent ad5c34f309
commit bee503b05f
4 changed files with 375 additions and 116 deletions
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30
include/wx/thread.h
View File

@@ -139,13 +139,13 @@ private:
class WXDLLEXPORT wxCriticalSectionLocker
{
public:
wxCriticalSectionLocker(wxCriticalSection *critsect)
{ (m_critsect = critsect)->Enter(); }
wxCriticalSectionLocker(wxCriticalSection& critsect) : m_critsect(critsect)
{ m_critsect.Enter(); }
~wxCriticalSectionLocker()
{ m_critsect->Leave(); }
{ m_critsect.Leave(); }
private:
wxCriticalSection *m_critsect;
wxCriticalSection& m_critsect;
};
#endif
@@ -253,6 +253,20 @@ private:
void WXDLLEXPORT wxMutexGuiEnter();
void WXDLLEXPORT wxMutexGuiLeave();
// implementation only
#ifdef __WXMSW__
// 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
void WXDLLEXPORT wxMutexGuiLeaveOrEnter();
// returns TRUE if the main thread has GUI lock
inline bool WXDLLEXPORT wxGuiOwnedByMainThread();
// wakes up the main thread if it's sleeping inside ::GetMessage()
inline void WXDLLEXPORT wxWakeUpMainThread();
#endif // MSW
#else // !wxUSE_THREADS
// no thread support
@@ -261,4 +275,12 @@ inline void WXDLLEXPORT wxMutexGuiLeave() { }
#endif // wxUSE_THREADS
// automatically unlock GUI mutex in dtor
class WXDLLEXPORT wxMutexGuiLocker
{
public:
wxMutexGuiLocker() { wxMutexGuiEnter(); }
~wxMutexGuiLocker() { wxMutexGuiLeave(); }
};
#endif // __THREADH__

133
samples/thread/test.cpp
View File

@@ -9,9 +9,17 @@
// Licence: wxWindows license
/////////////////////////////////////////////////////////////////////////////
/*
TODO:
1. show how SetPriority() works.
2. use worker threads to update progress controls instead of writing
messages - it will be more visual
*/
#ifdef __GNUG__
#pragma implementation "test.cpp"
#pragma interface "test.cpp"
#pragma implementation "test.cpp"
#pragma interface "test.cpp"
#endif
// For compilers that support precompilation, includes "wx/wx.h".
@@ -55,26 +63,35 @@ public:
// callbacks
void OnQuit(wxCommandEvent& event);
void OnAbout(wxCommandEvent& event);
void OnClear(wxCommandEvent& event);
void OnStartThread(wxCommandEvent& event);
void OnStopThread(wxCommandEvent& event);
void OnPauseThread(wxCommandEvent& event);
void OnResumeThread(wxCommandEvent& event);
void OnSize(wxSizeEvent &event);
void OnIdle(wxIdleEvent &event);
bool OnClose() { return TRUE; }
// called by dying thread
void OnThreadExit(wxThread *thread);
public:
wxArrayThread m_threads;
private:
void DeleteThread(size_t index);
// crit section protects access to the array below
wxCriticalSection m_critsect;
wxArrayInt m_aToDelete;
wxTextCtrl *m_txtctrl;
DECLARE_EVENT_TABLE()
};
class MyThread: public wxThread
class MyThread : public wxThread
{
public:
MyThread(MyFrame *frame);
@@ -82,6 +99,9 @@ public:
// thread execution starts here
virtual void *Entry();
// called when the thread exits - whether
virtual void OnExit();
// write something to the text control
void WriteText(const wxString& text);
@@ -104,9 +124,14 @@ void MyThread::WriteText(const wxString& text)
// before doing any GUI calls we must ensure that this thread is the only
// one doing it!
wxMutexGuiEnter();
wxMutexGuiLocker guiLocker;
m_frame->WriteText(msg);
wxMutexGuiLeave();
}
void MyThread::OnExit()
{
m_frame->OnThreadExit(this);
}
void *MyThread::Entry()
@@ -118,7 +143,7 @@ void *MyThread::Entry()
text.Printf("Thread 0x%x started.\n", GetID());
WriteText(text);
for ( m_count = 0; m_count < 20; m_count++ )
for ( m_count = 0; m_count < 10; m_count++ )
{
// check if we were asked to exit
if ( TestDestroy() )
@@ -127,7 +152,11 @@ void *MyThread::Entry()
text.Printf("[%u] Thread 0x%x here.\n", m_count, GetID());
WriteText(text);
#ifdef __WXMSW__
::Sleep(1000);
#else
wxSleep(1);
#endif
}
text.Printf("Thread 0x%x finished.\n", GetID());
@@ -142,22 +171,22 @@ enum
TEST_QUIT = 1,
TEST_TEXT = 101,
TEST_ABOUT = 102,
TEST_START_THREAD = 103,
TEST_STOP_THREAD = 104,
TEST_PAUSE_THREAD = 105,
TEST_RESUME_THREAD = 106
TEST_CLEAR = 103,
TEST_START_THREAD = 203,
TEST_STOP_THREAD = 204,
TEST_PAUSE_THREAD = 205,
TEST_RESUME_THREAD = 206
};
BEGIN_EVENT_TABLE(MyFrame, wxFrame)
EVT_MENU(TEST_QUIT, MyFrame::OnQuit)
EVT_MENU(TEST_ABOUT, MyFrame::OnAbout)
EVT_MENU(TEST_CLEAR, MyFrame::OnClear)
EVT_MENU(TEST_START_THREAD, MyFrame::OnStartThread)
EVT_MENU(TEST_STOP_THREAD, MyFrame::OnStopThread)
EVT_MENU(TEST_PAUSE_THREAD, MyFrame::OnPauseThread)
EVT_MENU(TEST_RESUME_THREAD, MyFrame::OnResumeThread)
EVT_SIZE(MyFrame::OnSize)
EVT_IDLE(MyFrame::OnIdle)
END_EVENT_TABLE()
@@ -168,12 +197,16 @@ IMPLEMENT_APP (MyApp)
bool MyApp::OnInit()
{
// Create the main frame window
MyFrame *frame = new MyFrame((wxFrame *)NULL, "", 50, 50, 450, 340);
MyFrame *frame = new MyFrame((wxFrame *)NULL, "wxWindows threads sample",
50, 50, 450, 340);
// Make a menubar
wxMenu *file_menu = new wxMenu;
file_menu->Append(TEST_CLEAR, "&Clear log");
file_menu->AppendSeparator();
file_menu->Append(TEST_ABOUT, "&About");
file_menu->AppendSeparator();
file_menu->Append(TEST_QUIT, "E&xit");
wxMenuBar *menu_bar = new wxMenuBar;
menu_bar->Append(file_menu, "&File");
@@ -199,13 +232,11 @@ bool MyApp::OnInit()
MyFrame::MyFrame(wxFrame *frame, char *title, int x, int y, int w, int h)
: wxFrame(frame, -1, title, wxPoint(x, y), wxSize(w, h))
{
wxPanel *panel = new wxPanel(this, -1, wxPoint(0, 0), wxSize(400, 200),
wxTAB_TRAVERSAL);
CreateStatusBar();
m_txtctrl = new wxTextCtrl(panel, -1, "", wxPoint(10,30), wxSize(390, 190),
wxTE_MULTILINE);
m_txtctrl = new wxTextCtrl(this, -1, "", wxPoint(0, 0), wxSize(0, 0),
wxTE_MULTILINE | wxTE_READONLY);
(void)new wxStaticText(panel, -1, "Log window", wxPoint(10,10));
}
void MyFrame::OnStartThread(wxCommandEvent& WXUNUSED(event) )
@@ -214,35 +245,43 @@ void MyFrame::OnStartThread(wxCommandEvent& WXUNUSED(event) )
thread->Create();
wxCriticalSectionLocker enter(m_critsect);
m_threads.Add(thread);
}
void MyFrame::OnStopThread(wxCommandEvent& WXUNUSED(event) )
{
int no_thrd = m_threads.Count()-1;
int no_thrd = m_threads.Count() - 1;
if ( no_thrd < 0 )
{
wxLogError("No thread to stop!");
if (no_thrd < 0)
return;
}
delete m_threads[no_thrd];
m_threads.Remove(no_thrd);
DeleteThread(no_thrd);
}
void MyFrame::OnResumeThread(wxCommandEvent& WXUNUSED(event) )
{
wxCriticalSectionLocker enter(m_critsect);
// resume first suspended thread
size_t n = 0;
while ( n < m_threads.Count() && m_threads[n]->IsPaused() )
n--;
if ( n < 0 )
wxLogError("No thread to pause!");
wxLogError("No thread to resume!");
else
m_threads[n]->Resume();
}
void MyFrame::OnPauseThread(wxCommandEvent& WXUNUSED(event) )
{
wxCriticalSectionLocker enter(m_critsect);
// pause last running thread
int n = m_threads.Count() - 1;
while ( n >= 0 && !m_threads[n]->IsRunning() )
@@ -257,6 +296,17 @@ void MyFrame::OnPauseThread(wxCommandEvent& WXUNUSED(event) )
// set the frame title indicating the current number of threads
void MyFrame::OnIdle(wxIdleEvent &event)
{
// first remove from the array all the threads which died since last call
{
wxCriticalSectionLocker enter(m_critsect);
size_t nCount = m_aToDelete.Count();
for ( size_t n = 0; n < nCount; n++ )
DeleteThread((size_t)m_aToDelete[n]);
m_aToDelete.Empty();
}
size_t nRunning = 0,
nCount = m_threads.Count();
for ( size_t n = 0; n < nCount; n++ )
@@ -265,19 +315,7 @@ void MyFrame::OnIdle(wxIdleEvent &event)
nRunning++;
}
wxString title;
title.Printf("wxWindows thread sample (%u threads, %u running).",
nCount, nRunning);
SetTitle(title);
}
void MyFrame::OnSize(wxSizeEvent& event)
{
wxFrame::OnSize(event);
wxSize size( GetClientSize() );
m_txtctrl->SetSize( 10, 30, size.x-20, size.y-40 );
wxLogStatus(this, "%u threads total, %u running.", nCount, nRunning);
}
void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event) )
@@ -291,11 +329,30 @@ void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event) )
void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event) )
{
wxMessageDialog dialog(this, "wxThread sample (based on minimal)\n"
"Julian Smart and Guilhem Lavaux",
"Julian Smart, Guilhem Lavaux, Vadim Zeitlin",
"About wxThread sample",
wxOK | wxICON_INFORMATION);
dialog.ShowModal();
}
void MyFrame::OnClear(wxCommandEvent& WXUNUSED(event))
{
m_txtctrl->Clear();
}
void MyFrame::OnThreadExit(wxThread *thread)
{
int index = m_threads.Index(thread);
wxCHECK_RET( index != -1, "unknown thread being deleted??" );
wxCriticalSectionLocker enter(m_critsect);
m_aToDelete.Add(index);
}
void MyFrame::DeleteThread(size_t index)
{
delete m_threads[index];
m_threads.Remove(index);
}

103
src/msw/app.cpp
View File

@@ -40,8 +40,15 @@
#include "wx/module.h"
#if wxUSE_THREADS
#include "wx/thread.h"
#endif
#include "wx/thread.h"
// define the array of MSG strutures
WX_DECLARE_OBJARRAY(MSG, wxMsgArray);
#include "wx/arrimpl.cpp"
WX_DEFINE_OBJARRAY(wxMsgArray);
#endif // wxUSE_THREADS
#if wxUSE_WX_RESOURCES
#include "wx/resource.h"
@@ -736,23 +743,81 @@ bool wxApp::Initialized()
/*
* Get and process a message, returning FALSE if WM_QUIT
* received.
* received (and also set the flag telling the app to exit the main loop)
*
*/
bool wxApp::DoMessage()
{
if (!::GetMessage(&s_currentMsg, (HWND) NULL, 0, 0))
BOOL rc = ::GetMessage(&s_currentMsg, (HWND) NULL, 0, 0);
if ( rc == 0 )
{
// got WM_QUIT
m_keepGoing = FALSE;
return FALSE;
}
else if ( rc == -1 )
{
// should never happen, but let's test for it nevertheless
wxLogLastError("GetMessage");
}
else
{
#if wxUSE_THREADS
wxASSERT_MSG( wxThread::IsMain(),
"only the main thread can process Windows messages" );
static bool s_hadGuiLock = TRUE;
static wxMsgArray s_aSavedMessages;
// if a secondary thread owns is doing GUI calls, save all messages for
// later processing - we can't process them right now because it will
// lead to recursive library calls (and we're not reentrant)
if ( !wxGuiOwnedByMainThread() )
{
s_hadGuiLock = FALSE;
s_aSavedMessages.Add(s_currentMsg);
return TRUE;
}
else
{
// have we just regained the GUI lock? if so, post all of the saved
// messages
//
// FIXME of course, it's not _exactly_ the same as processing the
// messages normally - expect some things to break...
if ( !s_hadGuiLock )
{
s_hadGuiLock = TRUE;
size_t count = s_aSavedMessages.Count();
for ( size_t n = 0; n < count; n++ )
{
MSG& msg = s_aSavedMessages[n];
if ( !ProcessMessage((WXMSG *)&msg) )
{
::TranslateMessage(&msg);
::DispatchMessage(&msg);
}
}
s_aSavedMessages.Empty();
}
}
#endif // wxUSE_THREADS
// Process the message
if (!ProcessMessage((WXMSG *)&s_currentMsg))
if ( !ProcessMessage((WXMSG *)&s_currentMsg) )
{
::TranslateMessage(&s_currentMsg);
wxApp::sm_lastMessageTime = s_currentMsg.time; /* MATTHEW: timeStamp impl. */
::DispatchMessage(&s_currentMsg);
}
}
return TRUE;
}
@@ -773,12 +838,19 @@ bool wxApp::DoMessage()
int wxApp::MainLoop()
{
m_keepGoing = TRUE;
while (m_keepGoing)
while ( m_keepGoing )
{
while (!::PeekMessage(&s_currentMsg, 0, 0, 0, PM_NOREMOVE) &&
ProcessIdle()) {}
if (!DoMessage())
m_keepGoing = FALSE;
#if wxUSE_THREADS
wxMutexGuiLeaveOrEnter();
#endif // wxUSE_THREADS
while ( !::PeekMessage(&s_currentMsg, 0, 0, 0, PM_NOREMOVE) &&
ProcessIdle() )
{
}
DoMessage();
}
return s_currentMsg.wParam;
@@ -806,8 +878,7 @@ bool wxApp::Pending()
void wxApp::Dispatch()
{
if (!DoMessage())
m_keepGoing = FALSE;
DoMessage();
}
/*
@@ -871,12 +942,6 @@ void wxApp::OnIdle(wxIdleEvent& event)
// idle events
event.RequestMore(TRUE);
}
#if wxUSE_THREADS
// give a chance to all other threads to perform GUI calls
wxMutexGuiLeave();
::Sleep(0);
wxMutexGuiEnter();
#endif
s_inOnIdle = FALSE;
}
@@ -1029,7 +1094,7 @@ bool wxYield()
// if we see a WM_QUIT. (?)
while (PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE) && msg.message != WM_QUIT)
{
if (!wxTheApp->DoMessage())
if ( !wxTheApp->DoMessage() )
break;
}

199
src/msw/thread.cpp
View File

@@ -2,10 +2,11 @@
// Name: thread.cpp
// Purpose: wxThread Implementation
// Author: Original from Wolfram Gloger/Guilhem Lavaux
// Modified by:
// Modified by: Vadim Zeitlin to make it work :-)
// Created: 04/22/98
// RCS-ID: $Id$
// Copyright: (c) Wolfram Gloger (1996, 1997); Guilhem Lavaux (1998)
// Copyright: (c) Wolfram Gloger (1996, 1997); Guilhem Lavaux (1998),
// Vadim Zeitlin (1999)
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
@@ -41,6 +42,7 @@ enum thread_state
{
STATE_IDLE = 0,
STATE_RUNNING,
STATE_PAUSED,
STATE_CANCELED,
STATE_EXITED
};
@@ -51,12 +53,21 @@ enum thread_state
// id of the main thread - the one which can call GUI functions without first
// calling wxMutexGuiEnter()
static HANDLE s_idMainThread;
static DWORD s_idMainThread = 0;
// if it's FALSE, some secondary thread is holding the GUI lock
static bool s_bGuiOwnedByMainThread = TRUE;
// critical section which controls access to all GUI functions: any secondary
// thread (i.e. except the main one) must enter this crit section before doing
// any GUI calls
static wxCriticalSection *s_critsectGui;
static wxCriticalSection *s_critsectGui = NULL;
// critical section which protects s_nWaitingForGui variable
static wxCriticalSection *s_critsectWaitingForGui = NULL;
// number of threads waiting for GUI in wxMutexGuiEnter()
static size_t s_nWaitingForGui = 0;
// ============================================================================
// Windows implementation of thread classes
@@ -263,40 +274,43 @@ void wxCriticalSection::Leave()
class wxThreadInternal
{
public:
static DWORD WinThreadStart(LPVOID arg);
static DWORD WinThreadStart(wxThread *thread);
HANDLE thread_id;
int state;
HANDLE hThread;
thread_state state;
int prio, defer;
DWORD tid;
};
DWORD wxThreadInternal::WinThreadStart(LPVOID arg)
DWORD wxThreadInternal::WinThreadStart(wxThread *thread)
{
wxThread *ptr = (wxThread *)arg;
DWORD ret;
ret = (DWORD)ptr->Entry();
ptr->p_internal->state = STATE_EXITED;
DWORD ret = (DWORD)thread->Entry();
thread->p_internal->state = STATE_EXITED;
thread->OnExit();
return ret;
}
wxThreadError wxThread::Create()
{
int prio = p_internal->prio;
p_internal->hThread = ::CreateThread
(
NULL, // default security
0, // default stack size
(LPTHREAD_START_ROUTINE)
wxThreadInternal::WinThreadStart, // entry point
(void *)this, // parameter
CREATE_SUSPENDED, // flags
&p_internal->tid // [out] thread id
);
p_internal->thread_id = CreateThread(NULL, 0,
(LPTHREAD_START_ROUTINE)wxThreadInternal::WinThreadStart,
(void *)this, CREATE_SUSPENDED, &p_internal->tid);
if ( p_internal->thread_id == NULL )
if ( p_internal->hThread == NULL )
{
wxLogSysError(_("Can't create thread"));
return wxTHREAD_NO_RESOURCE;
}
int win_prio;
int win_prio, prio = p_internal->prio;
if (prio <= 20)
win_prio = THREAD_PRIORITY_LOWEST;
else if (prio <= 40)
@@ -313,53 +327,65 @@ wxThreadError wxThread::Create()
win_prio = THREAD_PRIORITY_NORMAL;
}
SetThreadPriority(p_internal->thread_id, win_prio);
if ( SetThreadPriority(p_internal->hThread, win_prio) == 0 )
{
wxLogSysError(_("Can't set thread priority"));
}
ResumeThread(p_internal->thread_id);
p_internal->state = STATE_RUNNING;
return wxTHREAD_NO_ERROR;
return Resume();
}
wxThreadError wxThread::Destroy()
{
if (p_internal->state != STATE_RUNNING)
if ( p_internal->state != STATE_RUNNING )
return wxTHREAD_NOT_RUNNING;
if ( p_internal->defer )
{
// soft termination: just set the flag and wait until the thread
// auto terminates
p_internal->state = STATE_CANCELED;
}
else
{
// kill the thread
TerminateThread(p_internal->thread_id, 0);
OnExit();
if ( ::TerminateThread(p_internal->hThread, 0) == 0 )
{
wxLogLastError("TerminateThread");
}
}
return wxTHREAD_NO_ERROR;
}
wxThreadError wxThread::Pause()
{
DWORD nSuspendCount = ::SuspendThread(p_internal->thread_id);
DWORD nSuspendCount = ::SuspendThread(p_internal->hThread);
if ( nSuspendCount == (DWORD)-1 )
{
wxLogSysError(_("Can not suspend thread %x"), p_internal->thread_id);
wxLogSysError(_("Can not suspend thread %x"), p_internal->hThread);
return wxTHREAD_MISC_ERROR; // no idea what might provoke this error...
}
p_internal->state = STATE_PAUSED;
return wxTHREAD_NO_ERROR;
}
wxThreadError wxThread::Resume()
{
DWORD nSuspendCount = ::ResumeThread(p_internal->thread_id);
DWORD nSuspendCount = ::ResumeThread(p_internal->hThread);
if ( nSuspendCount == (DWORD)-1 )
{
wxLogSysError(_("Can not resume thread %x"), p_internal->thread_id);
wxLogSysError(_("Can not resume thread %x"), p_internal->hThread);
return wxTHREAD_MISC_ERROR; // no idea what might provoke this error...
}
p_internal->state = STATE_RUNNING;
return wxTHREAD_NO_ERROR;
}
@@ -396,14 +422,15 @@ void *wxThread::Join()
if (p_internal->state == STATE_IDLE)
return NULL;
if (wxThread::IsMain())
s_critsectGui->Leave();
WaitForSingleObject(p_internal->thread_id, INFINITE);
if (wxThread::IsMain())
s_critsectGui->Enter();
// FIXME this dead locks... wxThread class design must be changed
#if 0
WaitForSingleObject(p_internal->hThread, INFINITE);
#else
::TerminateThread(p_internal->hThread, 0);
#endif // 0
GetExitCodeThread(p_internal->thread_id, &exit_code);
CloseHandle(p_internal->thread_id);
GetExitCodeThread(p_internal->hThread, &exit_code);
CloseHandle(p_internal->hThread);
p_internal->state = STATE_IDLE;
@@ -427,7 +454,7 @@ bool wxThread::IsAlive() const
bool wxThread::IsMain()
{
return (GetCurrentThread() == s_idMainThread);
return ::GetCurrentThreadId() == s_idMainThread;
}
wxThread::wxThread()
@@ -468,9 +495,12 @@ IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule)
bool wxThreadModule::OnInit()
{
s_critsectWaitingForGui = new wxCriticalSection();
s_critsectGui = new wxCriticalSection();
s_critsectGui->Enter();
s_idMainThread = GetCurrentThread();
s_idMainThread = ::GetCurrentThreadId();
return TRUE;
}
@@ -483,18 +513,103 @@ void wxThreadModule::OnExit()
delete s_critsectGui;
s_critsectGui = NULL;
}
wxDELETE(s_critsectWaitingForGui);
}
// ----------------------------------------------------------------------------
// under Windows, these functions are implemented usign a critical section and
// not a mutex, so the names are a bit confusing
// ----------------------------------------------------------------------------
void WXDLLEXPORT wxMutexGuiEnter()
{
//s_critsectGui->Enter();
// this would dead lock everything...
wxASSERT_MSG( !wxThread::IsMain(),
"main thread doesn't want to block in wxMutexGuiEnter()!" );
// the order in which we enter the critical sections here is crucial!!
// set the flag telling to the main thread that we want to do some GUI
{
wxCriticalSectionLocker enter(*s_critsectWaitingForGui);
s_nWaitingForGui++;
}
wxWakeUpMainThread();
// now we may block here because the main thread will soon let us in
// (during the next iteration of OnIdle())
s_critsectGui->Enter();
}
void WXDLLEXPORT wxMutexGuiLeave()
{
//s_critsectGui->Leave();
wxCriticalSectionLocker enter(*s_critsectWaitingForGui);
if ( wxThread::IsMain() )
{
s_bGuiOwnedByMainThread = FALSE;
}
else
{
// decrement the number of waiters now
wxASSERT_MSG( s_nWaitingForGui > 0,
"calling wxMutexGuiLeave() without entering it first?" );
s_nWaitingForGui--;
wxWakeUpMainThread();
}
s_critsectGui->Leave();
}
void WXDLLEXPORT wxMutexGuiLeaveOrEnter()
{
wxASSERT_MSG( wxThread::IsMain(),
"only main thread may call wxMutexGuiLeaveOrEnter()!" );
wxCriticalSectionLocker enter(*s_critsectWaitingForGui);
if ( s_nWaitingForGui == 0 )
{
// no threads are waiting for GUI - so we may acquire the lock without
// any danger (but only if we don't already have it)
if ( !wxGuiOwnedByMainThread() )
{
s_critsectGui->Enter();
s_bGuiOwnedByMainThread = TRUE;
}
//else: already have it, nothing to do
}
else
{
// some threads are waiting, release the GUI lock if we have it
if ( wxGuiOwnedByMainThread() )
{
wxMutexGuiLeave();
}
//else: some other worker thread is doing GUI
}
}
bool WXDLLEXPORT wxGuiOwnedByMainThread()
{
return s_bGuiOwnedByMainThread;
}
// wake up the main thread if it's in ::GetMessage()
void WXDLLEXPORT wxWakeUpMainThread()
{
// sending any message would do - hopefully WM_NULL is harmless enough
if ( !::PostThreadMessage(s_idMainThread, WM_NULL, 0, 0) )
{
// should never happen
wxLogLastError("PostThreadMessage(WM_NULL)");
}
}
#endif // wxUSE_THREADS