// 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
/////////////////////////////////////////////////////////////////////////////
#ifdef __GNUG__
-#pragma implementation "thread.h"
+ #pragma implementation "thread.h"
#endif
+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------
+
+// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"
#if defined(__BORLANDC__)
-#pragma hdrstop
+ #pragma hdrstop
#endif
#ifndef WX_PRECOMP
-#include "wx/wx.h"
+ #include "wx/wx.h"
#endif
+#if wxUSE_THREADS
+
#include <stdio.h>
#include <windows.h>
+
#include "wx/module.h"
#include "wx/thread.h"
-enum thread_state {
- STATE_IDLE = 0,
- STATE_RUNNING,
- STATE_CANCELED,
- STATE_EXITED
+// the possible states of the thread ("=>" shows all possible transitions from
+// this state)
+enum wxThreadState
+{
+ STATE_NEW, // didn't start execution yet (=> RUNNING)
+ STATE_RUNNING, // thread is running (=> PAUSED, CANCELED)
+ STATE_PAUSED, // thread is temporarily suspended (=> RUNNING)
+ STATE_CANCELED, // thread should terminate a.s.a.p. (=> EXITED)
+ STATE_EXITED // thread is terminating
};
-/////////////////////////////////////////////////////////////////////////////
-// Static variables
-/////////////////////////////////////////////////////////////////////////////
+// ----------------------------------------------------------------------------
+// static variables
+// ----------------------------------------------------------------------------
-static HANDLE p_mainid;
-wxMutex wxMainMutex; // controls access to all GUI functions
+// TLS index of the slot where we store the pointer to the current thread
+static DWORD s_tlsThisThread = 0xFFFFFFFF;
-/////////////////////////////////////////////////////////////////////////////
-// Windows implementation
-/////////////////////////////////////////////////////////////////////////////
+// id of the main thread - the one which can call GUI functions without first
+// calling wxMutexGuiEnter()
+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 = NULL;
-class wxMutexInternal {
+// 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;
+
+// are we waiting for a thread termination?
+static bool s_waitingForThread = FALSE;
+
+// ============================================================================
+// Windows implementation of thread classes
+// ============================================================================
+
+// ----------------------------------------------------------------------------
+// wxMutex implementation
+// ----------------------------------------------------------------------------
+class wxMutexInternal
+{
public:
- HANDLE p_mutex;
+ HANDLE p_mutex;
};
-wxMutex::wxMutex(void)
+wxMutex::wxMutex()
{
- p_internal = new wxMutexInternal;
- p_internal->p_mutex = CreateMutex(NULL, FALSE, NULL);
- m_locked = 0;
+ p_internal = new wxMutexInternal;
+ p_internal->p_mutex = CreateMutex(NULL, FALSE, NULL);
+ if ( !p_internal->p_mutex )
+ {
+ wxLogSysError(_("Can not create mutex."));
+ }
+
+ m_locked = 0;
}
-wxMutex::~wxMutex(void)
+wxMutex::~wxMutex()
{
- CloseHandle(p_internal->p_mutex);
+ if (m_locked > 0)
+ wxLogDebug("Warning: freeing a locked mutex (%d locks).", m_locked);
+ CloseHandle(p_internal->p_mutex);
}
-wxMutexError wxMutex::Lock(void)
+wxMutexError wxMutex::Lock()
{
- DWORD ret;
+ DWORD ret;
- ret = WaitForSingleObject(p_internal->p_mutex, INFINITE);
- if (ret == WAIT_ABANDONED)
- return MUTEX_BUSY;
+ ret = WaitForSingleObject(p_internal->p_mutex, INFINITE);
+ switch ( ret )
+ {
+ case WAIT_ABANDONED:
+ return wxMUTEX_BUSY;
- m_locked++;
- return MUTEX_NO_ERROR;
+ case WAIT_OBJECT_0:
+ // ok
+ break;
+
+ case WAIT_FAILED:
+ wxLogSysError(_("Couldn't acquire a mutex lock"));
+ return wxMUTEX_MISC_ERROR;
+
+ case WAIT_TIMEOUT:
+ default:
+ wxFAIL_MSG("impossible return value in wxMutex::Lock");
+ }
+
+ m_locked++;
+ return wxMUTEX_NO_ERROR;
}
-wxMutexError wxMutex::TryLock(void)
+wxMutexError wxMutex::TryLock()
{
- DWORD ret;
+ DWORD ret;
- ret = WaitForSingleObject(p_internal->p_mutex, 0);
- if (ret == WAIT_TIMEOUT || ret == WAIT_ABANDONED)
- return MUTEX_BUSY;
+ ret = WaitForSingleObject(p_internal->p_mutex, 0);
+ if (ret == WAIT_TIMEOUT || ret == WAIT_ABANDONED)
+ return wxMUTEX_BUSY;
- m_locked++;
- return MUTEX_NO_ERROR;
+ m_locked++;
+ return wxMUTEX_NO_ERROR;
}
-wxMutexError wxMutex::Unlock(void)
+wxMutexError wxMutex::Unlock()
{
- BOOL ret;
+ if (m_locked > 0)
+ m_locked--;
- if (m_locked > 0)
- m_locked--;
+ BOOL ret = ReleaseMutex(p_internal->p_mutex);
+ if ( ret == 0 )
+ {
+ wxLogSysError(_("Couldn't release a mutex"));
+ return wxMUTEX_MISC_ERROR;
+ }
- // Why does this have 3 args? The redundant ones removed by JACS
-// ret = ReleaseMutex(p_internal->p_mutex, 1, NULL);
- ret = ReleaseMutex(p_internal->p_mutex);
- return MUTEX_NO_ERROR;
+ return wxMUTEX_NO_ERROR;
}
-class wxConditionInternal {
+// ----------------------------------------------------------------------------
+// wxCondition implementation
+// ----------------------------------------------------------------------------
+
+class wxConditionInternal
+{
public:
- HANDLE event;
- int waiters;
+ HANDLE event;
+ int waiters;
};
-wxCondition::wxCondition(void)
+wxCondition::wxCondition()
{
- p_internal = new wxConditionInternal;
- p_internal->event = CreateEvent(NULL, FALSE, FALSE, NULL);
- p_internal->waiters = 0;
+ p_internal = new wxConditionInternal;
+ p_internal->event = CreateEvent(NULL, FALSE, FALSE, NULL);
+ if ( !p_internal->event )
+ {
+ wxLogSysError(_("Can not create event object."));
+ }
+
+ p_internal->waiters = 0;
}
-wxCondition::~wxCondition(void)
+wxCondition::~wxCondition()
{
- CloseHandle(p_internal->event);
+ CloseHandle(p_internal->event);
}
void wxCondition::Wait(wxMutex& mutex)
{
- mutex.Unlock();
- p_internal->waiters++;
- WaitForSingleObject(p_internal->event, INFINITE);
- p_internal->waiters--;
- mutex.Lock();
+ mutex.Unlock();
+ p_internal->waiters++;
+ WaitForSingleObject(p_internal->event, INFINITE);
+ p_internal->waiters--;
+ mutex.Lock();
}
-bool wxCondition::Wait(wxMutex& mutex, unsigned long sec,
+bool wxCondition::Wait(wxMutex& mutex,
+ unsigned long sec,
unsigned long nsec)
{
- DWORD ret;
+ DWORD ret;
- mutex.Unlock();
- p_internal->waiters++;
- ret = WaitForSingleObject(p_internal->event, (sec*1000)+(nsec/1000000));
- p_internal->waiters--;
- mutex.Lock();
+ mutex.Unlock();
+ p_internal->waiters++;
+ ret = WaitForSingleObject(p_internal->event, (sec*1000)+(nsec/1000000));
+ p_internal->waiters--;
+ mutex.Lock();
- return (ret != WAIT_TIMEOUT);
+ return (ret != WAIT_TIMEOUT);
}
-void wxCondition::Signal(void)
+void wxCondition::Signal()
{
- SetEvent(p_internal->event);
+ SetEvent(p_internal->event);
}
-void wxCondition::Broadcast(void)
+void wxCondition::Broadcast()
{
- int i;
-
- for (i=0;i<p_internal->waiters;i++)
- SetEvent(p_internal->event);
+ int i;
+
+ for (i=0;i<p_internal->waiters;i++)
+ {
+ if ( SetEvent(p_internal->event) == 0 )
+ {
+ wxLogSysError(_("Couldn't change the state of event object."));
+ }
+ }
}
-class wxThreadInternal {
+// ----------------------------------------------------------------------------
+// wxCriticalSection implementation
+// ----------------------------------------------------------------------------
+
+class wxCriticalSectionInternal
+{
public:
- static DWORD WinThreadStart(LPVOID arg);
+ // init the critical section object
+ wxCriticalSectionInternal()
+ { ::InitializeCriticalSection(&m_data); }
+
+ // implicit cast to the associated data
+ operator CRITICAL_SECTION *() { return &m_data; }
+
+ // free the associated ressources
+ ~wxCriticalSectionInternal()
+ { ::DeleteCriticalSection(&m_data); }
+
+private:
+ CRITICAL_SECTION m_data;
+};
+
+wxCriticalSection::wxCriticalSection()
+{
+ m_critsect = new wxCriticalSectionInternal;
+}
+
+wxCriticalSection::~wxCriticalSection()
+{
+ delete m_critsect;
+}
+
+void wxCriticalSection::Enter()
+{
+ ::EnterCriticalSection(*m_critsect);
+}
- HANDLE thread_id;
- int state;
- int prio, defer;
- DWORD tid;
+void wxCriticalSection::Leave()
+{
+ ::LeaveCriticalSection(*m_critsect);
+}
+
+// ----------------------------------------------------------------------------
+// wxThread implementation
+// ----------------------------------------------------------------------------
+
+// wxThreadInternal class
+// ----------------------
+
+class wxThreadInternal
+{
+public:
+ wxThreadInternal()
+ {
+ m_hThread = 0;
+ m_state = STATE_NEW;
+ m_priority = WXTHREAD_DEFAULT_PRIORITY;
+ }
+
+ // create a new (suspended) thread (for the given thread object)
+ bool Create(wxThread *thread);
+
+ // suspend/resume/terminate
+ bool Suspend();
+ bool Resume();
+ void Cancel() { m_state = STATE_CANCELED; }
+
+ // thread state
+ void SetState(wxThreadState state) { m_state = state; }
+ wxThreadState GetState() const { return m_state; }
+
+ // thread priority
+ void SetPriority(unsigned int priority) { m_priority = priority; }
+ unsigned int GetPriority() const { return m_priority; }
+
+ // thread handle and id
+ HANDLE GetHandle() const { return m_hThread; }
+ DWORD GetId() const { return m_tid; }
+
+ // thread function
+ static DWORD WinThreadStart(wxThread *thread);
+
+private:
+ HANDLE m_hThread; // handle of the thread
+ wxThreadState m_state; // state, see wxThreadState enum
+ unsigned int m_priority; // thread priority in "wx" units
+ DWORD m_tid; // thread id
};
-DWORD wxThreadInternal::WinThreadStart(LPVOID arg)
+DWORD wxThreadInternal::WinThreadStart(wxThread *thread)
{
- wxThread *ptr = (wxThread *)arg;
- DWORD ret;
+ // store the thread object in the TLS
+ if ( !::TlsSetValue(s_tlsThisThread, thread) )
+ {
+ wxLogSysError(_("Can not start thread: error writing TLS."));
+
+ return (DWORD)-1;
+ }
- ret = (DWORD)ptr->Entry();
- ptr->p_internal->state = STATE_EXITED;
+ DWORD ret = (DWORD)thread->Entry();
+ thread->p_internal->SetState(STATE_EXITED);
+ thread->OnExit();
- return ret;
+ delete thread;
+
+ return ret;
}
-wxThreadError wxThread::Create(void)
+bool wxThreadInternal::Create(wxThread *thread)
{
- int win_prio, prio = p_internal->prio;
+ m_hThread = ::CreateThread
+ (
+ NULL, // default security
+ 0, // default stack size
+ (LPTHREAD_START_ROUTINE) // thread entry point
+ wxThreadInternal::WinThreadStart, //
+ (LPVOID)thread, // parameter
+ CREATE_SUSPENDED, // flags
+ &m_tid // [out] thread id
+ );
+
+ if ( m_hThread == NULL )
+ {
+ wxLogSysError(_("Can't create thread"));
+
+ return FALSE;
+ }
+
+ // translate wxWindows priority to the Windows one
+ int win_priority;
+ if (m_priority <= 20)
+ win_priority = THREAD_PRIORITY_LOWEST;
+ else if (m_priority <= 40)
+ win_priority = THREAD_PRIORITY_BELOW_NORMAL;
+ else if (m_priority <= 60)
+ win_priority = THREAD_PRIORITY_NORMAL;
+ else if (m_priority <= 80)
+ win_priority = THREAD_PRIORITY_ABOVE_NORMAL;
+ else if (m_priority <= 100)
+ win_priority = THREAD_PRIORITY_HIGHEST;
+ else
+ {
+ wxFAIL_MSG("invalid value of thread priority parameter");
+ win_priority = THREAD_PRIORITY_NORMAL;
+ }
+
+ if ( ::SetThreadPriority(m_hThread, win_priority) == 0 )
+ {
+ wxLogSysError(_("Can't set thread priority"));
+ }
- 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) {
- printf("Error = %d\n", GetLastError());
- return THREAD_NO_RESOURCE;
- }
+ return TRUE;
+}
+
+bool wxThreadInternal::Suspend()
+{
+ DWORD nSuspendCount = ::SuspendThread(m_hThread);
+ if ( nSuspendCount == (DWORD)-1 )
+ {
+ wxLogSysError(_("Can not suspend thread %x"), m_hThread);
- if (prio <= 20)
- win_prio = THREAD_PRIORITY_LOWEST;
- else if (prio <= 40)
- win_prio = THREAD_PRIORITY_BELOW_NORMAL;
- else if (prio <= 60)
- win_prio = THREAD_PRIORITY_NORMAL;
- else if (prio <= 80)
- win_prio = THREAD_PRIORITY_ABOVE_NORMAL;
- else if (prio <= 100)
- win_prio = THREAD_PRIORITY_HIGHEST;
+ return FALSE;
+ }
- SetThreadPriority(p_internal->thread_id, win_prio);
+ m_state = STATE_PAUSED;
- ResumeThread(p_internal->thread_id);
- p_internal->state = STATE_RUNNING;
-
- return THREAD_NO_ERROR;
+ return TRUE;
}
-wxThreadError wxThread::Destroy()
+bool wxThreadInternal::Resume()
{
- if (p_internal->state != STATE_RUNNING)
- return THREAD_NOT_RUNNING;
+ DWORD nSuspendCount = ::ResumeThread(m_hThread);
+ if ( nSuspendCount == (DWORD)-1 )
+ {
+ wxLogSysError(_("Can not resume thread %x"), m_hThread);
+
+ return FALSE;
+ }
- if (p_internal->defer == FALSE)
- TerminateThread(p_internal->thread_id, 0);
- else
- p_internal->state = STATE_CANCELED;
+ m_state = STATE_RUNNING;
- return THREAD_NO_ERROR;
+ return TRUE;
}
-void wxThread::Exit(void *status)
+// static functions
+// ----------------
+
+wxThread *wxThread::This()
{
- p_internal->state = STATE_EXITED;
- ExitThread((DWORD)status);
+ wxThread *thread = (wxThread *)::TlsGetValue(s_tlsThisThread);
+
+ // be careful, 0 may be a valid return value as well
+ if ( !thread && (::GetLastError() != NO_ERROR) )
+ {
+ wxLogSysError(_("Couldn't get the current thread pointer"));
+
+ // return NULL...
+ }
+
+ return thread;
}
-void wxThread::SetPriority(int prio)
+bool wxThread::IsMain()
{
- p_internal->prio = prio;
+ return ::GetCurrentThreadId() == s_idMainThread;
}
-int wxThread::GetPriority(void)
+#ifdef Yield
+#undef Yield
+#endif
+
+void wxThread::Yield()
{
- return p_internal->prio;
+ // 0 argument to Sleep() is special
+ ::Sleep(0);
}
-void wxThread::DeferDestroy(bool on)
+void wxThread::Sleep(unsigned long milliseconds)
{
- p_internal->defer = on;
+ ::Sleep(milliseconds);
}
-void wxThread::TestDestroy()
+// create/start thread
+// -------------------
+
+wxThreadError wxThread::Create()
{
- if (p_internal->state == STATE_CANCELED)
- ExitThread(0);
+ if ( !p_internal->Create(this) )
+ return wxTHREAD_NO_RESOURCE;
+
+ return wxTHREAD_NO_ERROR;
}
-void *wxThread::Join()
+wxThreadError wxThread::Run()
{
- DWORD exit_code;
+ wxCriticalSectionLocker lock(m_critsect);
- if (p_internal->state == STATE_IDLE)
- return NULL;
+ if ( p_internal->GetState() != STATE_NEW )
+ {
+ // actually, it may be almost any state at all, not only STATE_RUNNING
+ return wxTHREAD_RUNNING;
+ }
- if (wxThread::IsMain())
- wxMainMutex.Unlock();
- WaitForSingleObject(p_internal->thread_id, INFINITE);
- if (wxThread::IsMain())
- wxMainMutex.Lock();
+ return Resume();
+}
- GetExitCodeThread(p_internal->thread_id, &exit_code);
- CloseHandle(p_internal->thread_id);
+// suspend/resume thread
+// ---------------------
- p_internal->state = STATE_IDLE;
+wxThreadError wxThread::Pause()
+{
+ wxCriticalSectionLocker lock(m_critsect);
- return (void *)exit_code;
+ return p_internal->Suspend() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
}
-unsigned long wxThread::GetID()
+wxThreadError wxThread::Resume()
{
- return (unsigned long)p_internal->tid;
+ wxCriticalSectionLocker lock(m_critsect);
+
+ return p_internal->Resume() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
}
-bool wxThread::IsMain()
+// stopping thread
+// ---------------
+
+wxThread::ExitCode wxThread::Delete()
{
- return (GetCurrentThread() == p_mainid);
+ ExitCode rc = 0;
+
+ // Delete() is always safe to call, so consider all possible states
+ if ( IsPaused() )
+ Resume();
+
+ if ( IsRunning() )
+ {
+ if ( IsMain() )
+ {
+ // set flag for wxIsWaitingForThread()
+ s_waitingForThread = TRUE;
+
+ wxBeginBusyCursor();
+ }
+
+ HANDLE hThread;
+ {
+ wxCriticalSectionLocker lock(m_critsect);
+
+ p_internal->Cancel();
+ hThread = p_internal->GetHandle();
+ }
+
+ // we can't just wait for the thread to terminate because it might be
+ // calling some GUI functions and so it will never terminate before we
+ // process the Windows messages that result from these functions
+ DWORD result;
+ do
+ {
+ result = ::MsgWaitForMultipleObjects
+ (
+ 1, // number of objects to wait for
+ &hThread, // the objects
+ FALSE, // don't wait for all objects
+ INFINITE, // no timeout
+ QS_ALLEVENTS // return as soon as there are any events
+ );
+
+ switch ( result )
+ {
+ case 0xFFFFFFFF:
+ // error
+ wxLogSysError(_("Can not wait for thread termination"));
+ Kill();
+ return (ExitCode)-1;
+
+ case WAIT_OBJECT_0:
+ // thread we're waiting for terminated
+ break;
+
+ case WAIT_OBJECT_0 + 1:
+ // new message arrived, process it
+ if ( !wxTheApp->DoMessage() )
+ {
+ // WM_QUIT received: kill the thread
+ Kill();
+
+ return (ExitCode)-1;
+ }
+
+ if ( IsMain() )
+ {
+ // give the thread we're waiting for chance to exit
+ // from the GUI call it might have been in
+ if ( (s_nWaitingForGui > 0) && wxGuiOwnedByMainThread() )
+ {
+ wxMutexGuiLeave();
+ }
+ }
+
+ break;
+
+ default:
+ wxFAIL_MSG("unexpected result of MsgWaitForMultipleObject");
+ }
+ } while ( result != WAIT_OBJECT_0 );
+
+ if ( IsMain() )
+ {
+ s_waitingForThread = FALSE;
+
+ wxEndBusyCursor();
+ }
+
+ if ( !::GetExitCodeThread(hThread, (LPDWORD)&rc) )
+ {
+ wxLogLastError("GetExitCodeThread");
+
+ rc = (ExitCode)-1;
+ }
+
+ wxASSERT_MSG( (LPVOID)rc != (LPVOID)STILL_ACTIVE,
+ "thread must be already terminated." );
+
+ ::CloseHandle(hThread);
+ }
+
+ return rc;
}
-wxThread::wxThread()
+wxThreadError wxThread::Kill()
{
- p_internal = new wxThreadInternal();
+ if ( !IsRunning() )
+ return wxTHREAD_NOT_RUNNING;
+
+ if ( !::TerminateThread(p_internal->GetHandle(), (DWORD)-1) )
+ {
+ wxLogSysError(_("Couldn't terminate thread"));
+
+ return wxTHREAD_MISC_ERROR;
+ }
- p_internal->defer = FALSE;
- p_internal->prio = WXTHREAD_DEFAULT_PRIORITY;
- p_internal->state = STATE_IDLE;
+ delete this;
+
+ return wxTHREAD_NO_ERROR;
}
-wxThread::~wxThread()
+void wxThread::Exit(void *status)
+{
+ delete this;
+
+ ::ExitThread((DWORD)status);
+
+ wxFAIL_MSG("Couldn't return from ExitThread()!");
+}
+
+void wxThread::SetPriority(unsigned int prio)
+{
+ wxCriticalSectionLocker lock(m_critsect);
+
+ p_internal->SetPriority(prio);
+}
+
+unsigned int wxThread::GetPriority() const
+{
+ wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
+
+ return p_internal->GetPriority();
+}
+
+unsigned long wxThread::GetID() const
+{
+ wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
+
+ return (unsigned long)p_internal->GetId();
+}
+
+bool wxThread::IsRunning() const
+{
+ wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
+
+ return p_internal->GetState() == STATE_RUNNING;
+}
+
+bool wxThread::IsAlive() const
+{
+ wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
+
+ return (p_internal->GetState() == STATE_RUNNING) ||
+ (p_internal->GetState() == STATE_PAUSED);
+}
+
+bool wxThread::TestDestroy()
{
- Destroy();
- Join();
- delete p_internal;
+ wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
+
+ return p_internal->GetState() == STATE_CANCELED;
}
-// The default callback just joins the thread and throws away the result.
-void wxThread::OnExit()
+wxThread::wxThread()
{
- Join();
+ p_internal = new wxThreadInternal();
}
-// Automatic initialization
-class wxThreadModule : public wxModule {
- DECLARE_DYNAMIC_CLASS(wxThreadModule)
+wxThread::~wxThread()
+{
+ delete p_internal;
+}
+
+// ----------------------------------------------------------------------------
+// Automatic initialization for thread module
+// ----------------------------------------------------------------------------
+
+class wxThreadModule : public wxModule
+{
public:
- virtual bool OnInit(void) {
- p_mainid = GetCurrentThread();
- wxMainMutex.Lock();
- return TRUE;
- }
+ virtual bool OnInit();
+ virtual void OnExit();
- // Global cleanup
- virtual void OnExit(void) {
- wxMainMutex.Unlock();
- }
+private:
+ DECLARE_DYNAMIC_CLASS(wxThreadModule)
};
IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule)
+bool wxThreadModule::OnInit()
+{
+ // allocate TLS index for storing the pointer to the current thread
+ s_tlsThisThread = ::TlsAlloc();
+ if ( s_tlsThisThread == 0xFFFFFFFF )
+ {
+ // in normal circumstances it will only happen if all other
+ // TLS_MINIMUM_AVAILABLE (>= 64) indices are already taken - in other
+ // words, this should never happen
+ wxLogSysError(_("Thread module initialization failed: "
+ "impossible to allocate index in thread "
+ "local storage"));
+
+ return FALSE;
+ }
+
+ // main thread doesn't have associated wxThread object, so store 0 in the
+ // TLS instead
+ if ( !::TlsSetValue(s_tlsThisThread, (LPVOID)0) )
+ {
+ ::TlsFree(s_tlsThisThread);
+ s_tlsThisThread = 0xFFFFFFFF;
+
+ wxLogSysError(_("Thread module initialization failed: "
+ "can not store value in thread local storage"));
+
+ return FALSE;
+ }
+
+ s_critsectWaitingForGui = new wxCriticalSection();
+
+ s_critsectGui = new wxCriticalSection();
+ s_critsectGui->Enter();
+
+ // no error return for GetCurrentThreadId()
+ s_idMainThread = ::GetCurrentThreadId();
+
+ return TRUE;
+}
+
+void wxThreadModule::OnExit()
+{
+ if ( !::TlsFree(s_tlsThisThread) )
+ {
+ wxLogLastError("TlsFree failed.");
+ }
+
+ if ( s_critsectGui )
+ {
+ s_critsectGui->Leave();
+ 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()
+{
+ // 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()
+{
+ 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)");
+ }
+}
+
+bool WXDLLEXPORT wxIsWaitingForThread()
+{
+ return s_waitingForThread;
+}
+
+#endif // wxUSE_THREADS
projects / wxWidgets.git / blobdiff