// 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
+enum thread_state
+{
+ STATE_IDLE = 0,
+ STATE_RUNNING,
+ STATE_PAUSED,
+ STATE_CANCELED,
+ STATE_EXITED
};
-/////////////////////////////////////////////////////////////////////////////
-// Static variables
-/////////////////////////////////////////////////////////////////////////////
+// ----------------------------------------------------------------------------
+// static variables
+// ----------------------------------------------------------------------------
-static HANDLE p_mainid;
-wxMutex wxMainMutex; // controls access to all GUI functions
+// id of the main thread - the one which can call GUI functions without first
+// calling wxMutexGuiEnter()
+static DWORD s_idMainThread = 0;
-/////////////////////////////////////////////////////////////////////////////
-// Windows implementation
-/////////////////////////////////////////////////////////////////////////////
+// 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;
+
+// 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
+// ============================================================================
-class wxMutexInternal {
+// ----------------------------------------------------------------------------
+// wxMutex implementation
+// ----------------------------------------------------------------------------
+class wxMutexInternal
+{
public:
- HANDLE p_mutex;
+ HANDLE p_mutex;
};
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()
{
- if (m_locked > 0)
- wxDebugMsg("wxMutex warning: freeing a locked mutex (%d locks)\n", m_locked);
- 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()
{
- DWORD ret;
+ DWORD ret;
+
+ ret = WaitForSingleObject(p_internal->p_mutex, INFINITE);
+ switch ( ret )
+ {
+ case WAIT_ABANDONED:
+ return wxMUTEX_BUSY;
+
+ case WAIT_OBJECT_0:
+ // ok
+ break;
- ret = WaitForSingleObject(p_internal->p_mutex, INFINITE);
- if (ret == WAIT_ABANDONED)
- return MUTEX_BUSY;
+ case WAIT_FAILED:
+ wxLogSysError(_("Couldn't acquire a mutex lock"));
+ return wxMUTEX_MISC_ERROR;
- m_locked++;
- return MUTEX_NO_ERROR;
+ case WAIT_TIMEOUT:
+ default:
+ wxFAIL_MSG("impossible return value in wxMutex::Lock");
+ }
+
+ m_locked++;
+ return wxMUTEX_NO_ERROR;
}
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()
{
- 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()
{
- 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()
{
- 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()
{
- SetEvent(p_internal->event);
+ SetEvent(p_internal->event);
}
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; }
- HANDLE thread_id;
- int state;
- int prio, defer;
- DWORD tid;
+ // free the associated ressources
+ ~wxCriticalSectionInternal()
+ { ::DeleteCriticalSection(&m_data); }
+
+private:
+ CRITICAL_SECTION m_data;
};
-DWORD wxThreadInternal::WinThreadStart(LPVOID arg)
+wxCriticalSection::wxCriticalSection()
{
- wxThread *ptr = (wxThread *)arg;
- DWORD ret;
+ m_critsect = new wxCriticalSectionInternal;
+}
- ret = (DWORD)ptr->Entry();
- ptr->p_internal->state = STATE_EXITED;
+wxCriticalSection::~wxCriticalSection()
+{
+ delete m_critsect;
+}
- return ret;
+void wxCriticalSection::Enter()
+{
+ ::EnterCriticalSection(*m_critsect);
}
-wxThreadError wxThread::Create()
+void wxCriticalSection::Leave()
{
- int win_prio, prio = p_internal->prio;
+ ::LeaveCriticalSection(*m_critsect);
+}
+
+// ----------------------------------------------------------------------------
+// wxThread implementation
+// ----------------------------------------------------------------------------
- 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;
- }
+class wxThreadInternal
+{
+public:
+ static DWORD WinThreadStart(wxThread *thread);
- 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;
+ HANDLE hThread;
+ thread_state state;
+ int prio, defer;
+ DWORD tid;
+};
- SetThreadPriority(p_internal->thread_id, win_prio);
+DWORD wxThreadInternal::WinThreadStart(wxThread *thread)
+{
+ DWORD ret = (DWORD)thread->Entry();
+ thread->p_internal->state = STATE_EXITED;
+ thread->OnExit();
- ResumeThread(p_internal->thread_id);
- p_internal->state = STATE_RUNNING;
-
- return THREAD_NO_ERROR;
+ return ret;
+}
+
+wxThreadError wxThread::Create()
+{
+ 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
+ );
+
+ if ( p_internal->hThread == NULL )
+ {
+ wxLogSysError(_("Can't create thread"));
+ return wxTHREAD_NO_RESOURCE;
+ }
+
+ int win_prio, prio = p_internal->prio;
+ 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;
+ else
+ {
+ wxFAIL_MSG("invalid value of thread priority parameter");
+ win_prio = THREAD_PRIORITY_NORMAL;
+ }
+
+ if ( SetThreadPriority(p_internal->hThread, win_prio) == 0 )
+ {
+ wxLogSysError(_("Can't set thread priority"));
+ }
+
+ return Resume();
}
wxThreadError wxThread::Destroy()
{
- if (p_internal->state != STATE_RUNNING)
- return THREAD_NOT_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
+ OnExit();
+ if ( ::TerminateThread(p_internal->hThread, 0) == 0 )
+ {
+ wxLogLastError("TerminateThread");
+ }
+ }
+
+ return wxTHREAD_NO_ERROR;
+}
+
+wxThreadError wxThread::Pause()
+{
+ DWORD nSuspendCount = ::SuspendThread(p_internal->hThread);
+ if ( nSuspendCount == (DWORD)-1 )
+ {
+ 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->hThread);
+ if ( nSuspendCount == (DWORD)-1 )
+ {
+ wxLogSysError(_("Can not resume thread %x"), p_internal->hThread);
+
+ return wxTHREAD_MISC_ERROR; // no idea what might provoke this error...
+ }
- if (p_internal->defer == FALSE)
- TerminateThread(p_internal->thread_id, 0);
- else
- p_internal->state = STATE_CANCELED;
+ p_internal->state = STATE_RUNNING;
- return THREAD_NO_ERROR;
+ return wxTHREAD_NO_ERROR;
}
void wxThread::Exit(void *status)
{
- p_internal->state = STATE_EXITED;
- ExitThread((DWORD)status);
+ p_internal->state = STATE_EXITED;
+ ExitThread((DWORD)status);
}
void wxThread::SetPriority(int prio)
{
- p_internal->prio = prio;
+ p_internal->prio = prio;
}
int wxThread::GetPriority() const
{
- return p_internal->prio;
+ return p_internal->prio;
}
void wxThread::DeferDestroy(bool on)
{
- p_internal->defer = on;
+ p_internal->defer = on;
}
-void wxThread::TestDestroy()
+bool wxThread::TestDestroy()
{
- if (p_internal->state == STATE_CANCELED)
- ExitThread(0);
+ return p_internal->state == STATE_CANCELED;
}
void *wxThread::Join()
{
- DWORD exit_code;
+ DWORD exit_code;
- if (p_internal->state == STATE_IDLE)
- return NULL;
+ if (p_internal->state == STATE_IDLE)
+ return NULL;
- if (wxThread::IsMain())
- wxMainMutex.Unlock();
- WaitForSingleObject(p_internal->thread_id, INFINITE);
- if (wxThread::IsMain())
- wxMainMutex.Lock();
+ // 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;
+ p_internal->state = STATE_IDLE;
- return (void *)exit_code;
+ return (void *)exit_code;
}
unsigned long wxThread::GetID() const
{
- return (unsigned long)p_internal->tid;
+ return (unsigned long)p_internal->tid;
+}
+
+bool wxThread::IsRunning() const
+{
+ return (p_internal->state == STATE_RUNNING);
+}
+
+bool wxThread::IsAlive() const
+{
+ return (p_internal->state == STATE_RUNNING);
}
bool wxThread::IsMain()
{
- return (GetCurrentThread() == p_mainid);
+ return ::GetCurrentThreadId() == s_idMainThread;
}
wxThread::wxThread()
{
- p_internal = new wxThreadInternal();
+ p_internal = new wxThreadInternal();
- p_internal->defer = FALSE;
- p_internal->prio = WXTHREAD_DEFAULT_PRIORITY;
- p_internal->state = STATE_IDLE;
+ p_internal->defer = FALSE;
+ p_internal->prio = WXTHREAD_DEFAULT_PRIORITY;
+ p_internal->state = STATE_IDLE;
}
wxThread::~wxThread()
{
- Destroy();
- Join();
- delete p_internal;
+ Destroy();
+ Join();
+ delete p_internal;
}
-// The default callback just joins the thread and throws away the result.
void wxThread::OnExit()
{
- Join();
}
-// Automatic initialization
-class wxThreadModule : public wxModule {
- DECLARE_DYNAMIC_CLASS(wxThreadModule)
+// ----------------------------------------------------------------------------
+// Automatic initialization for thread module
+// ----------------------------------------------------------------------------
+
+class wxThreadModule : public wxModule
+{
public:
- virtual bool OnInit() {
- p_mainid = GetCurrentThread();
- wxMainMutex.Lock();
- return TRUE;
- }
+ virtual bool OnInit();
+ virtual void OnExit();
- // Global cleanup
- virtual void OnExit() {
- wxMainMutex.Unlock();
- }
+private:
+ DECLARE_DYNAMIC_CLASS(wxThreadModule)
};
IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule)
+bool wxThreadModule::OnInit()
+{
+ s_critsectWaitingForGui = new wxCriticalSection();
+
+ s_critsectGui = new wxCriticalSection();
+ s_critsectGui->Enter();
+
+ s_idMainThread = ::GetCurrentThreadId();
+
+ return TRUE;
+}
+
+void wxThreadModule::OnExit()
+{
+ 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)");
+ }
+}
+
+#endif // wxUSE_THREADS
projects / wxWidgets.git / blobdiff