// 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
/////////////////////////////////////////////////////////////////////////////
#include "wx/module.h"
#include "wx/thread.h"
-enum thread_state
+// the possible states of the thread ("=>" shows all possible transitions from
+// this state)
+enum wxThreadState
{
- STATE_IDLE = 0,
- STATE_RUNNING,
- STATE_CANCELED,
- STATE_EXITED
+ 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
// ----------------------------------------------------------------------------
+// TLS index of the slot where we store the pointer to the current thread
+static DWORD s_tlsThisThread = 0xFFFFFFFF;
+
// 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;
+
+// are we waiting for a thread termination?
+static bool s_waitingForThread = FALSE;
// ============================================================================
// Windows implementation of thread classes
wxMutex::~wxMutex()
{
if (m_locked > 0)
- wxLogDebug("Warning: freeing a locked mutex (%d locks).", m_locked);
+ wxLogDebug(wxT("Warning: freeing a locked mutex (%d locks)."), m_locked);
CloseHandle(p_internal->p_mutex);
}
case WAIT_TIMEOUT:
default:
- wxFAIL_MSG("impossible return value in wxMutex::Lock");
+ wxFAIL_MSG(wxT("impossible return value in wxMutex::Lock"));
}
m_locked++;
// wxThread implementation
// ----------------------------------------------------------------------------
+// wxThreadInternal class
+// ----------------------
+
class wxThreadInternal
{
public:
- static DWORD WinThreadStart(LPVOID arg);
+ 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; }
- HANDLE thread_id;
- int state;
- int prio, defer;
- DWORD tid;
+ // 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;
+ }
+
+ DWORD ret = (DWORD)thread->Entry();
+ thread->p_internal->SetState(STATE_EXITED);
+ thread->OnExit();
- ret = (DWORD)ptr->Entry();
- ptr->p_internal->state = STATE_EXITED;
+ delete thread;
return ret;
}
-wxThreadError wxThread::Create()
+bool wxThreadInternal::Create(wxThread *thread)
{
- int 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
+ );
- 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 ( m_hThread == NULL )
{
wxLogSysError(_("Can't create thread"));
- return wxTHREAD_NO_RESOURCE;
+
+ return FALSE;
}
- int win_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;
+ // 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_prio = THREAD_PRIORITY_NORMAL;
+ wxFAIL_MSG(wxT("invalid value of thread priority parameter"));
+ win_priority = THREAD_PRIORITY_NORMAL;
}
- SetThreadPriority(p_internal->thread_id, win_prio);
-
- ResumeThread(p_internal->thread_id);
- p_internal->state = STATE_RUNNING;
+ if ( ::SetThreadPriority(m_hThread, win_priority) == 0 )
+ {
+ wxLogSysError(_("Can't set thread priority"));
+ }
- return wxTHREAD_NO_ERROR;
+ return TRUE;
}
-wxThreadError wxThread::Destroy()
+bool wxThreadInternal::Suspend()
{
- if (p_internal->state != STATE_RUNNING)
- return wxTHREAD_NOT_RUNNING;
+ DWORD nSuspendCount = ::SuspendThread(m_hThread);
+ if ( nSuspendCount == (DWORD)-1 )
+ {
+ wxLogSysError(_("Can not suspend thread %x"), m_hThread);
- 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);
+ return FALSE;
+ }
- return wxTHREAD_NO_ERROR;
+ m_state = STATE_PAUSED;
+
+ return TRUE;
}
-wxThreadError wxThread::Pause()
+bool wxThreadInternal::Resume()
{
- DWORD nSuspendCount = ::SuspendThread(p_internal->thread_id);
+ DWORD nSuspendCount = ::ResumeThread(m_hThread);
if ( nSuspendCount == (DWORD)-1 )
{
- wxLogSysError(_("Can not suspend thread %x"), p_internal->thread_id);
+ wxLogSysError(_("Can not resume thread %x"), m_hThread);
- return wxTHREAD_MISC_ERROR; // no idea what might provoke this error...
+ return FALSE;
}
- return wxTHREAD_NO_ERROR;
+ m_state = STATE_RUNNING;
+
+ return TRUE;
}
-wxThreadError wxThread::Resume()
+// static functions
+// ----------------
+
+wxThread *wxThread::This()
{
- DWORD nSuspendCount = ::ResumeThread(p_internal->thread_id);
- if ( nSuspendCount == (DWORD)-1 )
+ wxThread *thread = (wxThread *)::TlsGetValue(s_tlsThisThread);
+
+ // be careful, 0 may be a valid return value as well
+ if ( !thread && (::GetLastError() != NO_ERROR) )
{
- wxLogSysError(_("Can not resume thread %x"), p_internal->thread_id);
+ wxLogSysError(_("Couldn't get the current thread pointer"));
- return wxTHREAD_MISC_ERROR; // no idea what might provoke this error...
+ // return NULL...
}
+ return thread;
+}
+
+bool wxThread::IsMain()
+{
+ return ::GetCurrentThreadId() == s_idMainThread;
+}
+
+#ifdef Yield
+ #undef Yield
+#endif
+
+void wxThread::Yield()
+{
+ // 0 argument to Sleep() is special
+ ::Sleep(0);
+}
+
+void wxThread::Sleep(unsigned long milliseconds)
+{
+ ::Sleep(milliseconds);
+}
+
+// create/start thread
+// -------------------
+
+wxThreadError wxThread::Create()
+{
+ if ( !p_internal->Create(this) )
+ return wxTHREAD_NO_RESOURCE;
+
return wxTHREAD_NO_ERROR;
}
-void wxThread::Exit(void *status)
+wxThreadError wxThread::Run()
{
- p_internal->state = STATE_EXITED;
- ExitThread((DWORD)status);
+ wxCriticalSectionLocker lock(m_critsect);
+
+ if ( p_internal->GetState() != STATE_NEW )
+ {
+ // actually, it may be almost any state at all, not only STATE_RUNNING
+ return wxTHREAD_RUNNING;
+ }
+
+ return Resume();
}
-void wxThread::SetPriority(int prio)
+// suspend/resume thread
+// ---------------------
+
+wxThreadError wxThread::Pause()
{
- p_internal->prio = prio;
+ wxCriticalSectionLocker lock(m_critsect);
+
+ return p_internal->Suspend() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
}
-int wxThread::GetPriority() const
+wxThreadError wxThread::Resume()
{
- return p_internal->prio;
+ wxCriticalSectionLocker lock(m_critsect);
+
+ return p_internal->Resume() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
}
-void wxThread::DeferDestroy(bool on)
+// stopping thread
+// ---------------
+
+wxThread::ExitCode wxThread::Delete()
{
- p_internal->defer = on;
+ 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(wxT("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,
+ wxT("thread must be already terminated.") );
+
+ ::CloseHandle(hThread);
+ }
+
+ return rc;
}
-bool wxThread::TestDestroy()
+wxThreadError wxThread::Kill()
{
- return p_internal->state == STATE_CANCELED;
+ if ( !IsRunning() )
+ return wxTHREAD_NOT_RUNNING;
+
+ if ( !::TerminateThread(p_internal->GetHandle(), (DWORD)-1) )
+ {
+ wxLogSysError(_("Couldn't terminate thread"));
+
+ return wxTHREAD_MISC_ERROR;
+ }
+
+ delete this;
+
+ return wxTHREAD_NO_ERROR;
}
-void *wxThread::Join()
+void wxThread::Exit(void *status)
{
- DWORD exit_code;
+ delete this;
- if (p_internal->state == STATE_IDLE)
- return NULL;
+ ::ExitThread((DWORD)status);
- if (wxThread::IsMain())
- s_critsectGui->Leave();
- WaitForSingleObject(p_internal->thread_id, INFINITE);
- if (wxThread::IsMain())
- s_critsectGui->Enter();
+ wxFAIL_MSG(wxT("Couldn't return from ExitThread()!"));
+}
+
+void wxThread::SetPriority(unsigned int prio)
+{
+ wxCriticalSectionLocker lock(m_critsect);
- GetExitCodeThread(p_internal->thread_id, &exit_code);
- CloseHandle(p_internal->thread_id);
+ p_internal->SetPriority(prio);
+}
- p_internal->state = STATE_IDLE;
+unsigned int wxThread::GetPriority() const
+{
+ wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
- return (void *)exit_code;
+ return p_internal->GetPriority();
}
unsigned long wxThread::GetID() const
{
- return (unsigned long)p_internal->tid;
+ wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
+
+ return (unsigned long)p_internal->GetId();
}
bool wxThread::IsRunning() const
{
- return (p_internal->state == STATE_RUNNING);
+ wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
+
+ return p_internal->GetState() == STATE_RUNNING;
}
bool wxThread::IsAlive() const
{
- return (p_internal->state == STATE_RUNNING);
+ wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
+
+ return (p_internal->GetState() == STATE_RUNNING) ||
+ (p_internal->GetState() == STATE_PAUSED);
}
-bool wxThread::IsMain()
+bool wxThread::IsPaused() const
{
- return (GetCurrentThread() == s_idMainThread);
+ wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
+
+ return (p_internal->GetState() == STATE_PAUSED);
}
-wxThread::wxThread()
+bool wxThread::TestDestroy()
{
- p_internal = new wxThreadInternal();
+ wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
- p_internal->defer = FALSE;
- p_internal->prio = WXTHREAD_DEFAULT_PRIORITY;
- p_internal->state = STATE_IDLE;
+ return p_internal->GetState() == STATE_CANCELED;
}
-wxThread::~wxThread()
+wxThread::wxThread()
{
- Destroy();
- Join();
- delete p_internal;
+ p_internal = new wxThreadInternal();
}
-void wxThread::OnExit()
+wxThread::~wxThread()
{
+ delete p_internal;
}
// ----------------------------------------------------------------------------
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();
- s_idMainThread = GetCurrentThread();
+
+ // 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()
{
- //s_critsectGui->Enter();
+ // this would dead lock everything...
+ wxASSERT_MSG( !wxThread::IsMain(),
+ wxT("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,
+ wxT("calling wxMutexGuiLeave() without entering it first?") );
+
+ s_nWaitingForGui--;
+
+ wxWakeUpMainThread();
+ }
+
+ s_critsectGui->Leave();
+}
+
+void WXDLLEXPORT wxMutexGuiLeaveOrEnter()
+{
+ wxASSERT_MSG( wxThread::IsMain(),
+ wxT("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