/////////////////////////////////////////////////////////////////////////////
#ifdef __GNUG__
-#pragma implementation "thread.h"
+ #pragma implementation "thread.h"
#endif
#include <stdio.h>
#include <unistd.h>
#include <pthread.h>
#include <errno.h>
+
+#ifdef __linux__
+ #include <sched.h>
+#endif
+
+#ifdef __SUN__
+extern int usleep(unsigned int useconds);
+#endif
+
+
#include "wx/thread.h"
#include "wx/module.h"
#include "wx/utils.h"
#include "wx/log.h"
+#include "wx/intl.h"
+#include "wx/dynarray.h"
#include "gdk/gdk.h"
#include "gtk/gtk.h"
-enum thread_state
+enum thread_state
{
- STATE_IDLE = 0,
- STATE_RUNNING,
- STATE_PAUSING,
- STATE_PAUSED,
- STATE_CANCELED,
- STATE_EXITED
+ STATE_NEW, // didn't start execution yet (=> RUNNING)
+ STATE_RUNNING,
+ STATE_PAUSED,
+ STATE_CANCELED,
+ STATE_EXITED
};
-//--------------------------------------------------------------------
+WX_DEFINE_ARRAY(wxThread *, wxArrayThread);
+
+// -----------------------------------------------------------------------------
// global data
-//--------------------------------------------------------------------
+// -----------------------------------------------------------------------------
+
+// we keep the list of all threads created by the application to be able to
+// terminate them on exit if there are some left - otherwise the process would
+// be left in memory
+static wxArrayThread gs_allThreads;
+
+// the id of the main thread
+static pthread_t gs_tidMain;
-static pthread_t p_mainid;
+// the key for the pointer to the associated wxThread object
+static pthread_key_t gs_keySelf;
-wxMutex *wxMainMutex; /* controls access to all GUI functions */
+// this mutex must be acquired before any call to a GUI function
+static wxMutex *gs_mutexGui;
//--------------------------------------------------------------------
// common GUI thread code
// wxMutex (Posix implementation)
//--------------------------------------------------------------------
-class wxMutexInternal
+class wxMutexInternal
{
public:
pthread_mutex_t p_mutex;
wxMutex::~wxMutex()
{
if (m_locked > 0)
- wxLogDebug( "wxMutex warning: freeing a locked mutex (%d locks)\n", m_locked );
+ wxLogDebug("Freeing a locked mutex (%d locks)", m_locked);
pthread_mutex_destroy( &(p_internal->p_mutex) );
delete p_internal;
int err = pthread_mutex_lock( &(p_internal->p_mutex) );
if (err == EDEADLK)
{
+ wxLogDebug("Locking this mutex would lead to deadlock!");
+
return wxMUTEX_DEAD_LOCK;
}
-
+
m_locked++;
-
+
return wxMUTEX_NO_ERROR;
}
{
return wxMUTEX_BUSY;
}
-
+
int err = pthread_mutex_trylock( &(p_internal->p_mutex) );
- switch (err)
+ switch (err)
{
case EBUSY: return wxMUTEX_BUSY;
}
-
+
m_locked++;
-
+
return wxMUTEX_NO_ERROR;
}
}
else
{
+ wxLogDebug("Unlocking not locked mutex.");
+
return wxMUTEX_UNLOCKED;
}
-
+
pthread_mutex_unlock( &(p_internal->p_mutex) );
-
+
return wxMUTEX_NO_ERROR;
}
// wxCondition (Posix implementation)
//--------------------------------------------------------------------
-class wxConditionInternal
+class wxConditionInternal
{
public:
pthread_cond_t p_condition;
wxCondition::~wxCondition()
{
pthread_cond_destroy( &(p_internal->p_condition) );
-
+
delete p_internal;
}
// wxThread (Posix implementation)
//--------------------------------------------------------------------
-class wxThreadInternal
+class wxThreadInternal
{
public:
- wxThreadInternal() { state = STATE_IDLE; }
- ~wxThreadInternal() {}
- static void *PthreadStart(void *ptr);
- pthread_t thread_id;
- int state;
- int prio;
- int defer_destroy;
+ wxThreadInternal();
+ ~wxThreadInternal();
+
+ // thread entry function
+ static void *PthreadStart(void *ptr);
+
+ // thread actions
+ // start the thread
+ wxThreadError Run();
+ // ask the thread to terminate
+ void Cancel();
+ // wake up threads waiting for our termination
+ void SignalExit();
+ // go to sleep until Resume() is called
+ void Pause();
+ // resume the thread
+ void Resume();
+
+ // accessors
+ // priority
+ int GetPriority() const { return m_prio; }
+ void SetPriority(int prio) { m_prio = prio; }
+ // state
+ thread_state GetState() const { return m_state; }
+ void SetState(thread_state state) { m_state = state; }
+ // id
+ pthread_t GetId() const { return thread_id; }
+ // "cancelled" flag
+ bool WasCancelled() const { return m_cancelled; }
+
+//private: -- should be!
+ pthread_t thread_id;
+
+private:
+ thread_state m_state; // see thread_state enum
+ int m_prio; // in wxWindows units: from 0 to 100
+
+ // set when the thread should terminate
+ bool m_cancelled;
+
+ // this (mutex, cond) pair is used to synchronize the main thread and this
+ // thread in several situations:
+ // 1. The thread function blocks until condition is signaled by Run() when
+ // it's initially created - this allows create thread in "suspended"
+ // state
+ // 2. The Delete() function blocks until the condition is signaled when the
+ // thread exits.
+ wxMutex m_mutex;
+ wxCondition m_cond;
+
+ // another (mutex, cond) pair for Pause()/Resume() usage
+ //
+ // VZ: it's possible that we might reuse the mutex and condition from above
+ // for this too, but as I'm not at all sure that it won't create subtle
+ // problems with race conditions between, say, Pause() and Delete() I
+ // prefer this may be a bit less efficient but much safer solution
+ wxMutex m_mutexSuspend;
+ wxCondition m_condSuspend;
};
void *wxThreadInternal::PthreadStart(void *ptr)
{
wxThread *thread = (wxThread *)ptr;
+ wxThreadInternal *pthread = thread->p_internal;
+
+ if ( pthread_setspecific(gs_keySelf, thread) != 0 )
+ {
+ wxLogError(_("Can not start thread: error writing TLS."));
+
+ return (void *)-1;
+ }
+
+ // wait for the condition to be signaled from Run()
+ // mutex state: currently locked by the thread which created us
+ pthread->m_cond.Wait(pthread->m_mutex);
- /* Call the main entry */
- pthread_setcanceltype( PTHREAD_CANCEL_ASYNCHRONOUS, (int*) NULL );
+ // mutex state: locked again on exit of Wait()
+
+ // call the main entry
void* status = thread->Entry();
+ // terminate the thread
thread->Exit(status);
+ wxFAIL_MSG("wxThread::Exit() can't return.");
+
return NULL;
}
-wxThreadError wxThread::Create()
+wxThreadInternal::wxThreadInternal()
{
- pthread_attr_t a;
- int min_prio, max_prio, p;
- struct sched_param sp;
+ m_state = STATE_NEW;
+ m_cancelled = FALSE;
- if (p_internal->state != STATE_IDLE)
- return wxTHREAD_RUNNING;
+ // this mutex is locked during almost all thread lifetime - it will only be
+ // unlocked in the very end
+ m_mutex.Lock();
- /* Change thread priority */
- pthread_attr_init(&a);
- pthread_attr_getschedpolicy(&a, &p);
+ // this mutex is used in Pause()/Resume() and is also locked all the time
+ // unless the thread is paused
+ m_mutexSuspend.Lock();
+}
- min_prio = sched_get_priority_min(p);
- max_prio = sched_get_priority_max(p);
+wxThreadInternal::~wxThreadInternal()
+{
+ m_mutexSuspend.Unlock();
- pthread_attr_getschedparam(&a, &sp);
- sp.sched_priority = min_prio +
- (p_internal->prio*(max_prio-min_prio))/100;
- pthread_attr_setschedparam(&a, &sp);
+ // note that m_mutex will be unlocked by the thread which waits for our
+ // termination
+}
- // this is the point of no return
- p_internal->state = STATE_RUNNING;
- if (pthread_create(&p_internal->thread_id, &a,
- wxThreadInternal::PthreadStart, (void *)this) != 0)
- {
- p_internal->state = STATE_IDLE;
- pthread_attr_destroy(&a);
- return wxTHREAD_NO_RESOURCE;
- }
- pthread_attr_destroy(&a);
+wxThreadError wxThreadInternal::Run()
+{
+ wxCHECK_MSG( GetState() == STATE_NEW, wxTHREAD_RUNNING,
+ "thread may only be started once after successful Create()" );
+
+ // the mutex was locked on Create(), so we will be able to lock it again
+ // only when the thread really starts executing and enters the wait -
+ // otherwise we might signal the condition before anybody is waiting for it
+ wxMutexLocker lock(m_mutex);
+ m_cond.Signal();
+
+ m_state = STATE_RUNNING;
return wxTHREAD_NO_ERROR;
+
+ // now the mutex is unlocked back - but just to allow Wait() function to
+ // terminate by relocking it, so the net result is that the worker thread
+ // starts executing and the mutex is still locked
}
-void wxThread::SetPriority(int prio)
+void wxThreadInternal::Cancel()
{
- if (p_internal->state == STATE_RUNNING)
- return;
+ // if the thread we're waiting for is waiting for the GUI mutex, we will
+ // deadlock so make sure we release it temporarily
+ if ( wxThread::IsMain() )
+ wxMutexGuiLeave();
+
+ // nobody ever writes this variable so it's safe to not use any
+ // synchronization here
+ m_cancelled = TRUE;
- if (prio > 100) prio = 100;
-
- if (prio < 0) prio = 0;
-
- p_internal->prio = prio;
+ // entering Wait() releases the mutex thus allowing SignalExit() to acquire
+ // it and to signal us its termination
+ m_cond.Wait(m_mutex);
+
+ // mutex is still in the locked state - relocked on exit from Wait(), so
+ // unlock it - we don't need it any more, the thread has already terminated
+ m_mutex.Unlock();
+
+ // reacquire GUI mutex
+ if ( wxThread::IsMain() )
+ wxMutexGuiEnter();
}
-int wxThread::GetPriority() const
+void wxThreadInternal::SignalExit()
{
- return p_internal->prio;
+ // as mutex is currently locked, this will block until some other thread
+ // (normally the same which created this one) unlocks it by entering Wait()
+ m_mutex.Lock();
+
+ // wake up all the threads waiting for our termination
+ m_cond.Broadcast();
+
+ // after this call mutex will be finally unlocked
+ m_mutex.Unlock();
}
-void wxThread::DeferDestroy(bool on)
+void wxThreadInternal::Pause()
{
- if (on)
- pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, (int*) NULL);
- else
- pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, (int*) NULL);
+ wxCHECK_RET( m_state == STATE_PAUSED,
+ "thread must first be paused with wxThread::Pause()." );
+
+ // wait until the condition is signaled from Resume()
+ m_condSuspend.Wait(m_mutexSuspend);
+}
+
+void wxThreadInternal::Resume()
+{
+ wxCHECK_RET( m_state == STATE_PAUSED,
+ "can't resume thread which is not suspended." );
+
+ // we will be able to lock this mutex only when Pause() starts waiting
+ wxMutexLocker lock(m_mutexSuspend);
+ m_condSuspend.Signal();
+
+ SetState(STATE_RUNNING);
+}
+
+// -----------------------------------------------------------------------------
+// static functions
+// -----------------------------------------------------------------------------
+
+wxThread *wxThread::This()
+{
+ return (wxThread *)pthread_getspecific(gs_keySelf);
+}
+
+bool wxThread::IsMain()
+{
+ return (bool)pthread_equal(pthread_self(), gs_tidMain);
+}
+
+void wxThread::Yield()
+{
+#ifdef HAVE_SCHED_YIELD
+ sched_yield();
+#else // !HAVE_SCHED_YIELD
+ // may be it will have the desired effect?
+ Sleep(0);
+#endif // HAVE_SCHED_YIELD
+}
+
+void wxThread::Sleep(unsigned long milliseconds)
+{
+ wxUsleep(milliseconds);
}
-wxThreadError wxThread::Destroy()
+// -----------------------------------------------------------------------------
+// creating thread
+// -----------------------------------------------------------------------------
+
+wxThread::wxThread()
{
- int res = 0;
+ // add this thread to the global list of all threads
+ gs_allThreads.Add(this);
- if (p_internal->state == STATE_RUNNING)
+ p_internal = new wxThreadInternal();
+}
+
+wxThreadError wxThread::Create()
+{
+ if (p_internal->GetState() != STATE_NEW)
+ return wxTHREAD_RUNNING;
+
+ // set up the thread attribute: right now, we only set thread priority
+ pthread_attr_t attr;
+ pthread_attr_init(&attr);
+
+#ifdef HAVE_THREAD_PRIORITY_FUNCTIONS
+ int prio;
+ if ( pthread_attr_getschedpolicy(&attr, &prio) != 0 )
+ {
+ wxLogError(_("Can not retrieve thread scheduling policy."));
+ }
+
+ int min_prio = sched_get_priority_min(prio),
+ max_prio = sched_get_priority_max(prio);
+
+ if ( min_prio == -1 || max_prio == -1 )
+ {
+ wxLogError(_("Can not get priority range for scheduling policy %d."),
+ prio);
+ }
+ else
{
- res = pthread_cancel(p_internal->thread_id);
- if (res == 0)
- p_internal->state = STATE_CANCELED;
+ struct sched_param sp;
+ pthread_attr_getschedparam(&attr, &sp);
+ sp.sched_priority = min_prio +
+ (p_internal->GetPriority()*(max_prio-min_prio))/100;
+ pthread_attr_setschedparam(&attr, &sp);
+ }
+#endif // HAVE_THREAD_PRIORITY_FUNCTIONS
+
+ // create the new OS thread object
+ int rc = pthread_create(&p_internal->thread_id, &attr,
+ wxThreadInternal::PthreadStart, (void *)this);
+ pthread_attr_destroy(&attr);
+
+ if ( rc != 0 )
+ {
+ p_internal->SetState(STATE_EXITED);
+ return wxTHREAD_NO_RESOURCE;
}
return wxTHREAD_NO_ERROR;
}
+wxThreadError wxThread::Run()
+{
+ return p_internal->Run();
+}
+
+// -----------------------------------------------------------------------------
+// misc accessors
+// -----------------------------------------------------------------------------
+
+void wxThread::SetPriority(unsigned int prio)
+{
+ wxCHECK_RET( ((int)WXTHREAD_MIN_PRIORITY <= (int)prio) &&
+ ((int)prio <= (int)WXTHREAD_MAX_PRIORITY),
+ "invalid thread priority" );
+
+ wxCriticalSectionLocker lock(m_critsect);
+
+ switch ( p_internal->GetState() )
+ {
+ case STATE_NEW:
+ // thread not yet started, priority will be set when it is
+ p_internal->SetPriority(prio);
+ break;
+
+ case STATE_RUNNING:
+ case STATE_PAUSED:
+#ifdef HAVE_THREAD_PRIORITY_FUNCTIONS
+ {
+ struct sched_param sparam;
+ sparam.sched_priority = prio;
+
+ if ( pthread_setschedparam(p_internal->GetId(),
+ SCHED_OTHER, &sparam) != 0 )
+ {
+ wxLogError(_("Failed to set thread priority %d."), prio);
+ }
+ }
+#endif // HAVE_THREAD_PRIORITY_FUNCTIONS
+ break;
+
+ case STATE_EXITED:
+ default:
+ wxFAIL_MSG("impossible to set thread priority in this state");
+ }
+}
+
+unsigned int wxThread::GetPriority() const
+{
+ wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
+
+ return p_internal->GetPriority();
+}
+
+unsigned long wxThread::GetID() const
+{
+ return (unsigned long)p_internal->thread_id;
+}
+
+// -----------------------------------------------------------------------------
+// pause/resume
+// -----------------------------------------------------------------------------
+
wxThreadError wxThread::Pause()
{
- if (p_internal->state != STATE_RUNNING)
+ wxCriticalSectionLocker lock(m_critsect);
+
+ if ( p_internal->GetState() != STATE_RUNNING )
+ {
+ wxLogDebug("Can't pause thread which is not running.");
+
return wxTHREAD_NOT_RUNNING;
+ }
- if (!p_internal->defer_destroy)
- return wxTHREAD_MISC_ERROR;
+ p_internal->SetState(STATE_PAUSED);
- p_internal->state = STATE_PAUSING;
return wxTHREAD_NO_ERROR;
}
wxThreadError wxThread::Resume()
{
- if (p_internal->state == STATE_PAUSING || p_internal->state == STATE_PAUSED)
- p_internal->state = STATE_RUNNING;
+ wxCriticalSectionLocker lock(m_critsect);
- return wxTHREAD_NO_ERROR;
+ if ( p_internal->GetState() == STATE_PAUSED )
+ {
+ p_internal->Resume();
+
+ return wxTHREAD_NO_ERROR;
+ }
+ else
+ {
+ wxLogDebug("Attempt to resume a thread which is not paused.");
+
+ return wxTHREAD_MISC_ERROR;
+ }
}
-void *wxThread::Join()
+// -----------------------------------------------------------------------------
+// exiting thread
+// -----------------------------------------------------------------------------
+
+wxThread::ExitCode wxThread::Delete()
{
- void* status = 0;
+ m_critsect.Enter();
+ thread_state state = p_internal->GetState();
+ m_critsect.Leave();
- if (p_internal->state != STATE_IDLE)
+ switch ( state )
{
- bool do_unlock = wxThread::IsMain();
+ case STATE_NEW:
+ case STATE_EXITED:
+ // nothing to do
+ break;
- while (p_internal->state == STATE_RUNNING)
- wxYield();
+ case STATE_PAUSED:
+ // resume the thread first
+ Resume();
- if (do_unlock) wxMainMutex->Unlock();
-
- pthread_join(p_internal->thread_id, &status);
-
- if (do_unlock) wxMainMutex->Lock();
+ // fall through
- p_internal->state = STATE_IDLE;
+ default:
+ // set the flag telling to the thread to stop and wait
+ p_internal->Cancel();
}
-
- return status;
+
+ return NULL;
}
-unsigned long wxThread::GetID() const
+wxThreadError wxThread::Kill()
{
- return p_internal->thread_id;
+ switch ( p_internal->GetState() )
+ {
+ case STATE_NEW:
+ case STATE_EXITED:
+ return wxTHREAD_NOT_RUNNING;
+
+ default:
+#ifdef HAVE_PTHREAD_CANCEL
+ if ( pthread_cancel(p_internal->GetId()) != 0 )
+#endif
+ {
+ wxLogError(_("Failed to terminate a thread."));
+
+ return wxTHREAD_MISC_ERROR;
+ }
+
+ return wxTHREAD_NO_ERROR;
+ }
}
void wxThread::Exit(void *status)
{
- wxThread* ptr = this;
+ // first call user-level clean up code
+ OnExit();
+
+ // next wake up the threads waiting for us (OTOH, this function won't return
+ // until someone waited for us!)
+ p_internal->SignalExit();
+
+ p_internal->SetState(STATE_EXITED);
- THREAD_SEND_EXIT_MSG(ptr);
- p_internal->state = STATE_EXITED;
+ // delete both C++ thread object and terminate the OS thread object
+ delete this;
pthread_exit(status);
}
+// also test whether we were paused
bool wxThread::TestDestroy()
{
- if (p_internal->state == STATE_PAUSING)
+ wxCriticalSectionLocker lock((wxCriticalSection&)m_critsect);
+
+ if ( p_internal->GetState() == STATE_PAUSED )
{
- p_internal->state = STATE_PAUSED;
- while (p_internal->state == STATE_PAUSED)
- {
- pthread_testcancel();
- usleep(1);
- }
+ // leave the crit section or the other threads will stop too if they try
+ // to call any of (seemingly harmless) IsXXX() functions while we sleep
+ m_critsect.Leave();
+
+ p_internal->Pause();
+
+ // enter it back before it's finally left in lock object dtor
+ m_critsect.Enter();
}
- // VZ: do I understand it correctly that it will terminate the thread all by
- // itself if it was cancelled?
- pthread_testcancel();
-
- return FALSE;
+ return p_internal->WasCancelled();
}
-bool wxThread::IsMain()
+wxThread::~wxThread()
{
- return (bool)pthread_equal(pthread_self(), p_mainid);
+ // remove this thread from the global array
+ gs_allThreads.Remove(this);
}
+// -----------------------------------------------------------------------------
+// state tests
+// -----------------------------------------------------------------------------
+
bool wxThread::IsRunning() const
{
- return (p_internal->state == STATE_RUNNING);
-}
+ wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
-bool wxThread::IsAlive() const
-{
- return (p_internal->state == STATE_RUNNING) ||
- (p_internal->state == STATE_PAUSING) ||
- (p_internal->state == STATE_PAUSED);
+ return p_internal->GetState() == STATE_RUNNING;
}
-wxThread::wxThread()
+bool wxThread::IsAlive() const
{
- p_internal = new wxThreadInternal();
-}
+ wxCriticalSectionLocker lock((wxCriticalSection&)m_critsect);
-wxThread::~wxThread()
-{
- Destroy();
- Join();
- delete p_internal;
-}
+ switch ( p_internal->GetState() )
+ {
+ case STATE_RUNNING:
+ case STATE_PAUSED:
+ return TRUE;
-/* The default callback just joins the thread and throws away the result. */
-void wxThread::OnExit()
-{
- Join();
+ default:
+ return FALSE;
+ }
}
//--------------------------------------------------------------------
-// wxThreadModule
+// wxThreadModule
//--------------------------------------------------------------------
class wxThreadModule : public wxModule
IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule)
-bool wxThreadModule::OnInit()
+bool wxThreadModule::OnInit()
{
- wxMainMutex = new wxMutex();
+ if ( pthread_key_create(&gs_keySelf, NULL /* dtor function */) != 0 )
+ {
+ wxLogError(_("Thread module initialization failed: "
+ "failed to create pthread key."));
+
+ return FALSE;
+ }
+
+ gs_mutexGui = new wxMutex();
wxThreadGuiInit();
- p_mainid = (int)getpid();
- wxMainMutex->Lock();
+ gs_tidMain = pthread_self();
+ gs_mutexGui->Lock();
+
return TRUE;
}
void wxThreadModule::OnExit()
{
- wxMainMutex->Unlock();
- wxThreadGuiExit();
- delete wxMainMutex;
-}
+ wxASSERT_MSG( wxThread::IsMain(), "only main thread can be here" );
+
+ // terminate any threads left
+ size_t count = gs_allThreads.GetCount();
+ if ( count != 0u )
+ wxLogDebug("Some threads were not terminated by the application.");
+ for ( size_t n = 0u; n < count; n++ )
+ {
+ gs_allThreads[n]->Delete();
+ }
+ // destroy GUI mutex
+ gs_mutexGui->Unlock();
+ wxThreadGuiExit();
+ delete gs_mutexGui;
+
+ // and free TLD slot
+ (void)pthread_key_delete(gs_keySelf);
+}
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