wxUsleep() introduced (and documented) to try to work around usleep() bug in

[wxWidgets.git] / src / motif / thread.cpp

/////////////////////////////////////////////////////////////////////////////
// Name:        thread.cpp
// Purpose:     wxThread Implementation for Posix threads
// Author:      Original from Wolfram Gloger/Guilhem Lavaux
// Modified by: Robert Roebling
// Created:     04/22/98
// RCS-ID:      $Id$
// Copyright:   (c) Wolfram Gloger (1996, 1997); Guilhem Lavaux (1998)
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

#ifdef __GNUG__
#pragma implementation "thread.h"
#endif

#include "wx/defs.h"

#if wxUSE_THREADS

#include "wx/module.h"
#include "wx/thread.h"
#include "wx/utils.h"
#include "wx/log.h"

#include <stdio.h>
#include <unistd.h>
#include <pthread.h>
#include <errno.h>

#include <stdio.h>
#include <unistd.h>

// for select()
#include <sys/time.h>
#include <sys/types.h>
#ifdef __sgi
#include <bstring.h>
#endif

//--------------------------------------------------------------------
// constants
//--------------------------------------------------------------------

enum thread_state 
{
  STATE_IDLE = 0,
  STATE_RUNNING,
  STATE_PAUSING,
  STATE_PAUSED,
  STATE_CANCELED,
  STATE_EXITED
};

//--------------------------------------------------------------------
// global data
//--------------------------------------------------------------------

static pthread_t p_mainid;

wxMutex *wxMainMutex = (wxMutex*) NULL; /* controls access to all GUI functions */

/* TODO for Xt */

static int p_thrd_pipe[2] = { -1, -1 };

//-------------------------------------------------------------------------
// global functions
//-------------------------------------------------------------------------

static void wxThreadGuiInit()
{
/* TODO for Xt */
}

static void wxThreadGuiExit()
{
/* TODO for Xt */
}

void wxMutexGuiEnter()
{
  if (wxMainMutex)
    wxMainMutex->Lock();
}

void wxMutexGuiLeave()
{
  if (wxMainMutex)
    wxMainMutex->Unlock();
}

//--------------------------------------------------------------------
// wxMutex (Posix implementation)
//--------------------------------------------------------------------

class wxMutexInternal 
{
public:
  pthread_mutex_t p_mutex;
};

wxMutex::wxMutex()
{
    p_internal = new wxMutexInternal;
    pthread_mutex_init(&(p_internal->p_mutex), NULL);
    m_locked = 0;
}

wxMutex::~wxMutex()
{
    if (m_locked > 0)
        wxLogDebug( "wxMutex warning: freeing a locked mutex (%d locks)\n", m_locked );

    pthread_mutex_destroy(&(p_internal->p_mutex));
    delete p_internal;
}

wxMutexError wxMutex::Lock()
{
    int err;

    err = pthread_mutex_lock(&(p_internal->p_mutex));
    if (err == EDEADLK)
        return wxMUTEX_DEAD_LOCK;
	
    m_locked++;
    return wxMUTEX_NO_ERROR;
}

wxMutexError wxMutex::TryLock()
{
    int err;

    if (m_locked)
        return wxMUTEX_BUSY;
	
    err = pthread_mutex_trylock(&(p_internal->p_mutex));
    switch (err) 
    {
        case EBUSY: return wxMUTEX_BUSY;
    }
    m_locked++;
    return wxMUTEX_NO_ERROR;
}

wxMutexError wxMutex::Unlock()
{
    if (m_locked > 0)
        m_locked--;
    else
        return wxMUTEX_UNLOCKED;
	
    pthread_mutex_unlock(&(p_internal->p_mutex));
    return wxMUTEX_NO_ERROR;
}

//--------------------------------------------------------------------
// wxCondition (Posix implementation)
//--------------------------------------------------------------------

class wxConditionInternal 
{
public:
  pthread_cond_t p_condition;
};

wxCondition::wxCondition()
{
    p_internal = new wxConditionInternal;
    pthread_cond_init(&(p_internal->p_condition), NULL);
}

wxCondition::~wxCondition()
{
    pthread_cond_destroy(&(p_internal->p_condition));
    delete p_internal;
}

void wxCondition::Wait(wxMutex& mutex)
{
    pthread_cond_wait(&(p_internal->p_condition), &(mutex.p_internal->p_mutex));
}

bool wxCondition::Wait(wxMutex& mutex, unsigned long sec, unsigned long nsec)
{
    struct timespec tspec;

    tspec.tv_sec = time(NULL)+sec;
    tspec.tv_nsec = nsec;
    return (pthread_cond_timedwait(&(p_internal->p_condition), &(mutex.p_internal->p_mutex), &tspec) != ETIMEDOUT);
}

void wxCondition::Signal()
{
    pthread_cond_signal(&(p_internal->p_condition));
}

void wxCondition::Broadcast()
{
    pthread_cond_broadcast(&(p_internal->p_condition));
}

//--------------------------------------------------------------------
// wxThread (Posix implementation)
//--------------------------------------------------------------------

class wxThreadInternal 
{
public:
  wxThreadInternal() { state = STATE_IDLE; }
  ~wxThreadInternal() {}
  static void *PthreadStart(void *ptr);
  pthread_t thread_id;
  int state;
  int prio;
  int defer_destroy;
};

void *wxThreadInternal::PthreadStart(void *ptr)
{
    wxThread *thread = (wxThread *)ptr;

    // Call the main entry
    pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
    void* status = thread->Entry();

    thread->Exit(status);

    return NULL;
}

wxThreadError wxThread::Create()
{
    pthread_attr_t a;
    int min_prio, max_prio, p;
    struct sched_param sp;

    if (p_internal->state != STATE_IDLE)
        return wxTHREAD_RUNNING;

    // Change thread priority
    pthread_attr_init(&a);
    pthread_attr_getschedpolicy(&a, &p);

    min_prio = sched_get_priority_min(p);
    max_prio = sched_get_priority_max(p);

    pthread_attr_getschedparam(&a, &sp);
    sp.sched_priority = min_prio +
               (p_internal->prio*(max_prio-min_prio))/100;
    pthread_attr_setschedparam(&a, &sp);

    // 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);

    return wxTHREAD_NO_ERROR;
}

void wxThread::SetPriority(int prio)
{
    if (p_internal->state == STATE_RUNNING)
        return;

    if (prio > 100) prio = 100;
	
    if (prio < 0) prio = 0;
    
    p_internal->prio = prio;
}

int wxThread::GetPriority() const
{
    return p_internal->prio;
}

void wxThread::DeferDestroy(bool on)
{
    if (on)
        pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, NULL);
    else
        pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
}

wxThreadError wxThread::Destroy()
{
    int res = 0;

    if (p_internal->state == STATE_RUNNING) 
    {
        res = pthread_cancel(p_internal->thread_id);
        if (res == 0)
	    p_internal->state = STATE_CANCELED;
    }

    return wxTHREAD_NO_ERROR;
}

wxThreadError wxThread::Pause()
{
    if (p_internal->state != STATE_RUNNING)
        return wxTHREAD_NOT_RUNNING;

    if (!p_internal->defer_destroy)
        return wxTHREAD_MISC_ERROR;

    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;

    return wxTHREAD_NO_ERROR;
}

void *wxThread::Join()
{
    void* status = 0;

    if (p_internal->state != STATE_IDLE) 
    {
        bool do_unlock = wxThread::IsMain();

        while (p_internal->state == STATE_RUNNING)
            wxYield();

        if (do_unlock) wxMainMutex->Unlock();
      
        pthread_join(p_internal->thread_id, &status);
      
        if (do_unlock) wxMainMutex->Lock();

        p_internal->state = STATE_IDLE;
    }
    
    return status;
}

unsigned long wxThread::GetID() const
{
    return p_internal->thread_id;
}

void wxThread::Exit(void *status)
{
    wxThread* ptr = this;

/*    THREAD_SEND_EXIT_MSG(ptr);  TODO for Xt */
    
    p_internal->state = STATE_EXITED;
    pthread_exit(status);
}

void wxThread::TestDestroy()
{
    if (p_internal->state == STATE_PAUSING) 
    {
        p_internal->state = STATE_PAUSED;
        while (p_internal->state == STATE_PAUSED) 
	{
            pthread_testcancel();
            usleep(1);
        }
    }
    pthread_testcancel();
}

bool wxThread::IsMain()
{
    return (bool)pthread_equal(pthread_self(), p_mainid);
}

bool wxThread::IsRunning() const
{
    return (p_internal->state == STATE_RUNNING);
}

bool wxThread::IsAlive() const
{
    return (p_internal->state == STATE_RUNNING) ||
           (p_internal->state == STATE_PAUSING) ||
           (p_internal->state == STATE_PAUSED);
}

wxThread::wxThread()
{
    p_internal = new wxThreadInternal();
}

wxThread::~wxThread()
{
    Destroy();
    Join();
    delete p_internal;
}

// The default callback just joins the thread and throws away the result.
void wxThread::OnExit()
{
    Join();
}

//--------------------------------------------------------------------
// wxThreadModule 
//--------------------------------------------------------------------

class wxThreadModule : public wxModule
{
public:
    virtual bool OnInit();
    virtual void OnExit();

private:
    DECLARE_DYNAMIC_CLASS(wxThreadModule)
};

IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule)

bool wxThreadModule::OnInit() 
{
    wxMainMutex = new wxMutex();
    wxThreadGuiInit();
    p_mainid = pthread_self();
    wxMainMutex->Lock();

    return TRUE;
}

void wxThreadModule::OnExit()
{
    wxMainMutex->Unlock();
    wxThreadGuiExit();
    delete wxMainMutex;
};

#endif
  // wxUSE_THREADS