Re: Problems with Linux CommonC++ Thread Class scheduling

[Ian Campbell]

Yes, and adding in a line that calls pthread_attr_setsched_policy() which
takes the the creating processes schedule policy and applies it to the new
thread. This effectively inherits the policy type.

Cheers,

Ian


Ian Campbell
Band-X
t: +44 (0) 207 932 8846
f: +44 (0) 207 932 8800
e: address@hidden

On Fri, 22 Jun 2001, David Sugar wrote:

> So all you are doing then is killing the line with the set inherit?
>
> Ian Campbell wrote:
>
> > Hello All,
> >         I have been experimenting with the CommonC++ Thread class on Linux
> > using the realtime pthread scheduler (either SCHED_RR or SCHED_FIFO) and
> > found it doesn't work properly in the 1.4.3 release. This fault means that
> > you can't give seperate threads a different priority from the creating
> > main process. This is caused by a call to pthread_attr_setinheritsched()
> > which according to the man page means that the priority and policy for
> > thread scheduler must be inherited from the creating thread. As such any
> > subsequent calls to pthread_attr_setschedpolicy() and
> > pthread_attr_setschedparam() will have no effect. Anyway the patch at the
> > end of this email should fixeth the problem.
> >
> > Cheers,
> >
> > Ian Campbell
> > Band-X
> > t: +44 (0) 207 932 8846
> > f: +44 (0) 207 932 8800
> > e: address@hidden
> >
> > diff -u -r CommonC++-1.4.3/posix/thread.cpp
> > CommonC++-1.4.3-sched.patch/posix/thread.cpp
> > --- CommonC++-1.4.3/posix/thread.cpp        Thu May 31 08:30:51 2001
> > +++ CommonC++-1.4.3-sched.patch/posix/thread.cpp    Thu Jun 21
> > 12:41:08 2001
> > @@ -1,23 +1,23 @@
> >  // Copyright (C) 1999-2001 Open Source Telecom Corporation.
> > -//
> > +//
> >  // This program is free software; you can redistribute it and/or modify
> >  // it under the terms of the GNU General Public License as published by
> >  // the Free Software Foundation; either version 2 of the License, or
> >  // (at your option) any later version.
> > -//
> > +//
> >  // This program is distributed in the hope that it will be useful,
> >  // but WITHOUT ANY WARRANTY; without even the implied warranty of
> >  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> >  // GNU General Public License for more details.
> > -//
> > +//
> >  // You should have received a copy of the GNU General Public License
> > -// along with this program; if not, write to the Free Software
> > +// along with this program; if not, write to the Free Software
> >  // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
> > USA.
> > -//
> > -// As a special exception to the GNU General Public License, permission
> > is
> > -// granted for additional uses of the text contained in its release
> > +//
> > +// As a special exception to the GNU General Public License, permission
> > is
> > +// granted for additional uses of the text contained in its release
> >  // of Common C++.
> > -//
> > +//
> >  // The exception is that, if you link the Common C++ library with other
> >  // files to produce an executable, this does not by itself cause the
> >  // resulting executable to be covered by the GNU General Public License.
> > @@ -27,16 +27,16 @@
> >  // This exception does not however invalidate any other reasons why
> >  // the executable file might be covered by the GNU General Public
> > License.
> >  //
> > -// This exception applies only to the code released under the
> > +// This exception applies only to the code released under the
> >  // name Common C++.  If you copy code from other releases into a copy of
> >  // Common C++, as the General Public License permits, the exception does
> >  // not apply to the code that you add in this way.  To avoid misleading
> >  // anyone as to the status of such modified files, you must delete
> >  // this exception notice from them.
> > -//
> > +//
> >  // If you write modifications of your own for Common C++, it is your
> > choice
> >  // whether to permit this exception to apply to your modifications.
> > -// If you do not wish that, delete this exception notice.
> > +// If you do not wish that, delete this exception notice.
> >
> >  #include "config.h"
> >  #include "macros.h"
> > @@ -137,7 +137,7 @@
> >             sigaction(SIGPOLL, &act, NULL);
> >  #else
> >             sigaction(SIGIO, &act, NULL);
> > -#endif
> > +#endif
> >
> >  #ifndef    _SIG_THREAD_STOPCONT
> >  #ifndef    _THR_SUNOS5
> > @@ -161,11 +161,11 @@
> >             sigaddset(&act.sa_mask, SIGPIPE);
> >
> >             sigaction(_SIG_THREAD_CANCEL, &act, NULL);
> > -#endif
> > +#endif
> >             _main = this;
> >             }
> >     _self.setKey(this);
> > -}
> > +}
> >
> >  Thread::Thread(Semaphore *start, int pri, size_t stack)
> >  {
> > @@ -176,7 +176,7 @@
> >
> >     pthread_attr_init(&_attr);
> >     pthread_attr_setdetachstate(&_attr, PTHREAD_CREATE_JOINABLE);
> > -   pthread_attr_setinheritsched(&_attr, PTHREAD_INHERIT_SCHED);
> > +
> >
> >  #ifdef     PTHREAD_STACK_MIN
> >     if(pthread_attr_setstacksize(&_attr, stack <= PTHREAD_STACK_MIN ?
> > PTHREAD_STACK_MIN : stack))
> > @@ -192,7 +192,7 @@
> >  #endif
> >
> >  #ifndef    __FreeBSD__
> > -#ifdef     _POSIX_THREAD_PRIORITY_SCHEDULING
> > +#ifdef     _POSIX_THREAD_PRIORITY_SCHEDULING
> >     if(pri)
> >     {
> >             struct sched_param sched;
> > @@ -220,8 +220,9 @@
> >                     pri = sched_get_priority_min(policy);
> >
> >             sched.sched_priority = pri;
> > +           pthread_attr_setschedpolicy(&_attr, policy);
> >             pthread_attr_setschedparam(&_attr, &sched);
> > -   }
> > +   }
> >  #endif
> >  #endif
> >
> > @@ -289,7 +290,7 @@
> >     {
> >             pthread_detach(_tid);
> >             if(_start)
> > -           {
> > +           {
> >                     _start->Post();
> >                     return 0;
> >             }
> > @@ -351,7 +352,7 @@
> >                     Thread::_timer->OnTimer();
> >             }
> >             else
> > -#endif
> > +#endif
> >                 if(th)
> >                     th->OnTimer();
> >             break;
> > @@ -386,7 +387,7 @@
> >
> >     if(!setjmp(th->_env))
> >     {
> > -           th->Initial();
> > +           th->Initial();
> >             if(th->getCancel() == THREAD_CANCEL_INITIAL)
> >                     th->setCancel(THREAD_CANCEL_DEFAULT);
> >
> > @@ -411,7 +412,7 @@
> >
> >  #ifdef     HAVE_SETITIMER
> >     struct itimerval itimer;
> > -
> > +
> >     memset(&itimer, 0, sizeof(itimer));
> >     itimer.it_value.tv_usec = (timer * 1000) % 1000000;
> >     itimer.it_value.tv_sec = timer / 1000;
> > @@ -419,7 +420,7 @@
> >     timer /= 1000;
> >  #endif
> >
> > -#ifndef    _SIG_THREAD_ALARM
> > +#ifndef    _SIG_THREAD_ALARM
> >     _arm;
> >     _timer = this;
> >  #endif
> > @@ -432,7 +433,7 @@
> >  #else
> >     alarm(timer);
> >  #endif
> > -}
> > +}
> >
> >  timeout_t Thread::getTimer(void)
> >  {
> > @@ -491,7 +492,7 @@
> >  #else
> >     sigwait(&mask, &signo);
> >  #endif
> > -}
> > +}
> >
> >  void       Thread::setSuspend(thread_suspend_t mode)
> >  {
> > @@ -518,7 +519,7 @@
> >
> >     sigemptyset(&mask);
> >     sigaddset(&mask, _SIG_THREAD_CANCEL);
> > -
> > +
> >     switch(mode)
> >     {
> >     case THREAD_CANCEL_IMMEDIATE:
> > @@ -545,7 +546,7 @@
> >             pthread_sigmask(SIG_UNBLOCK, &sigs, NULL);
> >     else
> >             pthread_sigmask(SIG_BLOCK, &sigs, NULL);
> > -}
> > +}
> >
> >  void       Thread::setCancel(thread_cancel_t mode)
> >  {
> > @@ -580,7 +581,7 @@
> >     sigemptyset(&cancel);
> >     sigaddset(&cancel, _SIG_THREAD_CANCEL);
> >
> > -   if(_cancel != THREAD_CANCEL_DISABLED &&
> > +   if(_cancel != THREAD_CANCEL_DISABLED &&
> >        _cancel != THREAD_CANCEL_INITIAL)
> >             pthread_sigmask(SIG_UNBLOCK, &cancel, &old);
> >  #else
> > @@ -600,28 +601,28 @@
> >  {
> >  #ifdef  _SIG_THREAD_CANCEL
> >          sigset_t cancel, old;
> > -
> > +
> >          sigemptyset(&cancel);
> >          sigaddset(&cancel, _SIG_THREAD_CANCEL);
> > -
> > +
> >          if(_cancel != THREAD_CANCEL_DISABLED &&
> >             _cancel != THREAD_CANCEL_INITIAL)
> >                  pthread_sigmask(SIG_UNBLOCK, &cancel, &old);
> >  #else
> >          pthread_testcancel();
> >  #endif
> > -
> > +
> >  #ifdef  _SIG_THREAD_CANCEL
> >          if(_cancel != THREAD_CANCEL_DISABLED)
> >                  pthread_sigmask(SIG_SETMASK, &old, NULL);
> >  #endif
> > -}
> > +}
> >
> >
> >  void siginstall(int signo)
> >  {
> >     struct sigaction act;
> > -
> > +
> >     act.sa_handler = (signalexec_t)&sigHandler;
> >     sigemptyset(&act.sa_mask);
> >
> >
> >
> >
> > _______________________________________________
> > Bug-commoncpp mailing list
> > address@hidden
> > http://mail.gnu.org/mailman/listinfo/bug-commoncpp
>
>