Orocos Real-Time Toolkit  2.5.0
SequentialActivity.cpp
00001 /***************************************************************************
00002   tag: Peter Soetens  Thu Oct 22 11:59:08 CEST 2009  SequentialActivity.cpp
00003 
00004                         SequentialActivity.cpp -  description
00005                            -------------------
00006     begin                : Thu October 22 2009
00007     copyright            : (C) 2009 Peter Soetens
00008     email                : peter@thesourcworks.com
00009 
00010  ***************************************************************************
00011  *   This library is free software; you can redistribute it and/or         *
00012  *   modify it under the terms of the GNU General Public                   *
00013  *   License as published by the Free Software Foundation;                 *
00014  *   version 2 of the License.                                             *
00015  *                                                                         *
00016  *   As a special exception, you may use this file as part of a free       *
00017  *   software library without restriction.  Specifically, if other files   *
00018  *   instantiate templates or use macros or inline functions from this     *
00019  *   file, or you compile this file and link it with other files to        *
00020  *   produce an executable, this file does not by itself cause the         *
00021  *   resulting executable to be covered by the GNU General Public          *
00022  *   License.  This exception does not however invalidate any other        *
00023  *   reasons why the executable file might be covered by the GNU General   *
00024  *   Public License.                                                       *
00025  *                                                                         *
00026  *   This library is distributed in the hope that it will be useful,       *
00027  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
00028  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU     *
00029  *   Lesser General Public License for more details.                       *
00030  *                                                                         *
00031  *   You should have received a copy of the GNU General Public             *
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00033  *   Foundation, Inc., 59 Temple Place,                                    *
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00035  *                                                                         *
00036  ***************************************************************************/
00037 
00038 
00039 #include "SequentialActivity.hpp"
00040 #include "../os/MainThread.hpp"
00041 #include "../os/MutexLock.hpp"
00042 
00043 namespace RTT {
00044     using namespace extras;
00045     using namespace base;
00046 
00047     SequentialActivity::SequentialActivity( RunnableInterface* run /*= 0*/ )
00048         : ActivityInterface(run), running(false), active(false)
00049     {
00050     }
00051 
00052     SequentialActivity::~SequentialActivity()
00053     {
00054         stop();
00055     }
00056 
00057     Seconds SequentialActivity::getPeriod() const
00058     {
00059         return 0.0;
00060     }
00061 
00062     bool SequentialActivity::setPeriod(Seconds s) {
00063         if ( s == 0.0)
00064             return true;
00065         return false;
00066     }
00067 
00068     unsigned SequentialActivity::getCpuAffinity() const
00069     {
00070       return ~0;
00071     }
00072 
00073     bool SequentialActivity::setCpuAffinity(unsigned cpu)
00074     {
00075       return false;
00076     }
00077 
00078     os::ThreadInterface* SequentialActivity::thread()
00079     {
00080         return os::MainThread::Instance();
00081     }
00082 
00083     bool SequentialActivity::initialize()
00084     {
00085         return true;
00086     }
00087 
00088     void SequentialActivity::step()
00089     {
00090     }
00091 
00092     bool SequentialActivity::breakLoop()
00093     {
00094         return false;
00095     }
00096 
00097 
00098     void SequentialActivity::finalize()
00099     {
00100     }
00101 
00102     bool SequentialActivity::start()
00103     {
00104         if (active == true )
00105             return false;
00106 
00107         active = true;
00108 
00109         if ( runner ? runner->initialize() : this->initialize() ) {
00110         } else {
00111             active = false;
00112         }
00113         return active;
00114     }
00115 
00116 
00117     bool SequentialActivity::stop()
00118     {
00119         if ( !active )
00120             return false;
00121 
00122         if (runner)
00123             runner->finalize();
00124         else
00125             this->finalize();
00126         active = false;
00127         return true;
00128     }
00129 
00130     bool SequentialActivity::isRunning() const
00131     {
00132         return running;
00133     }
00134 
00135     bool SequentialActivity::isPeriodic() const
00136     {
00137         return false;
00138     }
00139 
00140     bool SequentialActivity::isActive() const
00141     {
00142         return active;
00143     }
00144 
00145     bool SequentialActivity::trigger()
00146     {
00147         // This function may recurse, in which case it returns true.
00148         // We could also rely on the MutexTryLock to fail, but in
00149         // case an OS only has recursive mutexes, we'd need to
00150         // check running anyway before calling runner->step(). So
00151         // we moved that piece of code up front.
00152         // The other thread will complete the work. (hasWork).
00153         if (running)
00154             return true;
00155         if ( active ) {
00156             bool did_step = false;
00157             do {
00158                 os::MutexTryLock lock(execution_lock);
00159                 if ( lock.isSuccessful() ) {
00160                     running = true;
00161                     if (runner) runner->step(); else this->step();
00162                     running = false;
00163                     did_step = true;
00164                 } else {
00165                     // nop: step() is already being executed and
00166                     // should notice that new data is there.
00167                     // race: step() returns and trigger is called->
00168                     // trigger is ignored.
00169                     return true;
00170                 }
00171                 // mutex unlocked here.
00172             } // if the runner signals work again (ie a race occured),
00173               // rety to lock.
00174             while ( did_step && runner->hasWork() );
00175             return true;
00176         }
00177         return false;
00178     }
00179 
00180     bool SequentialActivity::execute()
00181     {
00182         return false;
00183     }
00184 
00185 
00186 }