Dining Philosophers Problem (DPP) example for the QP active object framework. Demonstrates: event-driven programming, hierarchical state machines in C++, modeling and graphical state machine design, code generation, preemptive multitasking, software tracing, power saving mode, direct event posting, publish-subscribe. More information available in the [[/users/QL/notebook|Quantum Leaps Notebook pages]]. See also [[http://www.state-machine.com|state-machine.com]].

Dependencies:   mbed qp

philo.cpp

Committer:
QL
Date:
2011-02-12
Revision:
0:efb9ac8d1a88
Child:
3:81ceb3127876

File content as of revision 0:efb9ac8d1a88:

//////////////////////////////////////////////////////////////////////////////
// Product: DPP example
// Last Updated for Version: 4.0.00
// Date of the Last Update:  Apr 06, 2008
//
//                    Q u a n t u m     L e a P s
//                    ---------------------------
//                    innovating embedded systems
//
// Copyright (C) 2002-2008 Quantum Leaps, LLC. All rights reserved.
//
// This software may be distributed and modified under the terms of the GNU
// General Public License version 2 (GPL) as published by the Free Software
// Foundation and appearing in the file GPL.TXT included in the packaging of
// this file. Please note that GPL Section 2[b] requires that all works based
// on this software must also be made publicly available under the terms of
// the GPL ("Copyleft").
//
// Alternatively, this software may be distributed and modified under the
// terms of Quantum Leaps commercial licenses, which expressly supersede
// the GPL and are specifically designed for licensees interested in
// retaining the proprietary status of their code.
//
// Contact information:
// Quantum Leaps Web site:  http://www.quantum-leaps.com
// e-mail:                  info@quantum-leaps.com
//////////////////////////////////////////////////////////////////////////////
#include "qp_port.h"
#include "dpp.h"
#include "bsp.h"

Q_DEFINE_THIS_FILE

// Active object class -------------------------------------------------------
class Philo : public QActive {
private:
    QTimeEvt m_timeEvt;                       // to timeout thinking or eating

public:
    Philo();

private:
    static QState initial (Philo *me, QEvent const *e);
    static QState thinking(Philo *me, QEvent const *e);
    static QState hungry  (Philo *me, QEvent const *e);
    static QState eating  (Philo *me, QEvent const *e);
};

// Local objects -------------------------------------------------------------
static Philo l_philo[N_PHILO];                       // storage for all Philos

#define THINK_TIME  23
#define EAT_TIME    19
                              // helper macro to provide the ID of Philo "me_"
#define PHILO_ID(me_)    ((uint8_t)((me_) - l_philo))

enum InternalSignals {                                     // internal signals
    TIMEOUT_SIG = MAX_SIG
};
// Global objects ------------------------------------------------------------
QActive * const AO_Philo[N_PHILO] = {        // "opaque" pointers to Philo AOs
    &l_philo[0],
    &l_philo[1],
    &l_philo[2],
    &l_philo[3],
    &l_philo[4]
};

//............................................................................
Philo::Philo()
    : QActive((QStateHandler)&Philo::initial),
      m_timeEvt(TIMEOUT_SIG)
{}
//............................................................................
QState Philo::initial(Philo *me, QEvent const *) {
    static uint8_t registered;            // starts off with 0, per C-standard
    if (!registered) {
        QS_OBJ_DICTIONARY(&l_philo[0]);
        QS_OBJ_DICTIONARY(&l_philo[0].m_timeEvt);
        QS_OBJ_DICTIONARY(&l_philo[1]);
        QS_OBJ_DICTIONARY(&l_philo[1].m_timeEvt);
        QS_OBJ_DICTIONARY(&l_philo[2]);
        QS_OBJ_DICTIONARY(&l_philo[2].m_timeEvt);
        QS_OBJ_DICTIONARY(&l_philo[3]);
        QS_OBJ_DICTIONARY(&l_philo[3].m_timeEvt);
        QS_OBJ_DICTIONARY(&l_philo[4]);
        QS_OBJ_DICTIONARY(&l_philo[4].m_timeEvt);

        QS_FUN_DICTIONARY(&Philo::initial);
        QS_FUN_DICTIONARY(&Philo::thinking);
        QS_FUN_DICTIONARY(&Philo::hungry);
        QS_FUN_DICTIONARY(&Philo::eating);

        registered = (uint8_t)1;
    }
    QS_SIG_DICTIONARY(HUNGRY_SIG, me);               // signal for each Philos
    QS_SIG_DICTIONARY(TIMEOUT_SIG, me);              // signal for each Philos

    me->subscribe(EAT_SIG);

    return Q_TRAN(&Philo::thinking);
}
//............................................................................
QState Philo::thinking(Philo *me, QEvent const *e) {
    switch (e->sig) {
        case Q_ENTRY_SIG: {
            me->m_timeEvt.postIn(me, THINK_TIME);
            return Q_HANDLED();
        }
        case TIMEOUT_SIG: {
            BSP_busyDelay();
            return Q_TRAN(&Philo::hungry);
        }
        case EAT_SIG:                            // intentionally fall-through
        case DONE_SIG: {
                         // EAT or DONE must be for other Philos than this one
            Q_ASSERT(((TableEvt const *)e)->philoNum != PHILO_ID(me));
            return Q_HANDLED();
        }
    }
    return Q_SUPER(&QHsm::top);
}
//............................................................................
QState Philo::hungry(Philo *me, QEvent const *e) {
    switch (e->sig) {
        case Q_ENTRY_SIG: {
            TableEvt *pe = Q_NEW(TableEvt, HUNGRY_SIG);
            pe->philoNum = PHILO_ID(me);
            AO_Table->postFIFO(pe);
            return Q_HANDLED();
        }
        case EAT_SIG: {
            if (((TableEvt *)e)->philoNum == PHILO_ID(me)) {
                BSP_busyDelay();
                return Q_TRAN(&Philo::eating);
            }
            break;
        }
        case DONE_SIG: {
                                // DONE must be for other Philos than this one
            Q_ASSERT(((TableEvt const *)e)->philoNum != PHILO_ID(me));
            return Q_HANDLED();
        }
    }
    return Q_SUPER(&QHsm::top);
}
//............................................................................
QState Philo::eating(Philo *me, QEvent const *e) {
    switch (e->sig) {
        case Q_ENTRY_SIG: {
            me->m_timeEvt.postIn(me, EAT_TIME);
            return Q_HANDLED();
        }
        case Q_EXIT_SIG: {
            TableEvt *pe = Q_NEW(TableEvt, DONE_SIG);
            pe->philoNum = PHILO_ID(me);
            QF::publish(pe);
            return Q_HANDLED();
        }
        case TIMEOUT_SIG: {
            BSP_busyDelay();
            return Q_TRAN(&Philo::thinking);
        }
        case EAT_SIG:                            // intentionally fall-through
        case DONE_SIG: {
                         // EAT or DONE must be for other Philos than this one
            Q_ASSERT(((TableEvt const *)e)->philoNum != PHILO_ID(me));
            return Q_HANDLED();
        }
    }
    return Q_SUPER(&QHsm::top);
}