![](/media/cache/profiles/7cca4a9404acc5243f0b77c16ff4a477.50x50_q85.jpg)
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]].
Diff: philo.cpp
- Revision:
- 0:efb9ac8d1a88
- Child:
- 3:81ceb3127876
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/philo.cpp Sat Feb 12 23:22:47 2011 +0000 @@ -0,0 +1,173 @@ +////////////////////////////////////////////////////////////////////////////// +// 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); +} +