bsp.c

state machine working with rtos

/*****************************************************************************
* Product: QDPP example
* Version: Compatible with QF/C 3.1.yy
* Updated: Feb 06, 2006
*
* Copyright (C) 2002-2006 Quantum Leaps, LLC. All rights reserved.
*
* This example is part of the Quantum Leaps QP/C software, and 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 in conjunction
* with a valid QP/C Quantum Leaps commercial license. Quantum Leaps
* commercial licenses are designed for users who want to retain proprietary
* status of their code. The users who license this software under one of
* Quantum Leaps commercial licenses do not use this software under the GPL
* and therefore are not subject to any of its terms.
*
* Contact information:
* Quantum Leaps Web site:  http://www.quantum-leaps.com
* Quantum Leaps licensing: http://www.quantum-leaps.com/licensing
* Quantum Leaps products:  http://www.quantum-leaps.com/products
* e-mail:                  [e-mail]
*****************************************************************************/
#include "qf_port.h"
#include "qassert.h"
#include "qdpp.h"

#include <stdlib.h>
#include <stdio.h>
#include <sys/select.h>
#include <termios.h>
#include <unistd.h>

Q_DEFINE_THIS_FILE

/*..........................................................................*/
static void *idleThread(void *me) {      /* the expected P-Thread signature */
    struct timeval timeout = { 0 };                 /* timeout for select() */
    struct termios tio;                     /* modified terminal attributes */

    tcgetattr(0, &tio);           /* obtain the current terminal attributes */
    tio.c_lflag &= ~(ICANON | ECHO);   /* disable the canonical mode & echo */
    tcsetattr(0, TCSANOW, &tio);                  /* set the new attributes */

    while (QF_running_) {
        fd_set con;                      /* FD set representing the console */
        FD_ZERO(&con);
        FD_SET(0, &con);
        timeout.tv_usec = 8000;

        /* sleep for the full tick or until a console input arrives, NOTE01 */
        if (0 != select(1, &con, 0, 0, &timeout)) {  /* any descriptor set? */
            char ch;
            read(0, &ch, 1);
            if (ch == '\33') {                              /* ESC pressed? */
                QF_publish(Q_NEW(QEvent, TERMINATE_SIG));
            }
        }
    }

    return (void *)0;                                     /* return success */
}
/*..........................................................................*/
void BSP_init(int argc, char *argv[]) {
    pthread_attr_t attr;
    struct sched_param param;
    pthread_t idle;

    pthread_attr_init(&attr);

    /* SCHED_FIFO corresponds to real-time preemptive priority-based scheduler
    * NOTE: This scheduling policy requires the superuser priviledges
    */
    pthread_attr_setschedpolicy(&attr, SCHED_FIFO);
    param.sched_priority = sched_get_priority_min(SCHED_FIFO);

    pthread_attr_setschedparam(&attr, &param);
    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);

    if (pthread_create(&idle, &attr, &idleThread, 0) != 0) {
               /* Creating the p-thread with the SCHED_FIFO policy failed.
               * Most probably this application has no superuser privileges,
               * so we just fall back to the default SCHED_OTHER policy
               * and priority 0.
               */
        pthread_attr_setschedpolicy(&attr, SCHED_OTHER);
        param.sched_priority = 0;
        pthread_attr_setschedparam(&attr, &param);
        Q_ALLEGE(pthread_create(&idle, &attr, &idleThread, 0) == 0);
    }
    pthread_attr_destroy(&attr);
}
/*..........................................................................*/
void displyPhilStat(uint8_t n, char const *stat) {
    printf("Philosopher %2d is %s\n", (int)n, stat);
}
/*..........................................................................*/
void Q_assert_handler(char const *file, int line) {
    fprintf(stderr, "Assertion failed in %s, line %d", file, line);
    QF_exit();
}

/*****************************************************************************
*
* NOTE01:
* The select() system call seems to deliver the finest time granularity of
* 1 clock tick. The timeout value passed to select() is rounded up to the
* nearest tick (10 ms on desktop Linux). The timeout cannot be too short,
* because the system might choose to busy-wait for very short timeouts.
* An alternative, POSIX nanosleep() system call seems to deliver only 20ms
* granularity.
*
* Here the select() call is used not just as a fairly portable way to sleep
* with subsecond precision. The select() call is also used to detect any
* characters typed on the console.
*
* Also according to man pages, on Linux, the function select() modifies
* timeout to reflect the amount of time not slept; most other implementations
* do not do this. This causes problems both when Linux code which reads
* timeout is ported to other operating systems, and when code is ported to
* Linux that reuses a struct timeval for multiple selects in a loop without
* reinitializing it. Here the microsecond part of the structure is re-
* initialized before each select() call.
*/