///////////////////////////////////////////////////////////////////////////////
//
//                          IMPORTANT NOTICE
//
// The following open source license statement does not apply to any
// entity in the Exception List published by FMSoft.
//
// For more information, please visit:
//
// https://www.fmsoft.cn/exception-list
//
//////////////////////////////////////////////////////////////////////////////
/*
 *   This file is part of MiniGUI, a mature cross-platform windowing
 *   and Graphics User Interface (GUI) support system for embedded systems
 *   and smart IoT devices.
 *
 *   Copyright (C) 2002~2018, Beijing FMSoft Technologies Co., Ltd.
 *   Copyright (C) 1998~2002, WEI Yongming
 *
 *   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 3 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, see <http://www.gnu.org/licenses/>.
 *
 *   Or,
 *
 *   As this program is a library, any link to this program must follow
 *   GNU General Public License version 3 (GPLv3). If you cannot accept
 *   GPLv3, you need to be licensed from FMSoft.
 *
 *   If you have got a commercial license of this program, please use it
 *   under the terms and conditions of the commercial license.
 *
 *   For more information about the commercial license, please refer to
 *   <http://www.minigui.com/blog/minigui-licensing-policy/>.
 */
/* timer_posix.c */

static timer_t mytimer;
static struct sigaction old_alarm_handler;

static void timer_handler (int sig, siginfo_t *extra, void *cruft)
{
    int sem_value;
    int noverflow;

#if 0
    if( (noverflow=timer_getoverrun(*(timer_t *)
       extra->si_value.sival_ptr)) != 0) {
       /*timer has overflowed -- error !*/
       printf ("timer overrun!\n");
    }
#endif

    __mg_timer_counter++;

    // alert desktop
    AlertDesktopTimerEvent ();

    return;
}

BOOL mg_InitTimer (void)
{
    struct itimerspec it;
    struct timespec resolution;
    struct sigaction sa;
    struct sigevent timer_event;

    sigemptyset(&sa.sa_mask);
    sa.sa_flags=SA_SIGINFO;         /*real-time signal*/
    sa.sa_sigaction=timer_handler;    /*pointer to action*/

    if(sigaction(SIGRTMIN, &sa, &old_alarm_handler) < 0){
        perror("sigaction error");
        return FALSE;
    }

    /* first determine whether the desired clock exists */

    if (clock_getres(CLOCK_REALTIME, &resolution) < 0){
        perror("clock_getres error");
        return FALSE;
    }

    /* create a timer based upon the CLOCK_REALTIME clock */

    it.it_interval.tv_sec=0;

    /* set resolution to one-tenth of the maximum allowed */

    it.it_interval.tv_nsec=resolution.tv_nsec;
    //it.it_interval.tv_nsec=10000000;
    it.it_value=it.it_interval;

    timer_event.sigev_notify=SIGEV_SIGNAL;
    timer_event.sigev_signo= SIGRTMIN;
    timer_event.sigev_value.sival_ptr = (void *)&mytimer;

    if (timer_create(CLOCK_REALTIME, &timer_event, &mytimer) < 0){
        perror("timer create error");
        return FALSE;
    }

    /* relative timer, go off at the end of the interval*/
    if (timer_settime(mytimer, 0 , &it, NULL) < 0){
        perror("settimer");
        return FALSE;
    }

    __mg_timer_counter = 0;

    return TRUE;
}

void mg_TerminateTimer (void)
{
    int i;

    timer_delete (mytimer);

    if (sigaction (SIGRTMIN, &old_alarm_handler, NULL) == -1) {
        fprintf (stderr, "KERNEL>Timer: sigaction call failed!\n");
        perror ("sigaction");
        return;
    }

    for (i=0; i<MAX_TIMERS; i++) {
        if (timerstr[i] != NULL)
            free ( timerstr[i] );
        timerstr[i] = NULL;
    }
}