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/*
* RTL scheduling accuracy measuring example
*
* (C) Michael Barabanov, 1997
* (C) FSMLabs 1999. baraban@fsmlabs.com
* Released under the GNU GENERAL PUBLIC LICENSE Version 2, June 1991
* Any use of this code must include this notice.
*/
#include <rtl.h>
#include <rtl_fifo.h>
#include <time.h>
#include <rtl_sched.h>
#include <rtl_sync.h>
#include <pthread.h>
#include <unistd.h>
#include <rtl_debug.h>
#include <errno.h>
#include "common.h"
int ntests=500;
int period=1000000;
int mode=0;
int fifo_size=4000;
int advance=0;
MODULE_PARM(period,"i");
MODULE_PARM(ntests,"i");
MODULE_PARM(mode,"i");
MODULE_PARM(advance,"i");
pthread_t thread;
int fd_fifo;
void *thread_code(void *param) {
hrtime_t start_time;
hrtime_t last_time = 0;
hrtime_t diff;
hrtime_t now;
hrtime_t min_diff;
hrtime_t max_diff;
struct sample samp;
int i;
int cnt = 0;
DECLARE_CPUID(cpu_id);
rtl_printf ("Measurement task starts on CPU %d\n", cpu_id);
if (mode) {
int ret = rtl_setclockmode (rtl_getschedclock(), RTL_CLOCK_MODE_PERIODIC, period);
if (ret != 0) {
conpr("Setting periodic mode failed\n");
mode = 0;
}
}
if (mode) {
struct timespec resolution;
/* need to round up the period; should this be done
* in pthread_make_periodic? */
clock_getres (rtl_getschedclock(), &resolution);
period = timespec_to_ns (&resolution);
} else {
rtl_setclockmode (rtl_getschedclock(), RTL_CLOCK_MODE_ONESHOT, 0);
}
start_time = clock_gethrtime(rtl_getschedclock()) + 2 * period;
if (advance) {
pthread_make_periodic_np (pthread_self(), start_time - advance, period);
} else {
pthread_make_periodic_np (pthread_self(), start_time, period);
}
fd_fifo = open("/dev/rtf0", O_NONBLOCK);
if (fd_fifo < 0) {
rtl_printf("/dev/rtf0 open returned %d\n", fd_fifo);
return (void *) -1;
}
if (advance) {
rtl_stop_interrupts(); /* Be careful with this! The task won't be preempted by anything else. This is probably only appropriate for small high-priority tasks. */
}
do {
min_diff = 2000000000;
max_diff = -2000000000;
for (i = 0; i < ntests; i++) {
++cnt;
pthread_wait_np();
start_time += period;
now = clock_gethrtime(CLOCK_UST);
if (advance && !mode) {
if (now < start_time) {
rtl_delay (start_time - now);
}
now = clock_gethrtime(CLOCK_UST);
}
if (!last_time) {
last_time = now;
continue;
}
diff = now - last_time - period;
if (diff < 0) {
diff = -diff;
}
if (diff < min_diff) {
min_diff = diff;
}
if (diff > max_diff) {
max_diff = diff;
}
last_time = now;
}
samp.min = min_diff;
samp.max = max_diff;
write (fd_fifo, &samp, sizeof(samp));
} while (1);
return 0;
}
int init_module(void)
{
pthread_attr_t attr;
struct sched_param sched_param;
int thread_status;
int fifo_status;
rtf_destroy(0);
fifo_status = rtf_create(0, fifo_size);
if (fifo_status) {
rtl_printf("RTL measurement test fail. fifo_status=%d\n",fifo_status);
return -1;
}
rtl_printf("RTL measurement module on CPU %d\n",rtl_getcpuid());
pthread_attr_init (&attr);
pthread_attr_setcpu_np(&attr, 0 /*!rtl_getcpuid()*/);
sched_param.sched_priority = 1;
pthread_attr_setschedparam (&attr, &sched_param);
rtl_printf("About to thread create\n");
thread_status = pthread_create (&thread, &attr, thread_code, (void *)1);
if (thread_status != 0) {
rtl_printf("failed to create RT-thread; errno=\n", errno);
return -1;
} else {
/* rtl_printf("created RT-thread\n"); */
}
return 0;
}
void cleanup_module(void)
{
rtl_printf ("Removing module on CPU %d\n", rtl_getcpuid());
pthread_delete_np (thread);
close(fd_fifo);
/* should be: pthread_cancel(thread); pthread_join(thread); */
/* or: rtl_pthread_kill_other_threads(); */
rtf_destroy(0);
}
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