app4.c

来自「pebble」· C语言 代码 · 共 189 行

/* 
 * Copyright 1999, 2000, 2001, 2002 Lucent Technologies Inc.
 * All Rights Reserved.
 * Information Sciences Research Center, Bell Labs.
 *
 * LUCENT TECHNOLOGIES DOES NOT CLAIM MERCHANTABILITY OF THIS SOFTWARE 
 * OR THE SUITABILITY OF THIS SOFTWARE FOR ANY PARTICULAR PURPOSE. The
 * software is provided "as is" without expressed or implied warranty 
 * of any kind.
 *
 * These notices must be retained in any copies of any part of this
 * software.
 *
 */

#include "unistd.h"
#include "pebble.h"
#include "synch.h"
#include "perfcount.h"

#define	N	10
#define	NTHREAD	4

Barrier *b;

void
do_hrsleep(int tid, Time elapsed[N], Time delay[N])
{
	int i, j;
	Time start;

	for (i = 0; i < N; i++) {
		j =  (i + tid + N) % N;
		delay[i] = 2000 + (2000 << j);
		start = hrtime();
		if (hrsleep(start + delay[i]) < 0)
			panic("hrsleep:");
		elapsed[i] = 2 * (hrtime() - start - delay[i]);
	}
}

void
test_hrsleep(int tid)
{
	int i, perf_ix;
	vlong elapsed[N], delay[N];
	uint perf_count;

	/* all copies are running here with private stacks */

	for (perf_ix = 0; perf_vec[perf_ix].name != NULL; perf_ix++) {
		printf("===============\n");
		printf("thread %d testing hrsleep\n", tid);

		/* wait until all have finished printing */
		if (barrier_wait(b, tid, NTHREAD) < 0)
			panic("barrier_wait:");

		/* only thread #0 sets the control register and */
		/* initializes the counter */
		if (tid == 0)
			set_perf_ctrl(perf_vec[perf_ix].ctrl);


		do_hrsleep(tid, elapsed, delay);

		/* wait until all have completed the measurements */
		if (barrier_wait(b, tid, NTHREAD) < 0)
			panic("barrier_wait:");
		perf_count = get_perf_count();

		printf("thread %d hrsleep accuracy:\n", tid);
		/* first delay is longer due to internal initializations */
		for (i = 0; i < N; i++)
			printf("hrsleep(%d): wakeup delay %d cycles\n",
				(int)delay[i], (int)elapsed[i]);

		if (tid == 0)
			printf("%s: %d\n", perf_vec[perf_ix].name, perf_count);

		/* wait until all have printed their results */
		if (barrier_wait(b, tid, NTHREAD) < 0)
			panic("barrier_wait:");
	}

	printf("task %d ended. bye!\n", tid);
	printf("TEST DONE\n");
	task_exit(0);
}


int
wait_a_sec(void)
{
	int t, last_t;

	last_t = time();
	if (last_t < 0)
		return -1;
	while ((t = time()) == last_t)
		yield();

	if (t < 0)
		return -1;
	else
		return 0;
}

int
main(int arg, char *argv[])
{
	int i;
	Time start_usec, end_usec, start_hrtime, end_hrtime;
	Time elapsed_usec[N], elapsed_hrtime[N], delay[N];
	int code;

	write(2, "app4", 4);
	
	printf("\ntesting RTC interrupts\n");
	printf("before wait_a_sec: current time=%d usec.\n", (int)uptime());
	if (wait_a_sec() < 0)
		panic("wait_a_sec:");
	printf("after wait_a_sec: current time=%d usec.\n", (int)uptime());

	printf("please wait %d seconds...\n", N);
	write(2, "10s.", 4);
	end_usec = uptime();
	end_hrtime = hrtime();
	for (i = 0; i < N; i++) {
		start_usec = end_usec;
		start_hrtime = end_hrtime;
		if (wait_a_sec() < 0)
			panic("wait_a_sec:");
		end_usec = uptime();
		end_hrtime = hrtime();
		elapsed_usec[i] = end_usec - start_usec;
		elapsed_hrtime[i] = end_hrtime - start_hrtime;
	}

	write(2, "thx.", 4);
	printf("elapsed time for wait_a_sec:\n");
	for (i = 1; i < N; i++) {
		printf("%d: %d usec\n", i, (int)elapsed_usec[i]);
		printf("%d: %d ticks\n", i, (int)elapsed_hrtime[i]);
	}

	printf("usleep to allow idle task to run for first time\n");
	usleep(1000);

	/* test usleep */
	start_usec = uptime();
	start_hrtime = hrtime();
	/* sleep for 1 second */
	usleep(SEC2USEC);
	end_usec = uptime();
	end_hrtime = hrtime();
	printf("usleep(1 second): elapsed usec=%d error=%d elapsed ticks=%d error=%d\n",
		(int)(end_usec - start_usec), (int)(end_usec - start_usec) - 1000000,
		(int)(end_hrtime - start_hrtime),
		(int)(end_hrtime - start_hrtime) - sec2ticks());

	printf("testing serial hrsleep (one process active):\n");
	do_hrsleep(0, elapsed_hrtime, delay);
	for (i = 0; i < N; i++)
		printf("hrsleep(%d): wakeup delay %d cycles\n",
			(int)delay[i], (int)elapsed_hrtime[i]);

	printf("starting concurrent hrsleep measurements\n");
	b = (Barrier *)shm_create(sizeof(Barrier));

	if (b == (Barrier *)-1)
		panic("shm_create");

	if (barrier_init(b) < 0)
		panic("barrier_init:");

	for (i = 1; i < NTHREAD; i++) {
		if ((code = fork()) < 0)
			panic("fork:");
		if (code == 0)
			test_hrsleep(i);
	}
	/* parent testing hrsleep */
	test_hrsleep(0);

	task_exit(0);
	return(1);
}