/*-
 * Copyright (c) 2004-2005 Robert N M Watson
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD$
 */

#include <sys/types.h>
#include <sys/time.h>
#include <sys/sysctl.h>
#include <sys/waitstat.h>

#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

static void usage(void)
{

	fprintf(stderr, "waitstat attach pid\n");
	fprintf(stderr, "waitstat dettach pid\n");
	fprintf(stderr, "waitstat trace pid\n");
	exit(-1);
}

static void
waitstat_attach(pid_t pid)
{

	if (sysctlbyname("kern.waitstat.register", NULL, NULL, &pid,
	    sizeof(pid)) < 0)
		errx(-1, "sysctlbyname: kern.waitstat.register: %s",
		    strerror(errno));
}

static void
waitstat_detach(pid_t pid)
{

	if (sysctlbyname("kern.waitstat.deregister", NULL, NULL, &pid,
	    sizeof(pid)) < 0)
		errx(-1, "sysctlbyname: kern.waitstat.register: %s",
		    strerror(errno));
}

#define	BUFLEN	128
static int
waitstat(pid_t pid, int *mib, int miblen)
{
	struct waitstat_channel *wpc;
	struct waitstat_proc wp;
	struct timespec ts;
	struct bintime bt;
	char buf[BUFLEN];
	int i, totallen;
	size_t len;

	printf("\n");

	len = sizeof(wp);
	if (sysctl(mib, miblen, &wp, &len, NULL, 0) < 0)
		errx(-1, "waitstat: sysctl: %s", strerror(errno));
	if (len != sizeof(wp))
		errx(-1, "waitstat: sysctl: data wrong size (%d / %d)", len,
		    sizeof(wp));

	if (wp.wp_session_started.sec != 0) {
		totallen = wp.wp_session_current.sec -
		    wp.wp_session_started.sec;
		printf("Process %d traced %ds waited %ds (%%%2.2f waited)\n",
		    pid, totallen, wp.wp_waited_time.sec,
		    100 * (float)wp.wp_waited_time.sec / totallen);
	} else {
		totallen = 0;
		printf("Process %d\n", pid);
	}
	printf("%16s %10s %12s %12s %12s %6s\n", "Wait channel", "Count",
	    "Total wait", "Average wait", "Max wait", "%Time");
	for (i = 0; i < WAITSTAT_MAX_STATES; i++) {
		wpc = &wp.wp_stats[i];
		if (wpc->wpc_wmesg[0] == '\0')
			break;

		/* wmesg */
		printf("%16s ", wpc->wpc_wmesg);

		/* number of waits */
		printf("%10d ", wpc->wpc_numwaits);

		/* total wait for the channel */
		bt = wpc->wpc_totwait;
		bintime2timespec(&bt, &ts);
		snprintf(buf, 12, "%d.%09ld", ts.tv_sec, ts.tv_nsec);
		printf("%12s ", buf);

		/* average wait for the channel */
		bt = wpc->wpc_totwait;
		bintime_divx(&bt, wpc->wpc_numwaits);
		bintime2timespec(&bt, &ts);
		snprintf(buf, 12, "%d.%09ld ", ts.tv_sec, ts.tv_nsec);
		printf("%12s ", buf);

		/* max wait for the channel */
		bt = wpc->wpc_maxwait;
		bintime2timespec(&bt, &ts);
		snprintf(buf, 12, "%d.%09ld", ts.tv_sec, ts.tv_nsec);
		printf("%12s", buf);

#if 0
		/* %time */
		bt = wpc->wpc_totwait;
		bintime_divx(&bt, wp.wp_waited_time.sec);
		/* bintime_mulx(&bt, 100); */
		bintime2timespec(&bt, &ts);
		snprintf(buf, 6, "%d.%02ld", ts.tv_sec, ts.tv_nsec);
		printf("%6s", buf);
#endif

		printf("\n");
	}
	return (0);
}

int
main(int argc, char *argv[])
{
	int mib[CTL_MAXNAME];
	size_t miblen;
	char *dummy;
	pid_t pid;
	long l;

	if (argc != 3)
		usage();

	/*
	 * XXX: Possibly poor assumption about the scope of valid pid values.
	 */
	l = strtol(argv[2], &dummy, 10);
	if (l < 0 || l > 65535 || *dummy != '\0')
		usage();
	pid = l;

	miblen = CTL_MAXNAME;
	if (sysctlnametomib("kern.waitstat.stats", mib, &miblen) == -1) {
		if (errno == ENOENT) {
			errno = EOPNOTSUPP;
			errx(-1, "WAITSTAT: %s", strerror(errno));
		}
		errx(-1, "kern.waitstat.stats: %s", strerror(errno));
	}

	if (miblen == CTL_MAXNAME)
		errx(-1, "sysctlnametomib: mib too large");

	mib[miblen] = pid;
	miblen++;

	if (strcmp(argv[1], "attach") == 0)
		waitstat_attach(pid);
	else if (strcmp(argv[1], "detach") == 0)
		waitstat_detach(pid);
	else if (strcmp(argv[1], "trace") == 0 ){
		while (1) {
			sleep(1);
			waitstat(pid, mib, miblen);
		}
	} else
		usage();

	return (0);
}