/*

 * task_attach_timeout.c - attach to another task for monitoring for a short while

 *

 * Copyright (c) 2009 Google, Inc

 * Contributed by Stephane Eranian <eranian@gmail.com>

 *

 * Based on:

 * Copyright (c) 2002-2006 Hewlett-Packard Development Company, L.P.

 * Contributed by Stephane Eranian <eranian@hpl.hp.com>

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies

 * of the Software, and to permit persons to whom the Software is furnished to do so,

 * subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in all

 * copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,

 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A

 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT

 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF

 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE

 * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

 */

#include <sys/types.h>

#include <inttypes.h>

#include <stdio.h>

#include <stdlib.h>

#include <stdarg.h>

#include <errno.h>

#include <unistd.h>

#include <string.h>

#include <stdarg.h>

#include <sys/wait.h>

#include <err.h>

#include <sys/poll.h>

#include "perf_util.h"

typedef struct {

	char *events;

	int delay;

	int print;

	int group;

	int pinned;

} options_t;

static options_t options;

static void

print_counts(perf_event_desc_t *fds, int num, int do_delta)

{

	ssize_t ret;

	int i;

	/*

	 * now simply read the results.

	 */

	for(i=0; i < num; i++) {

		uint64_t val;

		double ratio;

		ret = read(fds[i].fd, fds[i].values, sizeof(fds[i].values));

		if (ret < (ssize_t)sizeof(fds[i].values)) {

			if (ret == -1)

				err(1, "cannot read values event %s", fds[i].name);

			else

				warnx("could not read event%d", i);

		}

		val = perf_scale(fds[i].values);

		ratio = perf_scale_ratio(fds[i].values);

		val = do_delta ? perf_scale_delta(fds[i].values, fds[i].prev_values) : val;

		fds[i].prev_values[0] = fds[i].values[0];

		fds[i].prev_values[1] = fds[i].values[1];

		fds[i].prev_values[2] = fds[i].values[2];

		if (ratio == 1.0)

			printf("%20"PRIu64" %s\n", val, fds[i].name);

		else

			if (ratio == 0.0)

				printf("%20"PRIu64" %s (did not run: incompatible events, too many events in a group, competing session)\n", val, fds[i].name);

			else

				printf("%20"PRIu64" %s (scaled from %.2f%% of time)\n", val, fds[i].name, ratio*100.0);

	}

}

int

measure(pid_t pid)

{

	perf_event_desc_t *fds = NULL;

	int i, ret, num_fds = 0;

	char fn[32];

	if (pfm_initialize() != PFM_SUCCESS)

		errx(1, "libpfm initialization failed\n");

	ret = perf_setup_list_events(options.events, &fds, &num_fds);

	if (ret || (num_fds == 0))

		exit(1);

	fds[0].fd = -1;

	for(i=0; i < num_fds; i++) {

		fds[i].hw.disabled = 0; /* start immediately */

		/* request timing information necessary for scaling counts */

		fds[i].hw.read_format = PERF_FORMAT_SCALE;

		fds[i].hw.pinned = !i && options.pinned;

		fds[i].fd = perf_event_open(&fds[i].hw, pid, -1, (options.group? fds[0].fd : -1), 0);

		if (fds[i].fd == -1)

			errx(1, "cannot attach event %s", fds[i].name);

	}

	/*

	 * no notification is generated by perf_counters

	 * when the monitored thread exits. Thus we need

	 * to poll /proc/ to detect it has disappeared,

	 * otherwise we have to wait until the end of the

	 * timeout

	 */

	sprintf(fn, "/proc/%d/status", pid);

	while(access(fn, F_OK) == 0 && options.delay) {

		sleep(1);

		options.delay--;

		if (options.print)

			print_counts(fds, num_fds, 1);

	}

	if (options.delay)

		warn("thread %d terminated before timeout", pid);

	if (!options.print)

		print_counts(fds, num_fds, 0);

	for(i=0; i < num_fds; i++)

		close(fds[i].fd);

	perf_free_fds(fds, num_fds);

	/* free libpfm resources cleanly */

	pfm_terminate();

	return 0;

}

static void

usage(void)

{

	printf("usage: task_attach_timeout [-h] [-p] [-P] [-g] [-d delay] [-e event1,event2,...] pid\n");

}

int

main(int argc, char **argv)

{

	int c;

	while ((c=getopt(argc, argv,"he:vd:pgP")) != -1) {

		switch(c) {

			case 'e':

				options.events = optarg;

				break;

			case 'p':

				options.print = 1;

				break;

			case 'P':

				options.pinned = 1;

				break;

			case 'g':

				options.group = 1;

				break;

			case 'd':

				options.delay = atoi(optarg);

				break;

			case 'h':

				usage();

				exit(0);

			default:

				errx(1, "unknown error");

		}

	}

	if (!options.events)

		options.events = strdup("cycles,instructions");

	if (options.delay < 1)

		options.delay = 10;

	if (!argv[optind])

		errx(1, "you must specify pid to attach to\n");

	return measure(atoi(argv[optind]));

}