path: root/trace-cmd.c

/*
 * Copyright (C) 2008,2009, Steven Rostedt <srostedt@redhat.com>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 * 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; version 2 of the License (not later!)
 *
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */
#define _GNU_SOURCE
#include <dirent.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <pthread.h>
#include <fcntl.h>
#include <unistd.h>
#include <ctype.h>
#include <errno.h>

#include "parse-events.h"
#include "trace-cmd.h"

#define VERSION "0.5"

#define _STR(x) #x
#define STR(x) _STR(x)
#define MAX_PATH 256

#define TRACE_CTRL	"tracing_on"
#define TRACE		"trace"
#define AVAILABLE	"available_tracers"
#define CURRENT		"current_tracer"
#define ITER_CTRL	"trace_options"
#define MAX_LATENCY	"tracing_max_latency"

unsigned int page_size;

static const char *output_file = "trace.dat";
static int output_fd;

static int latency;

static int old_ftrace_name;

static int cpu_count;
static int *pids;

struct event_list {
	struct event_list *next;
	const char *event;
};

static struct event_list *event_selection;

struct events {
	struct events *sibling;
	struct events *children;
	struct events *next;
	char *name;
};

static void delete_temp_file(int cpu)
{
	char file[MAX_PATH];

	snprintf(file, MAX_PATH, "%s.cpu%d", output_file, cpu);
	unlink(file);
}

static void kill_threads(void)
{
	int i;

	if (!cpu_count)
		return;

	for (i = 0; i < cpu_count; i++) {
		if (pids[i] > 0) {
			kill(pids[i], SIGKILL);
			delete_temp_file(i);
			pids[i] = 0;
		}
	}
}

static void delete_thread_data(void)
{
	int i;

	if (!cpu_count)
		return;

	for (i = 0; i < cpu_count; i++) {
		if (pids[i]) {
			delete_temp_file(i);
			if (pids[i] < 0)
				pids[i] = 0;
		}
	}
}

static void stop_threads(void)
{
	int i;

	if (!cpu_count)
		return;

	for (i = 0; i < cpu_count; i++) {
		if (pids[i] > 0) {
			kill(pids[i], SIGINT);
			waitpid(pids[i], NULL, 0);
			pids[i] = -1;
		}
	}
}

void die(char *fmt, ...)
{
	va_list ap;
	int ret = errno;

	if (errno)
		perror("trace-cmd");
	else
		ret = -1;

	kill_threads();
	va_start(ap, fmt);
	fprintf(stderr, "  ");
	vfprintf(stderr, fmt, ap);
	va_end(ap);

	fprintf(stderr, "\n");
	exit(ret);
}

void warning(char *fmt, ...)
{
	va_list ap;

	if (errno)
		perror("trace-cmd");
	errno = 0;

	va_start(ap, fmt);
	fprintf(stderr, "  ");
	vfprintf(stderr, fmt, ap);
	va_end(ap);

	fprintf(stderr, "\n");
}

void *malloc_or_die(unsigned int size)
{
	void *data;

	data = malloc(size);
	if (!data)
		die("malloc");
	return data;
}

static const char *find_debugfs(void)
{
	static char debugfs[MAX_PATH+1];
	static int debugfs_found;
	char type[100];
	FILE *fp;

	if (debugfs_found)
		return debugfs;

	if ((fp = fopen("/proc/mounts","r")) == NULL)
		die("Can't open /proc/mounts for read");

	while (fscanf(fp, "%*s %"
		      STR(MAX_PATH)
		      "s %99