schedtop_u.c

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <fcntl.h>
#include <unistd.h>

#include <stdint.h>
#include <string.h>

#include <sys/stat.h>
#include <sys/types.h>
#include <dirent.h>
#include <signal.h>

#include <pwd.h>

struct thread_info {
	int pid;
	int tid;
	char name[64];
	uint64_t exec_time;
	uint64_t delay_time;
	uint32_t run_count;
};

struct thread_table {
	size_t allocated;
	size_t active;
	struct thread_info *data;
};

enum {
	FLAG_BATCH = 1U << 0,
	FLAG_HIDE_IDLE = 1U << 1,
	FLAG_SHOW_THREADS = 1U << 2,
	FLAG_USE_ALTERNATE_SCREEN = 1U << 3,
};

static int time_dp = 9;
static int time_div = 1;
#define NS_TO_S_D(ns) \
	(uint32_t)((ns) / 1000000000), time_dp, ((uint32_t)((ns) % 1000000000) / time_div)

struct thread_table processes;
struct thread_table last_processes;
struct thread_table threads;
struct thread_table last_threads;

static void grow_table(struct thread_table *table)
{
	size_t size = table->allocated;
	struct thread_info *new_table;
	if(size < 128) size = 128;
	else size *= 2;

	new_table = realloc(table->data, size * sizeof(*table->data));
	if(new_table == NULL) {
		fprintf(stderr, "Out of memory\n");
		exit(1);
	}
	table->data = new_table;
	table->allocated = size;
}

static struct thread_info *get_item(struct thread_table *table)
{
	if (table->active >= table->allocated)
		grow_table(table);
	return table->data + table->active;
}

static void commit_item(struct thread_table *table)
{
	table->active++;
}

static int read_line(char *line, size_t line_size) {
	int fd;
	int len;
	fd = open(line, O_RDONLY);
	if(fd == -1) return -1;
	len = read(fd, line, line_size - 1);
	close(fd);
	if(len <= 0) return -1;
	line[len] = 0;
	return 0;
}

static void add_thread(int pid, int tid, struct thread_info *proc_info) {
	//fprintf(stderr, "function: add_thread(%d, %d, %p)\n", pid, tid, proc_info);
	unsigned long long int exec_time, delay_time;
	char line[1024];
	char *name, *name_end;
	size_t name_len;
	struct thread_info *info;
	if(tid == 0) info = get_item(&processes);
	else info = get_item(&threads);
	info->pid = pid;
	info->tid = tid;

	if(tid) sprintf(line, "/proc/%d/task/%d/schedstat", pid, tid);
	else sprintf(line, "/proc/%d/schedstat", pid);
	if(read_line(line, sizeof line)) return;
	if(sscanf(line, "%llu %llu %u", &exec_time, &delay_time, &info->run_count) != 3) return;
	info->exec_time = exec_time;
	info->delay_time = delay_time;
	if(proc_info) {
		proc_info->exec_time += info->exec_time;
		proc_info->delay_time += info->delay_time;
		proc_info->run_count += info->run_count;
	}

	name = NULL;
	if (!tid) {
		sprintf(line, "/proc/%d/cmdline", pid);
		if (read_line(line, sizeof(line)) == 0 && line[0]) {
			name = line;
			name_len = strlen(name);
		}
	}
	if(!name) {
		if(tid) sprintf(line, "/proc/%d/task/%d/stat", pid, tid);
		else sprintf(line, "/proc/%d/stat", pid);
		if(read_line(line, sizeof(line))) return;
		name = strchr(line, '(');
		if(name == NULL) return;
		name_end = strchr(name, ')');
		if(name_end == NULL) return;
		name++;
		name_len = name_end - name;
	}
	if (name_len >= sizeof(info->name))
		name_len = sizeof(info->name) - 1;
	memcpy(info->name, name, name_len);
	info->name[name_len] = '\0';
	commit_item(tid ? &threads : &processes);
}

static void add_threads(int pid, struct thread_info *proc_info)
{
	char path[1024];
	DIR *d;
	struct dirent *de;
	sprintf(path, "/proc/%d/task", pid);
	d = opendir(path);
	if(!d) return;
	while((de = readdir(d))) {
		if(isdigit(de->d_name[0])) {
			int tid = atoi(de->d_name);
			add_thread(pid, tid, proc_info);
		}
	}
	closedir(d);
}

static void print_threads(int pid, uint32_t flags)
{
	size_t i, j;
	for(i = 0; i < last_threads.active; i++) {
		int epid = last_threads.data[i].pid;
		int tid = last_threads.data[i].tid;
		if(epid != pid) continue;
		for(j = 0; j < threads.active; j++) if(tid == threads.data[j].tid) break;
		if(j == threads.active) printf(" %5u died\n", tid);
		else if(!(flags & FLAG_HIDE_IDLE) || threads.data[j].run_count - last_threads.data[i].run_count) {
			printf(" %5u %2u.%0*u %2u.%0*u %5u %5u.%0*u %5u.%0*u %7u  %s\n", tid,
				NS_TO_S_D(threads.data[j].exec_time - last_threads.data[i].exec_time),
				NS_TO_S_D(threads.data[j].delay_time - last_threads.data[i].delay_time),
				threads.data[j].run_count - last_threads.data[i].run_count,
				NS_TO_S_D(threads.data[j].exec_time), NS_TO_S_D(threads.data[j].delay_time),
				threads.data[j].run_count, threads.data[j].name);
		}
	}
}

static void update_table(DIR *d, uint32_t flags)
{
	size_t i, j;
	struct dirent *de;

	rewinddir(d);
	while((de = readdir(d))) {
		//puts(de->d_name);
		if(isdigit(de->d_name[0])) {
			int pid = atoi(de->d_name);
			struct thread_info *proc_info;
			add_thread(pid, 0, NULL);
			proc_info = processes.data + processes.active - 1;
			proc_info->exec_time = 0;
			proc_info->delay_time = 0;
			proc_info->run_count = 0;
			add_threads(pid, proc_info);
		}
	}
	if(!(flags & FLAG_BATCH)) printf("\e[H\e[0J");
	printf("Processes: %lu, Threads %lu\n", (long int)processes.active, (long int)threads.active);
	switch (time_dp) {
		case 3:
			printf("   TID --- SINCE LAST ---- ---------- TOTAL ----------\n");
			printf("  PID  EXEC_T  DELAY SCHED EXEC_TIME DELAY_TIM   SCHED NAME\n");
			break;
		case 6:
			printf("   TID ------ SINCE LAST -------    ------------ TOTAL -----------\n");
			printf("  PID  EXEC_TIME DELAY_TIM SCHED    EXEC_TIME   DELAY_TIME   SCHED NAME\n");
			break;
		default:
			printf("   TID    -------- SINCE LAST --------       ------------- TOTAL -------------\n");
			printf("  PID     EXEC_TIME   DELAY_TIME SCHED       EXEC_TIME      DELAY_TIME   SCHED NAME\n");
			break;
	}
	for (i = 0; i < last_processes.active; i++) {
		int pid = last_processes.data[i].pid;
		int tid = last_processes.data[i].tid;
		for(j = 0; j < processes.active; j++) {
			if (pid == processes.data[j].pid) break;
		}
		if(j == processes.active) printf("%5u died\n", pid);
		else if (!(flags & FLAG_HIDE_IDLE) || processes.data[j].run_count - last_processes.data[i].run_count) {
			printf("%5u  %2u.%0*u %2u.%0*u %5u %5u.%0*u %5u.%0*u %7u %s\n", pid,
				NS_TO_S_D(processes.data[j].exec_time - last_processes.data[i].exec_time),
				NS_TO_S_D(processes.data[j].delay_time - last_processes.data[i].delay_time),
				processes.data[j].run_count - last_processes.data[i].run_count,
				NS_TO_S_D(processes.data[j].exec_time), NS_TO_S_D(processes.data[j].delay_time),
				processes.data[j].run_count, processes.data[j].name);
			if(flags & FLAG_SHOW_THREADS) print_threads(pid, flags);
		}
	}

	{
		struct thread_table tmp;
		tmp = last_processes;
		last_processes = processes;
		processes = tmp;
		processes.active = 0;
		tmp = last_threads;
		last_threads = threads;
		threads = tmp;
		threads.active = 0;
	}
}

static void sig(int signum) {
	printf("\e[?47l");
	exit(0);
}

int schedtop_main(int argc, char **argv) {
	DIR *d;
	char *namefilter = 0;
	int pidfilter = 0;
	uint32_t flags = 0;
	int delay = 3000000;
	float delay_f;

	while(1) {
		int c = getopt(argc, argv, "d:ibtamun");
		if(c == EOF) break;
		switch(c) {
			case 'd':
				delay_f = atof(optarg);
				delay = delay_f * 1000000;
				break;
			case 'b':
				flags |= FLAG_BATCH;
				break;
			case 'i':
				flags |= FLAG_HIDE_IDLE;
				break;
			case 't':
				flags |= FLAG_SHOW_THREADS;
				break;
			case 'a':
				flags |= FLAG_USE_ALTERNATE_SCREEN;
				break;
			case 'm':
				time_dp = 3;
				time_div = 1000000;
				break;
			case 'u':
				time_dp = 6;
				time_div = 1000;
				break;
			case 'n':
				time_dp = 9;
				time_div = 1;
				break;
		}
	}

	d = opendir("/proc");
	if(!d) return -1;

	if(!(flags & FLAG_BATCH)) {
		if(flags & FLAG_USE_ALTERNATE_SCREEN) {
			signal(SIGINT, sig);
			signal(SIGPIPE, sig);
			signal(SIGTERM, sig);
			printf("\e7\e[?47h");
		}
		printf("\e[2J");
	}
	while(1) {
		update_table(d, flags);
		usleep(delay);
	}
	closedir(d);
	return 0;
}