niced_threadstats

from collections import namedtuple
from time import sleep
import sys
import os

NICE_FIELD = 19 - 1
DELAYACCT_BLKIO_TICKS_FIELD = 42 - 1

clk_tck_factor = int(1e9 / os.sysconf('SC_CLK_TCK'))

STAT_FIELDS = (
    'blkio_delay_total',
)

SCHEDSTAT_FIELDS = (
    'cpu_run_virtual_total',
    'cpu_delay_total',
    'cpu_count',
)

ThreadStats = namedtuple('ThreadStats', STAT_FIELDS + SCHEDSTAT_FIELDS)

def ts_add(self, other):
    return self.__class__(*map(sum, zip(self, other)))

ThreadStats.__add__ = ts_add

def blank_threadstats():
    return ThreadStats(0, 0, 0, 0)

def get_thread_stats(tid, stat_fields):
    blk_delay = int(stat_fields[DELAYACCT_BLKIO_TICKS_FIELD])
    blk_delay *= clk_tck_factor

    try:
        split_schedstat = open('/proc/{}/schedstat'.format(tid)).read().split()
        split_schedstat = map(int, split_schedstat)
        return ThreadStats(blk_delay, *split_schedstat)
    except IOError:
        pass

def examine_thread(tid):
    try:
        stat_fields = open('/proc/{}/stat'.format(tid)).read().split()
        if stat_fields[NICE_FIELD] != '0':
            return get_thread_stats(tid, stat_fields)
    except IOError:
        pass

def get_all_thread_stats(pid):
    threads = os.listdir('/proc/{}/task'.format(pid))
    for tid in threads:
        info = examine_thread(tid)
        if info is not None:
            yield tid, info


def main():
    pid = sys.argv[1]
    exited_count = 0
    exited = blank_threadstats()
    old_threads = dict()
    while True:
        new_threads = dict(get_all_thread_stats(pid))
        for tid in new_threads:
            old_threads.pop(tid, None)
        exited = sum(old_threads.values(), exited)
        exited_count += len(old_threads)
        print exited_count, sum(new_threads.values(), exited)
        old_threads = new_threads
        sleep(1)


if __name__ == '__main__':
    main()