import subprocess, threading, time, gc, os

def spawn(event) :
    subprocess.check_output("true")
    event.set()

event = threading.Event()
i = 0
next_msg = time.monotonic() + 1.0
while True :
        if next_msg <= time.monotonic():
            print(i, "thread+subprocess", flush=True)
            os.system("grep VmRSS /proc/%s/status" % os.getpid())
            next_msg = time.monotonic() + 1.0

        event.clear()
        t = threading.Thread(target=spawn, args=(event,))
        t.start()
        event.wait()
        t.join()

        i += 1
        #gc.collect()