zulip/zerver/lib/parallel.py

73 lines
1.8 KiB
Python

from __future__ import absolute_import
from __future__ import print_function
import os
import pty
import sys
import errno
def run_parallel(job, data, threads=6):
pids = {}
def wait_for_one():
while True:
try:
(pid, status) = os.wait()
return status, pids.pop(pid)
except KeyError:
pass
for item in data:
pid = os.fork()
if pid == 0:
sys.stdin.close()
try:
os.close(pty.STDIN_FILENO)
except OSError as e:
if e.errno != errno.EBADF:
raise
sys.stdin = open("/dev/null", "r")
os._exit(job(item))
pids[pid] = item
threads = threads - 1
if threads == 0:
(status, item) = wait_for_one()
threads += 1
yield (status, item)
if status != 0:
# Stop if any error occurred
break
while True:
try:
(status, item) = wait_for_one()
yield (status, item)
except OSError as e:
if e.errno == errno.ECHILD:
break
else:
raise
if __name__ == "__main__":
# run some unit tests
import time
jobs = [10, 19, 18, 6, 14, 12, 8, 2, 1, 13, 3, 17, 9, 11, 5, 16, 7, 15, 4]
expected_output = [6, 10, 12, 2, 1, 14, 8, 3, 18, 19, 5, 9, 13, 11, 4, 7, 17, 16, 15]
def wait_and_print(x):
time.sleep(x * 0.1)
return 0
output = []
for (status, job) in run_parallel(wait_and_print, jobs):
output.append(job)
if output == expected_output:
print("Successfully passed test!")
else:
print("Failed test!")
print(jobs)
print(expected_output)
print(output)