projektAI/venv/Lib/site-packages/joblib/externals/loky/backend/fork_exec.py
2021-06-06 22:13:05 +02:00

49 lines
1.3 KiB
Python

###############################################################################
# Launch a subprocess using forkexec and make sure only the needed fd are
# shared in the two process.
#
# author: Thomas Moreau and Olivier Grisel
#
import os
import sys
if sys.platform == "darwin" and sys.version_info < (3, 3):
FileNotFoundError = OSError
def close_fds(keep_fds): # pragma: no cover
"""Close all the file descriptors except those in keep_fds."""
# Make sure to keep stdout and stderr open for logging purpose
keep_fds = set(keep_fds).union([1, 2])
# We try to retrieve all the open fds
try:
open_fds = set(int(fd) for fd in os.listdir('/proc/self/fd'))
except FileNotFoundError:
import resource
max_nfds = resource.getrlimit(resource.RLIMIT_NOFILE)[0]
open_fds = set(fd for fd in range(3, max_nfds))
open_fds.add(0)
for i in open_fds - keep_fds:
try:
os.close(i)
except OSError:
pass
def fork_exec(cmd, keep_fds, env=None):
# copy the environment variables to set in the child process
env = {} if env is None else env
child_env = os.environ.copy()
child_env.update(env)
pid = os.fork()
if pid == 0: # pragma: no cover
close_fds(keep_fds)
os.execve(sys.executable, cmd, child_env)
else:
return pid