Method _wait_pidfd

Lib/subprocess.py:2104–2129

Wait for PID to terminate using pidfd_open() + poll(). Linux >= 5.3 only.

(self, timeout)

            return (pid, sts)

        def _wait_pidfd(self, timeout):
            """Wait for PID to terminate using pidfd_open() + poll().
            Linux >= 5.3 only.
            """
            if not _CAN_USE_PIDFD_OPEN:
                return False
            try:
                pidfd = os.pidfd_open(self.pid, 0)
            except OSError:
                # May be:
                # - ESRCH: no such process
                # - EMFILE, ENFILE: too many open files (usually 1024)
                # - ENODEV: anonymous inode filesystem not supported
                # - EPERM, EACCES, ENOSYS: undocumented; may happen if
                #   blocked by security policy like SECCOMP
                return False

            try:
                poller = select.poll()
                poller.register(pidfd, select.POLLIN)
                events = poller.poll(timeout * 1000)
                if not events:
                    raise TimeoutExpired(self.args, timeout)
                return True
            finally:
                os.close(pidfd)

        def _wait_kqueue(self, timeout):
            """Wait for PID to terminate using kqueue(). macOS and BSD only."""