def _helper(pid, signal_, wait):
"""Simple helper to encapsulate the kill/waitpid sequence"""
if utils_wrapper.IgnoreProcessNotFound(os.kill, pid, signal_) and wait:
try:
os.waitpid(pid, os.WNOHANG)
except OSError:
pass
def _RunCmdPipe(cmd, env, via_shell, cwd, interactive, timeout, noclose_fds,
input_fd, postfork_fn=None,
_linger_timeout=constants.CHILD_LINGER_TIMEOUT):
"""Run a command and return its output.
@type cmd: string or list
@param cmd: Command to run
@type env: dict
@param env: The environment to use
@type via_shell: bool
@param via_shell: if we should run via the shell
@type cwd: string
@param cwd: the working directory for the program
@type interactive: boolean
@param interactive: Run command interactive (without piping)
@type timeout: int
@param timeout: Timeout after the programm gets terminated
@type noclose_fds: list
@param noclose_fds: list of additional (fd >=3) file descriptors to leave
open for the child process
@type input_fd: C{file}-like object or numeric file descriptor
@param input_fd: File descriptor for process' standard input
@type postfork_fn: Callable receiving PID as parameter
@param postfork_fn: Function run after fork but before timeout
@rtype: tuple
@return: (out, err, status)
"""
poller = select.poll()
if interactive:
stderr = None
stdout = None
else:
stderr = subprocess.PIPE
stdout = subprocess.PIPE
if input_fd:
stdin = input_fd
elif interactive:
stdin = None
else:
stdin = subprocess.PIPE
if noclose_fds:
preexec_fn = lambda: CloseFDs(noclose_fds)
close_fds = False
else:
preexec_fn = None
close_fds = True
child = subprocess.Popen(cmd, shell=via_shell,
stderr=stderr,
stdout=stdout,
stdin=stdin,
close_fds=close_fds, env=env,
cwd=cwd,
preexec_fn=preexec_fn)
if postfork_fn:
postfork_fn(child.pid)
out = StringIO()
err = StringIO()
linger_timeout = None
if timeout is None:
poll_timeout = None
else:
poll_timeout = utils_algo.RunningTimeout(timeout, True).Remaining
msg_timeout = ("Command %s (%d) run into execution timeout, terminating" %
(cmd, child.pid))
msg_linger = ("Command %s (%d) run into linger timeout, killing" %
(cmd, child.pid))
timeout_action = _TIMEOUT_NONE
# subprocess: "If the stdin argument is PIPE, this attribute is a file object
# that provides input to the child process. Otherwise, it is None."
assert (stdin == subprocess.PIPE) ^ (child.stdin is None), \
"subprocess' stdin did not behave as documented"
if not interactive:
if child.stdin is not None:
child.stdin.close()
poller.register(child.stdout, select.POLLIN)
poller.register(child.stderr, select.POLLIN)
fdmap = {
child.stdout.fileno(): (out, child.stdout),
child.stderr.fileno(): (err, child.stderr),
}
for fd in fdmap:
utils_wrapper.SetNonblockFlag(fd, True)
while fdmap:
if poll_timeout:
pt = poll_timeout() * 1000
if pt < 0:
if linger_timeout is None:
logging.warning(msg_timeout)
if child.poll() is None:
timeout_action = _TIMEOUT_TERM
utils_wrapper.IgnoreProcessNotFound(os.kill, child.pid,
signal.SIGTERM)
linger_timeout = \
utils_algo.RunningTimeout(_linger_timeout, True).Remaining
pt = linger_timeout() * 1000
if pt < 0:
break
else:
pt = None
pollresult = utils_wrapper.RetryOnSignal(poller.poll, pt)
for fd, event in pollresult:
if event & select.POLLIN or event & select.POLLPRI:
data = fdmap[fd][1].read()
# no data from read signifies EOF (the same as POLLHUP)
if not data:
poller.unregister(fd)
del fdmap[fd]
continue
fdmap[fd][0].write(data)
if (event & select.POLLNVAL or event & select.POLLHUP or
event & select.POLLERR):
poller.unregister(fd)
del fdmap[fd]
if timeout is not None:
assert callable(poll_timeout)
# We have no I/O left but it might still run
if child.poll() is None:
_WaitForProcess(child, poll_timeout())
# Terminate if still alive after timeout
if child.poll() is None:
if linger_timeout is None:
logging.warning(msg_timeout)
timeout_action = _TIMEOUT_TERM
utils_wrapper.IgnoreProcessNotFound(os.kill, child.pid, signal.SIGTERM)
lt = _linger_timeout
else:
lt = linger_timeout()
_WaitForProcess(child, lt)
# Okay, still alive after timeout and linger timeout? Kill it!
if child.poll() is None:
timeout_action = _TIMEOUT_KILL
logging.warning(msg_linger)
utils_wrapper.IgnoreProcessNotFound(os.kill, child.pid, signal.SIGKILL)
out = out.getvalue()
err = err.getvalue()
status = child.wait()
return out, err, status, timeout_action
