def NotifyDd(self):
"""Tells dd(1) to write statistics.
"""
if self._dd_pid is None:
# Can't notify
return False
if not self._dd_ready:
# There's a race condition between starting the program and sending
# signals. The signal handler is only registered after some time, so we
# have to check whether the program is ready. If it isn't, sending a
# signal will invoke the default handler (and usually abort the program).
if not utils.IsProcessHandlingSignal(self._dd_pid, DD_INFO_SIGNAL):
logging.debug("dd is not yet ready for signal %s",
DD_INFO_SIGNAL)
return False
logging.debug("dd is now handling signal %s", DD_INFO_SIGNAL)
self._dd_ready = True
logging.debug("Sending signal %s to PID %s", DD_INFO_SIGNAL,
self._dd_pid)
try:
os.kill(self._dd_pid, DD_INFO_SIGNAL)
except EnvironmentError, err:
if err.errno != errno.ESRCH:
raise
# Process no longer exists
logging.debug("dd exited")
self._dd_pid = None
def _TestRealProcess():
signal.signal(signal.SIGUSR1, signal.SIG_DFL)
if utils.IsProcessHandlingSignal(os.getpid(), signal.SIGUSR1):
raise Exception("SIGUSR1 is handled when it should not be")
signal.signal(signal.SIGUSR1, lambda signum, frame: None)
if not utils.IsProcessHandlingSignal(os.getpid(), signal.SIGUSR1):
raise Exception("SIGUSR1 is not handled when it should be")
signal.signal(signal.SIGUSR1, signal.SIG_IGN)
if utils.IsProcessHandlingSignal(os.getpid(), signal.SIGUSR1):
raise Exception("SIGUSR1 is not handled when it should be")
signal.signal(signal.SIGUSR1, signal.SIG_DFL)
if utils.IsProcessHandlingSignal(os.getpid(), signal.SIGUSR1):
raise Exception("SIGUSR1 is handled when it should not be")
return True
def test(self):
sp = utils.PathJoin(self.tmpdir, "status")
utils.WriteFile(sp, data="\n".join([
"Name: bash",
"State: S (sleeping)",
"SleepAVG: 98%",
"Pid: 22250",
"PPid: 10858",
"TracerPid: 0",
"SigBlk: 0000000000010000",
"SigIgn: 0000000000384004",
"SigCgt: 000000004b813efb",
"CapEff: 0000000000000000",
]))
self.assert_(utils.IsProcessHandlingSignal(1234, 10, status_path=sp))
def testNoSuchFile(self):
sp = utils.PathJoin(self.tmpdir, "notexist")
self.assertFalse(utils.IsProcessHandlingSignal(1234, 10, status_path=sp))
