import time
class Timeout(Exception):
- '''An exception sub-class that indicates that a timeout occurred.'''
+ """An exception sub-class that indicates that a timeout occurred."""
pass
class Spawn(object):
- '''Represents the stdio of a freshly created sub-process. Commands may be
+ """Represents the stdio of a freshly created sub-process. Commands may be
sent to the process, and responses waited for.
- '''
+ """
- def __init__(self, args):
- '''Spawn (fork/exec) the sub-process.
+ def __init__(self, args, cwd=None):
+ """Spawn (fork/exec) the sub-process.
Args:
- args: array of processs arguments. argv[0] is the command to execute.
+ args: array of processs arguments. argv[0] is the command to
+ execute.
+ cwd: the directory to run the process in, or None for no change.
Returns:
Nothing.
- '''
+ """
self.waited = False
self.buf = ''
# run under "go" (www.go.cd). Perhaps this happens under any
# background (non-interactive) system?
signal.signal(signal.SIGHUP, signal.SIG_DFL)
+ if cwd:
+ os.chdir(cwd)
os.execvp(args[0], args)
except:
print 'CHILD EXECEPTION:'
finally:
os._exit(255)
- self.poll = select.poll()
- self.poll.register(self.fd, select.POLLIN | select.POLLPRI | select.POLLERR | select.POLLHUP | select.POLLNVAL)
+ try:
+ self.poll = select.poll()
+ self.poll.register(self.fd, select.POLLIN | select.POLLPRI | select.POLLERR | select.POLLHUP | select.POLLNVAL)
+ except:
+ self.close()
+ raise
def kill(self, sig):
- '''Send unix signal "sig" to the child process.
+ """Send unix signal "sig" to the child process.
Args:
sig: The signal number to send.
Returns:
Nothing.
- '''
+ """
os.kill(self.pid, sig)
def isalive(self):
- '''Determine whether the child process is still running.
+ """Determine whether the child process is still running.
Args:
None.
Returns:
Boolean indicating whether process is alive.
- '''
+ """
if self.waited:
return False
return False
def send(self, data):
- '''Send data to the sub-process's stdin.
+ """Send data to the sub-process's stdin.
Args:
data: The data to send to the process.
Returns:
Nothing.
- '''
+ """
os.write(self.fd, data)
def expect(self, patterns):
- '''Wait for the sub-process to emit specific data.
+ """Wait for the sub-process to emit specific data.
This function waits for the process to emit one pattern from the
supplied list of patterns, or for a timeout to occur.
Notable exceptions:
Timeout, if the process did not emit any of the patterns within
the expected time.
- '''
+ """
for pi in xrange(len(patterns)):
if type(patterns[pi]) == type(''):
m = pattern.search(self.buf)
if not m:
continue
- if earliest_m and m.start() > earliest_m.start():
+ if earliest_m and m.start() >= earliest_m.start():
continue
earliest_m = m
earliest_pi = pi
if earliest_m:
pos = earliest_m.start()
- posafter = earliest_m.end() + 1
+ posafter = earliest_m.end()
self.before = self.buf[:pos]
self.after = self.buf[pos:posafter]
self.buf = self.buf[posafter:]
return earliest_pi
tnow_s = time.time()
- tdelta_ms = (tnow_s - tstart_s) * 1000
- if tdelta_ms > self.timeout:
- raise Timeout()
- events = self.poll.poll(self.timeout - tdelta_ms)
+ if self.timeout:
+ tdelta_ms = (tnow_s - tstart_s) * 1000
+ poll_maxwait = self.timeout - tdelta_ms
+ if tdelta_ms > self.timeout:
+ raise Timeout()
+ else:
+ poll_maxwait = None
+ events = self.poll.poll(poll_maxwait)
if not events:
raise Timeout()
c = os.read(self.fd, 1024)
self.logfile_read.flush()
def close(self):
- '''Close the stdio connection to the sub-process.
+ """Close the stdio connection to the sub-process.
This also waits a reasonable time for the sub-process to stop running.
Returns:
Nothing.
- '''
+ """
os.close(self.fd)
for i in xrange(100):