diff options
Diffstat (limited to 'scripts/qmp/qmp.py')
| -rw-r--r-- | scripts/qmp/qmp.py | 95 |
1 files changed, 65 insertions, 30 deletions
diff --git a/scripts/qmp/qmp.py b/scripts/qmp/qmp.py index 20b6ec795e..1d38e3e9e7 100644 --- a/scripts/qmp/qmp.py +++ b/scripts/qmp/qmp.py @@ -21,6 +21,9 @@ class QMPConnectError(QMPError): class QMPCapabilitiesError(QMPError): pass +class QMPTimeoutError(QMPError): + pass + class QEMUMonitorProtocol: def __init__(self, address, server=False): """ @@ -72,6 +75,44 @@ class QEMUMonitorProtocol: error = socket.error + def __get_events(self, wait=False): + """ + Check for new events in the stream and cache them in __events. + + @param wait (bool): block until an event is available. + @param wait (float): If wait is a float, treat it as a timeout value. + + @raise QMPTimeoutError: If a timeout float is provided and the timeout + period elapses. + @raise QMPConnectError: If wait is True but no events could be retrieved + or if some other error occurred. + """ + + # Check for new events regardless and pull them into the cache: + self.__sock.setblocking(0) + try: + self.__json_read() + except socket.error, err: + if err[0] == errno.EAGAIN: + # No data available + pass + self.__sock.setblocking(1) + + # Wait for new events, if needed. + # if wait is 0.0, this means "no wait" and is also implicitly false. + if not self.__events and wait: + if isinstance(wait, float): + self.__sock.settimeout(wait) + try: + ret = self.__json_read(only_event=True) + except socket.timeout: + raise QMPTimeoutError("Timeout waiting for event") + except: + raise QMPConnectError("Error while reading from socket") + if ret is None: + raise QMPConnectError("Error while reading from socket") + self.__sock.settimeout(None) + def connect(self, negotiate=True): """ Connect to the QMP Monitor and perform capabilities negotiation. @@ -140,43 +181,37 @@ class QEMUMonitorProtocol: """ Get and delete the first available QMP event. - @param wait: block until an event is available (bool) + @param wait (bool): block until an event is available. + @param wait (float): If wait is a float, treat it as a timeout value. + + @raise QMPTimeoutError: If a timeout float is provided and the timeout + period elapses. + @raise QMPConnectError: If wait is True but no events could be retrieved + or if some other error occurred. + + @return The first available QMP event, or None. """ - self.__sock.setblocking(0) - try: - self.__json_read() - except socket.error, err: - if err[0] == errno.EAGAIN: - # No data available - pass - self.__sock.setblocking(1) - if not self.__events and wait: - self.__json_read(only_event=True) - event = self.__events[0] - del self.__events[0] - return event + self.__get_events(wait) + + if self.__events: + return self.__events.pop(0) + return None def get_events(self, wait=False): """ Get a list of available QMP events. - @param wait: block until an event is available (bool) - """ - self.__sock.setblocking(0) - try: - self.__json_read() - except socket.error, err: - if err[0] == errno.EAGAIN: - # No data available - pass - self.__sock.setblocking(1) - if not self.__events and wait: - ret = self.__json_read(only_event=True) - if ret == None: - # We are in blocking mode, if don't get anything, something - # went wrong - raise QMPConnectError("Error while reading from socket") + @param wait (bool): block until an event is available. + @param wait (float): If wait is a float, treat it as a timeout value. + @raise QMPTimeoutError: If a timeout float is provided and the timeout + period elapses. + @raise QMPConnectError: If wait is True but no events could be retrieved + or if some other error occurred. + + @return The list of available QMP events. + """ + self.__get_events(wait) return self.__events def clear_events(self): |