diff --git a/python/qemu/qmp.py b/python/qemu/qmp.py index 96456f7aa0..2cd4d43036 100644 --- a/python/qemu/qmp.py +++ b/python/qemu/qmp.py @@ -164,8 +164,11 @@ class QEMUMonitorProtocol: retrieved or if some other error occurred. """ + # Current timeout and blocking status + current_timeout = self.__sock.gettimeout() + # Check for new events regardless and pull them into the cache: - self.__sock.setblocking(False) + self.__sock.settimeout(0) # i.e. setblocking(False) try: self.__json_read() except OSError as err: @@ -173,7 +176,7 @@ class QEMUMonitorProtocol: if err.errno != errno.EAGAIN: raise finally: - self.__sock.setblocking(True) + self.__sock.settimeout(current_timeout) # Wait for new events, if needed. # if wait is 0.0, this means "no wait" and is also implicitly false. @@ -187,9 +190,11 @@ class QEMUMonitorProtocol: except Exception as err: msg = "Error while reading from socket" raise QMPConnectError(msg) from err + finally: + self.__sock.settimeout(current_timeout) + if ret is None: raise QMPConnectError("Error while reading from socket") - self.__sock.settimeout(None) def __enter__(self) -> 'QEMUMonitorProtocol': # Implement context manager enter function. @@ -219,7 +224,7 @@ class QEMUMonitorProtocol: return self.__negotiate_capabilities() return None - def accept(self, timeout: float = 15.0) -> QMPMessage: + def accept(self, timeout: Optional[float] = 15.0) -> QMPMessage: """ Await connection from QMP Monitor and perform capabilities negotiation. @@ -338,13 +343,19 @@ class QEMUMonitorProtocol: if self.__sockfile: self.__sockfile.close() - def settimeout(self, timeout: float) -> None: + def settimeout(self, timeout: Optional[float]) -> None: """ Set the socket timeout. - @param timeout (float): timeout in seconds, or None. + @param timeout (float): timeout in seconds (non-zero), or None. @note This is a wrap around socket.settimeout + + @raise ValueError: if timeout was set to 0. """ + if timeout == 0: + msg = "timeout cannot be 0; this engages non-blocking mode." + msg += " Use 'None' instead to disable timeouts." + raise ValueError(msg) self.__sock.settimeout(timeout) def get_sock_fd(self) -> int: