Better identification of com. errors in RPC and XIA

bliss/comm/rpc.py

@@ -91,6 +91,7 @@ from bliss import global_map
 
 from bliss.common.msgpack_ext import MsgpackContext
 from bliss.comm.exceptions import CommunicationError
+from bliss.common.greenlet_utils import Timeout as GreenletTimeoutError
 
 
 MAX_MEMORY = min(psutil.virtual_memory().total, sys.maxsize)
@@ -541,9 +542,19 @@ class RpcConnection:
                 # Disable Nagle and set TOS to low delay
                 self._socket.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
                 self._socket.setsockopt(socket.SOL_IP, socket.IP_TOS, 0x10)
-            except socket.gaierror as sockexc:
-                _msg = f"RPC socket.gaierror connecting to {self.host}:{self.port} - ERR no {sockexc.errno} : {sockexc.strerror}"
-                raise CommunicationError(_msg) from sockexc
+
+            except socket.gaierror as sock_err:
+                _msg = f"socket.gaierror connecting to {self.host}:{self.port} - ERR no {sock_err.errno} : {sock_err.strerror}"
+                raise CommunicationError(_msg) from sock_err
+
+            except socket.timeout as sock_err:
+                _msg = f"socket.timeout error connecting to {self.host}:{self.port}"
+                raise CommunicationError(_msg) from sock_err
+
+            except GreenletTimeoutError as grt_err:
+                _msg = f"RPC GreenletTimeoutError connecting to {self.host}:{self.port}"
+                raise CommunicationError(_msg) from grt_err
+
             except ConnectionRefusedError as cnx_err:
                 _msg = f"RPC ConnectionRefusedError error connecting to {self.host}:{self.port}"
                 raise CommunicationError(_msg) from cnx_err
@@ -552,6 +563,7 @@ class RpcConnection:
             # ??? no  host
             self._socket = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
             self._socket.connect(self.port)
+
         self._reading_task = gevent.spawn(self._raw_read)
 
     def get_class(self):
@@ -639,6 +651,7 @@ class RpcConnection:
     def _raw_read(self):
         unpacker = msgpack.Unpacker(raw=False, max_buffer_size=MAX_BUFFER_SIZE)
         exception = None
+
         try:
             while True:
                 msg = self._socket.recv(READ_BUFFER_SIZE)
@@ -658,8 +671,8 @@ class RpcConnection:
                         wq = self._queues.get(call_id)
                         if wq:
                             wq.put(return_values)
-        except Exception as e:
-            exception = e
+        except Exception as err:
+            exception = err
             sys.excepthook(*sys.exc_info())
         finally:
             for _, wq in self._queues.items():

bliss/controllers/mca/xia.py

@@ -9,10 +9,14 @@
 
 # Imports
 import enum
+import socket
+
 from bliss import is_bliss_shell
 from bliss.common.logtools import log_debug, user_print
 from bliss.common import event
 from bliss.config.beacon_object import BeaconObject
+from bliss.comm.exceptions import CommunicationError
+from bliss.common.greenlet_utils import Timeout as GreenletTimeoutError
 
 from bliss.comm import rpc
 from .base import (
@@ -116,16 +120,37 @@ class BaseXIA(BaseMCA):
         self.gate_polarity = self.config.get("gate_polarity", GatePolarity.NORMAL)
 
     def initialize_hardware(self):
-        """ Called at session startup
+        """
+        Called at session startup
         """
         logger.debug("initialize_hardware()")
-        self._proxy = rpc.Client(self.beacon_obj.url)
-        event.connect(self._proxy, "data", self._event)
-        event.connect(self._proxy, "current_pixel", self._current_pixel_event)
+        try:
+            self._proxy = rpc.Client(self.beacon_obj.url)
+            event.connect(self._proxy, "data", self._event)
+            event.connect(self._proxy, "current_pixel", self._current_pixel_event)
+        except CommunicationError as prox_comm_err:
+            _msg = f"XIA init error: cannot connect to {self.url}"
+            #            breakpoint()
+            if isinstance(prox_comm_err.__cause__, GreenletTimeoutError):
+                _msg += " GreenletTimeoutError (check server is running ?)"
+            elif isinstance(prox_comm_err.__cause__, socket.gaierror):
+                _msg += " socket.gaierror (check host ?)"
+            elif isinstance(prox_comm_err.__cause__, ConnectionRefusedError):
+                _msg += " ConnectionRefusedError (check host/port/FW ?)"
+            else:
+                _msg += " CommError (check  ?)"
+            raise CommunicationError(_msg) from prox_comm_err
+        except BaseException as base_err:
+            # got a greenlet timeout...
+            _msg = f"XIA init error: cannot connect to {self.url}"
+            _msg += f" greenlet timeout (check server is running?)"
+            raise CommunicationError(_msg) from base_err
+
         # global_map.register(self._proxy, parents_list=[self], tag="comm")
         try:
-            # Getting the current configuration will
-            # Call load_configuration on the first peers.
+            # Accessing to current configuration will
+            #  call load_configuration on the first peers.
+            # pylint: disable=pointless-statement
             self.beacon_obj.current_configuration
             logger.debug(
                 "current_configuration=%s", self.beacon_obj.current_configuration

doc/docs/beacon_channels.md

@@ -110,3 +110,9 @@ BLISS [5]: ['event 0', 'event 1', 'event 2', 'event 3', 'event 4',
             'event 5', 'event 6', 'event 7', 'event 8', 'event 9']
 ```
 
+To disconnect the channel in process B:
+```python
+c.unregister_callback(f)
+```
+
+