def launcher(stopEvent):
ca.create_context()
print('launcher thread libca ctx =', ca.current_context())
sup.launch_monitors()
# Keep thread alive until it is time to go
stopEvent.wait()
print('(AtIocExit) launcher thread libca ctx =', ca.current_context())
def setup(logger):
'''Setup ophyd for use
Must be called once per session using ophyd
'''
# It's important to use the same context in the callback _dispatcher
# as the main thread, otherwise not-so-savvy users will be very
# confused
global _dispatcher
if _dispatcher is not None:
logger.debug('ophyd already setup')
return
epics.pv.default_pv_class = PyepicsShimPV
def _cleanup():
'''Clean up the ophyd session'''
global _dispatcher
if _dispatcher is None:
return
epics.pv.default_pv_class = epics.PV
if _dispatcher.is_alive():
_dispatcher.stop()
_dispatcher = None
logger.debug('Installing event dispatcher')
_dispatcher = EventDispatcher(thread_class=PyepicsCallbackThread,
context=ca.current_context(),
logger=logger)
atexit.register(_cleanup)
return _dispatcher
def build():
stopEvent = Event()
sup = bugSupport(name='bug')
print('pyDevSup thread libca ctx =', ca.current_context())
# In order to get a fresh context, lets do pyepics
# stuff in a different thread
def launcher(stopEvent):
ca.create_context()
print('launcher thread libca ctx =', ca.current_context())
sup.launch_monitors()
# Keep thread alive until it is time to go
stopEvent.wait()
print('(AtIocExit) launcher thread libca ctx =', ca.current_context())
t = Thread(target=launcher, args=(stopEvent, ))
def stopLauncher():
stopEvent.set()
t.join()
addHook('AtIocExit', stopLauncher)
# iocInit somehow messes up contexts, so start the thread
# after iocInit
addHook('AfterIocRunning', t.start)
return sup
def get_pv(pvname, form='time', connect=False, context=None, timeout=5.0,
connection_callback=None, access_callback=None, callback=None,
**kwargs):
"""Get a PV from PV cache or create one if needed.
Parameters
---------
form : str, optional
PV form: one of 'native' (default), 'time', 'ctrl'
connect : bool, optional
whether to wait for connection (default False)
context : int, optional
PV threading context (defaults to current context)
timeout : float, optional
connection timeout, in seconds (default 5.0)
"""
if form not in ('native', 'time', 'ctrl'):
form = 'native'
if context is None:
context = ca.current_context()
thispv = None
# TODO: this needs some work.
# thispv = epics.pv._PVcache_.get((pvname, form, context))
# if thispv is not None:
# if callback is not None:
# # wrapping is taken care of by `add_callback`
# thispv.add_callback(callback)
# if access_callback is not None:
# access_callback = wrap_callback(_dispatcher, 'metadata',
# access_callback)
# thispv.access_callbacks.append(access_callback)
# if connection_callback is not None:
# connection_callback = wrap_callback(_dispatcher, 'metadata',
# connection_callback)
# thispv.connection_callbacks.append(connection_callback)
# if thispv.connected:
# if connection_callback:
# thispv.force_connect()
# if access_callback:
# thispv.force_read_access_rights()
if thispv is None:
thispv = PyepicsShimPV(pvname, form=form, callback=callback,
connection_callback=connection_callback,
access_callback=access_callback, **kwargs)
if connect:
if not thispv.wait_for_connection(timeout=timeout):
ca.write('cannot connect to %s' % pvname)
return thispv
def setup(logger):
'''Setup ophyd for use
Must be called once per session using ophyd
'''
# It's important to use the same context in the callback _dispatcher
# as the main thread, otherwise not-so-savvy users will be very
# confused
global _dispatcher
if _dispatcher is not None:
logger.debug('ophyd already setup')
return
epics._get_pv = epics.get_pv
epics.get_pv = get_pv
epics.pv.get_pv = get_pv
def _cleanup():
'''Clean up the ophyd session'''
global _dispatcher
if _dispatcher is None:
return
epics.get_pv = epics._get_pv
epics.pv.get_pv = epics._get_pv
logger.debug('Performing ophyd cleanup')
if _dispatcher.is_alive():
logger.debug('Joining the dispatcher thread')
_dispatcher.stop()
_dispatcher = None
logger.debug('Installing event dispatcher')
_dispatcher = EventDispatcher(thread_class=PyepicsCallbackThread,
context=ca.current_context(), logger=logger)
atexit.register(_cleanup)
return _dispatcher
def get_pv(pvname,
form='time',
connect=False,
context=None,
timeout=5.0,
connection_callback=None,
access_callback=None,
callback=None,
**kwargs):
"""Get a PV from PV cache or create one if needed.
Parameters
---------
form : str, optional
PV form: one of 'native' (default), 'time', 'ctrl'
connect : bool, optional
whether to wait for connection (default False)
context : int, optional
PV threading context (defaults to current context)
timeout : float, optional
connection timeout, in seconds (default 5.0)
"""
if form not in ('native', 'time', 'ctrl'):
form = 'native'
if context is None:
context = ca.current_context()
thispv = None
# TODO: this needs some work.
# thispv = epics.pv._PVcache_.get((pvname, form, context))
# if thispv is not None:
# if callback is not None:
# # wrapping is taken care of by `add_callback`
# thispv.add_callback(callback)
# if access_callback is not None:
# access_callback = wrap_callback(_dispatcher, 'metadata',
# access_callback)
# thispv.access_callbacks.append(access_callback)
# if connection_callback is not None:
# connection_callback = wrap_callback(_dispatcher, 'metadata',
# connection_callback)
# thispv.connection_callbacks.append(connection_callback)
# if thispv.connected:
# if connection_callback:
# thispv.force_connect()
# if access_callback:
# thispv.force_read_access_rights()
if thispv is None:
thispv = PyepicsShimPV(pvname,
form=form,
callback=callback,
connection_callback=connection_callback,
access_callback=access_callback,
**kwargs)
if connect:
if not thispv.wait_for_connection(timeout=timeout):
ca.write('cannot connect to %s' % pvname)
return thispv
def detach_context(self):
super().detach_context()
if ca.current_context() is not None:
ca.detach_context()
def __enter__(self):
if current_context() != CA_CONTEXT:
attach_context(CA_CONTEXT)
return self
def threads_init():
if current_context() != CA_CONTEXT:
attach_context(CA_CONTEXT)
from datetime import datetime
from contextlib import ContextDecorator
from enum import Enum
import epics
import numpy
from gi.repository import GLib, GObject
from epics.ca import current_context, attach_context
CA_CONTEXT = current_context()
class Alarm(Enum):
NORMAL, MINOR, MAJOR, INVALID = range(4)
class BasePV(GObject.GObject):
"""
Process Variable Base Class
"""
__gsignals__ = {
'changed': (GObject.SignalFlags.RUN_FIRST, None, (object, )),
'active': (GObject.SignalFlags.RUN_FIRST, None, (bool, )),
'alarm': (GObject.SignalFlags.RUN_FIRST, None, (object, )),
'time': (GObject.SignalFlags.RUN_FIRST, None, (object, )),
}
def __init__(self, name, monitor=True):
"""