import os
import pkgutil
import sys
+import threading
import weakref
reschedule_delay = "1s"
def clsinit(cls):
""" Initializes template information (i.e. attributes and traces)
- for the ResourceManager class
- """
+ on classes derived from the ResourceManager class.
+
+ It is used as a decorator in the class declaration as follows:
+
+ @clsinit
+ class MyResourceManager(ResourceManager):
+
+ ...
+
+ """
+
cls._clsinit()
return cls
def clsinit_copy(cls):
""" Initializes template information (i.e. attributes and traces)
- for the ResourceManager class, inheriting attributes and traces
- from the parent class
+ on classes direved from the ResourceManager class.
+ It differs from the clsinit method in that it forces inheritance
+ of attributes and traces from the parent class.
+
+ It is used as a decorator in the class declaration as follows:
+
+ @clsinit
+ class MyResourceManager(ResourceManager):
+
+ ...
+
+
+ clsinit_copy should be prefered to clsinit when creating new
+ ResourceManager child classes.
+
"""
+
cls._clsinit_copy()
return cls
def failtrap(func):
+ """ Decorator function for instance methods that should set the
+ RM state to FAILED when an error is raised. The methods that must be
+ decorated are: discover, provision, deploy, start, stop and finish.
+
+ """
def wrapped(self, *args, **kwargs):
try:
return func(self, *args, **kwargs)
return wrapped
-# Decorator to invoke class initialization method
@clsinit
class ResourceManager(Logger):
""" Base clase for all ResourceManagers.
resource attribute
"""
+
cls._attributes[attr.name] = attr
@classmethod
resource attribute
"""
+
del cls._attributes[name]
@classmethod
resource trace
"""
+
cls._traces[trace.name] = trace
@classmethod
resource trace
"""
+
del cls._traces[name]
@classmethod
def _register_attributes(cls):
""" Resource subclasses will invoke this method to register
- resource attributes
+ resource attributes.
+
+ This method should be overriden in the RMs that define
+ attributes.
"""
- critical = Attribute("critical", "Defines whether the resource is critical. "
- " A failure on a critical resource will interrupt the experiment. ",
+
+ critical = Attribute("critical",
+ "Defines whether the resource is critical. "
+ "A failure on a critical resource will interrupt "
+ "the experiment. ",
type = Types.Bool,
default = True,
flags = Flags.ExecReadOnly)
""" Resource subclasses will invoke this method to register
resource traces
+ This method should be overriden in the RMs that define traces.
+
"""
+
pass
@classmethod
def _clsinit(cls):
- """ ResourceManager child classes have different attributes and traces.
- Since the templates that hold the information of attributes and traces
- are 'class attribute' dictionaries, initially they all point to the
- parent class ResourceManager instances of those dictionaries.
- In order to make these templates independent from the parent's one,
- it is necessary re-initialize the corresponding dictionaries.
- This is the objective of the _clsinit method
+ """ ResourceManager classes have different attributes and traces.
+ Attribute and traces are stored in 'class attribute' dictionaries.
+ When a new ResourceManager class is created, the _clsinit method is
+ called to create a new instance of those dictionaries and initialize
+ them.
+
+ The _clsinit method is called by the clsinit decorator method.
+
"""
+
# static template for resource attributes
cls._attributes = dict()
cls._register_attributes()
@classmethod
def _clsinit_copy(cls):
- """ Same as _clsinit, except that it also inherits all attributes and traces
- from the parent class.
+ """ Same as _clsinit, except that after creating new instances of the
+ dictionaries it copies all the attributes and traces from the parent
+ class.
+
+ The _clsinit_copy method is called by the clsinit_copy decorator method.
+
"""
# static template for resource attributes
cls._attributes = copy.deepcopy(cls._attributes)
self._state = ResourceState.NEW
+ # instance lock to synchronize exclusive state change methods (such
+ # as deploy and release methods), in order to prevent them from being
+ # executed at the same time
+ self._release_lock = threading.Lock()
+
@property
def guid(self):
""" Returns the global unique identifier of the RM """
@property
def ec(self):
- """ Returns the Experiment Controller """
+ """ Returns the Experiment Controller of the RM """
return self._ec()
@property
def connections(self):
- """ Returns the set of guids of connected RMs"""
+ """ Returns the set of guids of connected RMs """
return self._connections
@property
def conditions(self):
""" Returns the conditions to which the RM is subjected to.
- The object returned by this method is a dictionary indexed by
- ResourceAction."""
+ This method returns a dictionary of conditions lists indexed by
+ a ResourceAction.
+
+ """
return self._conditions
@property
def start_time(self):
- """ Returns the start time of the RM as a timestamp"""
+ """ Returns the start time of the RM as a timestamp """
return self._start_time
@property
def stop_time(self):
- """ Returns the stop time of the RM as a timestamp"""
+ """ Returns the stop time of the RM as a timestamp """
return self._stop_time
@property
def discover_time(self):
- """ Returns the time discovering was finished for the RM as a timestamp"""
+ """ Returns the discover time of the RM as a timestamp """
return self._discover_time
@property
def provision_time(self):
- """ Returns the time provisioning was finished for the RM as a timestamp"""
+ """ Returns the provision time of the RM as a timestamp """
return self._provision_time
@property
def ready_time(self):
- """ Returns the time deployment was finished for the RM as a timestamp"""
+ """ Returns the deployment time of the RM as a timestamp """
return self._ready_time
@property
def release_time(self):
- """ Returns the release time of the RM as a timestamp"""
+ """ Returns the release time of the RM as a timestamp """
return self._release_time
@property
def finish_time(self):
- """ Returns the finalization time of the RM as a timestamp"""
+ """ Returns the finalization time of the RM as a timestamp """
return self._finish_time
@property
def failed_time(self):
- """ Returns the time failure occured for the RM as a timestamp"""
+ """ Returns the time failure occured for the RM as a timestamp """
return self._failed_time
@property
:param msg: text message
:type msg: str
:rtype: str
+
"""
return " %s guid: %d - %s " % (self._rtype, self.guid, msg)
def register_connection(self, guid):
""" Registers a connection to the RM identified by guid
+ This method should not be overriden. Specific functionality
+ should be added in the do_connect method.
+
:param guid: Global unique identified of the RM to connect to
:type guid: int
+
"""
if self.valid_connection(guid):
- self.connect(guid)
+ self.do_connect(guid)
self._connections.add(guid)
def unregister_connection(self, guid):
""" Removes a registered connection to the RM identified by guid
+
+ This method should not be overriden. Specific functionality
+ should be added in the do_disconnect method.
:param guid: Global unique identified of the RM to connect to
:type guid: int
+
"""
if guid in self._connections:
- self.disconnect(guid)
+ self.do_disconnect(guid)
self._connections.remove(guid)
+ @failtrap
def discover(self):
""" Performs resource discovery.
-
+
This method is responsible for selecting an individual resource
matching user requirements.
- This method should be redefined when necessary in child classes.
- If overridden in child classes, make sure to use the failtrap
- decorator to ensure the RM state will be set to FAILED in the event
- of an exception.
+ This method should not be overriden directly. Specific functionality
+ should be added in the do_discover method.
"""
- self.set_discovered()
+ with self._release_lock:
+ if self._state != ResourceState.RELEASED:
+ self.do_discover()
+ @failtrap
def provision(self):
""" Performs resource provisioning.
This method is responsible for provisioning one resource.
After this method has been successfully invoked, the resource
should be accessible/controllable by the RM.
- This method should be redefined when necessary in child classes.
- If overridden in child classes, make sure to use the failtrap
- decorator to ensure the RM state will be set to FAILED in the event
- of an exception.
+ This method should not be overriden directly. Specific functionality
+ should be added in the do_provision method.
"""
- self.set_provisioned()
+ with self._release_lock:
+ if self._state != ResourceState.RELEASED:
+ self.do_provision()
+ @failtrap
def start(self):
- """ Starts the RM.
-
- There is no generic start behavior for all resources.
- This method should be redefined when necessary in child classes.
+ """ Starts the RM (e.g. launch remote process).
+
+ There is no standard start behavior. Some RMs will not need to perform
+ any actions upon start.
- If overridden in child classes, make sure to use the failtrap
- decorator to ensure the RM state will be set to FAILED in the event
- of an exception.
+ This method should not be overriden directly. Specific functionality
+ should be added in the do_start method.
"""
if not self.state in [ResourceState.READY, ResourceState.STOPPED]:
self.error("Wrong state %s for start" % self.state)
return
- self.set_started()
+ with self._release_lock:
+ if self._state != ResourceState.RELEASED:
+ self.do_start()
+ @failtrap
def stop(self):
""" Interrupts the RM, stopping any tasks the RM was performing.
-
- There is no generic stop behavior for all resources.
- This method should be redefined when necessary in child classes.
-
- If overridden in child classes, make sure to use the failtrap
- decorator to ensure the RM state will be set to FAILED in the event
- of an exception.
-
+
+ There is no standard stop behavior. Some RMs will not need to perform
+ any actions upon stop.
+
+ This method should not be overriden directly. Specific functionality
+ should be added in the do_stop method.
+
"""
if not self.state in [ResourceState.STARTED]:
self.error("Wrong state %s for stop" % self.state)
return
- self.set_stopped()
+ with self._release_lock:
+ self.do_stop()
+ @failtrap
def deploy(self):
""" Execute all steps required for the RM to reach the state READY.
- This method is responsible for deploying the resource (and invoking the
- discover and provision methods).
- This method should be redefined when necessary in child classes.
-
- If overridden in child classes, make sure to use the failtrap
- decorator to ensure the RM state will be set to FAILED in the event
- of an exception.
-
+ This method is responsible for deploying the resource (and invoking
+ the discover and provision methods).
+
+ This method should not be overriden directly. Specific functionality
+ should be added in the do_deploy method.
+
"""
if self.state > ResourceState.READY:
self.error("Wrong state %s for deploy" % self.state)
return
- self.debug("----- READY ---- ")
- self.set_ready()
+ with self._release_lock:
+ if self._state != ResourceState.RELEASED:
+ self.do_deploy()
+ self.debug("----- READY ---- ")
def release(self):
""" Perform actions to free resources used by the RM.
-
+
This method is responsible for releasing resources that were
used during the experiment by the RM.
- This method should be redefined when necessary in child classes.
-
- If overridden in child classes, this method should never
- raise an error and it must ensure the RM is set to state RELEASED.
+ This method should not be overriden directly. Specific functionality
+ should be added in the do_release method.
+
"""
- self.set_released()
-
+ with self._release_lock:
+ try:
+ self.do_release()
+ except:
+ import traceback
+ err = traceback.format_exc()
+ self.error(err)
+
+ self.set_released()
+ self.debug("----- RELEASED ---- ")
+
+ @failtrap
def finish(self):
""" Sets the RM to state FINISHED.
-
- The FINISHED state is different from STOPPED in that it should not be
- directly invoked by the user.
+
+ The FINISHED state is different from STOPPED state in that it
+ should not be directly invoked by the user.
STOPPED indicates that the user interrupted the RM, FINISHED means
that the RM concluded normally the actions it was supposed to perform.
- This method should be redefined when necessary in child classes.
+
+ This method should not be overriden directly. Specific functionality
+ should be added in the do_finish method.
- If overridden in child classes, make sure to use the failtrap
- decorator to ensure the RM state will be set to FAILED in the event
- of an exception.
-
"""
+ with self._release_lock:
+ if self._state != ResourceState.RELEASED:
+ self.do_finish()
- self.set_finished()
-
def fail(self):
""" Sets the RM to state FAILED.
- """
+ This method should not be overriden directly. Specific functionality
+ should be added in the do_fail method.
- self.set_failed()
+ """
+ with self._release_lock:
+ if self._state != ResourceState.RELEASED:
+ self.do_fail()
def set(self, name, value):
""" Set the value of the attribute
self.debug("----- STARTING ---- ")
self.deploy()
- def connect(self, guid):
+ def do_connect(self, guid):
""" Performs actions that need to be taken upon associating RMs.
This method should be redefined when necessary in child classes.
"""
pass
- def disconnect(self, guid):
+ def do_disconnect(self, guid):
""" Performs actions that need to be taken upon disassociating RMs.
This method should be redefined when necessary in child classes.
"""
"""
# TODO: Validate!
return True
-
+
+ def do_discover(self):
+ self.set_discovered()
+
+ def do_provision(self):
+ self.set_provisioned()
+
+ def do_start(self):
+ self.set_started()
+
+ def do_stop(self):
+ self.set_stopped()
+
+ def do_deploy(self):
+ self.set_ready()
+
+ def do_release(self):
+ pass
+
+ def do_finish(self):
+ self.set_finished()
+
+ def do_fail(self):
+ self.set_failed()
+
def set_started(self):
""" Mark ResourceManager as STARTED """
self.set_state(ResourceState.STARTED, "_start_time")