コード例 #1
0
ファイル: test_process.py プロジェクト: shroffk/pymalcolm
 def test_add_block(self):
     p = Process("proc", MagicMock())
     b = Block()
     b.set_process_path(p, ("name", ))
     c = MagicMock()
     p.add_block(b, c)
     self.assertEqual(p._blocks["name"], b)
     self.assertEqual(p._controllers["name"], c)
コード例 #2
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 def test_add_block(self):
     p = Process("proc", MagicMock())
     b = Block()
     b.set_process_path(p, ("name",))
     c = MagicMock()
     p.add_block(b, c)
     self.assertEqual(p._blocks["name"], b)
     self.assertEqual(p._controllers["name"], c)
コード例 #3
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 def test_add_block_calls_handle(self):
     s = SyncFactory("sched")
     p = Process("proc", s)
     b = Block()
     c = MagicMock()
     b.set_process_path(p, ("myblock",))
     p.add_block(b, c)
     p.start()
     p.stop()
     self.assertEqual(len(p._blocks), 2)
     self.assertEqual(p._blocks, dict(myblock=b, proc=p.process_block))
コード例 #4
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ファイル: test_process.py プロジェクト: shroffk/pymalcolm
 def test_add_block_calls_handle(self):
     s = SyncFactory("sched")
     p = Process("proc", s)
     b = Block()
     c = MagicMock()
     b.set_process_path(p, ("myblock", ))
     p.add_block(b, c)
     p.start()
     p.stop()
     self.assertEqual(len(p._blocks), 2)
     self.assertEqual(p._blocks, dict(myblock=b, proc=p.process_block))
コード例 #5
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 def test_get_block(self):
     p = Process("proc", MagicMock())
     p.process_block["remoteBlocks"].set_value(['name1'])
     b1 = p.get_block("name1")
     self.assertEqual(b1.status, "Waiting for connection...")
     self.assertEqual(p.get_block("name1"), b1)
     b2 = Block()
     b2.set_process_path(p, ("name2",))
     c = MagicMock()
     p.add_block(b2, c)
     self.assertEqual(p.get_block("name2"), b2)
     self.assertEqual(p.get_controller("name2"), c)
コード例 #6
0
ファイル: test_process.py プロジェクト: shroffk/pymalcolm
 def test_get_block(self):
     p = Process("proc", MagicMock())
     p.process_block["remoteBlocks"].set_value(['name1'])
     b1 = p.get_block("name1")
     self.assertEqual(b1.status, "Waiting for connection...")
     self.assertEqual(p.get_block("name1"), b1)
     b2 = Block()
     b2.set_process_path(p, ("name2", ))
     c = MagicMock()
     p.add_block(b2, c)
     self.assertEqual(p.get_block("name2"), b2)
     self.assertEqual(p.get_controller("name2"), c)
コード例 #7
0
ファイル: controller.py プロジェクト: dls-controls/pymalcolm
class Controller(Loggable):
    """Implement the logic that takes a Block through its state machine"""
    stateMachine = sm()

    # Attributes for all controllers
    state = None
    status = None
    busy = None
    # BlockMeta for descriptions
    meta = None

    def __init__(self, process, parts, params):
        """
        Args:
            process (Process): The process this should run under
            params (Map): The parameters specified in method_takes()
            parts (list): [Part]
        """
        self.process = process
        self.params = params
        self.mri = params.mri
        controller_name = "%s(%s)" % (type(self).__name__, self.mri)
        self.set_logger_name(controller_name)
        self.block = Block()
        self.log_debug("Creating block %r as %r", self.block, self.mri)
        self.lock = process.create_lock()
        # {part: task}
        self.part_tasks = {}
        # dictionary of dictionaries
        # {state (str): {Meta/MethodMeta/Attribute: writeable (bool)}
        self.children_writeable = {}
        # dict {hook: name}
        self.hook_names = self._find_hooks()
        self.parts = self._setup_parts(parts, controller_name)
        self._set_block_children()
        self._do_transition(sm.DISABLED, "Disabled")
        self.block.set_process_path(process, [self.mri])
        process.add_block(self.block, self)
        self.do_initial_reset()

    def _find_hooks(self):
        hook_names = {}
        for n in dir(self):
            attr = getattr(self, n)
            if isinstance(attr, Hook):
                assert attr not in hook_names, \
                    "Hook %s already in controller as %s" % (
                        n, hook_names[attr])
                hook_names[attr] = n
        return hook_names

    def _setup_parts(self, parts, controller_name):
        parts_dict = OrderedDict()
        for part in parts:
            part.set_logger_name("%s.%s" % (controller_name, part.name))
            # Check part hooks into one of our hooks
            for func_name, part_hook, _ in get_hook_decorated(part):
                assert part_hook in self.hook_names, \
                    "Part %s func %s not hooked into %s" % (
                        part.name, func_name, self)
            parts_dict[part.name] = part
        return parts_dict

    def do_initial_reset(self):
        pass

    def _set_block_children(self):
        # reconfigure block with new children
        child_list = [self.create_meta()]
        child_list += list(self.create_attributes())
        child_list += list(self.create_methods())
        for part in self.parts.values():
            child_list += list(part.create_attributes())
            child_list += list(part.create_methods())

        self.children_writeable = {}
        writeable_functions = {}
        children = OrderedDict()

        for name, child, writeable_func in child_list:
            if isinstance(child, Attribute):
                states = child.meta.writeable_in
            else:
                states = child.writeable_in
            children[name] = child
            if states:
                for state in states:
                    assert state in self.stateMachine.possible_states, \
                        "State %s is not one of the valid states %s" % \
                        (state, self.stateMachine.possible_states)
            elif writeable_func is not None:
                states = [
                    state for state in self.stateMachine.possible_states
                    if state not in (sm.DISABLING, sm.DISABLED)]
            else:
                continue
            self.register_child_writeable(name, states)
            if writeable_func:
                writeable_functions[name] = functools.partial(
                    self.call_writeable_function, writeable_func)

        self.block.replace_endpoints(children)
        self.block.set_writeable_functions(writeable_functions)

    def call_writeable_function(self, function, child, *args):
        with self.lock:
            if not child.writeable:
                raise ValueError(
                    "Child %r is not writeable" % (child.process_path,))
        result = function(*args)
        return result

    def create_meta(self):
        self.meta = BlockMeta()
        return "meta", self.meta, None

    def create_attributes(self):
        """Method that should provide Attribute instances for Block

        Yields:
            tuple: (string name, Attribute, callable put_function).
        """
        # Add the state, status and busy attributes
        self.state = ChoiceMeta(
            "State of Block", self.stateMachine.possible_states, label="State"
        ).make_attribute()
        yield "state", self.state, None
        self.status = StringMeta(
            "Status of Block", label="Status"
        ).make_attribute()
        yield "status", self.status, None
        self.busy = BooleanMeta(
            "Whether Block busy or not", label="Busy"
        ).make_attribute()
        yield "busy", self.busy, None

    def create_methods(self):
        """Method that should provide MethodMeta instances for Block

        Yields:
            tuple: (string name, MethodMeta, callable post_function).
        """
        return get_method_decorated(self)

    def transition(self, state, message):
        """
        Change to a new state if the transition is allowed

        Args:
            state(str): State to transition to
            message(str): Status message
        """
        with self.lock:
            if self.stateMachine.is_allowed(
                    initial_state=self.state.value, target_state=state):
                self._do_transition(state, message)
            else:
                raise TypeError("Cannot transition from %s to %s" %
                                (self.state.value, state))

    def _do_transition(self, state, message):
        # transition is allowed, so set attributes
        changes = []
        changes.append([["state", "value"], state])
        changes.append([["status", "value"], message])
        changes.append([["busy", "value"],
                        state in self.stateMachine.busy_states])

        # say which children are now writeable
        for name in self.block:
            try:
                writeable = self.children_writeable[state][name]
            except KeyError:
                continue
            child = self.block[name]
            if isinstance(child, Attribute):
                changes.append([[name, "meta", "writeable"], writeable])
            elif isinstance(child, MethodMeta):
                changes.append([[name, "writeable"], writeable])
                for ename in child.takes.elements:
                    path = [name, "takes", "elements", ename, "writeable"]
                    changes.append([path, writeable])

        self.log_debug("Transitioning to %s", state)
        self.block.apply_changes(*changes)

    def register_child_writeable(self, name, states):
        """
        Set the states that the given method can be called in

        Args:
            name (str): Child name that will be set writeable or not
            states (list[str]): states where method is writeable
        """
        for state in self.stateMachine.possible_states:
            writeable_dict = self.children_writeable.setdefault(state, {})
            is_writeable = state in states
            writeable_dict[name] = is_writeable

    def create_part_tasks(self):
        part_tasks = {}
        for part_name, part in self.parts.items():
            part_tasks[part] = Task("Task(%s)" % part_name, self.process)
        return part_tasks

    def run_hook(self, hook, part_tasks, *args, **params):
        hook_queue, hook_runners = self.start_hook(
            hook, part_tasks, *args, **params)
        return_dict = self.wait_hook(hook_queue, hook_runners)
        return return_dict

    def start_hook(self, hook, part_tasks, *args, **params):
        assert hook in self.hook_names, \
            "Hook %s doesn't appear in controller hooks %s" % (
                hook, self.hook_names)

        # ask the hook to find the functions it should run
        part_funcs = hook.find_hooked_functions(self.parts)
        hook_runners = {}
        self.log_debug("Run %s hook on %s",
                       self.hook_names[hook], [p.name for p in part_funcs])

        # now start them off
        hook_queue = self.process.create_queue()
        for part, func_name in part_funcs.items():
            task = weakref.proxy(part_tasks[part])
            hook_runner = HookRunner(
                hook_queue, part, func_name, task, *args, **params)
            hook_runner.start()
            hook_runners[part] = hook_runner

        return hook_queue, hook_runners

    def wait_hook(self, hook_queue, hook_runners):
        # Wait for them all to finish
        return_dict = {}
        while hook_runners:
            part, ret = hook_queue.get()
            hook_runner = hook_runners.pop(part)

            if isinstance(ret, AbortedError):
                # If AbortedError, all tasks have already been stopped.
                self.log_debug("Part %s Aborted", part.name)
                # Do not wait on them otherwise we might get a deadlock...
                raise ret

            # Wait for the process to terminate
            hook_runner.wait()
            return_dict[part.name] = ret
            self.log_debug("Part %s returned %r. Still waiting for %s",
                           part.name, ret, [p.name for p in hook_runners])

            if isinstance(ret, Exception):
                # Got an error, so stop and wait all hook runners
                for h in hook_runners.values():
                    h.stop()
                # Wait for them to finish
                for h in hook_runners.values():
                    h.wait()
                raise ret

        return return_dict
コード例 #8
0
ファイル: process.py プロジェクト: dls-controls/pymalcolm
class Process(Loggable):
    """Hosts a number of Blocks, distributing requests between them"""

    def __init__(self, name, sync_factory):
        self.set_logger_name(name)
        self.name = name
        self.sync_factory = sync_factory
        self.q = self.create_queue()
        self._blocks = OrderedDict()  # block_name -> Block
        self._controllers = OrderedDict()  # block_name -> Controller
        self._block_state_cache = Cache()
        self._recv_spawned = None
        self._other_spawned = []
        # lookup of all Subscribe requests, ordered to guarantee subscription
        # notification ordering
        # {Request.generate_key(): Subscribe}
        self._subscriptions = OrderedDict()
        self.comms = []
        self._client_comms = OrderedDict()  # client comms -> list of blocks
        self._handle_functions = {
            Post: self._forward_block_request,
            Put: self._forward_block_request,
            Get: self._handle_get,
            Subscribe: self._handle_subscribe,
            Unsubscribe: self._handle_unsubscribe,
            BlockChanges: self._handle_block_changes,
            BlockRespond: self._handle_block_respond,
            BlockAdd: self._handle_block_add,
            BlockList: self._handle_block_list,
            AddSpawned: self._add_spawned,
        }
        self.create_process_block()

    def recv_loop(self):
        """Service self.q, distributing the requests to the right block"""
        while True:
            request = self.q.get()
            self.log_debug("Received request %s", request)
            if request is PROCESS_STOP:
                # Got the sentinel, stop immediately
                break
            try:
                self._handle_functions[type(request)](request)
            except Exception as e:  # pylint:disable=broad-except
                self.log_exception("Exception while handling %s", request)
                try:
                    request.respond_with_error(str(e))
                except Exception:
                    pass

    def add_comms(self, comms):
        assert not self._recv_spawned, \
            "Can't add comms when process has been started"
        self.comms.append(comms)

    def start(self):
        """Start the process going"""
        self._recv_spawned = self.sync_factory.spawn(self.recv_loop)
        for comms in self.comms:
            comms.start()

    def stop(self, timeout=None):
        """Stop the process and wait for it to finish

        Args:
            timeout (float): Maximum amount of time to wait for each spawned
                process. None means forever
        """
        assert self._recv_spawned, "Process not started"
        self.q.put(PROCESS_STOP)
        for comms in self.comms:
            comms.stop()
        # Wait for recv_loop to complete first
        self._recv_spawned.wait(timeout=timeout)
        # Now wait for anything it spawned to complete
        for s, _ in self._other_spawned:
            s.wait(timeout=timeout)
        # Garbage collect the syncfactory
        del self.sync_factory

    def _forward_block_request(self, request):
        """Lookup target Block and spawn block.handle_request(request)

        Args:
            request (Request): The message that should be passed to the Block
        """
        block_name = request.endpoint[0]
        block = self._blocks[block_name]
        spawned = self.sync_factory.spawn(block.handle_request, request)
        self._add_spawned(AddSpawned(spawned, block.handle_request))

    def create_queue(self):
        """
        Create a queue using sync_factory object

        Returns:
            Queue: New queue
        """

        return self.sync_factory.create_queue()

    def create_lock(self):
        """
        Create a lock using sync_factory object

        Returns:
            New lock object
        """
        return self.sync_factory.create_lock()

    def spawn(self, function, *args, **kwargs):
        """Calls SyncFactory.spawn()"""
        def catching_function():
            try:
                function(*args, **kwargs)
            except Exception:
                self.log_exception(
                    "Exception calling %s(*%s, **%s)", function, args, kwargs)
                raise
        spawned = self.sync_factory.spawn(catching_function)
        request = AddSpawned(spawned, function)
        self.q.put(request)
        return spawned

    def _add_spawned(self, request):
        spawned = self._other_spawned
        self._other_spawned = []
        spawned.append((request.spawned, request.function))
        # Filter out the spawned that have completed to stop memory leaks
        for sp, f in spawned:
            if not sp.ready():
                self._other_spawned.append((sp, f))

    def get_client_comms(self, block_name):
        for client_comms, blocks in list(self._client_comms.items()):
            if block_name in blocks:
                return client_comms

    def create_process_block(self):
        self.process_block = Block()
        # TODO: add a meta here
        children = OrderedDict()
        children["blocks"] = StringArrayMeta(
            description="Blocks hosted by this Process"
        ).make_attribute([])
        children["remoteBlocks"] = StringArrayMeta(
                description="Blocks reachable via ClientComms"
        ).make_attribute([])
        self.process_block.replace_endpoints(children)
        self.process_block.set_process_path(self, [self.name])
        self.add_block(self.process_block, self)

    def update_block_list(self, client_comms, blocks):
        self.q.put(BlockList(client_comms=client_comms, blocks=blocks))

    def _handle_block_list(self, request):
        self._client_comms[request.client_comms] = request.blocks
        remotes = []
        for blocks in self._client_comms.values():
            remotes += [b for b in blocks if b not in remotes]
        self.process_block["remoteBlocks"].set_value(remotes)

    def _handle_block_changes(self, request):
        """Update subscribers with changes and applies stored changes to the
        cached structure"""
        # update cached dict
        subscription_changes = self._block_state_cache.apply_changes(
            *request.changes)

        # Send out the changes
        for subscription, changes in subscription_changes.items():
            if subscription.delta:
                # respond with the filtered changes
                subscription.respond_with_delta(changes)
            else:
                # respond with the structure of everything
                # below the endpoint
                d = self._block_state_cache.walk_path(subscription.endpoint)
                subscription.respond_with_update(d)

    def report_changes(self, *changes):
        self.q.put(BlockChanges(changes=list(changes)))

    def block_respond(self, response, response_queue):
        self.q.put(BlockRespond(response, response_queue))

    def _handle_block_respond(self, request):
        """Push the response to the required queue"""
        request.response_queue.put(request.response)

    def add_block(self, block, controller):
        """Add a block to be hosted by this process

        Args:
            block (Block): The block to be added
            controller (Controller): Its controller
        """
        path = block.process_path
        assert len(path) == 1, \
            "Expected block %r to have %r as parent, got path %r" % \
            (block, self, path)
        name = path[0]
        assert name not in self._blocks, \
            "There is already a block called %r" % name
        request = BlockAdd(block=block, controller=controller, name=name)
        if self._recv_spawned:
            # Started, so call in Process thread
            self.q.put(request)
        else:
            # Not started yet so we are safe to add in this thread
            self._handle_block_add(request)

    def _handle_block_add(self, request):
        """Add a block to be hosted by this process"""
        assert request.name not in self._blocks, \
            "There is already a block called %r" % request.name
        self._blocks[request.name] = request.block
        self._controllers[request.name] = request.controller
        serialized = request.block.to_dict()
        change_request = BlockChanges([[[request.name], serialized]])
        self._handle_block_changes(change_request)
        # Regenerate list of blocks
        self.process_block["blocks"].set_value(list(self._blocks))

    def get_block(self, block_name):
        try:
            return self._blocks[block_name]
        except KeyError:
            if block_name in self.process_block.remoteBlocks:
                return self.make_client_block(block_name)
            else:
                raise

    def make_client_block(self, block_name):
        params = ClientController.MethodMeta.prepare_input_map(
            mri=block_name)
        controller = ClientController(self, {}, params)
        return controller.block

    def get_controller(self, block_name):
        return self._controllers[block_name]

    def _handle_subscribe(self, request):
        """Add a new subscriber and respond with the current
        sub-structure state"""
        key = request.generate_key()
        assert key not in self._subscriptions, \
            "Subscription on %s already exists" % (key,)
        self._subscriptions[key] = request
        self._block_state_cache.add_subscriber(request, request.endpoint)
        d = self._block_state_cache.walk_path(request.endpoint)
        self.log_debug("Initial subscription value %s", d)
        if request.delta:
            request.respond_with_delta([[[], d]])
        else:
            request.respond_with_update(d)

    def _handle_unsubscribe(self, request):
        """Remove a subscriber and respond with success or error"""
        key = request.generate_key()
        try:
            subscription = self._subscriptions.pop(key)
        except KeyError:
            request.respond_with_error(
                "No subscription found for %s" % (key,))
        else:
            self._block_state_cache.remove_subscriber(
                subscription, subscription.endpoint)
            request.respond_with_return()

    def _handle_get(self, request):
        d = self._block_state_cache.walk_path(request.endpoint)
        request.respond_with_return(d)
コード例 #9
0
ファイル: process.py プロジェクト: shroffk/pymalcolm
class Process(Loggable):
    """Hosts a number of Blocks, distributing requests between them"""
    def __init__(self, name, sync_factory):
        self.set_logger_name(name)
        self.name = name
        self.sync_factory = sync_factory
        self.q = self.create_queue()
        self._blocks = OrderedDict()  # block_name -> Block
        self._controllers = OrderedDict()  # block_name -> Controller
        self._block_state_cache = Cache()
        self._recv_spawned = None
        self._other_spawned = []
        # lookup of all Subscribe requests, ordered to guarantee subscription
        # notification ordering
        # {Request.generate_key(): Subscribe}
        self._subscriptions = OrderedDict()
        self.comms = []
        self._client_comms = OrderedDict()  # client comms -> list of blocks
        self._handle_functions = {
            Post: self._forward_block_request,
            Put: self._forward_block_request,
            Get: self._handle_get,
            Subscribe: self._handle_subscribe,
            Unsubscribe: self._handle_unsubscribe,
            BlockChanges: self._handle_block_changes,
            BlockRespond: self._handle_block_respond,
            BlockAdd: self._handle_block_add,
            BlockList: self._handle_block_list,
            AddSpawned: self._add_spawned,
        }
        self.create_process_block()

    def recv_loop(self):
        """Service self.q, distributing the requests to the right block"""
        while True:
            request = self.q.get()
            self.log_debug("Received request %s", request)
            if request is PROCESS_STOP:
                # Got the sentinel, stop immediately
                break
            try:
                self._handle_functions[type(request)](request)
            except Exception as e:  # pylint:disable=broad-except
                self.log_exception("Exception while handling %s", request)
                try:
                    request.respond_with_error(str(e))
                except Exception:
                    pass

    def add_comms(self, comms):
        assert not self._recv_spawned, \
            "Can't add comms when process has been started"
        self.comms.append(comms)

    def start(self):
        """Start the process going"""
        self._recv_spawned = self.sync_factory.spawn(self.recv_loop)
        for comms in self.comms:
            comms.start()

    def stop(self, timeout=None):
        """Stop the process and wait for it to finish

        Args:
            timeout (float): Maximum amount of time to wait for each spawned
                process. None means forever
        """
        assert self._recv_spawned, "Process not started"
        self.q.put(PROCESS_STOP)
        for comms in self.comms:
            comms.stop()
        # Wait for recv_loop to complete first
        self._recv_spawned.wait(timeout=timeout)
        # Now wait for anything it spawned to complete
        for s, _ in self._other_spawned:
            s.wait(timeout=timeout)
        # Garbage collect the syncfactory
        del self.sync_factory

    def _forward_block_request(self, request):
        """Lookup target Block and spawn block.handle_request(request)

        Args:
            request (Request): The message that should be passed to the Block
        """
        block_name = request.endpoint[0]
        block = self._blocks[block_name]
        spawned = self.sync_factory.spawn(block.handle_request, request)
        self._add_spawned(AddSpawned(spawned, block.handle_request))

    def create_queue(self):
        """
        Create a queue using sync_factory object

        Returns:
            Queue: New queue
        """

        return self.sync_factory.create_queue()

    def create_lock(self):
        """
        Create a lock using sync_factory object

        Returns:
            New lock object
        """
        return self.sync_factory.create_lock()

    def spawn(self, function, *args, **kwargs):
        """Calls SyncFactory.spawn()"""
        def catching_function():
            try:
                function(*args, **kwargs)
            except Exception:
                self.log_exception("Exception calling %s(*%s, **%s)", function,
                                   args, kwargs)
                raise

        spawned = self.sync_factory.spawn(catching_function)
        request = AddSpawned(spawned, function)
        self.q.put(request)
        return spawned

    def _add_spawned(self, request):
        spawned = self._other_spawned
        self._other_spawned = []
        spawned.append((request.spawned, request.function))
        # Filter out the spawned that have completed to stop memory leaks
        for sp, f in spawned:
            if not sp.ready():
                self._other_spawned.append((sp, f))

    def get_client_comms(self, block_name):
        for client_comms, blocks in list(self._client_comms.items()):
            if block_name in blocks:
                return client_comms

    def create_process_block(self):
        self.process_block = Block()
        # TODO: add a meta here
        children = OrderedDict()
        children["blocks"] = StringArrayMeta(
            description="Blocks hosted by this Process").make_attribute([])
        children["remoteBlocks"] = StringArrayMeta(
            description="Blocks reachable via ClientComms").make_attribute([])
        self.process_block.replace_endpoints(children)
        self.process_block.set_process_path(self, [self.name])
        self.add_block(self.process_block, self)

    def update_block_list(self, client_comms, blocks):
        self.q.put(BlockList(client_comms=client_comms, blocks=blocks))

    def _handle_block_list(self, request):
        self._client_comms[request.client_comms] = request.blocks
        remotes = []
        for blocks in self._client_comms.values():
            remotes += [b for b in blocks if b not in remotes]
        self.process_block["remoteBlocks"].set_value(remotes)

    def _handle_block_changes(self, request):
        """Update subscribers with changes and applies stored changes to the
        cached structure"""
        # update cached dict
        subscription_changes = self._block_state_cache.apply_changes(
            *request.changes)

        # Send out the changes
        for subscription, changes in subscription_changes.items():
            if subscription.delta:
                # respond with the filtered changes
                subscription.respond_with_delta(changes)
            else:
                # respond with the structure of everything
                # below the endpoint
                d = self._block_state_cache.walk_path(subscription.endpoint)
                subscription.respond_with_update(d)

    def report_changes(self, *changes):
        self.q.put(BlockChanges(changes=list(changes)))

    def block_respond(self, response, response_queue):
        self.q.put(BlockRespond(response, response_queue))

    def _handle_block_respond(self, request):
        """Push the response to the required queue"""
        request.response_queue.put(request.response)

    def add_block(self, block, controller):
        """Add a block to be hosted by this process

        Args:
            block (Block): The block to be added
            controller (Controller): Its controller
        """
        path = block.process_path
        assert len(path) == 1, \
            "Expected block %r to have %r as parent, got path %r" % \
            (block, self, path)
        name = path[0]
        assert name not in self._blocks, \
            "There is already a block called %r" % name
        request = BlockAdd(block=block, controller=controller, name=name)
        if self._recv_spawned:
            # Started, so call in Process thread
            self.q.put(request)
        else:
            # Not started yet so we are safe to add in this thread
            self._handle_block_add(request)

    def _handle_block_add(self, request):
        """Add a block to be hosted by this process"""
        assert request.name not in self._blocks, \
            "There is already a block called %r" % request.name
        self._blocks[request.name] = request.block
        self._controllers[request.name] = request.controller
        serialized = request.block.to_dict()
        change_request = BlockChanges([[[request.name], serialized]])
        self._handle_block_changes(change_request)
        # Regenerate list of blocks
        self.process_block["blocks"].set_value(list(self._blocks))

    def get_block(self, block_name):
        try:
            return self._blocks[block_name]
        except KeyError:
            if block_name in self.process_block.remoteBlocks:
                return self.make_client_block(block_name)
            else:
                raise

    def make_client_block(self, block_name):
        params = ClientController.MethodMeta.prepare_input_map(mri=block_name)
        controller = ClientController(self, {}, params)
        return controller.block

    def get_controller(self, block_name):
        return self._controllers[block_name]

    def _handle_subscribe(self, request):
        """Add a new subscriber and respond with the current
        sub-structure state"""
        key = request.generate_key()
        assert key not in self._subscriptions, \
            "Subscription on %s already exists" % (key,)
        self._subscriptions[key] = request
        self._block_state_cache.add_subscriber(request, request.endpoint)
        d = self._block_state_cache.walk_path(request.endpoint)
        self.log_debug("Initial subscription value %s", d)
        if request.delta:
            request.respond_with_delta([[[], d]])
        else:
            request.respond_with_update(d)

    def _handle_unsubscribe(self, request):
        """Remove a subscriber and respond with success or error"""
        key = request.generate_key()
        try:
            subscription = self._subscriptions.pop(key)
        except KeyError:
            request.respond_with_error("No subscription found for %s" %
                                       (key, ))
        else:
            self._block_state_cache.remove_subscriber(subscription,
                                                      subscription.endpoint)
            request.respond_with_return()

    def _handle_get(self, request):
        d = self._block_state_cache.walk_path(request.endpoint)
        request.respond_with_return(d)
コード例 #10
0
ファイル: controller.py プロジェクト: shroffk/pymalcolm
class Controller(Loggable):
    """Implement the logic that takes a Block through its state machine"""
    stateMachine = sm()

    # Attributes for all controllers
    state = None
    status = None
    busy = None
    # BlockMeta for descriptions
    meta = None

    def __init__(self, process, parts, params):
        """
        Args:
            process (Process): The process this should run under
            params (Map): The parameters specified in method_takes()
            parts (list): [Part]
        """
        self.process = process
        self.params = params
        self.mri = params.mri
        controller_name = "%s(%s)" % (type(self).__name__, self.mri)
        self.set_logger_name(controller_name)
        self.block = Block()
        self.log_debug("Creating block %r as %r", self.block, self.mri)
        self.lock = process.create_lock()
        # {part: task}
        self.part_tasks = {}
        # dictionary of dictionaries
        # {state (str): {Meta/MethodMeta/Attribute: writeable (bool)}
        self.children_writeable = {}
        # dict {hook: name}
        self.hook_names = self._find_hooks()
        self.parts = self._setup_parts(parts, controller_name)
        self._set_block_children()
        self._do_transition(sm.DISABLED, "Disabled")
        self.block.set_process_path(process, [self.mri])
        process.add_block(self.block, self)
        self.do_initial_reset()

    def _find_hooks(self):
        hook_names = {}
        for n in dir(self):
            attr = getattr(self, n)
            if isinstance(attr, Hook):
                assert attr not in hook_names, \
                    "Hook %s already in controller as %s" % (
                        n, hook_names[attr])
                hook_names[attr] = n
        return hook_names

    def _setup_parts(self, parts, controller_name):
        parts_dict = OrderedDict()
        for part in parts:
            part.set_logger_name("%s.%s" % (controller_name, part.name))
            # Check part hooks into one of our hooks
            for func_name, part_hook, _ in get_hook_decorated(part):
                assert part_hook in self.hook_names, \
                    "Part %s func %s not hooked into %s" % (
                        part.name, func_name, self)
            parts_dict[part.name] = part
        return parts_dict

    def do_initial_reset(self):
        pass

    def _set_block_children(self):
        # reconfigure block with new children
        child_list = [self.create_meta()]
        child_list += list(self.create_attributes())
        child_list += list(self.create_methods())
        for part in self.parts.values():
            child_list += list(part.create_attributes())
            child_list += list(part.create_methods())

        self.children_writeable = {}
        writeable_functions = {}
        children = OrderedDict()

        for name, child, writeable_func in child_list:
            if isinstance(child, Attribute):
                states = child.meta.writeable_in
            else:
                states = child.writeable_in
            children[name] = child
            if states:
                for state in states:
                    assert state in self.stateMachine.possible_states, \
                        "State %s is not one of the valid states %s" % \
                        (state, self.stateMachine.possible_states)
            elif writeable_func is not None:
                states = [
                    state for state in self.stateMachine.possible_states
                    if state not in (sm.DISABLING, sm.DISABLED)
                ]
            else:
                continue
            self.register_child_writeable(name, states)
            if writeable_func:
                writeable_functions[name] = functools.partial(
                    self.call_writeable_function, writeable_func)

        self.block.replace_endpoints(children)
        self.block.set_writeable_functions(writeable_functions)

    def call_writeable_function(self, function, child, *args):
        with self.lock:
            if not child.writeable:
                raise ValueError("Child %r is not writeable" %
                                 (child.process_path, ))
        result = function(*args)
        return result

    def create_meta(self):
        self.meta = BlockMeta()
        return "meta", self.meta, None

    def create_attributes(self):
        """Method that should provide Attribute instances for Block

        Yields:
            tuple: (string name, Attribute, callable put_function).
        """
        # Add the state, status and busy attributes
        self.state = ChoiceMeta("State of Block",
                                self.stateMachine.possible_states,
                                label="State").make_attribute()
        yield "state", self.state, None
        self.status = StringMeta("Status of Block",
                                 label="Status").make_attribute()
        yield "status", self.status, None
        self.busy = BooleanMeta("Whether Block busy or not",
                                label="Busy").make_attribute()
        yield "busy", self.busy, None

    def create_methods(self):
        """Method that should provide MethodMeta instances for Block

        Yields:
            tuple: (string name, MethodMeta, callable post_function).
        """
        return get_method_decorated(self)

    def transition(self, state, message):
        """
        Change to a new state if the transition is allowed

        Args:
            state(str): State to transition to
            message(str): Status message
        """
        with self.lock:
            if self.stateMachine.is_allowed(initial_state=self.state.value,
                                            target_state=state):
                self._do_transition(state, message)
            else:
                raise TypeError("Cannot transition from %s to %s" %
                                (self.state.value, state))

    def _do_transition(self, state, message):
        # transition is allowed, so set attributes
        changes = []
        changes.append([["state", "value"], state])
        changes.append([["status", "value"], message])
        changes.append([["busy", "value"], state
                        in self.stateMachine.busy_states])

        # say which children are now writeable
        for name in self.block:
            try:
                writeable = self.children_writeable[state][name]
            except KeyError:
                continue
            child = self.block[name]
            if isinstance(child, Attribute):
                changes.append([[name, "meta", "writeable"], writeable])
            elif isinstance(child, MethodMeta):
                changes.append([[name, "writeable"], writeable])
                for ename in child.takes.elements:
                    path = [name, "takes", "elements", ename, "writeable"]
                    changes.append([path, writeable])

        self.log_debug("Transitioning to %s", state)
        self.block.apply_changes(*changes)

    def register_child_writeable(self, name, states):
        """
        Set the states that the given method can be called in

        Args:
            name (str): Child name that will be set writeable or not
            states (list[str]): states where method is writeable
        """
        for state in self.stateMachine.possible_states:
            writeable_dict = self.children_writeable.setdefault(state, {})
            is_writeable = state in states
            writeable_dict[name] = is_writeable

    def create_part_tasks(self):
        part_tasks = {}
        for part_name, part in self.parts.items():
            part_tasks[part] = Task("Task(%s)" % part_name, self.process)
        return part_tasks

    def run_hook(self, hook, part_tasks, *args, **params):
        hook_queue, hook_runners = self.start_hook(hook, part_tasks, *args,
                                                   **params)
        return_dict = self.wait_hook(hook_queue, hook_runners)
        return return_dict

    def start_hook(self, hook, part_tasks, *args, **params):
        assert hook in self.hook_names, \
            "Hook %s doesn't appear in controller hooks %s" % (
                hook, self.hook_names)

        # ask the hook to find the functions it should run
        part_funcs = hook.find_hooked_functions(self.parts)
        hook_runners = {}
        self.log_debug("Run %s hook on %s", self.hook_names[hook],
                       [p.name for p in part_funcs])

        # now start them off
        hook_queue = self.process.create_queue()
        for part, func_name in part_funcs.items():
            task = weakref.proxy(part_tasks[part])
            hook_runner = HookRunner(hook_queue, part, func_name, task, *args,
                                     **params)
            hook_runner.start()
            hook_runners[part] = hook_runner

        return hook_queue, hook_runners

    def wait_hook(self, hook_queue, hook_runners):
        # Wait for them all to finish
        return_dict = {}
        while hook_runners:
            part, ret = hook_queue.get()
            hook_runner = hook_runners.pop(part)

            if isinstance(ret, AbortedError):
                # If AbortedError, all tasks have already been stopped.
                self.log_debug("Part %s Aborted", part.name)
                # Do not wait on them otherwise we might get a deadlock...
                raise ret

            # Wait for the process to terminate
            hook_runner.wait()
            return_dict[part.name] = ret
            self.log_debug("Part %s returned %r. Still waiting for %s",
                           part.name, ret, [p.name for p in hook_runners])

            if isinstance(ret, Exception):
                # Got an error, so stop and wait all hook runners
                for h in hook_runners.values():
                    h.stop()
                # Wait for them to finish
                for h in hook_runners.values():
                    h.wait()
                raise ret

        return return_dict