Fixes #195. Changed event loops to support a poll only link and chang…

…ed the stack class to use that

HISTORY.md

@@ -1,5 +1,12 @@
 # Revision Change History
 
+## [0.7.2]
+
+### Fixes
+
+- Fixed an issue causing 100% cpu usage introduced in the scene sync code.
+  ([Issue #195)[I195])
+
 ## [0.7.1]
 
 ### Fixes
@@ -355,3 +362,4 @@
 [I189]: https://github.com/TD22057/insteon-mqtt/issues/189
 [I192]: https://github.com/TD22057/insteon-mqtt/issues/192
 [I193]: https://github.com/TD22057/insteon-mqtt/issues/193
+[I195]: https://github.com/TD22057/insteon-mqtt/issues/195

insteon_mqtt/cmd_line/start.py

@@ -38,7 +38,7 @@ def start(args, cfg):
     # Add the clients to the event loop.
     loop.add(mqtt_link, connected=False)
     loop.add(plm_link, connected=False)
-    loop.add(stack_link, connected=True)
+    loop.add_poll(stack_link)
 
     # Create the insteon message protocol, modem, and MQTT handler and
     # link them together.

insteon_mqtt/network/Stack.py

@@ -3,7 +3,6 @@
 # Stack class definition.
 #
 #===========================================================================
-import tempfile
 from ..Signal import Signal
 from .. import log
 
@@ -14,7 +13,11 @@ class Stack:
     """A Fake Network Interface for Queueing and 'Asynchronously' Running
     Functional Calls
 
-    This class appears as though it is a read/write interface that is handled
+    This is a polling only network "link".  Unlike regular links that do read
+    and write operations when they report they are ready, this class is
+    designed to only be polled during the event loop.
+
+    This is like a network link for reading and writing but  that is handled
     my the network manager.  But in reality it is just a wrapper for inserting
     function calls into the network loop.  This allows long functional calls
     to be broken up into multiple sub calls that can be called on seperate
@@ -35,56 +38,15 @@ def __init__(self):
         # Sent when the link is going down.  signature: (Link link)
         self.signal_closing = Signal()
 
-        # Sent when the link changes state on whether or not it has bytes
-        # that need to be written to the link.  signature: (Link link, bool
-        # write_active)
-        self.signal_needs_write = Signal()
-
         # The manager will emit this after the connection has been
         # established and everything is ready.  Links should usually not emit
         # this directly.  signature: (Link link, bool connected)
         self.signal_connected = Signal()
 
-        # Generate a fileno using a temp file.  We could just pass 0, which
-        # seems to work, but not sure if this could cause a subtle bug. It
-        # might be better to have this be an actual file
-        self.tempfile = tempfile.TemporaryFile()
-
         # The list of groups of functions to call.  Each item should be a
         # StackGroup
         self.groups = []
 
-    #-----------------------------------------------------------------------
-    def retry_connect_dt(self):
-        """Return a positive integer (seconds) if the link should reconnect.
-
-        If this returns None, the link will not be reconnected if it closes.
-        Otherwise this is the retry interval in seconds to try and reconnect
-        the link by calling connect().
-        """
-        return None
-
-    #-----------------------------------------------------------------------
-    def connect(self):
-        """Connect the link to the device.
-
-        This should connect to the socket, serial port, file, etc.
-
-        Returns:
-          bool:  Returns True if the connection was successful or False it
-          it failed.
-        """
-        return True
-
-    #-----------------------------------------------------------------------
-    def fileno(self):
-        """Return the file descriptor to watch for this link.
-
-        Returns:
-          int:  Returns the descriptor (obj.fileno() usually) to monitor.
-        """
-        return self.tempfile
-
     #-----------------------------------------------------------------------
     def poll(self, t):
         """Periodic poll callback.
@@ -137,47 +99,18 @@ def new(self, error_stop=True):
         self.groups.append(new_stack)
         return new_stack
 
-    #-----------------------------------------------------------------------
-    def read_from_link(self):
-        """Read data from the link.
-
-        This will be called by the manager when there is data available on
-        the file descriptor for reading.
-
-        Returns:
-           int:  Return -1 if the link had an error.  Or any other integer
-           to indicate success.
-        """
-        raise NotImplementedError("%s.read_from_link() not implemented" %
-                                  self.__class__)
-
-    #-----------------------------------------------------------------------
-    def write_to_link(self, t):
-        """Write data from the link.
-
-        This will be called by the manager when the file descriptor can be
-        written to.  It will only be called after the link as emitted the
-        signal_needs_write(True).  Once all the data has been written, the
-        link should call self.signal_needs_write.emit(False).
-
-        Args:
-           t (float):  The current time (time.time).
-        """
-        raise NotImplementedError("%s.write_to_link() not implemented" %
-                                  self.__class__)
-
     #-----------------------------------------------------------------------
     def close(self):
         """Close the link.
 
         The link must call self.signal_closing.emit() after closing.
         """
-        raise NotImplementedError("%s.close() not implemented" %
-                                  self.__class__)
+        self.signal_closing.emit()
 
     #-----------------------------------------------------------------------
 
 
+#===========================================================================
 class StackGroup:
     """A Simple Class for Grouping Functional Calls
 

insteon_mqtt/network/poll.py

@@ -4,6 +4,7 @@
 #
 #===========================================================================
 import errno
+import itertools
 import select
 import time
 from .. import log
@@ -57,6 +58,8 @@ def __init__(self):
 
         # Map of fileno to Link objects.
         self.links = {}
+        # List of links to only call poll() on.
+        self.poll_links = []
 
         # List of unconnected link tuples (Link, time) where time is the time
         # is the next time to try reconnecting the linnk.
@@ -71,6 +74,26 @@ def active(self):
         """
         return len(self.links) + len(self.unconnected)
 
+    #-----------------------------------------------------------------------
+    def add_poll(self, link):
+        """Add a Link that is only polled.
+
+        The input link does not need a file descriptor and only has to
+        support the poll() method from the Link class.  The link closing
+        signal can be used to remove the link from the manager.
+
+        Args:
+          link (Link):  Link object to add to the manager.
+
+        """
+        LOG.debug("Polling link added: %s", link)
+        self.poll_links.append(link)
+
+        # Mirror the link signals from a regular link.  We may never use
+        # these but the symmetry might come in handy later.
+        link.signal_closing.connect(self.poll_link_closing)
+        link.signal_connected.emit(link, True)
+
     #-----------------------------------------------------------------------
     def add(self, link, connected=True):
         """Add a Link to the manager.
@@ -222,8 +245,9 @@ def select(self, time_out=None):
         # any kind.  There are some cases where the MQTT client poll can
         # trigger a close - I'm not sure exactly why but it's shown up in
         # user reports.  So copy the links before iterating since closing the
-        # link mods the dict which isn't allowed.
-        for link in list(self.links.values()):
+        # link mods the dict which isn't allowed.  This isn't ideal but the
+        # number of links should be small so it probably doesn't matter.
+        for link in itertools.chain(list(self.links.values()), self.poll_links):
             link.poll(t)
 
     #-----------------------------------------------------------------------
@@ -248,6 +272,19 @@ def link_closing(self, link):
         # no longer connected.
         link.signal_connected.emit(link, False)
 
+    #-----------------------------------------------------------------------
+    def poll_link_closing(self, link):
+        """Callback when a poll only link is closing.
+
+        Arg:
+          link (Link):  The link that is closing.
+        """
+        self.poll_links.remove(link)
+
+        # Emit the connected signal to let anyone else know that the link is
+        # no longer connected.
+        link.signal_connected.emit(link, False)
+
     #-----------------------------------------------------------------------
     def link_needs_write(self, link, needs_write):
         """Callback when a link write status changes state.

insteon_mqtt/network/select.py

@@ -7,6 +7,7 @@
 #
 #===========================================================================
 import errno
+import itertools
 import select
 import time
 from .. import log
@@ -50,8 +51,10 @@ def __init__(self):
         self.write = []
         self.error = []
 
-        # Map of filno to Link objects.
+        # Map of fileno to Link objects.
         self.links = {}
+        # List of links to only call poll() on.
+        self.poll_links = []
 
         # List of unconnected link tuples (Link, time) where time is the time
         # is the next time to try reconnecting the linnk.
@@ -66,8 +69,29 @@ def active(self):
         """
         return len(self.links) + len(self.unconnected)
 
+    #-----------------------------------------------------------------------
+    def add_poll(self, link):
+        """Add a Link that is only polled.
+
+        The input link does not need a file descriptor and only has to
+        support the poll() method from the Link class.  The link closing
+        signal can be used to remove the link from the manager.
+
+        Args:
+          link (Link):  Link object to add to the manager.
+
+        """
+        LOG.debug("Polling link added: %s", link)
+        self.poll_links.append(link)
+
+        # Mirror the link signals from a regular link.  We may never use
+        # these but the symmetry might come in handy later.
+        link.signal_closing.connect(self.poll_link_closing)
+        link.signal_connected.emit(link, True)
+
     #-----------------------------------------------------------------------
     def add(self, link, connected=True):
+
         """Add a Link to the manager.
 
         To remove a link, call link.close().
@@ -216,8 +240,9 @@ def select(self, time_out=None):
         # any kind.  There are some cases where the MQTT client poll can
         # trigger a close - I'm not sure exactly why but it's shown up in
         # user reports.  So copy the links before iterating since closing the
-        # link mods the dict which isn't allowed.
-        for link in list(self.links.values()):
+        # link mods the dict which isn't allowed.  This isn't ideal but the
+        # number of links should be small so it probably doesn't matter.
+        for link in itertools.chain(list(self.links.values()), self.poll_links):
             link.poll(t)
 
     #-----------------------------------------------------------------------
@@ -242,6 +267,19 @@ def link_closing(self, link):
         # no longer connected.
         link.signal_connected.emit(link, False)
 
+    #-----------------------------------------------------------------------
+    def poll_link_closing(self, link):
+        """Callback when a poll only link is closing.
+
+        Arg:
+          link (Link):  The link that is closing.
+        """
+        self.poll_links.remove(link)
+
+        # Emit the connected signal to let anyone else know that the link is
+        # no longer connected.
+        link.signal_connected.emit(link, False)
+
     #-----------------------------------------------------------------------
     def link_needs_write(self, link, needs_write):
         """Callback when a link write status changes state.