From e411a2738ded599de6dfa2510a996561438f217d Mon Sep 17 00:00:00 2001
From: Sean Robinson <seankrobinson@gmail.com>
Date: Fri, 28 Mar 2014 04:50:46 -0700
Subject: [PATCH] Convert scanning_thread Queues to a Pipe

Signed-off-by: Sean Robinson <seankrobinson@gmail.com>
---
 wifiradar/connections.py | 47 +++++++++++++++++++++--------------------------
 1 file changed, 21 insertions(+), 26 deletions(-)

diff --git a/wifiradar/connections.py b/wifiradar/connections.py
index 28a20d5..83a55c9 100644
--- a/wifiradar/connections.py
+++ b/wifiradar/connections.py
@@ -66,21 +66,14 @@ def get_enc_mode(use_wpa, key):
     else:
         return 'wep'
 
-def scanning_thread(config_manager, apQueue, commandQueue, exit_event):
-    """ Scan for a limited time and return AP names and bssid found.
-    Access points we find will be put on the outgoing Queue, apQueue.
+def scanning_thread(config_manager, msg_pipe):
+    """ Scan for access point information and send a profile for each
+        on 'msg_pipe'.
 
     Parameters:
 
        'config_manager' -- ConfigManager - Configuration Manager
-
-       'apQueue' -- Queue - Queue on which to put AP profiles
-
-       'commandQueue' -- Queue - Queue from which to read commands
-
-    Returns:
-
-       nothing
+       'msg_pipe' -- Pipe - bi-directional pipe
     """
     # Setup our essid pattern matcher
     essid_pattern = re.compile("ESSID\s*(:|=)\s*\"([^\"]+)\"", re.I | re.M  | re.S)
@@ -95,14 +88,22 @@ def scanning_thread(config_manager, apQueue, commandQueue, exit_event):
     command = "scan"
     while True:
         # check for exit call before trying to process
-        if exit_event.isSet():
-            return
-        try:
-            command = commandQueue.get_nowait()
-            logger.info("received command: %s" % (command, ))
-            command_read = True
-        except queue.Empty:
-            command_read = False
+        if msg_pipe.poll(1):
+            try:
+                msg = msg_pipe.recv()
+            except (EOFError, IOError) as e:
+                # This is bad, really bad.
+                logger.critical('read on closed ' +
+                    'Pipe ({}), failing...'.format(rfd))
+                raise misc.PipeError(e)
+            else:
+                if msg.topic == 'EXIT':
+                    msg_pipe.close()
+                    break
+                elif msg.topic == 'SCAN-START':
+                    command = 'scan'
+                elif msg.topic == 'SCAN-STOP':
+                    command = 'pause'
         try:
             device = config_manager.get_network_device()
         except misc.NoDeviceError as e:
@@ -148,13 +149,7 @@ def scanning_thread(config_manager, apQueue, commandQueue, exit_event):
             for bssid in access_points:
                 access_points[bssid]['available'] = (access_points[bssid]['signal'] > 0)
                 # Put all, now or previously, sensed access_points into apQueue
-                try:
-                    apQueue.put_nowait(access_points[bssid])
-                except queue.Full:
-                    pass
-        if command_read:
-            commandQueue.task_done()
-        sleep(1)
+                msg_pipe.send(Message('ACCESSPOINT', access_points[bssid]))
 
 
 class ConnectionManager(object):
-- 
2.11.4.GIT