- fixed #64

- we cannot detect network status at socket.send method, immediately.
  - add ping_timeout argument to WebSocketApp.run_forever method.
    - ping_timeout is timeout seconds after ping.
    - if timeouted, raise WebSocketTimeoutException.

websocket/__init__.py

@@ -42,6 +42,7 @@ import uuid
 import hashlib
 import base64
 import threading
+import time
 import logging
 import traceback
 import sys
@@ -803,7 +804,7 @@ class WebSocket(object):
             if "timed out" in e.message:
                 raise WebSocketTimeoutException(e.message)
             else:
-                raise e
+                raise
 
     def _recv(self, bufsize):
         try:
@@ -892,6 +893,7 @@ class WebSocketApp(object):
         self.keep_running = keep_running
         self.get_mask_key = get_mask_key
         self.sock = None
+        self.last_ping_tm = 0
 
     def send(self, data, opcode=ABNF.OPCODE_TEXT):
         """
@@ -911,9 +913,10 @@ class WebSocketApp(object):
 
     def _send_ping(self, interval, event):
         while not event.wait(interval):
+            self.last_ping_tm = time.time()
             self.sock.ping()
 
-    def run_forever(self, sockopt=None, sslopt=None, ping_interval=0):
+    def run_forever(self, sockopt=None, sslopt=None, ping_interval=0, ping_timeout=None):
         """
         run event loop for WebSocket framework.
         This loop is infinite loop and is alive during websocket is available.
@@ -922,7 +925,10 @@ class WebSocketApp(object):
         sslopt: ssl socket optional dict.
         ping_interval: automatically send "ping" command every specified period(second)
             if set to 0, not send automatically.
+        ping_timeout: timeout(second) if the pong message is not recieved.
         """
+        if ping_timeout<=0:
+            ping_timeout = None
         if sockopt is None:
             sockopt = []
         if sslopt is None:
@@ -945,9 +951,14 @@ class WebSocketApp(object):
                 thread.start()
 
             while True:
-                select.select((self.sock.sock, ), (), ())
+                r, w, e = select.select((self.sock.sock, ), (), (), ping_timeout)
                 if not self.keep_running:
                     break
+                if ping_timeout and  time.time() - self.last_ping_tm > ping_timeout:
+                    self.last_ping_tm = 0
+                    raise WebSocketTimeoutException()
+                    
+                if r:
                     op_code, frame = self.sock.recv_data_frame(True)
                     if op_code == ABNF.OPCODE_CLOSE:
                         break