Source Code for Module baxter_dataflow.wait_for'

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27   
28  import errno 
29   
30  import rospy 
31   
32   
33 -def wait_for(test, timeout=1.0, raise_on_error=True, rate=100, 
34               timeout_msg="timeout expired", body=None): 
35      """ 
36      Waits until some condition evaluates to true. 
37   
38      @param test: zero param function to be evaluated 
39      @param timeout: max amount of time to wait. negative/inf for indefinitely 
40      @param raise_on_error: raise or just return False 
41      @param rate: the rate at which to check 
42      @param timout_msg: message to supply to the timeout exception 
43      @param body: optional function to execute while waiting 
44      """ 
45      end_time = rospy.get_time() + timeout 
46      rate = rospy.Rate(rate) 
47      notimeout = (timeout < 0.0) or timeout == float("inf") 
48      while not test(): 
49          if rospy.is_shutdown(): 
50              if raise_on_error: 
51                  raise OSError(errno.ESHUTDOWN, "ROS Shutdown") 
52              return False 
53          elif (not notimeout) and (rospy.get_time() >= end_time): 
54              if raise_on_error: 
55                  raise OSError(errno.ETIMEDOUT, timeout_msg) 
56              return False 
57          if callable(body): 
58              body() 
59          rate.sleep() 
60      return True 
61