[toranj] adding verify_within and updating test-014-ip-address-add. (#2871)

This commit adds a new function `verify_within` in `toranj` wpan
library. This function verifies that certain conditions (given as
function handler) pass within a given wait time interval. The
`verify` function is also changed to raise an exception (instead
of immediate `exit(1)`).

The new function is then used in `test-014` to allow faster checks
after device reset while giving longer wait time for test to pass.

tests/toranj/test-014-ip6-address-add.py

@@ -122,18 +122,13 @@ r2.add_ip6_address_on_interface(IP6_ADDR_1, prefix_len=64)
 fed1.add_ip6_address_on_interface(IP6_ADDR_2, prefix_len=64)
 sed2.add_ip6_address_on_interface(IP6_ADDR_3, prefix_len=64)
 
-for iter in range(2):
-
-    time.sleep(1.5)
-
+def check_addresses_and_prefixes():
     # Verify that the addresses are present in "IPv6:AllAddresses" wpantund property on the corresponding node.
-
     verify(r2.find_ip6_address_with_prefix(IP6_PREFIX_1)   == IP6_ADDR_1)
     verify(fed1.find_ip6_address_with_prefix(IP6_PREFIX_2) == IP6_ADDR_2)
     verify(sed2.find_ip6_address_with_prefix(IP6_PREFIX_3) == IP6_ADDR_3)
 
     # Verify that all prefixes are present in network data on all nodes (with correct flags).
-
     for prefix in [IP6_PREFIX_1, IP6_PREFIX_2, IP6_PREFIX_3]:
         for node in all_nodes:
             prefixes = wpan.parse_on_mesh_prefix_result(node.get(wpan.WPAN_THREAD_ON_MESH_PREFIXES))
@@ -150,35 +145,36 @@ for iter in range(2):
                     verify(p.priority == "med")
                     break
             else: # `for` loop finished without finding the prefix.
-                print 'Did not find prefix {} on node {}'.format(prefix, node)
-                exit(1)
+                raise wpan.VerifyError('Did not find prefix {} on node {}'.format(prefix, node))
 
     # Verify that IPv6 address of `sed2` is present on `r2` (its parent) "Thread:ChildTable:Addresses".
-
     addr_str = r2.get(wpan.WPAN_THREAD_CHILD_TABLE_ADDRESSES)
     # search for index on address in the `addr_str` and ensure it is non-negative.
     verify(addr_str.find(IP6_ADDR_3) >= 0)
 
-    if iter == 0:
-        # Reset the nodes and verify that all addresses/prefixes are preserved.
-        fed1.reset()
-        sed2.reset()
 
+# Check the addresses and prefixes (wait time 20 seconds)
+wpan.verify_within(check_addresses_and_prefixes, 15)
+
+# Reset the nodes and verify that all addresses/prefixes are preserved.
+fed1.reset()
+sed2.reset()
+wpan.verify_within(check_addresses_and_prefixes, 20)
 
 # Remove address from `r2`
-
 r2.remove_ip6_address_on_interface(IP6_ADDR_1, prefix_len=64)
 
-time.sleep(1.5)
+def check_address_prefix_removed():
+    # Verify that address is removed from r2
+    verify(r2.find_ip6_address_with_prefix(IP6_PREFIX_1) == '')
+    # Verify that the related prefix is also removed on all nodes
+    for node in all_nodes:
+        prefixes = wpan.parse_on_mesh_prefix_result(node.get(wpan.WPAN_THREAD_ON_MESH_PREFIXES))
+        for p in prefixes:
+            verify(p.prefix != IP6_PREFIX_1)
 
-# Verify that address is removed from r2
-verify(r2.find_ip6_address_with_prefix(IP6_PREFIX_1) == '')
-
-# Verify that the related prefix is also removed on all nodes
-for node in all_nodes:
-    prefixes = wpan.parse_on_mesh_prefix_result(node.get(wpan.WPAN_THREAD_ON_MESH_PREFIXES))
-    for p in prefixes:
-        verify(p.prefix != IP6_PREFIX_1)
+# Check the addresses and prefixes (wait time 15 seconds)
+wpan.verify_within(check_address_prefix_removed, 15)
 
 #-----------------------------------------------------------------------------------------------------------------------
 # Test finished

tests/toranj/wpan.py

@@ -514,7 +514,7 @@ class Node(object):
     #------------------------------------------------------------------------------------------------------------------
     # IPv6 message Sender and Receiver class
 
-    class _NodeError(BaseException):
+    class _NodeError(Exception):
         pass
 
     def prepare_tx(self, src, dst, data=40, count=1):
@@ -799,14 +799,45 @@ class AsyncReceiver(asyncore.dispatcher):
         self._node._remove_recver(self)
 
 #-----------------------------------------------------------------------------------------------------------------------
+class VerifyError(Exception):
+    pass
+
+_is_in_verify_within = False
 
 def verify(condition):
-    """Verifies that a `condition` is true, otherwise exits"""
+    """Verifies that a `condition` is true, otherwise raises a VerifyError"""
+    global _is_in_verify_within
     if not condition:
         calling_frame = inspect.currentframe().f_back
-        print 'verify() failed at line {} in "{}"'.format(calling_frame.f_lineno, calling_frame.f_code.co_filename)
-        exit(1)
+        error_message = 'verify() failed at line {} in "{}"'.format(calling_frame.f_lineno, calling_frame.f_code.co_filename)
+        if not _is_in_verify_within:
+            print error_message
+        raise VerifyError(error_message)
 
+def verify_within(condition_checker_func, wait_time, delay_time=0.1):
+    """Verifies that a given function `condition_checker_func` passes successfully within a given wait timeout.
+       `wait_time` is maximum time waiting for condition_checker to pass (in seconds).
+       `delay_time` specifies a delay interval added between failed attempts (in seconds).
+    """
+    global _is_in_verify_within
+    start_time = time.time()
+    old_is_in_verify_within = _is_in_verify_within
+    _is_in_verify_within = True
+    while True:
+        try:
+            condition_checker_func()
+        except VerifyError as e:
+            if time.time() - start_time > wait_time:
+                print 'Took too long to pass the condition ({}>{} sec)'.format(time.time() - start_time, wait_time)
+                print e.message
+                raise e
+        except:
+            raise
+        else:
+            break
+        if delay_time != 0:
+            time.sleep(delay_time)
+    _is_in_verify_within = old_is_in_verify_within
 
 #-----------------------------------------------------------------------------------------------------------------------
 # Parsing `wpanctl` output