# under the terms of the license (GNU LGPL) which comes with this package.
"""
-/* This example demonstrates how to dynamically modify a graph of tasks.
- *
- * Assuming we have two instances of a service placed on different hosts,
- * we want to send data alternatively to thoses instances.
- *
- * We consider the following graph:
+This example demonstrates how to dynamically modify a graph of tasks.
+
+Assuming we have two instances of a service placed on different hosts,
+we want to send data alternatively to thoses instances.
+
+We consider the following graph:
comm1
┌────────────────────────┐
│ │
└────────────────────────┘
comm2
- */
- """
+
+"""
from argparse import ArgumentParser
import sys
return parser.parse_args()
def callback(t):
- print(f'[{Engine.clock}] {t} finished ({t.count})')
+ print(f'[{Engine.clock}] {t} finished ({t.get_count()})')
+
+def switch_destination(t, hosts):
+ t.destination = hosts[switch_destination.count % 2]
+ switch_destination.count += 1
+switch_destination.count = 0
-def switch(t, hosts, execs):
- comm0.destination = hosts[t.count % 2]
- comm0.remove_successor(execs[t.count % 2 - 1])
- comm0.add_successor(execs[t.count % 2])
+def switch_successor(t, execs):
+ t.remove_successor(execs[t.get_count() % 2])
+ t.add_successor(execs[t.get_count() % 2 - 1])
if __name__ == '__main__':
args = parse()
exec1.add_successor(comm1)
exec2.add_successor(comm2)
- # Add a function to be called when tasks end for log purpose
+ # Add a callback when tasks end for log purpose
Task.on_completion_cb(callback)
- # Add a function to be called before each firing of comm0
- # This function modifies the graph of tasks by adding or removing
- # successors to comm0
- comm0.on_this_start_cb(lambda t: switch(t, [jupiter, fafard], [exec1,exec2]))
+ # Add a callback before each firing of comm0
+ # It switches the destination of comm0
+ comm0.on_this_start_cb(lambda t: switch_destination(t, [jupiter, fafard]))
+
+ # Add a callback before comm0 send tokens to successors
+ # It switches the successor of comm0
+ comm0.on_this_completion_cb(lambda t: switch_successor(t, [exec1,exec2]))
# Enqueue two firings for task exec1
comm0.enqueue_firings(4)
