--- /dev/null
+# Copyright (c) 2006-2023. The SimGrid Team. All rights reserved.
+#
+# This program is free software; you can redistribute it and/or modify it
+# under the terms of the license (GNU LGPL) which comes with this package.
+
+"""
+This example demonstrates how to create a variable load for tasks.
+We consider the following graph:
+
+comm -> exec
+
+With a small load each comm task is followed by an exec task.
+With a heavy load there is a burst of comm before the exec task can even finish once.
+"""
+
+from argparse import ArgumentParser
+import sys
+from simgrid import Engine, Task, CommTask, ExecTask, Actor, this_actor
+
+def parse():
+ parser = ArgumentParser()
+ parser.add_argument(
+ '--platform',
+ type=str,
+ required=True,
+ help='path to the platform description'
+ )
+ return parser.parse_args()
+
+def callback( t):
+ print(f'[{Engine.clock}] { t} finished ({ t.count})')
+
+def variable_load( t):
+ print('--- Small load ---')
+ for i in range(3):
+ t.enqueue_execs(1)
+ this_actor.sleep_for(100)
+ this_actor.sleep_for(1000)
+ print('--- Heavy load ---')
+ for i in range(3):
+ t.enqueue_execs(1)
+ this_actor.sleep_for(1)
+
+if __name__ == '__main__':
+ args = parse()
+ e = Engine(sys.argv)
+ e.load_platform(args.platform)
+ Task.init()
+
+ # Retrieve hosts
+ tremblay = e.host_by_name('Tremblay')
+ jupiter = e.host_by_name('Jupiter')
+
+ # Create tasks
+ comm = CommTask.init("comm", 1e7, tremblay, jupiter)
+ exec = ExecTask.init("exec", 1e9, jupiter)
+
+ # Create the graph by defining dependencies between tasks
+ comm.add_successor(exec)
+
+ # Add a function to be called when tasks end for log purpose
+ Task.on_end_cb(callback)
+
+ # Create the actor that will inject load during the simulation
+ Actor.create("input", tremblay, variable_load, comm)
+
+ # runs the simulation
+ e.run()
