Add run_in_background attribute to scenarios

This change adds the possibility to run scenarios as "background
tasks".

Background scenarios/tasks:
  - are started before all "normal scenarios"
  - runs in parallel with "normal scenarios"
  - terminates when all "normal scenarios" have completed
    their tasks

They are intended as a way to perform background tasks, e.g. collect
data such as cpuload etc, in parallel with the execution of normal
benchmarking scenarios.

Note that we already have the 'run_in_parallel' attribute but
this attribute has a couple of issues and do not solve all the
uses cases.

Change-Id: I9c5230bfdbbb66030f57b658ce1db87ff2c2d62b
Signed-off-by: Jo¶rgen Karlsson <jorgen.w.karlsson@ericsson.com>

1 files changed, 37 insertions, 4 deletions

diff --git a/yardstick/cmd/commands/task.py b/yardstick/cmd/commands/task.py
index d6cd6984c..a56824aac 100755
--- a/yardstick/cmd/commands/task.py
+++ b/yardstick/cmd/commands/task.py
@@ -16,6 +16,7 @@ import atexit
 import ipaddress
 import time
 import logging
+from itertools import ifilter
 from yardstick.benchmark.contexts.base import Context
 from yardstick.benchmark.runners import base as base_runner
 from yardstick.common.task_template import TaskTemplate
@@ -108,11 +109,20 @@ class TaskCommands(object):
         for context in Context.list:
             context.deploy()
 
+        background_runners = []
+
+        # Start all background scenarios
+        for scenario in ifilter(_is_background_scenario, scenarios):
+            scenario["runner"] = dict(type="Duration", duration=1000000000)
+            runner = run_one_scenario(scenario, output_file)
+            background_runners.append(runner)
+
         runners = []
         if run_in_parallel:
             for scenario in scenarios:
-                runner = run_one_scenario(scenario, output_file)
-                runners.append(runner)
+                if not _is_background_scenario(scenario):
+                    runner = run_one_scenario(scenario, output_file)
+                    runners.append(runner)
 
             # Wait for runners to finish
             for runner in runners:
@@ -121,9 +131,25 @@ class TaskCommands(object):
         else:
             # run serially
             for scenario in scenarios:
-                runner = run_one_scenario(scenario, output_file)
+                if not _is_background_scenario(scenario):
+                    runner = run_one_scenario(scenario, output_file)
+                    runner_join(runner)
+                    print "Runner ended, output in", output_file
+
+        # Abort background runners
+        for runner in background_runners:
+            runner.abort()
+
+        # Wait for background runners to finish
+        for runner in background_runners:
+            if runner.join(timeout=60) is None:
+                # Nuke if it did not stop nicely
+                base_runner.Runner.terminate(runner)
                 runner_join(runner)
-                print "Runner ended, output in", output_file
+            else:
+                base_runner.Runner.release(runner)
+            print "Background task ended"
+
 
 # TODO: Move stuff below into TaskCommands class !?
 
@@ -280,6 +306,13 @@ def _is_same_heat_context(host_attr, target_attr):
     return False
 
 
+def _is_background_scenario(scenario):
+    if "run_in_background" in scenario:
+        return scenario["run_in_background"]
+    else:
+        return False
+
+
 def run_one_scenario(scenario_cfg, output_file):
     '''run one scenario using context'''
     runner_cfg = scenario_cfg["runner"]