ftests: Add class to create and manage child processes

Add a class that can create and delete child processes.

Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>

diff --git a/ftests/ftests.py b/ftests/ftests.py
index 7b39d6c9ec373af3204f57dc6d71ea9998cf92e7..6ac5ba70966752b9f2d298eb3dbc07c95ef79eff 100755 (executable)
--- a/ftests/ftests.py
+++ b/ftests/ftests.py
@@ -29,6 +29,7 @@ import datetime
 import log
 from log import Log
 import os
+from process import Process
 from run import Run
 import sys
 import time
@@ -273,6 +274,9 @@ def run_tests(config):
 def teardown(config, record_time=False):
     global teardown_time
     start_time = time.time()
+
+    Process.join_children()
+
     try:
         config.container.stop()
     except Exception as e:

diff --git a/ftests/process.py b/ftests/process.py
new file mode 100644 (file)
index 0000000..82a40d2
--- /dev/null
+++ b/ftests/process.py
@@ -0,0 +1,78 @@
+#
+# Cgroup class for the libcgroup functional tests
+#
+# Copyright (c) 2020 Oracle and/or its affiliates.
+# Author: Tom Hromatka <tom.hromatka@oracle.com>
+#
+
+#
+# This library is free software; you can redistribute it and/or modify it
+# under the terms of version 2.1 of the GNU Lesser General Public License as
+# published by the Free Software Foundation.
+#
+# This library is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
+# for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this library; if not, see <http://www.gnu.org/licenses>.
+#
+
+from cgroup import Cgroup
+import multiprocessing as mp
+from run import Run
+import time
+
+children = list()
+
+class Process(object):
+    @staticmethod
+    def __infinite_loop(config, sleep_time=1, in_container=True):
+        cmd = ['nohup', 'perl', '-e', '\'while(1){{sleep({})}};\''.format(sleep_time), '&']
+
+        if in_container:
+            config.container.run(cmd, shell_bool=True)
+        else:
+            Run.run(cmd, shell_bool=True)
+
+    @staticmethod
+    def create_process(config, in_container=True):
+        # To allow for multiple processes to be created, each new process
+        # sleeps for a different amount of time.  This lets us uniquely find
+        # each process later in this function
+        sleep_time = len(children) + 1
+
+        p = mp.Process(target=Process.__infinite_loop,
+                       args=(config, sleep_time, ))
+        p.start()
+
+        # wait for the process to start.  If we don't wait, then the getpid
+        # logic below may not find the process
+        time.sleep(2)
+
+        # get the PID of the newly spawned infinite loop
+        cmd = 'ps x | grep perl | grep "sleep({})" | awk \'{{print $1}}\''.format(sleep_time)
+        if in_container:
+            pid = config.container.run(cmd, shell_bool=True)
+        else:
+            pid = Run.run(cmd, shell_bool=True)
+
+        if pid == "" or int(pid) <= 0:
+            raise ValueException('Failed to get the pid of the child process: {}'.format(pid))
+
+        children.append(p)
+        return pid
+
+    # Create a simple process in the requested cgroup
+    @staticmethod
+    def create_process_in_cgroup(config, controller, cgname, in_container=True):
+        child_pid = Process.create_process(config, in_container=in_container)
+        Cgroup.classify(config, controller, cgname, child_pid,
+                        in_container=in_container)
+
+    # The caller will block until all children are stopped.
+    @staticmethod
+    def join_children():
+        for child in children:
+             child.join(1)