1 files changed, 63 insertions, 0 deletions

diff --git a/experiment/litmus_util.py b/experiment/litmus_util.py
new file mode 100644
index 0000000..114f4c9
--- /dev/null
+++ b/experiment/litmus_util.py
@@ -0,0 +1,63 @@
+import re
+import time
+import subprocess
+import os
+import stat
+import config.config as conf
+
+def num_cpus():
+    """Return the number of CPUs in the system."""
+
+    lnx_re = re.compile(r'^(processor|online)')
+    cpus = 0
+
+    with open('/proc/cpuinfo', 'r') as f:
+        for line in f:
+            if lnx_re.match(line):
+                cpus += 1
+    return cpus
+
+def switch_scheduler(switch_to_in):
+    """Switch the scheduler to whatever is passed in.
+
+    This methods sleeps for two seconds to give Linux the chance to execute
+    schedule switching code. Raises an exception if the switch does not work.
+
+    """
+
+    switch_to = str(switch_to_in).strip()
+
+    with open('/proc/litmus/active_plugin', 'w') as active_plugin:
+        subprocess.Popen(["echo", switch_to], stdout=active_plugin)
+
+    # it takes a bit to do the switch, sleep an arbitrary amount of time
+    time.sleep(2)
+
+    with open('/proc/litmus/active_plugin', 'r') as active_plugin:
+        cur_plugin = active_plugin.read().strip()
+
+    if switch_to != cur_plugin:
+        raise Exception("Could not switch to plugin: %s" % switch_to)
+
+
+def is_executable(fname):
+    """Return whether the file passed in is executable"""
+    mode = os.stat(fname)[stat.ST_MODE]
+    return mode & stat.S_IXUSR and mode & stat.S_IRUSR
+
+def is_device(dev):
+    if not os.path.exists(dev):
+        return False
+    mode = os.stat(dev)[stat.ST_MODE]
+    return not (not mode & stat.S_IFCHR)
+
+def release_tasks():
+
+    try:
+        data = subprocess.check_output([conf.BINS['release']])
+    except subprocess.CalledProcessError:
+        raise Exception('Something went wrong in release_ts')
+
+    released = re.findall(r"([0-9]+) real-time", data)[0]
+
+    return int(released)