add oslo-lock tracer

Change-Id: I7dbfe8c1b683af8705cadfb7e7aae7a2062040e5

scalpels/agents/base.py

@@ -65,3 +65,20 @@ def parse_rabbit(out):
                "rtype": "log",
                "data": out}
     return (rbt_ret, )
+
+def parse_oslolock(out):
+    """
+    in:
+        ts, 4
+        ts, 0
+        ...
+    out:
+        name: Oslo-Lock
+        unit: Count
+        data: [(ts, 0), ...)
+    """
+    ret = {"name": "Oslo-Lock",
+           "unit": "count",
+           "rtype": "stream",
+           "data": out}
+    return (ret, )

scalpels/cli/actions/start.py

@@ -40,6 +40,7 @@ agents_map = {
     "rabbit": "python %s/rbt-trace.py",
     "rpc": "bash %s/port-input-traffic.sh 5672",
     "traffic": "bash %s/device-input-traffic.sh eth0",
+    "oslolock": "stap %s/oslo-lock.stp", # with sudo, need add current user to stapdev group
 }
 
 def run(config):

scripts/oslo-lock.stp

@@ -0,0 +1,14 @@
+#!/usr/bin/stap
+
+global count = 0;
+global old_count = 0;
+probe python.function.entry {
+	if ((funcname == "lock") && isinstr(filename, "oslo_concurrency/lockutils.py") && (lineno == 163)) {
+		count = count + 1;
+	}
+}
+probe timer.ms(1000) {
+	new_count = count - old_count;
+	printf("%d\n", new_count);
+	old_count = count;
+}