hwsim tests: Allow run-tests.py to start tracing

In order to get tracing per test, allow run-tests.py to start
and stop tracing per test case. This is implemented using a
python 'with' context so it starts/stops automatically at the
right spots.

Instead of starting global tracing, also use it from run-all.sh
and put the trace files into the log dir.

Note that this only works right if you use a separate log dir
for all test runs as the trace files aren't timestamped.

Signed-hostap: Johannes Berg <johannes.berg@intel.com>

tests/hwsim/run-all.sh

@@ -44,9 +44,11 @@ fi
 if [ "x$1" = "xtrace" ] ; then
 	TRACE=trace
 	SUFFIX=$SUFFIX-trace
+	TRACE_ARGS="-T $LOGDIR"
 	shift
 else
 	unset TRACE
+	unset TRACE_ARGS
 fi
 
 if ! ./start.sh $CONCURRENT $VALGRIND $TRACE; then
@@ -55,14 +57,7 @@ if ! ./start.sh $CONCURRENT $VALGRIND $TRACE; then
 fi
 DATE=`ls -1tr $LOGDIR | tail -1 | cut -f1 -d-`
 rm $LOGDIR/last-debug 2>/dev/null
-RUNTESTS="./run-tests.py -l $LOGDIR/$DATE-run $DB -e $LOGDIR/$DATE-failed -r $LOGDIR/results.txt $CONCURRENT_TESTS $@"
-
-if [ "$TRACE" != "" ] ; then
-	sudo trace-cmd record -o $LOGDIR/$DATE-trace.dat -e mac80211 -e cfg80211 su $USER -c $RUNTESTS || errors=1
-else
-	$RUNTESTS || errors=1
-fi
-
+./run-tests.py $TRACE_ARGS -l $LOGDIR/$DATE-run $DB -e $LOGDIR/$DATE-failed -r $LOGDIR/results.txt $CONCURRENT_TESTS $@ || errors=1
 
 cat $LOGDIR/$DATE-run >> $LOGDIR/last-debug
 ./stop-wifi.sh

tests/hwsim/run-tests.py

@@ -12,6 +12,7 @@ import sys
 import time
 from datetime import datetime
 import argparse
+import subprocess
 
 import logging
 logger = logging.getLogger(__name__)
@@ -47,6 +48,28 @@ def report(conn, build, commit, run, test, result, diff):
             print "sqlite: " + str(e)
             print "sql: %r" % (params, )
 
+class Tracer(object):
+    def __init__(self, tracedir, testname):
+        self._tracedir = tracedir
+        self._testname = testname
+    def __enter__(self):
+        if not self._tracedir:
+            return
+        output = os.path.join(self._tracedir, '%s.dat' % (self._testname, ))
+        self._trace_cmd = subprocess.Popen(['sudo', 'trace-cmd', 'record', '-o', output, '-e', 'mac80211', '-e', 'cfg80211', 'sh', '-c', 'echo STARTED ; read l'],
+                                           stdin=subprocess.PIPE,
+                                           stdout=subprocess.PIPE,
+                                           stderr=open('/dev/null', 'w'),
+                                           cwd=self._tracedir)
+        l = self._trace_cmd.stdout.read(7)
+        while not 'STARTED' in l:
+            l += self._trace_cmd.stdout.read(1)
+    def __exit__(self, type, value, traceback):
+        if not self._tracedir:
+            return
+        self._trace_cmd.stdin.write('DONE\n')
+        self._trace_cmd.wait()
+
 def main():
     tests = []
     test_modules = []
@@ -86,6 +109,8 @@ def main():
     parser.add_argument('-b', metavar='<build>', dest='build', help='build ID')
     parser.add_argument('-L', action='store_true', dest='update_tests_db',
                         help='List tests (and update descriptions in DB)')
+    parser.add_argument('-T', metavar='<dir>', dest='tracedir',
+                        help='tracing directory - will get a trace file per test')
     parser.add_argument('-f', dest='testmodules', metavar='<test module>',
                         help='execute only tests from these test modules',
                         type=str, choices=[[]] + test_modules, nargs='+')
@@ -165,6 +190,7 @@ def main():
         if args.testmodules:
             if not t.__module__ in args.testmodules:
                 continue
+        with Tracer(args.tracedir, t.__name__):
             reset_devs(dev, apdev)
             logger.info("START " + t.__name__)
             if log_to_file: