ts = datetime.datetime.fromtimestamp(time.time()).strftime('%Y-%m-%d-%H-%M-%S-%f')

tracedir = os.environ['HOME'] + "/lttng-traces/" + session_name + "-" + ts

print('Writing trace to ' + tracedir)

lttng.destroy(session_name)

res = lttng.create(session_name, tracedir)

if res<0:

raise Exception("Failed to create lttng session")

dom = lttng.Domain()

dom.type = lttng.DOMAIN_UST

han = None

han = lttng.Handle(session_name, dom)

if han is None:

raise Exception("Handle not created")

channel = lttng.Channel()

channel.name = "channel0"

channel.attr.overwrite = 0

channel.attr.subbuf_size = 1048576

channel.attr.num_subbuf = 8

channel.attr.switch_timer_interval = 0

channel.attr.read_timer_interval = 0

channel.attr.output = lttng.EVENT_MMAP

res = lttng.enable_channel(han, channel)

if res<0:

raise Exception("Failed to enable channel")

for n in names:

# lttng enable-event -u 'memcached:*'

event = lttng.Event()

event.type = lttng.EVENT_TRACEPOINT

event.name = n

lttng.enable_event(han, event, "channel0")

os.system("lttng add-context -s" + session_name + " -u -t perf:thread:cycles -t pthread_id")

# ctx = lttng.EventContext()

# ctx.type = EVENT_CONTEXT_PTHREAD_ID

# res = lttng.add_context(han, ctx, None, None)

# assert res >= 0

#

# ctx.type = EVENT_CONTEXT_PERF_COUNTER

# ctx.u.perf_counter.name = "cpu-cycles"

# res = lttng.add_context(han, ctx, None, None)

# assert res >= 0

lttng.start(session_name)

print("running ", command)

os.system(command)

lttng.stop(session_name)

lttng.destroy(session_name)

subdir = subprocess.check_output(['ls', tracedir+'/ust/pid/']).decode("utf-8").rstrip()

babeldir = tracedir+'/ust/pid/'+subdir

print("analyzing trace in", babeldir)

col = babeltrace.TraceCollection()

if col.add_trace(babeldir, 'ctf') is None:

raise RuntimeError('Cannot add trace')