def _enable_channel(handle: lttng.Handle, channel: lttng.Channel) -> None:
"""
Enable channel for a handle, and check for errors.
:param handle: the handle to be used
:param channel: the channel to enable
"""
result = lttng.enable_channel(handle, channel)
if result < 0:
raise RuntimeError(
f'channel enabling failed: {lttng.strerror(result)}')
def __init__(self, sess_type, **kwargs):
self.name = 'untitled_'+sess_type if kwargs.get('name')==None else kwargs.get('name')
self.path = '/lttng-traces/'+self.name if kwargs.get('path')==None else kwargs.get('path')+'/'+self.name
# Making sure session does not already exist
lttng.destroy(self.name)
#Creating LTTng session domain
self.domain = lttng.Domain()
if sess_type=='kernel':
self.domain.type = lttng.DOMAIN_KERNEL
elif sess_type=='ust':
self.domain.type = lttng.DOMAIN_UST
else:
print("invalid tracing session type '%r', session not created" %(sess_type))
#Enabling channel
self.channel = lttng.Channel()
self.channel.name="channel_1"
self.channel.attr.overwrite = 0
self.channel.attr.subbuf_size = 4096
self.channel.attr.num_subbuf = 8
self.channel.attr.switch_timer_interval = 0
self.channel.attr.read_timer_interval = 200
self.channel.attr.output = lttng.EVENT_MMAP
#creating handle
self.handle = None
self.handle = lttng.Handle(self.name, self.domain)
if self.handle is None:
raise LTTngError("Handle not created")
#creating session
ret = lttng.create(self.name,self.path)
if ret < 0:
raise LTTngError(lttng.strerror(ret))
#enabling channel on handle
lttng.enable_channel(self.handle, self.channel)
# Enabling all events
self.event = lttng.Event()
self.event.type = lttng.EVENT_ALL
self.event.loglevel_type = lttng.EVENT_LOGLEVEL_ALL
print
ret = lttng.enable_event(self.handle, self.event, self.channel.name)
if ret < 0:
raise LTTngError(lttng.strerror(ret))
def lttng_start(events=["*"], domain_type=lttng.DOMAIN_UST):
if lttng.session_daemon_alive() == 0:
daemon_cmd = "lttng-sessiond --background"
daemon_cmd += " --pidfile " + sessiond_pidfile
subprocess.check_call(daemon_cmd,
shell=True,
stdout=sessiond_logfile,
stderr=sessiond_logfile)
lttng.destroy(session_name)
ret = lttng.create_snapshot(session_name, trace_path)
if ret < 0:
raise RuntimeError("LTTng: " + lttng.strerror(ret))
domain = lttng.Domain()
domain.type = domain_type
channel = lttng.Channel()
channel.name = "channel0"
lttng.channel_set_default_attr(domain, channel.attr)
han = lttng.Handle(session_name, domain)
if han is None:
raise RuntimeError("LTTng: failed to create handle")
ret = lttng.enable_channel(han, channel)
if ret < 0:
raise RuntimeError("LTTng: " + lttng.strerror(ret))
for name in events:
event = lttng.Event()
event.name = name
event.type = lttng.EVENT_TRACEPOINT
event.loglevel = lttng.EVENT_LOGLEVEL_ALL
ret = lttng.enable_event(han, event, channel.name)
if ret < 0:
raise RuntimeError("LTTng: " + lttng.strerror(ret))
ret = lttng.start(session_name)
if ret < 0:
raise RuntimeError("LTTng: " + lttng.strerror(ret))
def lttng_start(events = ["*"], domain_type = lttng.DOMAIN_UST):
if lttng.session_daemon_alive() == 0:
daemon_cmd = "lttng-sessiond --daemonize --quiet"
daemon_cmd += " --pidfile " + sessiond_pidfile
subprocess.check_call(daemon_cmd, shell=True)
lttng.destroy(session_name)
ret = lttng.create_snapshot(session_name, trace_path)
if ret < 0:
raise RuntimeError("LTTng: " + lttng.strerror(ret))
domain = lttng.Domain()
domain.type = domain_type
channel = lttng.Channel()
channel.name = "channel0"
lttng.channel_set_default_attr(domain, channel.attr)
han = lttng.Handle(session_name, domain)
if han is None:
raise RuntimeError("LTTng: failed to create handle")
ret = lttng.enable_channel(han, channel)
if ret < 0:
raise RuntimeError("LTTng: " + lttng.strerror(ret))
for name in events:
event = lttng.Event()
event.name = name
event.type = lttng.EVENT_TRACEPOINT
event.loglevel = lttng.EVENT_LOGLEVEL_ALL
ret = lttng.enable_event(han, event, channel.name)
if ret < 0:
raise RuntimeError("LTTng: " + lttng.strerror(ret))
ret = lttng.start(session_name)
if ret < 0:
raise RuntimeError("LTTng: " + lttng.strerror(ret))
def lttng_session(session_name, command, names, analyzer):
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')
return analyzer(col)
channel.attr.overwrite = 0
channel.attr.subbuf_size = 4096
channel.attr.num_subbuf = 8
channel.attr.switch_timer_interval = 0
channel.attr.read_timer_interval = 200
channel.attr.output = lttng.EVENT_SPLICE
event = lttng.Event()
event.name = "sched_switch"
event.type = lttng.EVENT_TRACEPOINT
event.loglevel_type = lttng.EVENT_LOGLEVEL_ALL
ret = lttng.create(sess_name, trace_dest)
assert ret == 0
han = None
han = lttng.Handle(sess_name, dom)
assert han != None
lttng.enable_channel(han, channel)
lttng.enable_event(han, event, channel.name)
print(lttng.list_channels(han))
lttng.start(sess_name)
time.sleep(0.1)
lttng.stop(sess_name)
ret = lttng.destroy(sess_name)
assert ret == 0
