extras/bindings/swig/python/tests/example.py

   1 #This example shows basically how to use the lttng-tools python module
   2
   3 from lttng import *
   4
   5 # This error will be raised is something goes wrong
   6 class LTTngError(Exception):
   7         def __init__(self, value):
   8                 self.value = value
   9         def __str__(self):
  10                 return repr(self.value)
  11
  12 #Setting up the domain to use
  13 dom = Domain()
  14 dom.type = DOMAIN_KERNEL
  15
  16 #Setting up a channel to use
  17 channel = Channel()
  18 channel.name = "mychan"
  19 channel.attr.overwrite = 0
  20 channel.attr.subbuf_size = 4096
  21 channel.attr.num_subbuf = 8
  22 channel.attr.switch_timer_interval = 0
  23 channel.attr.read_timer_interval = 200
  24 channel.attr.output = EVENT_SPLICE
  25
  26 #Setting up some events that will be used
  27 event = Event()
  28 event.type = EVENT_TRACEPOINT
  29 event.loglevel_type = EVENT_LOGLEVEL_ALL
  30
  31 sched_switch = Event()
  32 sched_switch.name = "sched_switch"
  33 sched_switch.type = EVENT_TRACEPOINT
  34 sched_switch.loglevel_type = EVENT_LOGLEVEL_ALL
  35
  36 sched_process_exit = Event()
  37 sched_process_exit.name = "sched_process_exit"
  38 sched_process_exit.type = EVENT_TRACEPOINT
  39 sched_process_exit.loglevel_type = EVENT_LOGLEVEL_ALL
  40
  41 sched_process_free = Event()
  42 sched_process_free.name = "sched_process_free"
  43 sched_process_free.type = EVENT_TRACEPOINT
  44 sched_process_free.loglevel_type = EVENT_LOGLEVEL_ALL
  45
  46
  47 #Creating a new session
  48 res = create("test","/lttng-traces/test")
  49 if res<0:
  50         raise LTTngError(strerror(res))
  51
  52 #Creating handle
  53 han = None
  54 han = Handle("test", dom)
  55 if han is None:
  56         raise LTTngError("Handle not created")
  57
  58 #Enabling the kernel channel
  59 res = enable_channel(han, channel)
  60 if res<0:
  61         raise LTTngError(strerror(res))
  62
  63 #Enabling some events in given channel
  64 #To enable all events in default channel, use
  65 #enable_event(han, event, None)
  66 res = enable_event(han, sched_switch, channel.name)
  67 if res<0:
  68         raise LTTngError(strerror(res))
  69
  70 res = enable_event(han, sched_process_exit, channel.name)
  71 if res<0:
  72         raise LTTngError(strerror(res))
  73
  74 res = enable_event(han, sched_process_free, channel.name)
  75 if res<0:
  76         raise LTTngError(strerror(res))
  77
  78 #Disabling an event
  79 res = disable_event(han, sched_switch.name, channel.name)
  80 if res<0:
  81         raise LTTngError(strerror(res))
  82
  83 #Getting a list of the channels
  84 l = list_channels(han)
  85 if type(l) is int:
  86                 raise LTTngError(strerror(l))
  87
  88 #Starting the trace
  89 res = start("test")
  90 if res<0:
  91         raise LTTngError(strerror(res))
  92
  93 #Stopping the trace
  94 res = stop("test")
  95 if res<0:
  96         raise LTTngError(strerror(res))
  97
  98 #Disabling a channel
  99 res = disable_channel(han, channel.name)
 100 if res<0:
 101         raise LTTngError(strerror(res))
 102
 103 #Destroying the handle
 104 del han
 105
 106 #Destroying the session
 107 res = destroy("test")
 108 if res<0:
 109         raise LTTngError(strerror(res))