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

   1 #
   2 # Copyright (C) 2012 Danny Serres <danny.serres@efficios.com>
   3 #
   4 # SPDX-License-Identifier: GPL-2.0-only
   5 #
   6 # This example shows basically how to use the lttng-tools python module
   7
   8 from lttng import *
   9
  10
  11 # This error will be raised is something goes wrong
  12 class LTTngError(Exception):
  13     def __init__(self, value):
  14         self.value = value
  15
  16     def __str__(self):
  17         return repr(self.value)
  18
  19
  20 # Setting up the domain to use
  21 dom = Domain()
  22 dom.type = DOMAIN_KERNEL
  23
  24 # Setting up a channel to use
  25 channel = Channel()
  26 channel.name = "mychan"
  27 channel.attr.overwrite = 0
  28 channel.attr.subbuf_size = 4096
  29 channel.attr.num_subbuf = 8
  30 channel.attr.switch_timer_interval = 0
  31 channel.attr.read_timer_interval = 200
  32 channel.attr.output = EVENT_SPLICE
  33
  34 # Setting up some events that will be used
  35 event = Event()
  36 event.type = EVENT_TRACEPOINT
  37 event.loglevel_type = EVENT_LOGLEVEL_ALL
  38
  39 sched_switch = Event()
  40 sched_switch.name = "sched_switch"
  41 sched_switch.type = EVENT_TRACEPOINT
  42 sched_switch.loglevel_type = EVENT_LOGLEVEL_ALL
  43
  44 sched_process_exit = Event()
  45 sched_process_exit.name = "sched_process_exit"
  46 sched_process_exit.type = EVENT_TRACEPOINT
  47 sched_process_exit.loglevel_type = EVENT_LOGLEVEL_ALL
  48
  49 sched_process_free = Event()
  50 sched_process_free.name = "sched_process_free"
  51 sched_process_free.type = EVENT_TRACEPOINT
  52 sched_process_free.loglevel_type = EVENT_LOGLEVEL_ALL
  53
  54
  55 # Creating a new session
  56 res = create("test", "/lttng-traces/test")
  57 if res < 0:
  58     raise LTTngError(strerror(res))
  59
  60 # Creating handle
  61 han = None
  62 han = Handle("test", dom)
  63 if han is None:
  64     raise LTTngError("Handle not created")
  65
  66 # Enabling the kernel channel
  67 res = enable_channel(han, channel)
  68 if res < 0:
  69     raise LTTngError(strerror(res))
  70
  71 # Enabling some events in given channel
  72 # To enable all events in default channel, use
  73 # enable_event(han, event, None)
  74 res = enable_event(han, sched_switch, channel.name)
  75 if res < 0:
  76     raise LTTngError(strerror(res))
  77
  78 res = enable_event(han, sched_process_exit, channel.name)
  79 if res < 0:
  80     raise LTTngError(strerror(res))
  81
  82 res = enable_event(han, sched_process_free, channel.name)
  83 if res < 0:
  84     raise LTTngError(strerror(res))
  85
  86 # Disabling an event
  87 res = disable_event(han, sched_switch.name, channel.name)
  88 if res < 0:
  89     raise LTTngError(strerror(res))
  90
  91 # Getting a list of the channels
  92 l = list_channels(han)
  93 if type(l) is int:
  94     raise LTTngError(strerror(l))
  95
  96 # Starting the trace
  97 res = start("test")
  98 if res < 0:
  99     raise LTTngError(strerror(res))
 100
 101 # Stopping the trace
 102 res = stop("test")
 103 if res < 0:
 104     raise LTTngError(strerror(res))
 105
 106 # Disabling a channel
 107 res = disable_channel(han, channel.name)
 108 if res < 0:
 109     raise LTTngError(strerror(res))
 110
 111 # Destroying the handle
 112 del han
 113
 114 # Destroying the session
 115 res = destroy("test")
 116 if res < 0:
 117     raise LTTngError(strerror(res))