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