bindings/python/examples/babeltrace_and_lttng.py

   1 #!/usr/bin/env python3
   2 # babeltrace_and_lttng.py
   3 #
   4 # Babeltrace and LTTng example script
   5 #
   6 # Copyright 2012 EfficiOS Inc.
   7 #
   8 # Author: Danny Serres <danny.serres@efficios.com>
   9 #
  10 # Permission is hereby granted, free of charge, to any person obtaining a copy
  11 # of this software and associated documentation files (the "Software"), to deal
  12 # in the Software without restriction, including without limitation the rights
  13 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  14 # copies of the Software, and to permit persons to whom the Software is
  15 # furnished to do so, subject to the following conditions:
  16 #
  17 # The above copyright notice and this permission notice shall be included in
  18 # all copies or substantial portions of the Software.
  19
  20
  21 # This script uses both lttng-tools and babeltrace
  22 # python modules.  It creates a session, enables
  23 # events, starts tracing for 2 seconds, stops tracing,
  24 # destroys the session and outputs the trace in the
  25 # specified output file.
  26 #
  27 # WARNING: will destroy any existing trace having
  28 #          the same name as ses_name
  29
  30
  31 # ------------------------------------------------------
  32 ses_name = "babeltrace-lttng-test"
  33 trace_path = "/lttng-traces/babeltrace-lttng-trace/"
  34 out_file = "babeltrace-lttng-trace-text-output.txt"
  35 # ------------------------------------------------------
  36
  37
  38 import time
  39 try:
  40     import babeltrace
  41     import lttng
  42 except ImportError:
  43     raise ImportError(  "both babeltrace and lttng-tools "
  44                        "python modules must be installed")
  45
  46
  47 # Errors to raise if something goes wrong
  48 class LTTngError(Exception):
  49     pass
  50
  51
  52 class BabeltraceError(Exception):
  53     pass
  54
  55
  56 # LTTNG-TOOLS
  57
  58 # Making sure session does not already exist
  59 lttng.destroy(ses_name)
  60
  61 # Creating a new session and handle
  62 ret = lttng.create(ses_name, trace_path)
  63 if ret < 0:
  64     raise LTTngError(lttng.strerror(ret))
  65
  66 domain = lttng.Domain()
  67 domain.type = lttng.DOMAIN_KERNEL
  68
  69 han = None
  70 han = lttng.Handle(ses_name, domain)
  71 if han is None:
  72     raise LTTngError("Handle not created")
  73
  74
  75 # Enabling all events
  76 event = lttng.Event()
  77 event.type = lttng.EVENT_ALL
  78 event.loglevel_type = lttng.EVENT_LOGLEVEL_ALL
  79 ret = lttng.enable_event(han, event, None)
  80 if ret < 0:
  81     raise LTTngError(lttng.strerror(ret))
  82
  83 # Start, wait, stop
  84 ret = lttng.start(ses_name)
  85 if ret < 0:
  86     raise LTTngError(lttng.strerror(ret))
  87 print("Tracing...")
  88 time.sleep(2)
  89 print("Stopped.")
  90 ret = lttng.stop(ses_name)
  91 if ret < 0:
  92     raise LTTngError(lttng.strerror(ret))
  93
  94
  95 # Destroying tracing session
  96 ret = lttng.destroy(ses_name)
  97 if ret < 0:
  98     raise LTTngError(lttng.strerror(ret))
  99
 100
 101 # BABELTRACE
 102
 103 # Create TraceCollecion and add trace:
 104 traces = babeltrace.TraceCollection()
 105 ret = traces.add_trace(trace_path + "/kernel", "ctf")
 106 if ret is None:
 107     raise BabeltraceError("Error adding trace")
 108
 109 # Reading events from trace
 110 # and outputting timestamps and event names
 111 # in out_file
 112 print("Writing trace file...")
 113 output = open(out_file, "wt")
 114
 115 for event in traces.events:
 116     output.write("TS: {}, {} : {}\n".format(
 117         event.timestamp, event.cycles, event.name))
 118
 119 # Closing file
 120 output.close()
 121
 122 print("Done.")