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 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  23 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  25 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  26 # SOFTWARE.
  27
  28
  29 # This script uses both lttng-tools and babeltrace
  30 # python modules.  It creates a session, enables
  31 # events, starts tracing for 2 seconds, stops tracing,
  32 # destroys the session and outputs the trace in the
  33 # specified output file.
  34 #
  35 # WARNING: will destroy any existing trace having
  36 #          the same name as ses_name
  37
  38
  39 # ------------------------------------------------------
  40 ses_name = "babeltrace-lttng-test"
  41 trace_path = "/lttng-traces/babeltrace-lttng-trace/"
  42 out_file = "babeltrace-lttng-trace-text-output.txt"
  43 # ------------------------------------------------------
  44
  45
  46 import time
  47 try:
  48     import babeltrace
  49     import lttng
  50 except ImportError:
  51     raise ImportError(  "both babeltrace and lttng-tools "
  52                        "python modules must be installed")
  53
  54
  55 # Errors to raise if something goes wrong
  56 class LTTngError(Exception):
  57     pass
  58
  59
  60 class BabeltraceError(Exception):
  61     pass
  62
  63
  64 # LTTNG-TOOLS
  65
  66 # Making sure session does not already exist
  67 lttng.destroy(ses_name)
  68
  69 # Creating a new session and handle
  70 ret = lttng.create(ses_name, trace_path)
  71 if ret < 0:
  72     raise LTTngError(lttng.strerror(ret))
  73
  74 domain = lttng.Domain()
  75 domain.type = lttng.DOMAIN_KERNEL
  76
  77 han = None
  78 han = lttng.Handle(ses_name, domain)
  79 if han is None:
  80     raise LTTngError("Handle not created")
  81
  82
  83 # Enabling all events
  84 event = lttng.Event()
  85 event.type = lttng.EVENT_ALL
  86 event.loglevel_type = lttng.EVENT_LOGLEVEL_ALL
  87 ret = lttng.enable_event(han, event, None)
  88 if ret < 0:
  89     raise LTTngError(lttng.strerror(ret))
  90
  91 # Start, wait, stop
  92 ret = lttng.start(ses_name)
  93 if ret < 0:
  94     raise LTTngError(lttng.strerror(ret))
  95 print("Tracing...")
  96 time.sleep(2)
  97 print("Stopped.")
  98 ret = lttng.stop(ses_name)
  99 if ret < 0:
 100     raise LTTngError(lttng.strerror(ret))
 101
 102
 103 # Destroying tracing session
 104 ret = lttng.destroy(ses_name)
 105 if ret < 0:
 106     raise LTTngError(lttng.strerror(ret))
 107
 108
 109 # BABELTRACE
 110
 111 # Create TraceCollecion and add trace:
 112 traces = babeltrace.TraceCollection()
 113 ret = traces.add_trace(trace_path + "/kernel", "ctf")
 114 if ret is None:
 115     raise BabeltraceError("Error adding trace")
 116
 117 # Reading events from trace
 118 # and outputting timestamps and event names
 119 # in out_file
 120 print("Writing trace file...")
 121 output = open(out_file, "wt")
 122
 123 for event in traces.events:
 124     output.write("TS: {}, {} : {}\n".format(
 125         event.timestamp, event.cycles, event.name))
 126
 127 # Closing file
 128 output.close()
 129
 130 print("Done.")