xref: /openbmc/qemu/scripts/simpletrace.py (revision 8f3cd250)
1#!/usr/bin/env python
2#
3# Pretty-printer for simple trace backend binary trace files
4#
5# Copyright IBM, Corp. 2010
6#
7# This work is licensed under the terms of the GNU GPL, version 2.  See
8# the COPYING file in the top-level directory.
9#
10# For help see docs/devel/tracing.txt
11
12from __future__ import print_function
13import struct
14import re
15import inspect
16from tracetool import read_events, Event
17from tracetool.backend.simple import is_string
18
19header_event_id = 0xffffffffffffffff
20header_magic    = 0xf2b177cb0aa429b4
21dropped_event_id = 0xfffffffffffffffe
22
23record_type_mapping = 0
24record_type_event = 1
25
26log_header_fmt = '=QQQ'
27rec_header_fmt = '=QQII'
28
29def read_header(fobj, hfmt):
30    '''Read a trace record header'''
31    hlen = struct.calcsize(hfmt)
32    hdr = fobj.read(hlen)
33    if len(hdr) != hlen:
34        return None
35    return struct.unpack(hfmt, hdr)
36
37def get_record(edict, idtoname, rechdr, fobj):
38    """Deserialize a trace record from a file into a tuple
39       (name, timestamp, pid, arg1, ..., arg6)."""
40    if rechdr is None:
41        return None
42    if rechdr[0] != dropped_event_id:
43        event_id = rechdr[0]
44        name = idtoname[event_id]
45        rec = (name, rechdr[1], rechdr[3])
46        try:
47            event = edict[name]
48        except KeyError as e:
49            import sys
50            sys.stderr.write('%s event is logged but is not declared ' \
51                             'in the trace events file, try using ' \
52                             'trace-events-all instead.\n' % str(e))
53            sys.exit(1)
54
55        for type, name in event.args:
56            if is_string(type):
57                l = fobj.read(4)
58                (len,) = struct.unpack('=L', l)
59                s = fobj.read(len)
60                rec = rec + (s,)
61            else:
62                (value,) = struct.unpack('=Q', fobj.read(8))
63                rec = rec + (value,)
64    else:
65        rec = ("dropped", rechdr[1], rechdr[3])
66        (value,) = struct.unpack('=Q', fobj.read(8))
67        rec = rec + (value,)
68    return rec
69
70def get_mapping(fobj):
71    (event_id, ) = struct.unpack('=Q', fobj.read(8))
72    (len, ) = struct.unpack('=L', fobj.read(4))
73    name = fobj.read(len).decode()
74
75    return (event_id, name)
76
77def read_record(edict, idtoname, fobj):
78    """Deserialize a trace record from a file into a tuple (event_num, timestamp, pid, arg1, ..., arg6)."""
79    rechdr = read_header(fobj, rec_header_fmt)
80    return get_record(edict, idtoname, rechdr, fobj)
81
82def read_trace_header(fobj):
83    """Read and verify trace file header"""
84    header = read_header(fobj, log_header_fmt)
85    if header is None:
86        raise ValueError('Not a valid trace file!')
87    if header[0] != header_event_id:
88        raise ValueError('Not a valid trace file, header id %d != %d' %
89                         (header[0], header_event_id))
90    if header[1] != header_magic:
91        raise ValueError('Not a valid trace file, header magic %d != %d' %
92                         (header[1], header_magic))
93
94    log_version = header[2]
95    if log_version not in [0, 2, 3, 4]:
96        raise ValueError('Unknown version of tracelog format!')
97    if log_version != 4:
98        raise ValueError('Log format %d not supported with this QEMU release!'
99                         % log_version)
100
101def read_trace_records(edict, idtoname, fobj):
102    """Deserialize trace records from a file, yielding record tuples (event_num, timestamp, pid, arg1, ..., arg6).
103
104    Note that `idtoname` is modified if the file contains mapping records.
105
106    Args:
107        edict (str -> Event): events dict, indexed by name
108        idtoname (int -> str): event names dict, indexed by event ID
109        fobj (file): input file
110
111    """
112    while True:
113        t = fobj.read(8)
114        if len(t) == 0:
115            break
116
117        (rectype, ) = struct.unpack('=Q', t)
118        if rectype == record_type_mapping:
119            event_id, name = get_mapping(fobj)
120            idtoname[event_id] = name
121        else:
122            rec = read_record(edict, idtoname, fobj)
123
124            yield rec
125
126class Analyzer(object):
127    """A trace file analyzer which processes trace records.
128
129    An analyzer can be passed to run() or process().  The begin() method is
130    invoked, then each trace record is processed, and finally the end() method
131    is invoked.
132
133    If a method matching a trace event name exists, it is invoked to process
134    that trace record.  Otherwise the catchall() method is invoked.
135
136    Example:
137    The following method handles the runstate_set(int new_state) trace event::
138
139      def runstate_set(self, new_state):
140          ...
141
142    The method can also take a timestamp argument before the trace event
143    arguments::
144
145      def runstate_set(self, timestamp, new_state):
146          ...
147
148    Timestamps have the uint64_t type and are in nanoseconds.
149
150    The pid can be included in addition to the timestamp and is useful when
151    dealing with traces from multiple processes::
152
153      def runstate_set(self, timestamp, pid, new_state):
154          ...
155    """
156
157    def begin(self):
158        """Called at the start of the trace."""
159        pass
160
161    def catchall(self, event, rec):
162        """Called if no specific method for processing a trace event has been found."""
163        pass
164
165    def end(self):
166        """Called at the end of the trace."""
167        pass
168
169def process(events, log, analyzer, read_header=True):
170    """Invoke an analyzer on each event in a log."""
171    if isinstance(events, str):
172        events = read_events(open(events, 'r'), events)
173    if isinstance(log, str):
174        log = open(log, 'rb')
175
176    if read_header:
177        read_trace_header(log)
178
179    dropped_event = Event.build("Dropped_Event(uint64_t num_events_dropped)")
180    edict = {"dropped": dropped_event}
181    idtoname = {dropped_event_id: "dropped"}
182
183    for event in events:
184        edict[event.name] = event
185
186    # If there is no header assume event ID mapping matches events list
187    if not read_header:
188        for event_id, event in enumerate(events):
189            idtoname[event_id] = event.name
190
191    def build_fn(analyzer, event):
192        if isinstance(event, str):
193            return analyzer.catchall
194
195        fn = getattr(analyzer, event.name, None)
196        if fn is None:
197            return analyzer.catchall
198
199        event_argcount = len(event.args)
200        fn_argcount = len(inspect.getargspec(fn)[0]) - 1
201        if fn_argcount == event_argcount + 1:
202            # Include timestamp as first argument
203            return lambda _, rec: fn(*(rec[1:2] + rec[3:3 + event_argcount]))
204        elif fn_argcount == event_argcount + 2:
205            # Include timestamp and pid
206            return lambda _, rec: fn(*rec[1:3 + event_argcount])
207        else:
208            # Just arguments, no timestamp or pid
209            return lambda _, rec: fn(*rec[3:3 + event_argcount])
210
211    analyzer.begin()
212    fn_cache = {}
213    for rec in read_trace_records(edict, idtoname, log):
214        event_num = rec[0]
215        event = edict[event_num]
216        if event_num not in fn_cache:
217            fn_cache[event_num] = build_fn(analyzer, event)
218        fn_cache[event_num](event, rec)
219    analyzer.end()
220
221def run(analyzer):
222    """Execute an analyzer on a trace file given on the command-line.
223
224    This function is useful as a driver for simple analysis scripts.  More
225    advanced scripts will want to call process() instead."""
226    import sys
227
228    read_header = True
229    if len(sys.argv) == 4 and sys.argv[1] == '--no-header':
230        read_header = False
231        del sys.argv[1]
232    elif len(sys.argv) != 3:
233        sys.stderr.write('usage: %s [--no-header] <trace-events> ' \
234                         '<trace-file>\n' % sys.argv[0])
235        sys.exit(1)
236
237    events = read_events(open(sys.argv[1], 'r'), sys.argv[1])
238    process(events, sys.argv[2], analyzer, read_header=read_header)
239
240if __name__ == '__main__':
241    class Formatter(Analyzer):
242        def __init__(self):
243            self.last_timestamp = None
244
245        def catchall(self, event, rec):
246            timestamp = rec[1]
247            if self.last_timestamp is None:
248                self.last_timestamp = timestamp
249            delta_ns = timestamp - self.last_timestamp
250            self.last_timestamp = timestamp
251
252            fields = [event.name, '%0.3f' % (delta_ns / 1000.0),
253                      'pid=%d' % rec[2]]
254            i = 3
255            for type, name in event.args:
256                if is_string(type):
257                    fields.append('%s=%s' % (name, rec[i]))
258                else:
259                    fields.append('%s=0x%x' % (name, rec[i]))
260                i += 1
261            print(' '.join(fields))
262
263    run(Formatter())
264