xref: /qemu/scripts/simpletrace.py (revision 01b2ffce)
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/tracing.txt
11
12import struct
13import re
14import inspect
15from tracetool import read_events, Event
16from tracetool.backend.simple import is_string
17
18header_event_id = 0xffffffffffffffff
19header_magic    = 0xf2b177cb0aa429b4
20dropped_event_id = 0xfffffffffffffffe
21
22record_type_mapping = 0
23record_type_event = 1
24
25log_header_fmt = '=QQQ'
26rec_header_fmt = '=QQII'
27
28def read_header(fobj, hfmt):
29    '''Read a trace record header'''
30    hlen = struct.calcsize(hfmt)
31    hdr = fobj.read(hlen)
32    if len(hdr) != hlen:
33        return None
34    return struct.unpack(hfmt, hdr)
35
36def get_record(edict, idtoname, rechdr, fobj):
37    """Deserialize a trace record from a file into a tuple
38       (name, timestamp, pid, arg1, ..., arg6)."""
39    if rechdr is None:
40        return None
41    if rechdr[0] != dropped_event_id:
42        event_id = rechdr[0]
43        name = idtoname[event_id]
44        rec = (name, rechdr[1], rechdr[3])
45        try:
46            event = edict[name]
47        except KeyError, e:
48            import sys
49            sys.stderr.write('%s event is logged but is not declared ' \
50                             'in the trace events file, try using ' \
51                             'trace-events-all instead.\n' % str(e))
52            sys.exit(1)
53
54        for type, name in event.args:
55            if is_string(type):
56                l = fobj.read(4)
57                (len,) = struct.unpack('=L', l)
58                s = fobj.read(len)
59                rec = rec + (s,)
60            else:
61                (value,) = struct.unpack('=Q', fobj.read(8))
62                rec = rec + (value,)
63    else:
64        rec = ("dropped", rechdr[1], rechdr[3])
65        (value,) = struct.unpack('=Q', fobj.read(8))
66        rec = rec + (value,)
67    return rec
68
69def get_mapping(fobj):
70    (event_id, ) = struct.unpack('=Q', fobj.read(8))
71    (len, ) = struct.unpack('=L', fobj.read(4))
72    name = fobj.read(len)
73
74    return (event_id, name)
75
76def read_record(edict, idtoname, fobj):
77    """Deserialize a trace record from a file into a tuple (event_num, timestamp, pid, arg1, ..., arg6)."""
78    rechdr = read_header(fobj, rec_header_fmt)
79    return get_record(edict, idtoname, rechdr, fobj)
80
81def read_trace_header(fobj):
82    """Read and verify trace file header"""
83    header = read_header(fobj, log_header_fmt)
84    if header is None:
85        raise ValueError('Not a valid trace file!')
86    if header[0] != header_event_id:
87        raise ValueError('Not a valid trace file, header id %d != %d' %
88                         (header[0], header_event_id))
89    if header[1] != header_magic:
90        raise ValueError('Not a valid trace file, header magic %d != %d' %
91                         (header[1], header_magic))
92
93    log_version = header[2]
94    if log_version not in [0, 2, 3, 4]:
95        raise ValueError('Unknown version of tracelog format!')
96    if log_version != 4:
97        raise ValueError('Log format %d not supported with this QEMU release!'
98                         % log_version)
99
100def read_trace_records(edict, fobj):
101    """Deserialize trace records from a file, yielding record tuples (event_num, timestamp, pid, arg1, ..., arg6)."""
102    idtoname = {
103        dropped_event_id: "dropped"
104    }
105    while True:
106        t = fobj.read(8)
107        if len(t) == 0:
108            break
109
110        (rectype, ) = struct.unpack('=Q', t)
111        if rectype == record_type_mapping:
112            event_id, name = get_mapping(fobj)
113            idtoname[event_id] = name
114        else:
115            rec = read_record(edict, idtoname, fobj)
116
117            yield rec
118
119class Analyzer(object):
120    """A trace file analyzer which processes trace records.
121
122    An analyzer can be passed to run() or process().  The begin() method is
123    invoked, then each trace record is processed, and finally the end() method
124    is invoked.
125
126    If a method matching a trace event name exists, it is invoked to process
127    that trace record.  Otherwise the catchall() method is invoked.
128
129    Example:
130    The following method handles the runstate_set(int new_state) trace event::
131
132      def runstate_set(self, new_state):
133          ...
134
135    The method can also take a timestamp argument before the trace event
136    arguments::
137
138      def runstate_set(self, timestamp, new_state):
139          ...
140
141    Timestamps have the uint64_t type and are in nanoseconds.
142
143    The pid can be included in addition to the timestamp and is useful when
144    dealing with traces from multiple processes::
145
146      def runstate_set(self, timestamp, pid, new_state):
147          ...
148    """
149
150    def begin(self):
151        """Called at the start of the trace."""
152        pass
153
154    def catchall(self, event, rec):
155        """Called if no specific method for processing a trace event has been found."""
156        pass
157
158    def end(self):
159        """Called at the end of the trace."""
160        pass
161
162def process(events, log, analyzer, read_header=True):
163    """Invoke an analyzer on each event in a log."""
164    if isinstance(events, str):
165        events = read_events(open(events, 'r'))
166    if isinstance(log, str):
167        log = open(log, 'rb')
168
169    if read_header:
170        read_trace_header(log)
171
172    dropped_event = Event.build("Dropped_Event(uint64_t num_events_dropped)")
173    edict = {"dropped": dropped_event}
174
175    for event in events:
176        edict[event.name] = event
177
178    def build_fn(analyzer, event):
179        if isinstance(event, str):
180            return analyzer.catchall
181
182        fn = getattr(analyzer, event.name, None)
183        if fn is None:
184            return analyzer.catchall
185
186        event_argcount = len(event.args)
187        fn_argcount = len(inspect.getargspec(fn)[0]) - 1
188        if fn_argcount == event_argcount + 1:
189            # Include timestamp as first argument
190            return lambda _, rec: fn(*((rec[1:2],) + rec[3:3 + event_argcount]))
191        elif fn_argcount == event_argcount + 2:
192            # Include timestamp and pid
193            return lambda _, rec: fn(*rec[1:3 + event_argcount])
194        else:
195            # Just arguments, no timestamp or pid
196            return lambda _, rec: fn(*rec[3:3 + event_argcount])
197
198    analyzer.begin()
199    fn_cache = {}
200    for rec in read_trace_records(edict, log):
201        event_num = rec[0]
202        event = edict[event_num]
203        if event_num not in fn_cache:
204            fn_cache[event_num] = build_fn(analyzer, event)
205        fn_cache[event_num](event, rec)
206    analyzer.end()
207
208def run(analyzer):
209    """Execute an analyzer on a trace file given on the command-line.
210
211    This function is useful as a driver for simple analysis scripts.  More
212    advanced scripts will want to call process() instead."""
213    import sys
214
215    read_header = True
216    if len(sys.argv) == 4 and sys.argv[1] == '--no-header':
217        read_header = False
218        del sys.argv[1]
219    elif len(sys.argv) != 3:
220        sys.stderr.write('usage: %s [--no-header] <trace-events> ' \
221                         '<trace-file>\n' % sys.argv[0])
222        sys.exit(1)
223
224    events = read_events(open(sys.argv[1], 'r'))
225    process(events, sys.argv[2], analyzer, read_header=read_header)
226
227if __name__ == '__main__':
228    class Formatter(Analyzer):
229        def __init__(self):
230            self.last_timestamp = None
231
232        def catchall(self, event, rec):
233            timestamp = rec[1]
234            if self.last_timestamp is None:
235                self.last_timestamp = timestamp
236            delta_ns = timestamp - self.last_timestamp
237            self.last_timestamp = timestamp
238
239            fields = [event.name, '%0.3f' % (delta_ns / 1000.0),
240                      'pid=%d' % rec[2]]
241            i = 3
242            for type, name in event.args:
243                if is_string(type):
244                    fields.append('%s=%s' % (name, rec[i]))
245                else:
246                    fields.append('%s=0x%x' % (name, rec[i]))
247                i += 1
248            print ' '.join(fields)
249
250    run(Formatter())
251