xref: /openbmc/qemu/scripts/simpletrace.py (revision 14a650ec)
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
22log_header_fmt = '=QQQ'
23rec_header_fmt = '=QQII'
24
25def read_header(fobj, hfmt):
26    '''Read a trace record header'''
27    hlen = struct.calcsize(hfmt)
28    hdr = fobj.read(hlen)
29    if len(hdr) != hlen:
30        return None
31    return struct.unpack(hfmt, hdr)
32
33def get_record(edict, rechdr, fobj):
34    """Deserialize a trace record from a file into a tuple (event_num, timestamp, arg1, ..., arg6)."""
35    if rechdr is None:
36        return None
37    rec = (rechdr[0], rechdr[1])
38    if rechdr[0] != dropped_event_id:
39        event_id = rechdr[0]
40        event = edict[event_id]
41        for type, name in event.args:
42            if is_string(type):
43                l = fobj.read(4)
44                (len,) = struct.unpack('=L', l)
45                s = fobj.read(len)
46                rec = rec + (s,)
47            else:
48                (value,) = struct.unpack('=Q', fobj.read(8))
49                rec = rec + (value,)
50    else:
51        (value,) = struct.unpack('=Q', fobj.read(8))
52        rec = rec + (value,)
53    return rec
54
55
56def read_record(edict, fobj):
57    """Deserialize a trace record from a file into a tuple (event_num, timestamp, arg1, ..., arg6)."""
58    rechdr = read_header(fobj, rec_header_fmt)
59    return get_record(edict, rechdr, fobj) # return tuple of record elements
60
61def read_trace_file(edict, fobj):
62    """Deserialize trace records from a file, yielding record tuples (event_num, timestamp, arg1, ..., arg6)."""
63    header = read_header(fobj, log_header_fmt)
64    if header is None or \
65       header[0] != header_event_id or \
66       header[1] != header_magic:
67        raise ValueError('Not a valid trace file!')
68    if header[2] != 0 and \
69       header[2] != 2:
70        raise ValueError('Unknown version of tracelog format!')
71
72    log_version = header[2]
73    if log_version == 0:
74        raise ValueError('Older log format, not supported with this QEMU release!')
75
76    while True:
77        rec = read_record(edict, fobj)
78        if rec is None:
79            break
80
81        yield rec
82
83class Analyzer(object):
84    """A trace file analyzer which processes trace records.
85
86    An analyzer can be passed to run() or process().  The begin() method is
87    invoked, then each trace record is processed, and finally the end() method
88    is invoked.
89
90    If a method matching a trace event name exists, it is invoked to process
91    that trace record.  Otherwise the catchall() method is invoked."""
92
93    def begin(self):
94        """Called at the start of the trace."""
95        pass
96
97    def catchall(self, event, rec):
98        """Called if no specific method for processing a trace event has been found."""
99        pass
100
101    def end(self):
102        """Called at the end of the trace."""
103        pass
104
105def process(events, log, analyzer):
106    """Invoke an analyzer on each event in a log."""
107    if isinstance(events, str):
108        events = _read_events(open(events, 'r'))
109    if isinstance(log, str):
110        log = open(log, 'rb')
111
112    enabled_events = []
113    dropped_event = Event.build("Dropped_Event(uint64_t num_events_dropped)")
114    edict = {dropped_event_id: dropped_event}
115
116    for e in events:
117        if 'disable' not in e.properties:
118            enabled_events.append(e)
119    for num, event in enumerate(enabled_events):
120        edict[num] = event
121
122    def build_fn(analyzer, event):
123        if isinstance(event, str):
124            return analyzer.catchall
125
126        fn = getattr(analyzer, event.name, None)
127        if fn is None:
128            return analyzer.catchall
129
130        event_argcount = len(event.args)
131        fn_argcount = len(inspect.getargspec(fn)[0]) - 1
132        if fn_argcount == event_argcount + 1:
133            # Include timestamp as first argument
134            return lambda _, rec: fn(*rec[1:2 + event_argcount])
135        else:
136            # Just arguments, no timestamp
137            return lambda _, rec: fn(*rec[2:2 + event_argcount])
138
139    analyzer.begin()
140    fn_cache = {}
141    for rec in read_trace_file(edict, log):
142        event_num = rec[0]
143        event = edict[event_num]
144        if event_num not in fn_cache:
145            fn_cache[event_num] = build_fn(analyzer, event)
146        fn_cache[event_num](event, rec)
147    analyzer.end()
148
149def run(analyzer):
150    """Execute an analyzer on a trace file given on the command-line.
151
152    This function is useful as a driver for simple analysis scripts.  More
153    advanced scripts will want to call process() instead."""
154    import sys
155
156    if len(sys.argv) != 3:
157        sys.stderr.write('usage: %s <trace-events> <trace-file>\n' % sys.argv[0])
158        sys.exit(1)
159
160    events = _read_events(open(sys.argv[1], 'r'))
161    process(events, sys.argv[2], analyzer)
162
163if __name__ == '__main__':
164    class Formatter(Analyzer):
165        def __init__(self):
166            self.last_timestamp = None
167
168        def catchall(self, event, rec):
169            i = 1
170            timestamp = rec[1]
171            if self.last_timestamp is None:
172                self.last_timestamp = timestamp
173            delta_ns = timestamp - self.last_timestamp
174            self.last_timestamp = timestamp
175
176            fields = [event.name, '%0.3f' % (delta_ns / 1000.0)]
177            for type, name in event.args:
178                if is_string(type):
179                    fields.append('%s=%s' % (name, rec[i + 1]))
180                else:
181                    fields.append('%s=0x%x' % (name, rec[i + 1]))
182                i += 1
183            print ' '.join(fields)
184
185    run(Formatter())
186