xref: /openbmc/qemu/scripts/simpletrace.py (revision 8f1e884b)
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
69    log_version = header[2]
70    if log_version not in [0, 2, 3]:
71        raise ValueError('Unknown version of tracelog format!')
72    if log_version != 3:
73        raise ValueError('Log format %d not supported with this QEMU release!'
74                         % log_version)
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    dropped_event = Event.build("Dropped_Event(uint64_t num_events_dropped)")
113    edict = {dropped_event_id: dropped_event}
114
115    for num, event in enumerate(events):
116        edict[num] = event
117
118    def build_fn(analyzer, event):
119        if isinstance(event, str):
120            return analyzer.catchall
121
122        fn = getattr(analyzer, event.name, None)
123        if fn is None:
124            return analyzer.catchall
125
126        event_argcount = len(event.args)
127        fn_argcount = len(inspect.getargspec(fn)[0]) - 1
128        if fn_argcount == event_argcount + 1:
129            # Include timestamp as first argument
130            return lambda _, rec: fn(*rec[1:2 + event_argcount])
131        else:
132            # Just arguments, no timestamp
133            return lambda _, rec: fn(*rec[2:2 + event_argcount])
134
135    analyzer.begin()
136    fn_cache = {}
137    for rec in read_trace_file(edict, log):
138        event_num = rec[0]
139        event = edict[event_num]
140        if event_num not in fn_cache:
141            fn_cache[event_num] = build_fn(analyzer, event)
142        fn_cache[event_num](event, rec)
143    analyzer.end()
144
145def run(analyzer):
146    """Execute an analyzer on a trace file given on the command-line.
147
148    This function is useful as a driver for simple analysis scripts.  More
149    advanced scripts will want to call process() instead."""
150    import sys
151
152    if len(sys.argv) != 3:
153        sys.stderr.write('usage: %s <trace-events> <trace-file>\n' % sys.argv[0])
154        sys.exit(1)
155
156    events = _read_events(open(sys.argv[1], 'r'))
157    process(events, sys.argv[2], analyzer)
158
159if __name__ == '__main__':
160    class Formatter(Analyzer):
161        def __init__(self):
162            self.last_timestamp = None
163
164        def catchall(self, event, rec):
165            i = 1
166            timestamp = rec[1]
167            if self.last_timestamp is None:
168                self.last_timestamp = timestamp
169            delta_ns = timestamp - self.last_timestamp
170            self.last_timestamp = timestamp
171
172            fields = [event.name, '%0.3f' % (delta_ns / 1000.0)]
173            for type, name in event.args:
174                if is_string(type):
175                    fields.append('%s=%s' % (name, rec[i + 1]))
176                else:
177                    fields.append('%s=0x%x' % (name, rec[i + 1]))
178                i += 1
179            print ' '.join(fields)
180
181    run(Formatter())
182