xref: /openbmc/qemu/scripts/simpletrace.py (revision 6e99f574)
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        event = edict[name]
46        for type, name in event.args:
47            if is_string(type):
48                l = fobj.read(4)
49                (len,) = struct.unpack('=L', l)
50                s = fobj.read(len)
51                rec = rec + (s,)
52            else:
53                (value,) = struct.unpack('=Q', fobj.read(8))
54                rec = rec + (value,)
55    else:
56        rec = ("dropped", rechdr[1], rechdr[3])
57        (value,) = struct.unpack('=Q', fobj.read(8))
58        rec = rec + (value,)
59    return rec
60
61def get_mapping(fobj):
62    (event_id, ) = struct.unpack('=Q', fobj.read(8))
63    (len, ) = struct.unpack('=L', fobj.read(4))
64    name = fobj.read(len)
65
66    return (event_id, name)
67
68def read_record(edict, idtoname, fobj):
69    """Deserialize a trace record from a file into a tuple (event_num, timestamp, pid, arg1, ..., arg6)."""
70    rechdr = read_header(fobj, rec_header_fmt)
71    return get_record(edict, idtoname, rechdr, fobj)
72
73def read_trace_header(fobj):
74    """Read and verify trace file header"""
75    header = read_header(fobj, log_header_fmt)
76    if header is None or \
77       header[0] != header_event_id or \
78       header[1] != header_magic:
79        raise ValueError('Not a valid trace file!')
80
81    log_version = header[2]
82    if log_version not in [0, 2, 3, 4]:
83        raise ValueError('Unknown version of tracelog format!')
84    if log_version != 4:
85        raise ValueError('Log format %d not supported with this QEMU release!'
86                         % log_version)
87
88def read_trace_records(edict, fobj):
89    """Deserialize trace records from a file, yielding record tuples (event_num, timestamp, pid, arg1, ..., arg6)."""
90    idtoname = {
91        dropped_event_id: "dropped"
92    }
93    while True:
94        t = fobj.read(8)
95        if len(t) == 0:
96            break
97
98        (rectype, ) = struct.unpack('=Q', t)
99        if rectype == record_type_mapping:
100            event_id, name = get_mapping(fobj)
101            idtoname[event_id] = name
102        else:
103            rec = read_record(edict, idtoname, fobj)
104
105            yield rec
106
107class Analyzer(object):
108    """A trace file analyzer which processes trace records.
109
110    An analyzer can be passed to run() or process().  The begin() method is
111    invoked, then each trace record is processed, and finally the end() method
112    is invoked.
113
114    If a method matching a trace event name exists, it is invoked to process
115    that trace record.  Otherwise the catchall() method is invoked."""
116
117    def begin(self):
118        """Called at the start of the trace."""
119        pass
120
121    def catchall(self, event, rec):
122        """Called if no specific method for processing a trace event has been found."""
123        pass
124
125    def end(self):
126        """Called at the end of the trace."""
127        pass
128
129def process(events, log, analyzer, read_header=True):
130    """Invoke an analyzer on each event in a log."""
131    if isinstance(events, str):
132        events = read_events(open(events, 'r'))
133    if isinstance(log, str):
134        log = open(log, 'rb')
135
136    if read_header:
137        read_trace_header(log)
138
139    dropped_event = Event.build("Dropped_Event(uint64_t num_events_dropped)")
140    edict = {"dropped": dropped_event}
141
142    for event in events:
143        edict[event.name] = event
144
145    def build_fn(analyzer, event):
146        if isinstance(event, str):
147            return analyzer.catchall
148
149        fn = getattr(analyzer, event.name, None)
150        if fn is None:
151            return analyzer.catchall
152
153        event_argcount = len(event.args)
154        fn_argcount = len(inspect.getargspec(fn)[0]) - 1
155        if fn_argcount == event_argcount + 1:
156            # Include timestamp as first argument
157            return lambda _, rec: fn(*((rec[1:2],) + rec[3:3 + event_argcount]))
158        elif fn_argcount == event_argcount + 2:
159            # Include timestamp and pid
160            return lambda _, rec: fn(*rec[1:3 + event_argcount])
161        else:
162            # Just arguments, no timestamp or pid
163            return lambda _, rec: fn(*rec[3:3 + event_argcount])
164
165    analyzer.begin()
166    fn_cache = {}
167    for rec in read_trace_records(edict, log):
168        event_num = rec[0]
169        event = edict[event_num]
170        if event_num not in fn_cache:
171            fn_cache[event_num] = build_fn(analyzer, event)
172        fn_cache[event_num](event, rec)
173    analyzer.end()
174
175def run(analyzer):
176    """Execute an analyzer on a trace file given on the command-line.
177
178    This function is useful as a driver for simple analysis scripts.  More
179    advanced scripts will want to call process() instead."""
180    import sys
181
182    read_header = True
183    if len(sys.argv) == 4 and sys.argv[1] == '--no-header':
184        read_header = False
185        del sys.argv[1]
186    elif len(sys.argv) != 3:
187        sys.stderr.write('usage: %s [--no-header] <trace-events> ' \
188                         '<trace-file>\n' % sys.argv[0])
189        sys.exit(1)
190
191    events = read_events(open(sys.argv[1], 'r'))
192    process(events, sys.argv[2], analyzer, read_header=read_header)
193
194if __name__ == '__main__':
195    class Formatter(Analyzer):
196        def __init__(self):
197            self.last_timestamp = None
198
199        def catchall(self, event, rec):
200            timestamp = rec[1]
201            if self.last_timestamp is None:
202                self.last_timestamp = timestamp
203            delta_ns = timestamp - self.last_timestamp
204            self.last_timestamp = timestamp
205
206            fields = [event.name, '%0.3f' % (delta_ns / 1000.0),
207                      'pid=%d' % rec[2]]
208            i = 3
209            for type, name in event.args:
210                if is_string(type):
211                    fields.append('%s=%s' % (name, rec[i]))
212                else:
213                    fields.append('%s=0x%x' % (name, rec[i]))
214                i += 1
215            print ' '.join(fields)
216
217    run(Formatter())
218