xref: /openbmc/qemu/scripts/simpletrace.py (revision ba632924)
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 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 as 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).decode()
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, idtoname, fobj):
101    """Deserialize trace records from a file, yielding record tuples (event_num, timestamp, pid, arg1, ..., arg6).
102
103    Note that `idtoname` is modified if the file contains mapping records.
104
105    Args:
106        edict (str -> Event): events dict, indexed by name
107        idtoname (int -> str): event names dict, indexed by event ID
108        fobj (file): input file
109
110    """
111    while True:
112        t = fobj.read(8)
113        if len(t) == 0:
114            break
115
116        (rectype, ) = struct.unpack('=Q', t)
117        if rectype == record_type_mapping:
118            event_id, name = get_mapping(fobj)
119            idtoname[event_id] = name
120        else:
121            rec = read_record(edict, idtoname, fobj)
122
123            yield rec
124
125class Analyzer(object):
126    """A trace file analyzer which processes trace records.
127
128    An analyzer can be passed to run() or process().  The begin() method is
129    invoked, then each trace record is processed, and finally the end() method
130    is invoked.
131
132    If a method matching a trace event name exists, it is invoked to process
133    that trace record.  Otherwise the catchall() method is invoked.
134
135    Example:
136    The following method handles the runstate_set(int new_state) trace event::
137
138      def runstate_set(self, new_state):
139          ...
140
141    The method can also take a timestamp argument before the trace event
142    arguments::
143
144      def runstate_set(self, timestamp, new_state):
145          ...
146
147    Timestamps have the uint64_t type and are in nanoseconds.
148
149    The pid can be included in addition to the timestamp and is useful when
150    dealing with traces from multiple processes::
151
152      def runstate_set(self, timestamp, pid, new_state):
153          ...
154    """
155
156    def begin(self):
157        """Called at the start of the trace."""
158        pass
159
160    def catchall(self, event, rec):
161        """Called if no specific method for processing a trace event has been found."""
162        pass
163
164    def end(self):
165        """Called at the end of the trace."""
166        pass
167
168def process(events, log, analyzer, read_header=True):
169    """Invoke an analyzer on each event in a log."""
170    if isinstance(events, str):
171        events = read_events(open(events, 'r'), events)
172    if isinstance(log, str):
173        log = open(log, 'rb')
174
175    if read_header:
176        read_trace_header(log)
177
178    dropped_event = Event.build("Dropped_Event(uint64_t num_events_dropped)")
179    edict = {"dropped": dropped_event}
180    idtoname = {dropped_event_id: "dropped"}
181
182    for event in events:
183        edict[event.name] = event
184
185    # If there is no header assume event ID mapping matches events list
186    if not read_header:
187        for event_id, event in enumerate(events):
188            idtoname[event_id] = event.name
189
190    def build_fn(analyzer, event):
191        if isinstance(event, str):
192            return analyzer.catchall
193
194        fn = getattr(analyzer, event.name, None)
195        if fn is None:
196            return analyzer.catchall
197
198        event_argcount = len(event.args)
199        fn_argcount = len(inspect.getargspec(fn)[0]) - 1
200        if fn_argcount == event_argcount + 1:
201            # Include timestamp as first argument
202            return lambda _, rec: fn(*(rec[1:2] + rec[3:3 + event_argcount]))
203        elif fn_argcount == event_argcount + 2:
204            # Include timestamp and pid
205            return lambda _, rec: fn(*rec[1:3 + event_argcount])
206        else:
207            # Just arguments, no timestamp or pid
208            return lambda _, rec: fn(*rec[3:3 + event_argcount])
209
210    analyzer.begin()
211    fn_cache = {}
212    for rec in read_trace_records(edict, idtoname, log):
213        event_num = rec[0]
214        event = edict[event_num]
215        if event_num not in fn_cache:
216            fn_cache[event_num] = build_fn(analyzer, event)
217        fn_cache[event_num](event, rec)
218    analyzer.end()
219
220def run(analyzer):
221    """Execute an analyzer on a trace file given on the command-line.
222
223    This function is useful as a driver for simple analysis scripts.  More
224    advanced scripts will want to call process() instead."""
225    import sys
226
227    read_header = True
228    if len(sys.argv) == 4 and sys.argv[1] == '--no-header':
229        read_header = False
230        del sys.argv[1]
231    elif len(sys.argv) != 3:
232        sys.stderr.write('usage: %s [--no-header] <trace-events> ' \
233                         '<trace-file>\n' % sys.argv[0])
234        sys.exit(1)
235
236    events = read_events(open(sys.argv[1], 'r'), sys.argv[1])
237    process(events, sys.argv[2], analyzer, read_header=read_header)
238
239if __name__ == '__main__':
240    class Formatter(Analyzer):
241        def __init__(self):
242            self.last_timestamp = None
243
244        def catchall(self, event, rec):
245            timestamp = rec[1]
246            if self.last_timestamp is None:
247                self.last_timestamp = timestamp
248            delta_ns = timestamp - self.last_timestamp
249            self.last_timestamp = timestamp
250
251            fields = [event.name, '%0.3f' % (delta_ns / 1000.0),
252                      'pid=%d' % rec[2]]
253            i = 3
254            for type, name in event.args:
255                if is_string(type):
256                    fields.append('%s=%s' % (name, rec[i]))
257                else:
258                    fields.append('%s=0x%x' % (name, rec[i]))
259                i += 1
260            print(' '.join(fields))
261
262    run(Formatter())
263