simpletrace.py (8707B)
1 #!/usr/bin/env python3 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.rst 11 12 import struct 13 import inspect 14 from tracetool import read_events, Event 15 from tracetool.backend.simple import is_string 16 17 header_event_id = 0xffffffffffffffff 18 header_magic = 0xf2b177cb0aa429b4 19 dropped_event_id = 0xfffffffffffffffe 20 21 record_type_mapping = 0 22 record_type_event = 1 23 24 log_header_fmt = '=QQQ' 25 rec_header_fmt = '=QQII' 26 27 def read_header(fobj, hfmt): 28 '''Read a trace record header''' 29 hlen = struct.calcsize(hfmt) 30 hdr = fobj.read(hlen) 31 if len(hdr) != hlen: 32 return None 33 return struct.unpack(hfmt, hdr) 34 35 def get_record(edict, idtoname, rechdr, fobj): 36 """Deserialize a trace record from a file into a tuple 37 (name, timestamp, pid, arg1, ..., arg6).""" 38 if rechdr is None: 39 return None 40 if rechdr[0] != dropped_event_id: 41 event_id = rechdr[0] 42 name = idtoname[event_id] 43 rec = (name, rechdr[1], rechdr[3]) 44 try: 45 event = edict[name] 46 except KeyError as e: 47 import sys 48 sys.stderr.write('%s event is logged but is not declared ' \ 49 'in the trace events file, try using ' \ 50 'trace-events-all instead.\n' % str(e)) 51 sys.exit(1) 52 53 for type, name in event.args: 54 if is_string(type): 55 l = fobj.read(4) 56 (len,) = struct.unpack('=L', l) 57 s = fobj.read(len) 58 rec = rec + (s,) 59 else: 60 (value,) = struct.unpack('=Q', fobj.read(8)) 61 rec = rec + (value,) 62 else: 63 rec = ("dropped", rechdr[1], rechdr[3]) 64 (value,) = struct.unpack('=Q', fobj.read(8)) 65 rec = rec + (value,) 66 return rec 67 68 def get_mapping(fobj): 69 (event_id, ) = struct.unpack('=Q', fobj.read(8)) 70 (len, ) = struct.unpack('=L', fobj.read(4)) 71 name = fobj.read(len).decode() 72 73 return (event_id, name) 74 75 def read_record(edict, idtoname, fobj): 76 """Deserialize a trace record from a file into a tuple (event_num, timestamp, pid, arg1, ..., arg6).""" 77 rechdr = read_header(fobj, rec_header_fmt) 78 return get_record(edict, idtoname, rechdr, fobj) 79 80 def read_trace_header(fobj): 81 """Read and verify trace file header""" 82 header = read_header(fobj, log_header_fmt) 83 if header is None: 84 raise ValueError('Not a valid trace file!') 85 if header[0] != header_event_id: 86 raise ValueError('Not a valid trace file, header id %d != %d' % 87 (header[0], header_event_id)) 88 if header[1] != header_magic: 89 raise ValueError('Not a valid trace file, header magic %d != %d' % 90 (header[1], header_magic)) 91 92 log_version = header[2] 93 if log_version not in [0, 2, 3, 4]: 94 raise ValueError('Unknown version of tracelog format!') 95 if log_version != 4: 96 raise ValueError('Log format %d not supported with this QEMU release!' 97 % log_version) 98 99 def read_trace_records(edict, idtoname, fobj): 100 """Deserialize trace records from a file, yielding record tuples (event_num, timestamp, pid, arg1, ..., arg6). 101 102 Note that `idtoname` is modified if the file contains mapping records. 103 104 Args: 105 edict (str -> Event): events dict, indexed by name 106 idtoname (int -> str): event names dict, indexed by event ID 107 fobj (file): input file 108 109 """ 110 while True: 111 t = fobj.read(8) 112 if len(t) == 0: 113 break 114 115 (rectype, ) = struct.unpack('=Q', t) 116 if rectype == record_type_mapping: 117 event_id, name = get_mapping(fobj) 118 idtoname[event_id] = name 119 else: 120 rec = read_record(edict, idtoname, fobj) 121 122 yield rec 123 124 class Analyzer(object): 125 """A trace file analyzer which processes trace records. 126 127 An analyzer can be passed to run() or process(). The begin() method is 128 invoked, then each trace record is processed, and finally the end() method 129 is invoked. 130 131 If a method matching a trace event name exists, it is invoked to process 132 that trace record. Otherwise the catchall() method is invoked. 133 134 Example: 135 The following method handles the runstate_set(int new_state) trace event:: 136 137 def runstate_set(self, new_state): 138 ... 139 140 The method can also take a timestamp argument before the trace event 141 arguments:: 142 143 def runstate_set(self, timestamp, new_state): 144 ... 145 146 Timestamps have the uint64_t type and are in nanoseconds. 147 148 The pid can be included in addition to the timestamp and is useful when 149 dealing with traces from multiple processes:: 150 151 def runstate_set(self, timestamp, pid, new_state): 152 ... 153 """ 154 155 def begin(self): 156 """Called at the start of the trace.""" 157 pass 158 159 def catchall(self, event, rec): 160 """Called if no specific method for processing a trace event has been found.""" 161 pass 162 163 def end(self): 164 """Called at the end of the trace.""" 165 pass 166 167 def process(events, log, analyzer, read_header=True): 168 """Invoke an analyzer on each event in a log.""" 169 if isinstance(events, str): 170 events = read_events(open(events, 'r'), events) 171 if isinstance(log, str): 172 log = open(log, 'rb') 173 174 if read_header: 175 read_trace_header(log) 176 177 frameinfo = inspect.getframeinfo(inspect.currentframe()) 178 dropped_event = Event.build("Dropped_Event(uint64_t num_events_dropped)", 179 frameinfo.lineno + 1, frameinfo.filename) 180 edict = {"dropped": dropped_event} 181 idtoname = {dropped_event_id: "dropped"} 182 183 for event in events: 184 edict[event.name] = event 185 186 # If there is no header assume event ID mapping matches events list 187 if not read_header: 188 for event_id, event in enumerate(events): 189 idtoname[event_id] = event.name 190 191 def build_fn(analyzer, event): 192 if isinstance(event, str): 193 return analyzer.catchall 194 195 fn = getattr(analyzer, event.name, None) 196 if fn is None: 197 return analyzer.catchall 198 199 event_argcount = len(event.args) 200 fn_argcount = len(inspect.getargspec(fn)[0]) - 1 201 if fn_argcount == event_argcount + 1: 202 # Include timestamp as first argument 203 return lambda _, rec: fn(*(rec[1:2] + rec[3:3 + event_argcount])) 204 elif fn_argcount == event_argcount + 2: 205 # Include timestamp and pid 206 return lambda _, rec: fn(*rec[1:3 + event_argcount]) 207 else: 208 # Just arguments, no timestamp or pid 209 return lambda _, rec: fn(*rec[3:3 + event_argcount]) 210 211 analyzer.begin() 212 fn_cache = {} 213 for rec in read_trace_records(edict, idtoname, log): 214 event_num = rec[0] 215 event = edict[event_num] 216 if event_num not in fn_cache: 217 fn_cache[event_num] = build_fn(analyzer, event) 218 fn_cache[event_num](event, rec) 219 analyzer.end() 220 221 def run(analyzer): 222 """Execute an analyzer on a trace file given on the command-line. 223 224 This function is useful as a driver for simple analysis scripts. More 225 advanced scripts will want to call process() instead.""" 226 import sys 227 228 read_header = True 229 if len(sys.argv) == 4 and sys.argv[1] == '--no-header': 230 read_header = False 231 del sys.argv[1] 232 elif len(sys.argv) != 3: 233 sys.stderr.write('usage: %s [--no-header] <trace-events> ' \ 234 '<trace-file>\n' % sys.argv[0]) 235 sys.exit(1) 236 237 events = read_events(open(sys.argv[1], 'r'), sys.argv[1]) 238 process(events, sys.argv[2], analyzer, read_header=read_header) 239 240 if __name__ == '__main__': 241 class Formatter(Analyzer): 242 def __init__(self): 243 self.last_timestamp = None 244 245 def catchall(self, event, rec): 246 timestamp = rec[1] 247 if self.last_timestamp is None: 248 self.last_timestamp = timestamp 249 delta_ns = timestamp - self.last_timestamp 250 self.last_timestamp = timestamp 251 252 fields = [event.name, '%0.3f' % (delta_ns / 1000.0), 253 'pid=%d' % rec[2]] 254 i = 3 255 for type, name in event.args: 256 if is_string(type): 257 fields.append('%s=%s' % (name, rec[i])) 258 else: 259 fields.append('%s=0x%x' % (name, rec[i])) 260 i += 1 261 print(' '.join(fields)) 262 263 run(Formatter())