| # |
| # Copyright (C) International Business Machines Corp., 2009 |
| # |
| # This program is free software; you can redistribute it and/or modify |
| # it under the terms of the GNU General Public License as published by |
| # the Free Software Foundation; either version 2 of the License, or |
| # (at your option) any later version. |
| # |
| # This program is distributed in the hope that it will be useful, |
| # but WITHOUT ANY WARRANTY; without even the implied warranty of |
| # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| # GNU General Public License for more details. |
| # |
| # You should have received a copy of the GNU General Public License |
| # along with this program; if not, write to the Free Software |
| # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| # |
| # 2009-Dec-17: Initial version by Darren Hart <dvhltc@us.ibm.com> |
| # |
| |
| from functools import update_wrapper |
| from ctracecmd import * |
| from UserDict import DictMixin |
| |
| """ |
| Python interface to the tracecmd library for parsing ftrace traces |
| |
| Python tracecmd applications should be written to this interface. It will be |
| updated as the tracecmd C API changes and try to minimze the impact to python |
| applications. The ctracecmd Python module is automatically generated using SWIG |
| and it is recommended applications not use it directly. |
| |
| TODO: consider a complete class hierarchy of ftrace events... |
| """ |
| |
| def cached_property(func, name=None): |
| if name is None: |
| name = func.__name__ |
| def _get(self): |
| try: |
| return self.__cached_properties[name] |
| except AttributeError: |
| self.__cached_properties = {} |
| except KeyError: |
| pass |
| value = func(self) |
| self.__cached_properties[name] = value |
| return value |
| update_wrapper(_get, func) |
| def _del(self): |
| self.__cached_properties.pop(name, None) |
| return property(_get, None, _del) |
| |
| class Event(object, DictMixin): |
| """ |
| This class can be used to access event data |
| according to an event's record and format. |
| """ |
| def __init__(self, pevent, record, format): |
| self._pevent = pevent |
| self._record = record |
| self._format = format |
| |
| def __str__(self): |
| return "%d.%d CPU%d %s: pid=%d comm=%s type=%d" % \ |
| (self.ts/1000000000, self.ts%1000000000, self.cpu, self.name, |
| self.num_field("common_pid"), self.comm, self.type) |
| |
| def __del__(self): |
| free_record(self._record) |
| |
| def __getitem__(self, n): |
| f = pevent_find_field(self._format, n) |
| if f is None: |
| raise KeyError("no field '%s'" % n) |
| return Field(self._record, f) |
| |
| def keys(self): |
| return py_format_get_keys(self._format) |
| |
| @cached_property |
| def comm(self): |
| return pevent_data_comm_from_pid(self._pevent, self.pid) |
| |
| @cached_property |
| def cpu(self): |
| return pevent_record_cpu_get(self._record) |
| |
| @cached_property |
| def name(self): |
| return event_format_name_get(self._format) |
| |
| @cached_property |
| def pid(self): |
| return pevent_data_pid(self._pevent, self._record) |
| |
| @cached_property |
| def ts(self): |
| return pevent_record_ts_get(self._record) |
| |
| @cached_property |
| def type(self): |
| return pevent_data_type(self._pevent, self._record) |
| |
| def num_field(self, name): |
| f = pevent_find_any_field(self._format, name) |
| if f is None: |
| return None |
| ret, val = pevent_read_number_field(f, pevent_record_data_get(self._record)) |
| if ret: |
| return None |
| return val |
| |
| def str_field(self, name): |
| f = pevent_find_any_field(self._format, name) |
| if f is None: |
| return None |
| return py_field_get_str(f, self._record) |
| |
| def stack_field(self, long_size): |
| return py_field_get_stack(self._pevent, self._record, self._format, |
| long_size) |
| |
| class TraceSeq(object): |
| def __init__(self, trace_seq): |
| self._trace_seq = trace_seq |
| |
| def puts(self, s): |
| return trace_seq_puts(self._trace_seq, s) |
| |
| class FieldError(Exception): |
| pass |
| |
| class Field(object): |
| def __init__(self, record, field): |
| self._record = record |
| self._field = field |
| |
| @cached_property |
| def data(self): |
| return py_field_get_data(self._field, self._record) |
| |
| def __long__(self): |
| ret, val = pevent_read_number_field(self._field, |
| pevent_record_data_get(self._record)) |
| if ret: |
| raise FieldError("Not a number field") |
| return val |
| __int__ = __long__ |
| |
| def __str__(self): |
| return py_field_get_str(self._field, self._record) |
| |
| class PEvent(object): |
| def __init__(self, pevent): |
| self._pevent = pevent |
| |
| def _handler(self, cb, s, record, event_fmt): |
| return cb(TraceSeq(s), Event(self._pevent, record, event_fmt)) |
| |
| def register_event_handler(self, subsys, event_name, callback): |
| l = lambda s, r, e: self._handler(callback, s, r, e) |
| |
| py_pevent_register_event_handler( |
| self._pevent, -1, subsys, event_name, l) |
| |
| @cached_property |
| def file_endian(self): |
| if pevent_is_file_bigendian(self._pevent): |
| return '>' |
| return '<' |
| |
| |
| class FileFormatError(Exception): |
| pass |
| |
| class Trace(object): |
| """ |
| Trace object represents the trace file it is created with. |
| |
| The Trace object aggregates the tracecmd structures and functions that are |
| used to manage the trace and extract events from it. |
| """ |
| def __init__(self, filename): |
| self._handle = tracecmd_alloc(filename) |
| |
| if tracecmd_read_headers(self._handle): |
| raise FileFormatError("Invalid headers") |
| |
| if tracecmd_init_data(self._handle): |
| raise FileFormatError("Failed to init data") |
| |
| self._pevent = tracecmd_get_pevent(self._handle) |
| |
| @cached_property |
| def cpus(self): |
| return tracecmd_cpus(self._handle) |
| |
| @cached_property |
| def long_size(self): |
| return tracecmd_long_size(self._handle) |
| |
| def read_event(self, cpu): |
| rec = tracecmd_read_data(self._handle, cpu) |
| if rec: |
| type = pevent_data_type(self._pevent, rec) |
| format = pevent_data_event_from_type(self._pevent, type) |
| # rec ownership goes over to Event instance |
| return Event(self._pevent, rec, format) |
| return None |
| |
| def read_event_at(self, offset): |
| res = tracecmd_read_at(self._handle, offset) |
| # SWIG only returns the CPU if the record is None for some reason |
| if isinstance(res, int): |
| return None |
| rec, cpu = res |
| type = pevent_data_type(self._pevent, rec) |
| format = pevent_data_event_from_type(self._pevent, type) |
| # rec ownership goes over to Event instance |
| return Event(self._pevent, rec, format) |
| |
| def read_next_event(self): |
| res = tracecmd_read_next_data(self._handle) |
| if isinstance(res, int): |
| return None |
| rec, cpu = res |
| type = pevent_data_type(self._pevent, rec) |
| format = pevent_data_event_from_type(self._pevent, type) |
| return Event(self._pevent, rec, format) |
| |
| def peek_event(self, cpu): |
| rec = tracecmd_peek_data_ref(self._handle, cpu) |
| if rec is None: |
| return None |
| type = pevent_data_type(self._pevent, rec) |
| format = pevent_data_event_from_type(self._pevent, type) |
| # rec ownership goes over to Event instance |
| return Event(self._pevent, rec, format) |
| |
| |
| # Basic builtin test, execute module directly |
| if __name__ == "__main__": |
| t = Trace("trace.dat") |
| print "Trace contains data for %d cpus" % (t.cpus) |
| |
| for cpu in range(0, t.cpus): |
| print "CPU %d" % (cpu) |
| ev = t.read_event(cpu) |
| while ev: |
| print "\t%s" % (ev) |
| ev = t.read_event(cpu) |
| |
| |
| |
