1 # Copyright (c) 2013 The Chromium Authors. All rights reserved. 2 # Use of this source code is governed by a BSD-style license that can be 3 # found in the LICENSE file. 4 5 class TimelineEvent(object): 6 """Represents a timeline event. 7 8 thread_start, thread_duration and thread_end are the start time, duration 9 and end time of this event as measured by the thread-specific CPU clock 10 (ticking when the thread is actually scheduled). Thread time is optional 11 on trace events and the corresponding attributes in TimelineEvent will be 12 set to None (not 0) if not present. Users of this class need to properly 13 handle this case. 14 """ 15 def __init__(self, category, name, start, duration, thread_start=None, 16 thread_duration=None, args=None): 17 self.category = category 18 self.name = name 19 self.start = start 20 self.duration = duration 21 self.thread_start = thread_start 22 self.thread_duration = thread_duration 23 self.args = args 24 25 @property 26 def end(self): 27 return self.start + self.duration 28 29 @property 30 def thread_end(self): 31 """Thread-specific CPU time when this event ended. 32 33 May be None if the trace event didn't have thread time data. 34 """ 35 if self.thread_start == None or self.thread_duration == None: 36 return None 37 return self.thread_start + self.thread_duration 38 39 def __repr__(self): 40 if self.args: 41 args_str = ', ' + repr(self.args) 42 else: 43 args_str = '' 44 45 return ("TimelineEvent(name='%s', start=%f, duration=%s, " + 46 "thread_start=%s, thread_duration=%s%s)") % ( 47 self.name, 48 self.start, 49 self.duration, 50 self.thread_start, 51 self.thread_duration, 52 args_str) 53
