Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(139)

Side by Side Diff: src/platform/elapsed-timer.h

Issue 23490015: Reland^2 "Add Chromium-style TimeDelta, Time and TimeTicks classes, and a new ElapsedTimer class." (Closed) Base URL: https://v8.googlecode.com/svn/branches/bleeding_edge
Patch Set: Some windows cleanup Created 7 years, 3 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View unified diff | Download patch | Annotate | Revision Log
« no previous file with comments | « src/platform-win32.cc ('k') | src/platform/time.h » ('j') | no next file with comments »
Toggle Intra-line Diffs ('i') | Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
OLDNEW
(Empty)
1 // Copyright 2013 the V8 project authors. All rights reserved.
2 // Redistribution and use in source and binary forms, with or without
3 // modification, are permitted provided that the following conditions are
4 // met:
5 //
6 // * Redistributions of source code must retain the above copyright
7 // notice, this list of conditions and the following disclaimer.
8 // * Redistributions in binary form must reproduce the above
9 // copyright notice, this list of conditions and the following
10 // disclaimer in the documentation and/or other materials provided
11 // with the distribution.
12 // * Neither the name of Google Inc. nor the names of its
13 // contributors may be used to endorse or promote products derived
14 // from this software without specific prior written permission.
15 //
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
28 #ifndef V8_PLATFORM_ELAPSED_TIMER_H_
29 #define V8_PLATFORM_ELAPSED_TIMER_H_
30
31 #include "checks.h"
32 #include "platform/time.h"
33
34 namespace v8 {
35 namespace internal {
36
37 class ElapsedTimer V8_FINAL BASE_EMBEDDED {
38 public:
39 #ifdef DEBUG
40 ElapsedTimer() : started_(false) {}
41 #endif
42
43 // Starts this timer. Once started a timer can be checked with
44 // |Elapsed()| or |HasExpired()|, and may be restarted using |Restart()|.
45 // This method must not be called on an already started timer.
46 void Start() {
47 ASSERT(!IsStarted());
48 start_ticks_ = Now();
49 #ifdef DEBUG
50 started_ = true;
51 #endif
52 ASSERT(IsStarted());
53 }
54
55 // Stops this timer. Must not be called on a timer that was not
56 // started before.
57 void Stop() {
58 ASSERT(IsStarted());
59 start_ticks_ = TimeTicks();
60 #ifdef DEBUG
61 started_ = false;
62 #endif
63 ASSERT(!IsStarted());
64 }
65
66 // Returns |true| if this timer was started previously.
67 bool IsStarted() const {
68 ASSERT(started_ || start_ticks_.IsNull());
69 ASSERT(!started_ || !start_ticks_.IsNull());
70 return !start_ticks_.IsNull();
71 }
72
73 // Restarts the timer and returns the time elapsed since the previous start.
74 // This method is equivalent to obtaining the elapsed time with |Elapsed()|
75 // and then starting the timer again, but does so in one single operation,
76 // avoiding the need to obtain the clock value twice. It may only be called
77 // on a previously started timer.
78 TimeDelta Restart() {
79 ASSERT(IsStarted());
80 TimeTicks ticks = Now();
81 TimeDelta elapsed = ticks - start_ticks_;
82 ASSERT(elapsed.InMicroseconds() >= 0);
83 start_ticks_ = ticks;
84 ASSERT(IsStarted());
85 return elapsed;
86 }
87
88 // Returns the time elapsed since the previous start. This method may only
89 // be called on a previously started timer.
90 MUST_USE_RESULT TimeDelta Elapsed() const {
91 ASSERT(IsStarted());
92 TimeDelta elapsed = Now() - start_ticks_;
93 ASSERT(elapsed.InMicroseconds() >= 0);
94 return elapsed;
95 }
96
97 // Returns |true| if the specified |time_delta| has elapsed since the
98 // previous start, or |false| if not. This method may only be called on
99 // a previously started timer.
100 MUST_USE_RESULT bool HasExpired(TimeDelta time_delta) const {
101 ASSERT(IsStarted());
102 return Elapsed() >= time_delta;
103 }
104
105 private:
106 MUST_USE_RESULT V8_INLINE(static TimeTicks Now()) {
107 TimeTicks now = TimeTicks::HighResNow();
108 ASSERT(!now.IsNull());
109 return now;
110 }
111
112 TimeTicks start_ticks_;
113 #ifdef DEBUG
114 bool started_;
115 #endif
116 };
117
118 } } // namespace v8::internal
119
120 #endif // V8_PLATFORM_ELAPSED_TIMER_H_
OLDNEW
« no previous file with comments | « src/platform-win32.cc ('k') | src/platform/time.h » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698