FreeFOAM The Cross-Platform CFD Toolkit
cpuTimeImpl.C
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1 /*---------------------------------------------------------------------------*\
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3  \\ / F ield | OpenFOAM: The Open Source CFD Toolbox
4  \\ / O peration |
5  \\ / A nd | Copyright (C) 1991-2010 OpenCFD Ltd.
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10 
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21  You should have received a copy of the GNU General Public License
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23 
24 Description
25  Starts timing CPU usage and return elapsed time from start.
26 
27 \*---------------------------------------------------------------------------*/
28 
29 #include "cpuTimeImpl.H"
30 
31 #include <unistd.h>
32 
33 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
34 
35 namespace Foam
36 {
37 
38 // * * * * * * * * * * * * * * * Static Members * * * * * * * * * * * * * * //
39 
40 long cpuTimeImpl::Hz_(sysconf(_SC_CLK_TCK));
41 
42 
43 // * * * * * * * * * * * * * Private Member Functions * * * * * * * * * * * //
44 
45 void cpuTimeImpl::getTime(struct tms& t)
46 {
47  times(&t);
48 }
49 
50 
51 double cpuTimeImpl::timeDifference
52 (
53  const struct tms& start,
54  const struct tms& end
55 )
56 {
57  return
58  (
59  double
60  (
61  (end.tms_utime + end.tms_stime)
62  - (start.tms_utime + start.tms_stime)
63  )/Hz_
64  );
65 }
66 
67 
68 // * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
69 
71 {
72  getTime(startTime_);
73  lastTime_ = startTime_;
74  newTime_ = startTime_;
75 }
76 
77 
78 // * * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * //
79 
81 {
82  getTime(newTime_);
83  return timeDifference(startTime_, newTime_);
84 }
85 
86 
88 {
89  lastTime_ = newTime_;
90  getTime(newTime_);
91  return timeDifference(lastTime_, newTime_);
92 }
93 
94 
95 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
96 
97 } // End namespace Foam
98 
99 // ************************ vim: set sw=4 sts=4 et: ************************ //