Cantera  3.1.0a1
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clockWC.h
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1/**
2 * @file clockWC.h
3 * Declarations for a simple class that implements an Ansi C wall clock timer
4 * (see @ref Cantera::clockWC).
5 */
6
7// This file is part of Cantera. See License.txt in the top-level directory or
8// at https://cantera.org/license.txt for license and copyright information.
9
10#ifndef CT_CLOCKWC_H
11#define CT_CLOCKWC_H
12
13#include <time.h>
14namespace Cantera
15{
16
17//! @defgroup globalUtilFuncs Global Utility Functions
18
19//! The class provides the wall clock timer in seconds
20/*!
21 * This routine relies on the ANSI C routine, clock(), for its basic operation.
22 * Therefore, it should be fairly portable.
23 *
24 * The clock will rollover if the calculation is long enough. The wraparound
25 * time is roughly 72 minutes for a 32 bit system. This object senses that by
26 * seeing if the raw tick counter is has decreased from the last time. If it
27 * senses a wraparound has occurred, it increments an internal counter to
28 * account for this. Therefore, for long calculations, this object must be
29 * called at regular intervals for the seconds timer to be accurate.
30 *
31 * An example of how to use the timer is given below. timeToDoCalcs contains the
32 * wall clock time calculated for the operation.
33 *
34 * @code
35 * clockWC wc;
36 * do_hefty_calculations_atLeastgreaterThanAMillisecond();
37 * double timeToDoCalcs = wc.secondsWC();
38 * @endcode
39 *
40 * In general, the process to be timed must take more than a millisecond for
41 * this clock to enough of a significant resolution to be accurate.
42 *
43 * @ingroup globalUtilFuncs
44 *
45 */
47{
48public:
49 //! Constructor
50 /*!
51 * This also serves to initialize the ticks within the object
52 */
53 clockWC();
54
55 //! Resets the internal counters and returns the wall clock time in seconds
56 double start();
57
58 //! Returns the wall clock time in seconds since the last reset.
59 /*!
60 * Returns system cpu and wall clock time in seconds. This is a strictly
61 * Ansi C timer, since clock() is defined as an Ansi C function. On some
62 * machines clock() returns type unsigned long (HP) and on others (SUN)
63 * it returns type long. An attempt to recover the actual time for clocks
64 * which have rolled over is made also. However, it only works if this
65 * function is called fairly regularly during the solution procedure.
66 */
67 double secondsWC();
68
69private:
70 //! Counters the value of the number of ticks from the last call.
72
73 //! Number of clock rollovers since the last initialization
74 /*!
75 * The clock will rollover if the calculation is long enough. This object
76 * senses that by seeing if the raw tick counter is has decreased from the
77 * last time.
78 */
79 unsigned int clock_rollovers;
80
81 //! Counter containing the value of the number of ticks from the first call
82 //! (or the reset call).
83 clock_t start_ticks;
84
85 //! internal constant containing clock ticks per second
86 const double inv_clocks_per_sec;
87
88 //! internal constant containing the total number of ticks per rollover.
89 const double clock_width;
90};
91}
92#endif
The class provides the wall clock timer in seconds.
Definition clockWC.h:47
clock_t last_num_ticks
Counters the value of the number of ticks from the last call.
Definition clockWC.h:71
double start()
Resets the internal counters and returns the wall clock time in seconds.
Definition clockWC.cpp:25
unsigned int clock_rollovers
Number of clock rollovers since the last initialization.
Definition clockWC.h:79
clock_t start_ticks
Counter containing the value of the number of ticks from the first call (or the reset call).
Definition clockWC.h:83
double secondsWC()
Returns the wall clock time in seconds since the last reset.
Definition clockWC.cpp:32
const double inv_clocks_per_sec
internal constant containing clock ticks per second
Definition clockWC.h:86
clockWC()
Constructor.
Definition clockWC.cpp:15
const double clock_width
internal constant containing the total number of ticks per rollover.
Definition clockWC.h:89
Namespace for the Cantera kernel.
Definition AnyMap.cpp:564