Cantera 2.6.0

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>
14 namespace Cantera
15{
16
17//! The class provides the wall clock timer in seconds
18/*!
19 * This routine relies on the ANSI C routine, clock(), for its basic operation.
20 * Therefore, it should be fairly portable.
21 *
22 * The clock will rollover if the calculation is long enough. The wraparound
23 * time is roughly 72 minutes for a 32 bit system. This object senses that by
24 * seeing if the raw tick counter is has decreased from the last time. If it
25 * senses a wraparound has occurred, it increments an internal counter to
26 * account for this. Therefore, for long calculations, this object must be
27 * called at regular intervals for the seconds timer to be accurate.
28 *
29 * An example of how to use the timer is given below. timeToDoCalcs contains the
30 * wall clock time calculated for the operation.
31 *
32 * @code
33 * clockWC wc;
34 * do_hefty_calculations_atLeastgreaterThanAMillisecond();
35 * double timeToDoCalcs = wc.secondsWC();
36 * @endcode
37 *
38 * In general, the process to be timed must take more than a millisecond for
39 * this clock to enough of a significant resolution to be accurate.
40 *
41 * @ingroup globalUtilFuncs
42 *
43 */
44 class clockWC
45{
46 public:
47 //! Constructor
48 /*!
49 * This also serves to initialize the ticks within the object
50 */
51 clockWC();
52
53 //! Resets the internal counters and returns the wall clock time in seconds
54 double start();
55
56 //! Returns the wall clock time in seconds since the last reset.
57 /*!
58 * Returns system cpu and wall clock time in seconds. This is a strictly
59 * Ansi C timer, since clock() is defined as an Ansi C function. On some
60 * machines clock() returns type unsigned long (HP) and on others (SUN)
61 * it returns type long. An attempt to recover the actual time for clocks
62 * which have rolled over is made also. However, it only works if this
63 * function is called fairly regularily during the solution procedure.
64 */
65 double secondsWC();
66
67 private:
68 //! Counters the value of the number of ticks from the last call.
69 clock_t last_num_ticks;
70
71 //! Number of clock rollovers since the last initialization
72 /*!
73 * The clock will rollover if the calculation is long enough. This object
74 * senses that by seeing if the raw tick counter is has decreased from the
75 * last time.
76 */
77 unsigned int clock_rollovers;
78
79 //! Counter containing the value of the number of ticks from the first call
80 //! (or the reset call).
81 clock_t start_ticks;
82
83 //! internal constant containing clock ticks per second
84 const double inv_clocks_per_sec;
85
86 //! internal constant containing the total number of ticks per rollover.
87 const double clock_width;
88};
89}
90#endif
Cantera::clockWC
The class provides the wall clock timer in seconds.
Definition: clockWC.h:45
Cantera::clockWC::last_num_ticks
clock_t last_num_ticks
Counters the value of the number of ticks from the last call.
Definition: clockWC.h:69
Cantera::clockWC::start
double start()
Resets the internal counters and returns the wall clock time in seconds.
Definition: clockWC.cpp:25
Cantera::clockWC::clock_rollovers
unsigned int clock_rollovers
Number of clock rollovers since the last initialization.
Definition: clockWC.h:77
Cantera::clockWC::start_ticks
clock_t start_ticks
Counter containing the value of the number of ticks from the first call (or the reset call).
Definition: clockWC.h:81
Cantera::clockWC::secondsWC
double secondsWC()
Returns the wall clock time in seconds since the last reset.
Definition: clockWC.cpp:32
Cantera::clockWC::inv_clocks_per_sec
const double inv_clocks_per_sec
internal constant containing clock ticks per second
Definition: clockWC.h:84
Cantera::clockWC::clockWC
clockWC()
Constructor.
Definition: clockWC.cpp:15
Cantera::clockWC::clock_width
const double clock_width
internal constant containing the total number of ticks per rollover.
Definition: clockWC.h:87
Cantera
Namespace for the Cantera kernel.
Definition: AnyMap.cpp:557