5 * (c) 2023 Straylight/Edgeware
8 /*----- Licensing notice --------------------------------------------------*
10 * This file is part of the mLib utilities library.
12 * mLib is free software: you can redistribute it and/or modify it under
13 * the terms of the GNU Library General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or (at
15 * your option) any later version.
17 * mLib is distributed in the hope that it will be useful, but WITHOUT
18 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
19 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
20 * License for more details.
22 * You should have received a copy of the GNU Library General Public
23 * License along with mLib. If not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
35 /*----- Header files ------------------------------------------------------*/
47 /*----- Data structures ---------------------------------------------------*/
50 unsigned f; /* flags */
51 #define BTF_TIMEOK 1u /* @s@ ad @ns@ slots are value */
52 #define BTF_CYOK 2u /* @cy@ slot is valid */
53 #define BTF_ANY (BTF_TIMEOK | BTF_CYOK) /* some part is useful */
55 struct { kludge64 s; uint32 ns; } ts; /* @struct timespec@-ish */
56 clock_t clk; /* @clock@ */
57 kludge64 rawns; /* raw nanosecond count */
59 kludge64 cy; /* count of CPU cycles */
63 unsigned f; /* flags (@BTF_...@) */
64 double n, t, cy; /* count, time, and cycles */
67 struct bench_timer { const struct bench_timerops *ops; };
69 struct bench_timerops {
70 void (*describe)(struct bench_timer */*bt*/, dstr */*d*/);
71 /* Write a description of the timer to @d@. */
73 int (*now)(struct bench_timer */*bt*/, struct bench_time */*t_out*/,
75 #define BTF_T0 0u /* fetching first time of a pair */
76 #define BTF_T1 1u /* fetching second time of a pair */
77 /* Fill in @*t_out@ with the current time. Return zero on success
78 * %%\emph{or} permanent failure; return %$-1$% on temporary failure.
81 void (*diff)(struct bench_timer */*bt*/,
82 struct bench_timing */*delta_out*/,
83 const struct bench_time */*t0*/,
84 const struct bench_time */*t1*/);
85 /* Subtract the time @t0@ from the time @t1@, leaving the result in
86 * @*delta_out@, setting flags as appropriate.
89 void (*destroy)(struct bench_timer */*bt*/);
90 /* Release the timer and any resources it holds. */
94 struct bench_timer *tm; /* a timer */
95 double target_s; /* target time to run benchmarks */
96 unsigned f; /* calibration flags (@BTF_...@) */
97 #define BTF_CLB 0x0100 /* tried calibrating */
98 struct { double m, c; } clk, cy; /* calculated overheads */
101 typedef void bench_fn(unsigned long /*n*/, void */*ctx*/);
102 /* Run the benchmark @n@ times, given a context pointer @ctx@. */
104 /*----- Functions provided ------------------------------------------------*/
106 /* --- @bench_createtimer@ --- *
108 * Arguments: @const char *config@ = user-supplied configuration string
110 * Returns: A freshly constructed standard timer object, or null on
113 * Use: Allocate a timer. Dispose of it by calling
114 * @tm->ops->destroy(tm)@ when you're done.
116 * Applications should not set configuration strings except as
117 * established by user action, e.g., from a command-line option,
118 * environment variable, or configuration file.
121 extern struct bench_timer *bench_createtimer(const char *config);
123 /* --- @bench_init@ --- *
125 * Arguments: @struct bench_state *b@ = bench state to initialize
126 * @struct bench_timer *tm@ = timer to attach, or null
128 * Returns: Zero on success, %$-1$% on failure.
130 * Use: Initialize the benchmark state. On success, the timer state
131 * still needs to be calibrated (use @bench_calibrate@) before
132 * it can be used, but this will be done automatically by
133 * @bench_measure@ if it's not done by hand earlier. The timer
134 * is now owned by the benchmark state and will be destroyed by
137 * The only reason for failure is if @tm@ was null on entry,
138 * and automatic construction of a timer failed. The state is
139 * safe to discard, but calling @bench_destroy@ is safe too.
142 extern int bench_init(struct bench_state */*b*/, struct bench_timer */*tm*/);
144 /* --- @bench_destroy@ --- *
146 * Arguments: @struct bench_state *b@ = bench state
150 * Use: Destroy the benchmark state, releasing the resources that it
154 extern void bench_destroy(struct bench_state */*b*/);
156 /* --- @bench_calibrate@ --- *
158 * Arguments: @struct bench_state *b@ = bench state
160 * Returns: Zero on success, %$-1$% if calibration failed.
162 * Use: Calibrate the benchmark state, so that it can be used to
163 * measure performance reasonably accurately.
166 extern int bench_calibrate(struct bench_state */*b*/);
168 /* --- @bench_measure@ --- *
170 * Arguments: @struct bench_state *b@ = benchmark state
171 * @struct bench_timing *t_out@ = where to leave the timing
172 * @double base@ = number of internal units per call
173 * @bench_fn *fn@, @void *ctx@ = benchmark function to run
175 * Returns: Zero on success, %$-1$% if timing failed.
177 * Use: Measure a function. The function @fn@ is called adaptively
178 * with an iteration count @n@ set so as to run for
179 * approximately @b->target_s@ seconds.
181 * The result is left in @*t_out@, with @t_out->n@ counting the
182 * final product of the iteration count and @base@ (which might,
183 * e.g., reflect the number of inner iterations the function
184 * performs, or the number of bytes it processes per iteration).
187 extern int bench_measure(struct bench_state */*b*/,
188 struct bench_timing */*t_out*/,
189 double /*base*/, bench_fn */*fn*/, void */*ctx*/);
191 /*----- That's all, folks -------------------------------------------------*/