bench: simplify the bench helpers

Trim the API a bit.

Also, just always use gettimeofday(), which is portable. Hopefully the
system clock doesn't change while a benchmark is running.

Signed-off-by: Ran Benita <ran234@gmail.com>

bench/bench.c

@@ -22,130 +22,54 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
-#if defined(HAVE_CLOCK_GETTIME)
-#define USE_CLOCK_GETTIME
-#include <time.h>
-#elif defined(__MACH__) && __MACH__ == 1
-#define USE_MACH_ABSOLUTE_TIME
-#include <mach/mach_time.h>
-#else
-/* gettimeofday() - a last resort */
-#include <sys/time.h>
-#endif
-
 #include <assert.h>
-#include <stdlib.h>
-#include <stdint.h>
-#include <string.h>
 #include <stdio.h>
+#include <sys/time.h>
 
 #include "bench.h"
 
-static void
-set_bench_time(struct bench_time *dest, long seconds, long milliseconds)
-{
-    dest->seconds = seconds;
-    dest->milliseconds = milliseconds;
-}
-
-static void
-normalize_bench_time(struct bench_time *obj)
-{
-    if (obj->milliseconds >= 0) {
-        return;
-    }
-    obj->milliseconds += 1000000;
-    obj->seconds--;
-}
-
 void
-bench_timer_reset(struct bench_timer *self)
+bench_start(struct bench *bench)
 {
-#if defined(USE_MACH_ABSOLUTE_TIME)
-    mach_timebase_info_data_t info;
-    if (mach_timebase_info(&info) == 0) {
-        self->scaling_factor = info.numer / info.denom;
-    }
-#endif
-    self->start.seconds = 0L;
-    self->start.milliseconds = 0L;
-    self->stop.seconds = 0L;
-    self->stop.milliseconds = 0L;
-}
-
-void
-bench_timer_start(struct bench_timer *self)
-{
-#if defined(USE_CLOCK_GETTIME)
-    struct timespec val;
-
-    (void) clock_gettime(CLOCK_MONOTONIC, &val);
-
-    /* With conversion from nanosecond to millisecond */
-    set_bench_time(&self->start, val.tv_sec, val.tv_nsec / 1000);
-#elif defined(USE_MACH_ABSOLUTE_TIME)
-    uint64_t val;
-
-    val = mach_absolute_time();
-
-    /* With conversion from nanosecond to millisecond */
-    set_bench_time(&self->start,
-                   self->scaling_factor * val / 1000000000,
-                   self->scaling_factor * val % 1000000000 / 1000);
-#else
     struct timeval val;
-
     (void) gettimeofday(&val, NULL);
-
-    set_bench_time(&self->start, val.tv_sec, val.tv_usec);
-#endif
+    bench->start = (struct bench_time) {
+        .seconds = val.tv_sec,
+        .microseconds = val.tv_usec,
+    };
 }
 
 void
-bench_timer_stop(struct bench_timer *self)
+bench_stop(struct bench *bench)
 {
-#if defined(USE_CLOCK_GETTIME)
-    struct timespec val;
-
-    (void) clock_gettime(CLOCK_MONOTONIC, &val);
-
-    /* With conversion from nanosecond to millisecond */
-    set_bench_time(&self->stop, val.tv_sec, val.tv_nsec / 1000);
-#elif defined(USE_MACH_ABSOLUTE_TIME)
-    uint64_t val;
-
-    val = mach_absolute_time();
-
-    /* With conversion from nanosecond to millisecond */
-    set_bench_time(&self->stop,
-                   self->scaling_factor * val / 1000000000,
-                   self->scaling_factor * val % 1000000000 / 1000);
-#else
     struct timeval val;
-
     (void) gettimeofday(&val, NULL);
-
-    set_bench_time(&self->stop, val.tv_sec, val.tv_usec);
-#endif
+    bench->stop = (struct bench_time) {
+        .seconds = val.tv_sec,
+        .microseconds = val.tv_usec,
+    };
 }
 
 void
-bench_timer_get_elapsed_time(struct bench_timer *self, struct bench_time *result)
+bench_elapsed(const struct bench *bench, struct bench_time *result)
 {
-    result->seconds = self->stop.seconds - self->start.seconds;
-    result->milliseconds = self->stop.milliseconds - self->start.milliseconds;
+    result->seconds = bench->stop.seconds - bench->start.seconds;
+    result->microseconds = bench->stop.microseconds - bench->start.microseconds;
+    if (result->microseconds < 0) {
+        result->microseconds += 1000000;
+        result->seconds--;
+    }
 }
 
 char *
-bench_timer_get_elapsed_time_str(struct bench_timer *self)
+bench_elapsed_str(const struct bench *bench)
 {
     struct bench_time elapsed;
     char *buf;
     int ret;
 
-    bench_timer_get_elapsed_time(self, &elapsed);
-    normalize_bench_time(&elapsed);
-    ret = asprintf(&buf, "%ld.%06ld", elapsed.seconds, elapsed.milliseconds);
+    bench_elapsed(bench, &elapsed);
+    ret = asprintf(&buf, "%ld.%06ld", elapsed.seconds, elapsed.microseconds);
     assert(ret >= 0);
 
     return buf;

bench/bench.h

@@ -25,28 +25,25 @@
 #ifndef LIBXKBCOMMON_BENCH_H
 #define LIBXKBCOMMON_BENCH_H
 
-#include <stdint.h>
-
 struct bench_time {
     long seconds;
-    long milliseconds;
+    long microseconds;
 };
 
-struct bench_timer {
+struct bench {
     struct bench_time start;
     struct bench_time stop;
-#if defined(__MACH__) && __MACH__ == 1
-    uint64_t scaling_factor;
-#endif
 };
 
-void bench_timer_reset(struct bench_timer *self);
+void
+bench_start(struct bench *bench);
+void
+bench_stop(struct bench *bench);
 
-void bench_timer_start(struct bench_timer *self);
-void bench_timer_stop(struct bench_timer *self);
-
-void bench_timer_get_elapsed_time(struct bench_timer *self, struct bench_time *result);
-/* It's caller's responsibility to release the returned string using free(). */
-char *bench_timer_get_elapsed_time_str(struct bench_timer *self);
+void
+bench_elapsed(const struct bench *bench, struct bench_time *result);
+/* The caller is responsibile to free() the returned string. */
+char *
+bench_elapsed_str(const struct bench *bench);
 
 #endif /* LIBXKBCOMMON_BENCH_H */

bench/compose.c

@@ -37,7 +37,7 @@ main(void)
     char *path;
     FILE *file;
     struct xkb_compose_table *table;
-    struct bench_timer timer;
+    struct bench bench;
     char *elapsed;
 
     ctx = test_get_context(CONTEXT_NO_FLAG);
@@ -55,9 +55,7 @@ main(void)
     xkb_context_set_log_level(ctx, XKB_LOG_LEVEL_CRITICAL);
     xkb_context_set_log_verbosity(ctx, 0);
 
-    bench_timer_reset(&timer);
-
-    bench_timer_start(&timer);
+    bench_start(&bench);
     for (int i = 0; i < BENCHMARK_ITERATIONS; i++) {
         rewind(file);
         table = xkb_compose_table_new_from_file(ctx, file, "",
@@ -66,12 +64,12 @@ main(void)
         assert(table);
         xkb_compose_table_unref(table);
     }
-    bench_timer_stop(&timer);
+    bench_stop(&bench);
 
     fclose(file);
     free(path);
 
-    elapsed = bench_timer_get_elapsed_time_str(&timer);
+    elapsed = bench_elapsed_str(&bench);
     fprintf(stderr, "compiled %d compose tables in %ss\n",
             BENCHMARK_ITERATIONS, elapsed);
     free(elapsed);

bench/key-proc.c

@@ -30,7 +30,7 @@
 #define BENCHMARK_ITERATIONS 20000000
 
 static void
-bench(struct xkb_state *state)
+bench_key_proc(struct xkb_state *state)
 {
     int8_t keys[256] = { 0 };
     xkb_keycode_t keycode;
@@ -57,7 +57,7 @@ main(void)
     struct xkb_context *ctx;
     struct xkb_keymap *keymap;
     struct xkb_state *state;
-    struct bench_timer timer;
+    struct bench bench;
     char *elapsed;
 
     ctx = test_get_context(0);
@@ -75,13 +75,11 @@ main(void)
 
     srand(time(NULL));
 
-    bench_timer_reset(&timer);
+    bench_start(&bench);
+    bench_key_proc(state);
+    bench_stop(&bench);
 
-    bench_timer_start(&timer);
-    bench(state);
-    bench_timer_stop(&timer);
-
-    elapsed = bench_timer_get_elapsed_time_str(&timer);
+    elapsed = bench_elapsed_str(&bench);
     fprintf(stderr, "ran %d iterations in %ss\n",
             BENCHMARK_ITERATIONS, elapsed);
     free(elapsed);

bench/rules.c

@@ -39,7 +39,7 @@ main(int argc, char *argv[])
         "evdev", "pc105", "us,il", ",", "ctrl:nocaps,grp:menu_toggle",
     };
     struct xkb_component_names kccgst;
-    struct bench_timer timer;
+    struct bench bench;
     char *elapsed;
 
     ctx = test_get_context(0);
@@ -48,9 +48,7 @@ main(int argc, char *argv[])
     xkb_context_set_log_level(ctx, XKB_LOG_LEVEL_CRITICAL);
     xkb_context_set_log_verbosity(ctx, 0);
 
-    bench_timer_reset(&timer);
-
-    bench_timer_start(&timer);
+    bench_start(&bench);
     for (i = 0; i < BENCHMARK_ITERATIONS; i++) {
         assert(xkb_components_from_rules(ctx, &rmlvo, &kccgst));
         free(kccgst.keycodes);
@@ -58,9 +56,9 @@ main(int argc, char *argv[])
         free(kccgst.compat);
         free(kccgst.symbols);
     }
-    bench_timer_stop(&timer);
+    bench_stop(&bench);
 
-    elapsed = bench_timer_get_elapsed_time_str(&timer);
+    elapsed = bench_elapsed_str(&bench);
     fprintf(stderr, "processed %d rule files in %ss\n",
             BENCHMARK_ITERATIONS, elapsed);
     free(elapsed);

bench/rulescomp.c

@@ -33,7 +33,7 @@ main(int argc, char *argv[])
 {
     struct xkb_context *ctx;
     struct xkb_keymap *keymap;
-    struct bench_timer timer;
+    struct bench bench;
     char *elapsed;
     int i;
 
@@ -43,17 +43,15 @@ main(int argc, char *argv[])
     xkb_context_set_log_level(ctx, XKB_LOG_LEVEL_CRITICAL);
     xkb_context_set_log_verbosity(ctx, 0);
 
-    bench_timer_reset(&timer);
-
-    bench_timer_start(&timer);
+    bench_start(&bench);
     for (i = 0; i < BENCHMARK_ITERATIONS; i++) {
         keymap = test_compile_rules(ctx, "evdev", "evdev", "us", "", "");
         assert(keymap);
         xkb_keymap_unref(keymap);
     }
-    bench_timer_stop(&timer);
+    bench_stop(&bench);
 
-    elapsed = bench_timer_get_elapsed_time_str(&timer);
+    elapsed = bench_elapsed_str(&bench);
     fprintf(stderr, "compiled %d keymaps in %ss\n",
             BENCHMARK_ITERATIONS, elapsed);
     free(elapsed);

configure.ac

@@ -100,12 +100,6 @@ AM_CONDITIONAL([HAVE_NO_UNDEFINED], [test "x$have_no_undefined" = xyes])
 XORG_CHECK_LINKER_FLAGS([-Wl,--version-script="$srcdir/xkbcommon.map"], [have_version_script=yes])
 AM_CONDITIONAL([HAVE_VERSION_SCRIPT], [test "x$have_version_script" = xyes])
 
-AC_CHECK_LIB(rt, clock_gettime,
-    [AC_SUBST(RT_LIBS, "-lrt")],
-    [AC_SUBST(RT_LIBS, "")],
-    [-lrt])
-AC_CHECK_FUNCS([clock_gettime])
-
 # Define a configuration option for the XKB config root
 xkb_base=`$PKG_CONFIG --variable=xkb_base xkeyboard-config`
 AS_IF([test "x$xkb_base" = x], [

meson.build

@@ -421,13 +421,10 @@ endif
 
 
 # Benchmarks.
-# For clock_gettime, on some systems.
-rt_dep = cc.find_library('rt', required: false)
 libxkbcommon_bench_internal = static_library(
     'xkbcommon-bench-internal',
     'bench/bench.c',
     'bench/bench.h',
-    dependencies: rt_dep,
     link_with: libxkbcommon_test_internal,
 )
 bench_dep = declare_dependency(