[Python-checkins] peps: PEP 418: Add bench_time.c
victor.stinner
python-checkins at python.org
Thu Apr 12 00:33:19 CEST 2012
http://hg.python.org/peps/rev/153b3f58f371
changeset: 4221:153b3f58f371
user: Victor Stinner <victor.stinner at gmail.com>
date: Thu Apr 12 00:32:44 2012 +0200
summary:
PEP 418: Add bench_time.c
files:
pep-0418/bench_time.c | 162 ++++++++++++++++++++++++++++++
1 files changed, 162 insertions(+), 0 deletions(-)
diff --git a/pep-0418/bench_time.c b/pep-0418/bench_time.c
new file mode 100644
--- /dev/null
+++ b/pep-0418/bench_time.c
@@ -0,0 +1,162 @@
+/*
+ * Benchmark program written for the PEP 418.
+ *
+ * gcc bench_time.c -O3 -lrt -o bench_time && ./bench_time
+ */
+
+#include <time.h>
+#include <stdio.h>
+#include <sys/time.h>
+
+#define NRUN 5
+#define NLOOP 1000000
+#define UNROLL(expr) \
+ expr; expr; expr; expr; expr; expr; expr; expr; expr; expr
+#define NUNROLL 10
+
+typedef struct {
+ const char *name;
+ clockid_t identifier;
+} CLOCK;
+
+CLOCK clocks[] = {
+#ifdef CLOCK_REALTIME_COARSE
+ {"CLOCK_REALTIME_COARSE", CLOCK_REALTIME_COARSE},
+#endif
+#ifdef CLOCK_MONOTONIC_COARSE
+ {"CLOCK_MONOTONIC_COARSE", CLOCK_MONOTONIC_COARSE},
+#endif
+#ifdef CLOCK_THREAD_CPUTIME_ID
+ {"CLOCK_THREAD_CPUTIME_ID", CLOCK_THREAD_CPUTIME_ID},
+#endif
+#ifdef CLOCK_PROCESS_CPUTIME_ID
+ {"CLOCK_PROCESS_CPUTIME_ID", CLOCK_PROCESS_CPUTIME_ID},
+#endif
+#ifdef CLOCK_MONOTONIC_RAW
+ {"CLOCK_MONOTONIC_RAW", CLOCK_MONOTONIC_RAW},
+#endif
+#ifdef CLOCK_VIRTUAL
+ {"CLOCK_VIRTUAL", CLOCK_VIRTUAL},
+#endif
+#ifdef CLOCK_UPTIME_FAST
+ {"CLOCK_UPTIME_FAST", CLOCK_UPTIME_FAST},
+#endif
+#ifdef CLOCK_UPTIME_PRECISE
+ {"CLOCK_UPTIME_PRECISE", CLOCK_UPTIME_PRECISE},
+#endif
+#ifdef CLOCK_UPTIME
+ {"CLOCK_UPTIME", CLOCK_UPTIME},
+#endif
+#ifdef CLOCK_MONOTONIC_FAST
+ {"CLOCK_MONOTONIC_FAST", CLOCK_MONOTONIC_FAST},
+#endif
+#ifdef CLOCK_MONOTONIC_PRECISE
+ {"CLOCK_MONOTONIC_PRECISE", CLOCK_MONOTONIC_PRECISE},
+#endif
+#ifdef CLOCK_REALTIME_FAST
+ {"CLOCK_REALTIME_FAST", CLOCK_REALTIME_FAST},
+#endif
+#ifdef CLOCK_REALTIME_PRECISE
+ {"CLOCK_REALTIME_PRECISE", CLOCK_REALTIME_PRECISE},
+#endif
+#ifdef CLOCK_SECOND
+ {"CLOCK_SECOND", CLOCK_SECOND},
+#endif
+#ifdef CLOCK_PROF
+ {"CLOCK_PROF", CLOCK_PROF},
+#endif
+ {"CLOCK_MONOTONIC", CLOCK_MONOTONIC},
+ {"CLOCK_REALTIME", CLOCK_REALTIME}
+};
+#define NCLOCKS (sizeof(clocks) / sizeof(clocks[0]))
+
+void bench_clock_gettime(clockid_t clkid)
+{
+ unsigned long loop;
+ struct timespec tmpspec;
+
+ for (loop=0; loop<NLOOP; loop++) {
+ UNROLL( (void)clock_gettime(clkid, &tmpspec) );
+ }
+}
+
+void bench_time(clockid_t clkid)
+{
+ unsigned long loop;
+ for (loop=0; loop<NLOOP; loop++) {
+ UNROLL( (void)time(NULL) );
+ }
+}
+
+void bench_usleep(clockid_t clkid)
+{
+ unsigned long loop;
+ for (loop=0; loop<NLOOP; loop++) {
+ UNROLL( (void)usleep(1000) );
+ }
+}
+
+void bench_gettimeofday(clockid_t clkid)
+{
+ unsigned long loop;
+ struct timeval tmpval;
+ for (loop=0; loop<NLOOP; loop++) {
+ UNROLL( (void)gettimeofday(&tmpval, NULL) );
+ }
+}
+
+void bench_clock(clockid_t clkid)
+{
+ unsigned long loop;
+ for (loop=0; loop<NLOOP; loop++) {
+ UNROLL( (void)clock() );
+ }
+}
+
+void benchmark(const char *name, void (*func) (clockid_t clkid), clockid_t clkid)
+{
+ unsigned int run;
+ double dt, best;
+ struct timespec before, after, tmpspec;
+ struct timeval tmpval;
+
+ best = 0;
+ for (run=0; run<NRUN; run++) {
+ clock_gettime(CLOCK_MONOTONIC, &before);
+ (*func) (clkid);
+ clock_gettime(CLOCK_MONOTONIC, &after);
+
+ dt = after.tv_sec - before.tv_sec;
+ if (after.tv_nsec >= before.tv_nsec)
+ dt += (after.tv_nsec - before.tv_nsec) * 1e-9;
+ else
+ {
+ dt -= 1.0;
+ dt += (before.tv_nsec - after.tv_nsec) * 1e-9;
+ }
+ dt *= (double)1e9 / NLOOP / NUNROLL;
+
+ if (best != 0.0) {
+ if (dt < best)
+ best = dt;
+ }
+ else
+ best = dt;
+ }
+ printf("%s: %.0f ns\n", name, best, NLOOP);
+}
+
+int main()
+{
+ clockid_t clkid;
+ int i;
+
+ for (i=0; i<NCLOCKS; i++) {
+ benchmark(clocks[i].name, bench_clock_gettime, clocks[i].identifier);
+ }
+ benchmark("clock()", bench_clock, 0);
+ benchmark("gettimeofday()", bench_gettimeofday, 0);
+ benchmark("time()", bench_time, 0);
+ return 0;
+}
+
--
Repository URL: http://hg.python.org/peps
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