1 files changed, 98 insertions, 0 deletions
diff --git a/src/cmd/timebench.c b/src/cmd/timebench.c
new file mode 100644
index 0000000..9985c7f
--- /dev/null
+++ b/src/cmd/timebench.c
@@ -0,0 +1,98 @@
+#include <camellia.h>
+#include <camellia/syscalls.h>
+#include <err.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+uint64_t
+gettime_ascii(hid_t h)
+{
+	char buf[32];
+	_sys_read(h, buf, 32, 0);
+	return strtol(buf, NULL, 10);
+}
+
+uint64_t
+gettime_binary(hid_t h)
+{
+	uint64_t t;
+	_sys_read(h, &t, 8, 0);
+	return t;
+}
+
+uint64_t
+gettime_syscall(hid_t)
+{
+	return _sys_time(0);
+}
+
+void
+usage(int ret)
+{
+	fprintf(stderr,
+		"usage: timebench [-a file | -b file | -s]\n"
+		"  e.g. timebench -a /dev/ntp\n"
+		"       timebench -b /dev/bintime\n"
+		"       timebench -s\n"
+	);
+	exit(ret);
+}
+
+int
+main(int argc, char *argv[])
+{
+	uint64_t (*fn)(hid_t) = NULL;
+	hid_t h = -1;
+
+	int opt;
+	while ((opt = getopt(argc, argv, "abs")) != -1) {
+		switch (opt) {
+		case 'a':
+			if (fn) usage(1);
+			fn = gettime_ascii;
+			break;
+		case 'b':
+			if (fn) usage(1);
+			fn = gettime_binary;
+			break;
+		case 's':
+			if (fn) usage(1);
+			fn = gettime_syscall;
+			break;
+		default:
+			usage(1);
+		}
+	}
+	if (fn == NULL) {
+		usage(1);
+	} else if (fn == gettime_syscall) {
+		if (optind < argc) {
+			usage(1);
+		}
+	} else {
+		if (optind + 1 != argc) {
+			usage(1);
+		}
+		h = camellia_open(argv[optind], OPEN_READ);
+		if (h < 0) {
+			err(1, "open %s", argv[optind]);
+		}
+	}
+
+	uint64_t target = 5000l * 1000000l;
+	uint64_t start;
+	uint64_t count = 0;
+	uint64_t last;
+
+	start = fn(h);
+	target += start;
+	for (;;) {
+		last = fn(h);
+		count++;
+		if (last >= target) break;
+	}
+	printf("%lu calls in %lums\n", count, (last-start) / 1000000);
+	printf("%luμs per call\n", (last-start) / count);
+	printf("last %lu\n", last);
+}