clock abstraction

src/ucore_clock.c

@@ -0,0 +1,81 @@
+#include <ucore/ucore_clock.h>
+#include <ucore/ucore_utils.h>
+
+#ifdef __GNUC__
+#define UNUSED __attribute__((__unused__))
+#else
+#define UNUSED
+#endif
+
+static void ucore_timeofday_now(struct ucore_clock *clock UNUSED, struct timeval *tv)
+{
+    gettimeofday(tv, NULL);
+}
+
+static void ucore_time_now(struct ucore_clock *clock UNUSED, struct timeval *tv)
+{
+    tv->tv_sec = time(NULL);
+    tv->tv_usec = 0;
+}
+
+struct ucore_clock ucore_timeofday_clock = {
+    .name = "gettimeofday",
+    .now = ucore_timeofday_now,
+};
+
+struct ucore_clock ucore_time_clock = {
+    .name = "time",
+    .now = ucore_time_now,
+};
+
+static void ucore_cached_clock_now(struct ucore_clock *clock UNUSED,
+                                    struct timeval *tv)
+{
+    struct ucore_cached_clock *cached_clock;
+    cached_clock = CONTAINER_OF(clock, struct ucore_cached_clock, clock),
+
+    *tv = cached_clock->cache;
+}
+
+void ucore_cached_clock_init(struct ucore_cached_clock *clock, struct ucore_clock *real_clock)
+{
+    clock->clock.name = "cached clock";
+    clock->clock.now = ucore_cached_clock_now;
+
+    clock->real_clock = real_clock;
+
+    ucore_cached_clock_update(clock);
+}
+
+void ucore_cached_clock_update(struct ucore_cached_clock *clock)
+{
+    clock->real_clock->now(&clock->clock, &clock->cache);
+}
+
+static void ucore_settable_clock_now(struct ucore_clock *clock, struct timeval *tv)
+{
+    struct ucore_settable_clock *cached_clock;
+    cached_clock = CONTAINER_OF(clock, struct ucore_settable_clock, clock),
+
+    *tv = cached_clock->now;
+}
+
+void ucore_settable_clock_init(struct ucore_settable_clock *clock)
+{
+    clock->clock.name = "settable clock";
+    clock->clock.now = ucore_settable_clock_now;
+
+    clock->now.tv_sec = 0;
+    clock->now.tv_usec = 0;
+}
+
+void ucore_settable_clock_set_tv(struct ucore_settable_clock *clock, const struct timeval *tv)
+{
+    clock->now = *tv;
+}
+
+void ucore_settable_clock_set(struct ucore_settable_clock *clock, time_t secs, suseconds_t usecs)
+{
+    clock->now.tv_sec = secs;
+    clock->now.tv_usec = usecs;
+}