Introduce multiple clocks to GPR
diff --git a/include/grpc/support/time.h b/include/grpc/support/time.h
index 1fd3181..fb8371b 100644
--- a/include/grpc/support/time.h
+++ b/include/grpc/support/time.h
@@ -62,8 +62,20 @@
#define GPR_NS_PER_US 1000
#define GPR_US_PER_MS 1000
-/* Return the current time measured from the system's default epoch. */
-gpr_timespec gpr_now(void);
+/* The clocks we support. */
+typedef enum {
+ /* Monotonic clock. Epoch undefined. Always moves forwards. */
+ GPR_CLOCK_MONOTONIC = 0,
+ /* Realtime clock. May jump forwards or backwards. Settable by
+ the system administrator. Has its epoch at 0:00:00 UTC 1 Jan 1970. */
+ GPR_CLOCK_REALTIME
+} gpr_clock_type;
+
+/* initialize time subsystem */
+void gpr_time_init(void);
+
+/* Return the current time measured from the given clocks epoch. */
+gpr_timespec gpr_now(gpr_clock_type clock);
/* Return -ve, 0, or +ve according to whether a < b, a == b, or a > b
respectively. */