Introduce a clock type field onto gpr_timespec.

Use it to validate that arithmetic on time types makes even some vague
kind of sense.

2 files changed, 18 insertions, 13 deletions

diff --git a/include/grpc++/completion_queue.h b/include/grpc++/completion_queue.h
index f32cbff06c..0523ab6a0e 100644
--- a/include/grpc++/completion_queue.h
+++ b/include/grpc++/completion_queue.h
@@ -105,7 +105,8 @@ class CompletionQueue : public GrpcLibrary {
   // Returns false if the queue is ready for destruction, true if event
 
   bool Next(void** tag, bool* ok) {
-    return (AsyncNextInternal(tag, ok, gpr_inf_future) != SHUTDOWN);
+    return (AsyncNextInternal(tag, ok, gpr_inf_future(GPR_CLOCK_REALTIME)) !=
+            SHUTDOWN);
   }
 
   // Shutdown has to be called, and the CompletionQueue can only be
diff --git a/include/grpc/support/time.h b/include/grpc/support/time.h
index a5c947dfc8..dbf2548d1b 100644
--- a/include/grpc/support/time.h
+++ b/include/grpc/support/time.h
@@ -45,15 +45,28 @@
 extern "C" {
 #endif
 
+/* 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,
+  /* Unmeasurable clock type: no base, created by taking the difference
+     between two times */
+  GPR_TIMESPAN
+} gpr_clock_type;
+
 typedef struct gpr_timespec {
   time_t tv_sec;
   int tv_nsec;
+  gpr_clock_type clock_type;
 } gpr_timespec;
 
 /* Time constants. */
-extern const gpr_timespec gpr_time_0;     /* The zero time interval. */
-extern const gpr_timespec gpr_inf_future; /* The far future */
-extern const gpr_timespec gpr_inf_past;   /* The far past. */
+gpr_timespec gpr_time_0(gpr_clock_type type);     /* The zero time interval. */
+gpr_timespec gpr_inf_future(gpr_clock_type type); /* The far future */
+gpr_timespec gpr_inf_past(gpr_clock_type type);   /* The far past. */
 
 #define GPR_MS_PER_SEC 1000
 #define GPR_US_PER_SEC 1000000
@@ -62,15 +75,6 @@ extern const gpr_timespec gpr_inf_past;   /* The far past. */
 #define GPR_NS_PER_US 1000
 #define GPR_US_PER_MS 1000
 
-/* 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);