WIP: Change instr_time to just store nanoseconds, that's cheaper.

Author:
Reviewed-By:
Discussion: https://postgr.es/m/
Backpatch:

diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h
index 39a4f0600e23737c3b35199ef213d8c78bc81140..d70747e7d60b3f3487c175f0448e1de47f9cbf28 100644 (file)
--- a/src/include/portability/instr_time.h
+++ b/src/include/portability/instr_time.h
@@ -83,63 +83,53 @@
 #define PG_INSTR_CLOCK CLOCK_REALTIME
 #endif
 
-typedef struct timespec instr_time;
+typedef int64 instr_time;
+#define NS_PER_S INT64CONST(1000000000)
+#define US_PER_S INT64CONST(1000000)
+#define MS_PER_S INT64CONST(1000)
 
-#define INSTR_TIME_IS_ZERO(t)  ((t).tv_nsec == 0 && (t).tv_sec == 0)
+#define NS_PER_MS INT64CONST(1000000)
+#define NS_PER_US INT64CONST(1000)
 
-#define INSTR_TIME_SET_ZERO(t) ((t).tv_sec = 0, (t).tv_nsec = 0)
+#define INSTR_TIME_IS_ZERO(t)  ((t) == 0)
 
-#define INSTR_TIME_SET_CURRENT(t)  ((void) clock_gettime(PG_INSTR_CLOCK, &(t)))
+#define INSTR_TIME_SET_ZERO(t) ((t) = 0)
+
+static inline instr_time pg_clock_gettime_ns(void)
+{
+   struct timespec tmp;
+
+   clock_gettime(PG_INSTR_CLOCK, &tmp);
+
+   return tmp.tv_sec * NS_PER_S + tmp.tv_nsec;
+}
+
+#define INSTR_TIME_SET_CURRENT(t) \
+   (t) = pg_clock_gettime_ns()
 
 #define INSTR_TIME_ADD(x,y) \
    do { \
-       (x).tv_sec += (y).tv_sec; \
-       (x).tv_nsec += (y).tv_nsec; \
-       /* Normalize */ \
-       while ((x).tv_nsec >= 1000000000) \
-       { \
-           (x).tv_nsec -= 1000000000; \
-           (x).tv_sec++; \
-       } \
+       (x) += (y); \
    } while (0)
 
 #define INSTR_TIME_SUBTRACT(x,y) \
    do { \
-       (x).tv_sec -= (y).tv_sec; \
-       (x).tv_nsec -= (y).tv_nsec; \
-       /* Normalize */ \
-       while ((x).tv_nsec < 0) \
-       { \
-           (x).tv_nsec += 1000000000; \
-           (x).tv_sec--; \
-       } \
+       (x) -= (y); \
    } while (0)
 
 #define INSTR_TIME_ACCUM_DIFF(x,y,z) \
    do { \
-       (x).tv_sec += (y).tv_sec - (z).tv_sec; \
-       (x).tv_nsec += (y).tv_nsec - (z).tv_nsec; \
-       /* Normalize after each add to avoid overflow/underflow of tv_nsec */ \
-       while ((x).tv_nsec < 0) \
-       { \
-           (x).tv_nsec += 1000000000; \
-           (x).tv_sec--; \
-       } \
-       while ((x).tv_nsec >= 1000000000) \
-       { \
-           (x).tv_nsec -= 1000000000; \
-           (x).tv_sec++; \
-       } \
+       (x) += (y) - (z); \
    } while (0)
 
 #define INSTR_TIME_GET_DOUBLE(t) \
-   (((double) (t).tv_sec) + ((double) (t).tv_nsec) / 1000000000.0)
+   ((double) (t) / NS_PER_S)
 
 #define INSTR_TIME_GET_MILLISEC(t) \
-   (((double) (t).tv_sec * 1000.0) + ((double) (t).tv_nsec) / 1000000.0)
+   ((double) (t) / NS_PER_MS)
 
 #define INSTR_TIME_GET_MICROSEC(t) \
-   (((uint64) (t).tv_sec * (uint64) 1000000) + (uint64) ((t).tv_nsec / 1000))
+   ((double) (t) / NS_PER_US)
 
 #else                          /* !HAVE_CLOCK_GETTIME */