Remove redundant gettimeofday() calls to the extent practical without

changing semantics too much.  statement_timestamp is now set immediately
upon receipt of a client command message, and the various places that used
to do their own gettimeofday() calls to mark command startup are referenced
to that instead.  I have also made stats_command_string use that same
value for pg_stat_activity.query_start for both the command itself and
its eventual replacement by <IDLE> or <idle in transaction>.  There was
some debate about that, but no argument that seemed convincing enough to
justify an extra gettimeofday() call.

2 files changed, 17 insertions, 4 deletions

diff --git a/src/include/libpq/libpq-be.h b/src/include/libpq/libpq-be.h
index d42f4e19598..de85ce10d63 100644
--- a/src/include/libpq/libpq-be.h
+++ b/src/include/libpq/libpq-be.h
@@ -11,7 +11,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/libpq/libpq-be.h,v 1.55 2006/03/05 15:58:56 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/libpq/libpq-be.h,v 1.56 2006/06/20 22:52:00 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -31,6 +31,7 @@
 
 #include "libpq/hba.h"
 #include "libpq/pqcomm.h"
+#include "utils/timestamp.h"
 
 
 typedef enum CAC_state
@@ -80,7 +81,8 @@ typedef struct Port
 	 * but since it gets used by elog.c in the same way as database_name and
 	 * other members of this struct, we may as well keep it here.
 	 */
-	struct timeval session_start;		/* for session duration logging */
+	TimestampTz	SessionStartTime;	/* backend start time */
+	time_t		session_start;		/* same, in time_t format */
 
 	/*
 	 * TCP keepalive settings.
@@ -97,7 +99,8 @@ typedef struct Port
 	int			keepalives_count;
 
 	/*
-	 * SSL structures
+	 * SSL structures (keep these last so that USE_SSL doesn't affect
+	 * locations of other fields)
 	 */
 #ifdef USE_SSL
 	SSL		   *ssl;
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index 4e9e0c3f6f7..47832c8b3fc 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/utils/timestamp.h,v 1.60 2006/04/25 00:25:22 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/utils/timestamp.h,v 1.61 2006/06/20 22:52:00 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -177,6 +177,12 @@ typedef double fsec_t;
 #define INTERVAL_PRECISION(t) ((t) & INTERVAL_PRECISION_MASK)
 #define INTERVAL_RANGE(t) (((t) >> 16) & INTERVAL_RANGE_MASK)
 
+#ifdef HAVE_INT64_TIMESTAMP
+#define TimestampTzPlusMilliseconds(tz,ms) ((tz) + ((ms) * 1000))
+#else
+#define TimestampTzPlusMilliseconds(tz,ms) ((tz) + ((ms) / 1000.0))
+#endif
+
 
 /* Set at postmaster start */
 extern TimestampTz PgStartTime;
@@ -293,7 +299,11 @@ extern Datum pgsql_postmaster_start_time(PG_FUNCTION_ARGS);
 
 extern TimestampTz GetCurrentTimestamp(void);
 
+extern void TimestampDifference(TimestampTz start_time, TimestampTz stop_time,
+								long *secs, int *microsecs);
+
 extern TimestampTz time_t_to_timestamptz(time_t tm);
+extern time_t timestamptz_to_time_t(TimestampTz t);
 
 extern int	tm2timestamp(struct pg_tm * tm, fsec_t fsec, int *tzp, Timestamp *dt);
 extern int timestamp2tm(Timestamp dt, int *tzp, struct pg_tm * tm,