clock_gettime_for_EXPLAIN_1.patch

diff --git a/configure b/configure
index 0f143a0..e5dd6fb 100755
*** a/configure
--- b/configure
*************** if test "$ac_res" != no; then :
*** 9055,9060 ****
--- 9055,9116 ----
  
  fi
  
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing clock_gettime" >&5
+ $as_echo_n "checking for library containing clock_gettime... " >&6; }
+ if ${ac_cv_search_clock_gettime+:} false; then :
+   $as_echo_n "(cached) " >&6
+ else
+   ac_func_search_save_LIBS=$LIBS
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+ /* end confdefs.h.  */
+ 
+ /* Override any GCC internal prototype to avoid an error.
+    Use char because int might match the return type of a GCC
+    builtin and then its argument prototype would still apply.  */
+ #ifdef __cplusplus
+ extern "C"
+ #endif
+ char clock_gettime ();
+ int
+ main ()
+ {
+ return clock_gettime ();
+   ;
+   return 0;
+ }
+ _ACEOF
+ for ac_lib in '' rt posix4; do
+   if test -z "$ac_lib"; then
+     ac_res="none required"
+   else
+     ac_res=-l$ac_lib
+     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
+   fi
+   if ac_fn_c_try_link "$LINENO"; then :
+   ac_cv_search_clock_gettime=$ac_res
+ fi
+ rm -f core conftest.err conftest.$ac_objext \
+     conftest$ac_exeext
+   if ${ac_cv_search_clock_gettime+:} false; then :
+   break
+ fi
+ done
+ if ${ac_cv_search_clock_gettime+:} false; then :
+ 
+ else
+   ac_cv_search_clock_gettime=no
+ fi
+ rm conftest.$ac_ext
+ LIBS=$ac_func_search_save_LIBS
+ fi
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_clock_gettime" >&5
+ $as_echo "$ac_cv_search_clock_gettime" >&6; }
+ ac_res=$ac_cv_search_clock_gettime
+ if test "$ac_res" != no; then :
+   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
+ 
+ fi
+ 
  # Solaris:
  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing fdatasync" >&5
  $as_echo_n "checking for library containing fdatasync... " >&6; }
*************** fi
*** 12520,12526 ****
  LIBS_including_readline="$LIBS"
  LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
  
! for ac_func in cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstat pthread_is_threaded_np readlink setproctitle setsid shm_open symlink sync_file_range towlower utime utimes wcstombs wcstombs_l
  do :
    as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
  ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
--- 12576,12582 ----
  LIBS_including_readline="$LIBS"
  LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
  
! for ac_func in cbrt clock_gettime dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstat pthread_is_threaded_np readlink setproctitle setsid shm_open symlink sync_file_range towlower utime utimes wcstombs wcstombs_l
  do :
    as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
  ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
diff --git a/configure.in b/configure.in
index b9831bc..77aa3b4 100644
*** a/configure.in
--- b/configure.in
*************** AC_SEARCH_LIBS(getopt_long, [getopt gnug
*** 1016,1021 ****
--- 1016,1022 ----
  AC_SEARCH_LIBS(crypt, crypt)
  AC_SEARCH_LIBS(shm_open, rt)
  AC_SEARCH_LIBS(shm_unlink, rt)
+ AC_SEARCH_LIBS(clock_gettime, [rt posix4])
  # Solaris:
  AC_SEARCH_LIBS(fdatasync, [rt posix4])
  # Required for thread_test.c on Solaris
*************** PGAC_FUNC_WCSTOMBS_L
*** 1415,1421 ****
  LIBS_including_readline="$LIBS"
  LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
  
! AC_CHECK_FUNCS([cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstat pthread_is_threaded_np readlink setproctitle setsid shm_open symlink sync_file_range towlower utime utimes wcstombs wcstombs_l])
  
  AC_REPLACE_FUNCS(fseeko)
  case $host_os in
--- 1416,1422 ----
  LIBS_including_readline="$LIBS"
  LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
  
! AC_CHECK_FUNCS([cbrt clock_gettime dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstat pthread_is_threaded_np readlink setproctitle setsid shm_open symlink sync_file_range towlower utime utimes wcstombs wcstombs_l])
  
  AC_REPLACE_FUNCS(fseeko)
  case $host_os in
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 42a3fc8..b9dfdd4 100644
*** a/src/include/pg_config.h.in
--- b/src/include/pg_config.h.in
***************
*** 105,110 ****
--- 105,113 ----
  /* Define to 1 if you have the `class' function. */
  #undef HAVE_CLASS
  
+ /* Define to 1 if you have the `clock_gettime' function. */
+ #undef HAVE_CLOCK_GETTIME
+ 
  /* Define to 1 if you have the <crtdefs.h> header file. */
  #undef HAVE_CRTDEFS_H
  
diff --git a/src/include/pg_config.h.win32 b/src/include/pg_config.h.win32
index ceb8b79..199668c 100644
*** a/src/include/pg_config.h.win32
--- b/src/include/pg_config.h.win32
***************
*** 75,80 ****
--- 75,83 ----
  /* Define to 1 if you have the `class' function. */
  /* #undef HAVE_CLASS */
  
+ /* Define to 1 if you have the `clock_gettime' function. */
+ /* #undef HAVE_CLOCK_GETTIME */
+ 
  /* Define to 1 if you have the `crypt' function. */
  /* #undef HAVE_CRYPT */
  
diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h
index 16caf6e..b10d6f0 100644
*** a/src/include/portability/instr_time.h
--- b/src/include/portability/instr_time.h
***************
*** 4,13 ****
   *	  portable high-precision interval timing
   *
   * This file provides an abstraction layer to hide portability issues in
!  * interval timing.  On Unix we use gettimeofday(), but on Windows that
!  * gives a low-precision result so we must use QueryPerformanceCounter()
!  * instead.  These macros also give some breathing room to use other
!  * high-precision-timing APIs on yet other platforms.
   *
   * The basic data type is instr_time, which all callers should treat as an
   * opaque typedef.  instr_time can store either an absolute time (of
--- 4,13 ----
   *	  portable high-precision interval timing
   *
   * This file provides an abstraction layer to hide portability issues in
!  * interval timing.  On Unix we use clock_gettime() if available, else
!  * gettimeofday().  On Windows, gettimeofday() gives a low-precision result
!  * so we must use QueryPerformanceCounter() instead.  These macros also give
!  * some breathing room to use other high-precision-timing APIs.
   *
   * The basic data type is instr_time, which all callers should treat as an
   * opaque typedef.  instr_time can store either an absolute time (of
***************
*** 54,59 ****
--- 54,147 ----
  
  #ifndef WIN32
  
+ #ifdef HAVE_CLOCK_GETTIME
+ 
+ /* Use clock_gettime() */
+ 
+ #include <time.h>
+ 
+ /*
+  * The best clockid to use according to the POSIX spec is CLOCK_MONOTONIC,
+  * since that will give reliable interval timing even in the face of changes
+  * to the system clock.  However, POSIX doesn't require implementations to
+  * provide anything except CLOCK_REALTIME, so fall back to that if we don't
+  * find CLOCK_MONOTONIC.
+  *
+  * Also, some implementations have nonstandard clockids with better properties
+  * than CLOCK_MONOTONIC.  In particular, as of macOS 10.12, Apple provides
+  * CLOCK_MONOTONIC_RAW which is both faster to read and higher resolution than
+  * their version of CLOCK_MONOTONIC.
+  */
+ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW)
+ #define PG_INSTR_CLOCK	CLOCK_MONOTONIC_RAW
+ #elif defined(CLOCK_MONOTONIC)
+ #define PG_INSTR_CLOCK	CLOCK_MONOTONIC
+ #else
+ #define PG_INSTR_CLOCK	CLOCK_REALTIME
+ #endif
+ 
+ typedef struct timespec instr_time;
+ 
+ #define INSTR_TIME_IS_ZERO(t)	((t).tv_nsec == 0 && (t).tv_sec == 0)
+ 
+ #define INSTR_TIME_SET_ZERO(t)	((t).tv_sec = 0, (t).tv_nsec = 0)
+ 
+ #define INSTR_TIME_SET_CURRENT(t)	((void) clock_gettime(PG_INSTR_CLOCK, &(t)))
+ 
+ #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++; \
+ 		} \
+ 	} 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--; \
+ 		} \
+ 	} 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++; \
+ 		} \
+ 	} while (0)
+ 
+ #define INSTR_TIME_GET_DOUBLE(t) \
+ 	(((double) (t).tv_sec) + ((double) (t).tv_nsec) / 1000000000.0)
+ 
+ #define INSTR_TIME_GET_MILLISEC(t) \
+ 	(((double) (t).tv_sec * 1000.0) + ((double) (t).tv_nsec) / 1000000.0)
+ 
+ #define INSTR_TIME_GET_MICROSEC(t) \
+ 	(((uint64) (t).tv_sec * (uint64) 1000000) + (uint64) ((t).tv_nsec / 1000))
+ 
+ #else							/* !HAVE_CLOCK_GETTIME */
+ 
+ /* Use gettimeofday() */
+ 
  #include <sys/time.h>
  
  typedef struct timeval instr_time;
*************** typedef struct timeval instr_time;
*** 113,120 ****
--- 201,213 ----
  
  #define INSTR_TIME_GET_MICROSEC(t) \
  	(((uint64) (t).tv_sec * (uint64) 1000000) + (uint64) (t).tv_usec)
+ 
+ #endif   /* HAVE_CLOCK_GETTIME */
+ 
  #else							/* WIN32 */
  
+ /* Use QueryPerformanceCounter() */
+ 
  typedef LARGE_INTEGER instr_time;
  
  #define INSTR_TIME_IS_ZERO(t)	((t).QuadPart == 0)
*************** GetTimerFrequency(void)
*** 149,154 ****
--- 242,248 ----
  	QueryPerformanceFrequency(&f);
  	return (double) f.QuadPart;
  }
+ 
  #endif   /* WIN32 */
  
  #endif   /* INSTR_TIME_H */