Remove dead getrusage replacement code.

getrusage() is in SUSv2 and all targeted Unix systems have it.

Note that POSIX only covers ru_utime and ru_stime and we rely on many
more fields without any kind of configure probe, but that predates this
commit.

The only supported system we need replacement code for now is Windows,
and that can be done without a configure probe.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Greg Stark <stark@mit.edu>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Discussion: https://postgr.es/m/CA+hUKGJ3LHeP9w5Fgzdr4G8AnEtJ=z=p6hGDEm4qYGEUX5B6fQ@mail.gmail.com

configure

@@ -16797,19 +16797,6 @@ esac
 
 fi
 
-ac_fn_c_check_func "$LINENO" "getrusage" "ac_cv_func_getrusage"
-if test "x$ac_cv_func_getrusage" = xyes; then :
-  $as_echo "#define HAVE_GETRUSAGE 1" >>confdefs.h
-
-else
-  case " $LIBOBJS " in
-  *" getrusage.$ac_objext "* ) ;;
-  *) LIBOBJS="$LIBOBJS getrusage.$ac_objext"
- ;;
-esac
-
-fi
-
 ac_fn_c_check_func "$LINENO" "inet_aton" "ac_cv_func_inet_aton"
 if test "x$ac_cv_func_inet_aton" = xyes; then :
   $as_echo "#define HAVE_INET_ATON 1" >>confdefs.h
@@ -17125,6 +17112,12 @@ esac
  ;;
 esac
 
+  case " $LIBOBJS " in
+  *" getrusage.$ac_objext "* ) ;;
+  *) LIBOBJS="$LIBOBJS getrusage.$ac_objext"
+ ;;
+esac
+
   case " $LIBOBJS " in
   *" kill.$ac_objext "* ) ;;
   *) LIBOBJS="$LIBOBJS kill.$ac_objext"

configure.ac

@@ -1911,7 +1911,6 @@ AC_REPLACE_FUNCS(m4_normalize([
 	explicit_bzero
 	getopt
 	getpeereid
-	getrusage
 	inet_aton
 	link
 	mkdtemp
@@ -1986,6 +1985,7 @@ if test "$PORTNAME" = "win32"; then
   AC_REPLACE_FUNCS(gettimeofday)
   AC_LIBOBJ(dirmod)
   AC_LIBOBJ(fdatasync)
+  AC_LIBOBJ(getrusage)
   AC_LIBOBJ(kill)
   AC_LIBOBJ(open)
   AC_LIBOBJ(system)

src/backend/tcop/postgres.c

@@ -32,7 +32,7 @@
 #include <sys/resource.h>
 #endif
 
-#ifndef HAVE_GETRUSAGE
+#ifdef WIN32
 #include "rusagestub.h"
 #endif
 
@@ -4860,7 +4860,14 @@ ShowUsage(const char *title)
 					 (long) user.tv_usec,
 					 (long) sys.tv_sec,
 					 (long) sys.tv_usec);
-#if defined(HAVE_GETRUSAGE)
+#ifndef WIN32
+
+	/*
+	 * The following rusage fields are not defined by POSIX, but they're
+	 * present on all current Unix-like systems so we use them without any
+	 * special checks.  Some of these could be provided in our Windows
+	 * emulation in src/port/getrusage.c with more work.
+	 */
 	appendStringInfo(&str,
 					 "!\t%ld kB max resident size\n",
 #if defined(__darwin__)
@@ -4896,7 +4903,7 @@ ShowUsage(const char *title)
 					 r.ru_nvcsw - Save_r.ru_nvcsw,
 					 r.ru_nivcsw - Save_r.ru_nivcsw,
 					 r.ru_nvcsw, r.ru_nivcsw);
-#endif							/* HAVE_GETRUSAGE */
+#endif							/* !WIN32 */
 
 	/* remove trailing newline */
 	if (str.data[str.len - 1] == '\n')

src/include/pg_config.h.in

@@ -250,9 +250,6 @@
 /* Define to 1 if you have the `getrlimit' function. */
 #undef HAVE_GETRLIMIT
 
-/* Define to 1 if you have the `getrusage' function. */
-#undef HAVE_GETRUSAGE
-
 /* Define to 1 if you have the `gettimeofday' function. */
 #undef HAVE_GETTIMEOFDAY
 

src/include/rusagestub.h

@@ -15,9 +15,6 @@
 #define RUSAGESTUB_H
 
 #include <sys/time.h>			/* for struct timeval */
-#ifndef WIN32
-#include <sys/times.h>			/* for struct tms */
-#endif
 #include <limits.h>				/* for CLK_TCK */
 
 #define RUSAGE_SELF		0

src/port/getrusage.c

@@ -17,19 +17,14 @@
 
 #include "rusagestub.h"
 
-/* This code works on:
- *		solaris_i386
- *		solaris_sparc
- *		win32
- * which currently is all the supported platforms that don't have a
- * native version of getrusage().  So, if configure decides to compile
- * this file at all, we just use this version unconditionally.
+/*
+ * This code works on Windows, which is the only supported platform without a
+ * native version of getrusage().
  */
 
 int
 getrusage(int who, struct rusage *rusage)
 {
-#ifdef WIN32
 	FILETIME	starttime;
 	FILETIME	exittime;
 	FILETIME	kerneltime;
@@ -66,44 +61,6 @@ getrusage(int who, struct rusage *rusage)
 	li.QuadPart /= 10L;			/* Convert to microseconds */
 	rusage->ru_utime.tv_sec = li.QuadPart / 1000000L;
 	rusage->ru_utime.tv_usec = li.QuadPart % 1000000L;
-#else							/* all but WIN32 */
-
-	struct tms	tms;
-	int			tick_rate = CLK_TCK;	/* ticks per second */
-	clock_t		u,
-				s;
-
-	if (rusage == (struct rusage *) NULL)
-	{
-		errno = EFAULT;
-		return -1;
-	}
-	if (times(&tms) < 0)
-	{
-		/* errno set by times */
-		return -1;
-	}
-	switch (who)
-	{
-		case RUSAGE_SELF:
-			u = tms.tms_utime;
-			s = tms.tms_stime;
-			break;
-		case RUSAGE_CHILDREN:
-			u = tms.tms_cutime;
-			s = tms.tms_cstime;
-			break;
-		default:
-			errno = EINVAL;
-			return -1;
-	}
-#define TICK_TO_SEC(T, RATE)	((T)/(RATE))
-#define TICK_TO_USEC(T,RATE)	(((T)%(RATE)*1000000)/RATE)
-	rusage->ru_utime.tv_sec = TICK_TO_SEC(u, tick_rate);
-	rusage->ru_utime.tv_usec = TICK_TO_USEC(u, tick_rate);
-	rusage->ru_stime.tv_sec = TICK_TO_SEC(s, tick_rate);
-	rusage->ru_stime.tv_usec = TICK_TO_USEC(u, tick_rate);
-#endif							/* WIN32 */
 
 	return 0;
 }

src/tools/msvc/Solution.pm

@@ -277,7 +277,6 @@ sub GenerateFiles
 		HAVE_GETPEERUCRED                           => undef,
 		HAVE_GETPWUID_R                             => undef,
 		HAVE_GETRLIMIT                              => undef,
-		HAVE_GETRUSAGE                              => undef,
 		HAVE_GETTIMEOFDAY                           => undef,
 		HAVE_GSSAPI_GSSAPI_H                        => undef,
 		HAVE_GSSAPI_H                               => undef,