Remove configure probe for sys/resource.h and refactor.

<sys/resource.h> is in SUSv2 and is on all targeted Unix systems.  We
have a replacement for getrusage() on Windows, so let's just move its
declarations into src/include/port/win32/sys/resource.h so that we can
use a standard-looking #include.  Also remove an obsolete reference to
CLK_TCK.  Also rename src/port/getrusage.c to win32getrusage.c,
following the convention for Windows-only fallback code.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CA%2BhUKG%2BL_3brvh%3D8e0BW_VfX9h7MtwgN%3DnFHP5o7X2oZucY9dg%40mail.gmail.com

configure

@@ -13874,7 +13874,7 @@ $as_echo "#define HAVE_STDBOOL_H 1" >>confdefs.h
 fi
 
 
-for ac_header in atomic.h copyfile.h execinfo.h getopt.h ifaddrs.h langinfo.h mbarrier.h net/if.h netinet/tcp.h sys/epoll.h sys/event.h sys/personality.h sys/prctl.h sys/procctl.h sys/resource.h sys/signalfd.h sys/sockio.h sys/ucred.h termios.h ucred.h
+for ac_header in atomic.h copyfile.h execinfo.h getopt.h ifaddrs.h langinfo.h mbarrier.h net/if.h netinet/tcp.h sys/epoll.h sys/event.h sys/personality.h sys/prctl.h sys/procctl.h sys/signalfd.h sys/sockio.h sys/ucred.h termios.h ucred.h
 do :
   as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
 ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"
@@ -16734,12 +16734,6 @@ done
  ;;
 esac
 
-  case " $LIBOBJS " in
-  *" getrusage.$ac_objext "* ) ;;
-  *) LIBOBJS="$LIBOBJS getrusage.$ac_objext"
- ;;
-esac
-
   case " $LIBOBJS " in
   *" kill.$ac_objext "* ) ;;
   *) LIBOBJS="$LIBOBJS kill.$ac_objext"
@@ -16782,6 +16776,12 @@ esac
  ;;
 esac
 
+  case " $LIBOBJS " in
+  *" win32getrusage.$ac_objext "* ) ;;
+  *) LIBOBJS="$LIBOBJS win32getrusage.$ac_objext"
+ ;;
+esac
+
   case " $LIBOBJS " in
   *" win32link.$ac_objext "* ) ;;
   *) LIBOBJS="$LIBOBJS win32link.$ac_objext"

configure.ac

@@ -1459,7 +1459,6 @@ AC_CHECK_HEADERS(m4_normalize([
 	sys/personality.h
 	sys/prctl.h
 	sys/procctl.h
-	sys/resource.h
 	sys/signalfd.h
 	sys/sockio.h
 	sys/ucred.h
@@ -1897,7 +1896,6 @@ fi
 if test "$PORTNAME" = "win32"; then
   AC_CHECK_FUNCS(_configthreadlocale)
   AC_LIBOBJ(dirmod)
-  AC_LIBOBJ(getrusage)
   AC_LIBOBJ(kill)
   AC_LIBOBJ(open)
   AC_LIBOBJ(system)
@@ -1905,6 +1903,7 @@ if test "$PORTNAME" = "win32"; then
   AC_LIBOBJ(win32env)
   AC_LIBOBJ(win32error)
   AC_LIBOBJ(win32fdatasync)
+  AC_LIBOBJ(win32getrusage)
   AC_LIBOBJ(win32link)
   AC_LIBOBJ(win32ntdll)
   AC_LIBOBJ(win32pread)

src/backend/storage/file/fd.c

@@ -75,6 +75,7 @@
 #include <dirent.h>
 #include <sys/file.h>
 #include <sys/param.h>
+#include <sys/resource.h>		/* for getrlimit */
 #include <sys/stat.h>
 #include <sys/types.h>
 #ifndef WIN32
@@ -83,9 +84,6 @@
 #include <limits.h>
 #include <unistd.h>
 #include <fcntl.h>
-#ifdef HAVE_SYS_RESOURCE_H
-#include <sys/resource.h>		/* for getrlimit */
-#endif
 
 #include "access/xact.h"
 #include "access/xlog.h"

src/backend/tcop/postgres.c

@@ -23,16 +23,10 @@
 #include <limits.h>
 #include <signal.h>
 #include <unistd.h>
+#include <sys/resource.h>
 #include <sys/select.h>
 #include <sys/socket.h>
-#ifdef HAVE_SYS_RESOURCE_H
 #include <sys/time.h>
-#include <sys/resource.h>
-#endif
-
-#ifdef WIN32
-#include "rusagestub.h"
-#endif
 
 #include "access/parallel.h"
 #include "access/printtup.h"
@@ -4860,7 +4854,7 @@ ShowUsage(const char *title)
 	 * 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.
+	 * emulation in src/port/win32getrusage.c with more work.
 	 */
 	appendStringInfo(&str,
 					 "!\t%ld kB max resident size\n",

src/bin/pg_ctl/pg_ctl.c

@@ -14,14 +14,12 @@
 #include <fcntl.h>
 #include <signal.h>
 #include <time.h>
+#include <sys/resource.h>
 #include <sys/stat.h>
+#include <sys/time.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
-#ifdef HAVE_SYS_RESOURCE_H
-#include <sys/time.h>
-#include <sys/resource.h>
-#endif
 
 #include "catalog/pg_control.h"
 #include "common/controldata_utils.h"

src/bin/pgbench/pgbench.c

@@ -40,9 +40,7 @@
 #include <signal.h>
 #include <time.h>
 #include <sys/time.h>
-#ifdef HAVE_SYS_RESOURCE_H
 #include <sys/resource.h>		/* for getrlimit */
-#endif
 
 /* For testing, PGBENCH_USE_SELECT can be defined to force use of that code */
 #if defined(HAVE_PPOLL) && !defined(PGBENCH_USE_SELECT)

src/include/pg_config.h.in

@@ -505,9 +505,6 @@
 /* Define to 1 if you have the <sys/procctl.h> header file. */
 #undef HAVE_SYS_PROCCTL_H
 
-/* Define to 1 if you have the <sys/resource.h> header file. */
-#undef HAVE_SYS_RESOURCE_H
-
 /* Define to 1 if you have the <sys/signalfd.h> header file. */
 #undef HAVE_SYS_SIGNALFD_H
 

src/include/port/win32/sys/resource.h

@@ -0,0 +1,20 @@
+/*
+ * Replacement for <sys/resource.h> for Windows.
+ */
+#ifndef WIN32_SYS_RESOURCE_H
+#define WIN32_SYS_RESOURCE_H
+
+#include <sys/time.h>			/* for struct timeval */
+
+#define RUSAGE_SELF		0
+#define RUSAGE_CHILDREN (-1)
+
+struct rusage
+{
+	struct timeval ru_utime;	/* user time used */
+	struct timeval ru_stime;	/* system time used */
+};
+
+extern int	getrusage(int who, struct rusage *rusage);
+
+#endif							/* WIN32_SYS_RESOURCE_H */

src/include/rusagestub.h

@@ -1,31 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * rusagestub.h
- *	  Stubs for getrusage(3).
- *
- *
- * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * src/include/rusagestub.h
- *
- *-------------------------------------------------------------------------
- */
-#ifndef RUSAGESTUB_H
-#define RUSAGESTUB_H
-
-#include <sys/time.h>			/* for struct timeval */
-#include <limits.h>				/* for CLK_TCK */
-
-#define RUSAGE_SELF		0
-#define RUSAGE_CHILDREN (-1)
-
-struct rusage
-{
-	struct timeval ru_utime;	/* user time used */
-	struct timeval ru_stime;	/* system time used */
-};
-
-extern int	getrusage(int who, struct rusage *rusage);
-
-#endif							/* RUSAGESTUB_H */

src/include/utils/pg_rusage.h

@@ -14,13 +14,8 @@
 #ifndef PG_RUSAGE_H
 #define PG_RUSAGE_H
 
-#include <sys/time.h>
-
-#ifdef HAVE_SYS_RESOURCE_H
 #include <sys/resource.h>
-#else
-#include "rusagestub.h"
-#endif
+#include <sys/time.h>
 
 
 /* State structure for pg_rusage_init/pg_rusage_show */

src/port/win32getrusage.c

@@ -1,6 +1,6 @@
 /*-------------------------------------------------------------------------
  *
- * getrusage.c
+ * win32getrusage.c
  *	  get information about resource utilisation
  *
  * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
@@ -8,19 +8,14 @@
  *
  *
  * IDENTIFICATION
- *	  src/port/getrusage.c
+ *	  src/port/win32getrusage.c
  *
  *-------------------------------------------------------------------------
  */
 
 #include "c.h"
 
-#include "rusagestub.h"
-
-/*
- * This code works on Windows, which is the only supported platform without a
- * native version of getrusage().
- */
+#include <sys/resource.h>
 
 int
 getrusage(int who, struct rusage *rusage)

src/test/regress/pg_regress.c

@@ -19,16 +19,13 @@
 #include "postgres_fe.h"
 
 #include <ctype.h>
+#include <sys/resource.h>
 #include <sys/stat.h>
+#include <sys/time.h>
 #include <sys/wait.h>
 #include <signal.h>
 #include <unistd.h>
 
-#ifdef HAVE_SYS_RESOURCE_H
-#include <sys/time.h>
-#include <sys/resource.h>
-#endif
-
 #include "common/logging.h"
 #include "common/restricted_token.h"
 #include "common/string.h"

src/tools/msvc/Mkvcbuild.pm

@@ -100,7 +100,7 @@ sub mkvcbuild
 
 	our @pgportfiles = qw(
 	  chklocale.c explicit_bzero.c
-	  getpeereid.c getrusage.c inet_aton.c
+	  getpeereid.c inet_aton.c
 	  getaddrinfo.c inet_net_ntop.c kill.c open.c
 	  snprintf.c strlcat.c strlcpy.c dirmod.c noblock.c path.c
 	  dirent.c getopt.c getopt_long.c
@@ -111,6 +111,7 @@ sub mkvcbuild
 	  win32dlopen.c
 	  win32env.c win32error.c
 	  win32fdatasync.c
+	  win32getrusage.c
 	  win32gettimeofday.c
 	  win32link.c
 	  win32pread.c

src/tools/msvc/Solution.pm

@@ -364,7 +364,6 @@ sub GenerateFiles
 		HAVE_SYS_PERSONALITY_H                   => undef,
 		HAVE_SYS_PRCTL_H                         => undef,
 		HAVE_SYS_PROCCTL_H                       => undef,
-		HAVE_SYS_RESOURCE_H                      => undef,
 		HAVE_SYS_SIGNALFD_H                      => undef,
 		HAVE_SYS_SOCKIO_H                        => undef,
 		HAVE_SYS_STAT_H                          => 1,

src/tools/pginclude/cpluspluscheck

@@ -71,6 +71,7 @@ do
 
 	# Additional Windows-specific headers.
 	test "$f" = src/include/port/win32_port.h && continue
+	test "$f" = src/include/port/win32/sys/resource.h && continue
 	test "$f" = src/include/port/win32/sys/socket.h && continue
 	test "$f" = src/include/port/win32_msvc/dirent.h && continue
 	test "$f" = src/include/port/win32_msvc/utime.h && continue
@@ -90,10 +91,6 @@ do
 	test "$f" = src/include/port/atomics/generic-msvc.h && continue
 	test "$f" = src/include/port/atomics/generic-sunpro.h && continue
 
-	# rusagestub.h is also platform-specific, and will be included
-	# by utils/pg_rusage.h if necessary.
-	test "$f" = src/include/rusagestub.h && continue
-
 	# sepgsql.h depends on headers that aren't there on most platforms.
 	test "$f" = contrib/sepgsql/sepgsql.h && continue
 

src/tools/pginclude/headerscheck

@@ -86,10 +86,6 @@ do
 	test "$f" = src/include/port/atomics/generic-msvc.h && continue
 	test "$f" = src/include/port/atomics/generic-sunpro.h && continue
 
-	# rusagestub.h is also platform-specific, and will be included
-	# by utils/pg_rusage.h if necessary.
-	test "$f" = src/include/rusagestub.h && continue
-
 	# sepgsql.h depends on headers that aren't there on most platforms.
 	test "$f" = contrib/sepgsql/sepgsql.h && continue