gettimeofday: port recent C++ fix to Emacs

[gnulib.git] / lib / pagealign_alloc.c

diff --git a/lib/pagealign_alloc.c b/lib/pagealign_alloc.c
index 8483670..6d8ac61 100644 (file)
--- a/lib/pagealign_alloc.c
+++ b/lib/pagealign_alloc.c
@@ -1,53 +1,58 @@
 /* Memory allocation aligned to system page boundaries.
 
-   Copyright (C) 2005 Free Software Foundation, Inc.
+   Copyright (C) 2005-2007, 2009-2013 Free Software Foundation, Inc.
 
-   This program is free software; you can redistribute it and/or modify it
-   under the terms of the GNU General Public License as published
-   by the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   General Public License for more details.
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
 
-   You should have received a copy of the GNU General Public
-   License along with this program; if not, write to the Free Software
-   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
-   USA.  */
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 /* Written by Derek R. Price <derek@ximbiot.com>.  */
 
-#ifdef HAVE_CONFIG_H
-# include <config.h>
-#endif
+#include <config.h>
 
 #include "pagealign_alloc.h"
 
 #include <errno.h>
 #include <stdlib.h>
 
-#if HAVE_FCNTL_H
-# include <fcntl.h>
-#endif
-
-#if HAVE_UNISTD_H
-# include <unistd.h>
-#endif
+#include <fcntl.h>
+#include <unistd.h>
 
 #if HAVE_MMAP
 # include <sys/mman.h>
 #endif
 
 #include "error.h"
-#include "exit.h"
-#include "getpagesize.h"
 #include "xalloc.h"
 #include "gettext.h"
 
 #define _(str) gettext (str)
 
+#if HAVE_MMAP
+/* Define MAP_FILE when it isn't otherwise.  */
+# ifndef MAP_FILE
+#  define MAP_FILE 0
+# endif
+/* Define MAP_FAILED for old systems which neglect to.  */
+# ifndef MAP_FAILED
+#  define MAP_FAILED ((void *)-1)
+# endif
+#endif
+
+/* The results of open() in this file are not used with fchdir,
+   therefore save some unnecessary work in fchdir.c.  */
+#undef open
+#undef close
+
 
 #if HAVE_MMAP || ! HAVE_POSIX_MEMALIGN
 
@@ -77,7 +82,7 @@ static memnode_t *memnode_table = NULL;
 static void
 new_memnode (void *aligned_ptr, info_t info)
 {
-  memnode_t *new_node = (memnode_t *) xmalloc (sizeof (memnode_t));
+  memnode_t *new_node = XMALLOC (memnode_t);
   new_node->aligned_ptr = aligned_ptr;
   new_node->info = info;
   new_node->next = memnode_table;
@@ -118,20 +123,23 @@ void *
 pagealign_alloc (size_t size)
 {
   void *ret;
+  /* We prefer the mmap() approach over the posix_memalign() or malloc()
+     based approaches, since the latter often waste an entire memory page
+     per call.  */
 #if HAVE_MMAP
 # ifdef HAVE_MAP_ANONYMOUS
   const int fd = -1;
   const int flags = MAP_ANONYMOUS | MAP_PRIVATE;
 # else /* !HAVE_MAP_ANONYMOUS */
   static int fd = -1;  /* Only open /dev/zero once in order to avoid limiting
-                         the amount of memory we may allocate based on the
-                         number of open file descriptors.  */
+                          the amount of memory we may allocate based on the
+                          number of open file descriptors.  */
   const int flags = MAP_FILE | MAP_PRIVATE;
   if (fd == -1)
     {
       fd = open ("/dev/zero", O_RDONLY, 0666);
       if (fd < 0)
-       error (EXIT_FAILURE, errno, _("Failed to open /dev/zero for read"));
+        error (EXIT_FAILURE, errno, _("Failed to open /dev/zero for read"));
     }
 # endif /* HAVE_MAP_ANONYMOUS */
   ret = mmap (NULL, size, PROT_READ | PROT_WRITE, flags, fd, 0);
@@ -151,7 +159,7 @@ pagealign_alloc (size_t size)
   if (unaligned_ptr == NULL)
     {
       /* Set errno.  We don't know whether malloc already set errno: some
-        implementations of malloc do, some don't.  */
+         implementations of malloc do, some don't.  */
       errno = ENOMEM;
       return NULL;
     }