--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2011-01-18  Bruno Haible  <bruno@clisp.org>
+
+	New module 'get-rusage-as'.
+	* modules/get-rusage-as: New file.
+	* lib/resource-ext.h: New file.
+	* lib/get-rusage-as.c: New file.
+
 2011-01-17  Eric Blake  <eblake@redhat.com>
 
 	sigaction: relax license from LGPLv3+ to LGPLv2+

new file mode 100644
--- /dev/null
+++ b/lib/get-rusage-as.c
@@ -0,0 +1,707 @@
+/* Getter for RLIMIT_AS.
+   Copyright (C) 2011 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2011.
+
+   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.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "resource-ext.h"
+
+/* The "address space size" is defined as the total size of the virtual memory
+   areas of the current process.  This includes
+     - areas belonging to the executable and shared libraries,
+     - areas allocated by malloc() or mmap(),
+     - the stack and environment areas,
+     - gaps and guard pages (mappings with PROT_NONE),
+     - other system dependent areas, such as vsyscall or vdso on Linux.
+
+   There are two ways of retrieving the current address space size:
+     a) by trying setrlimit with various values and observing whether the
+        kernel allows additional mmap calls,
+     b) by using system dependent APIs that allow to iterate over the list
+        of virtual memory areas.
+   We don't use the mincore() based approach here, because it would be very
+   slow when applied to an entire address space, especially on 64-bit
+   platforms.
+   We define two functions
+     get_rusage_as_via_setrlimit(),
+     get_rusage_as_via_iterator().
+
+   Discussion per platform:
+
+   Linux:
+     a) setrlimit with RLIMIT_AS works.
+     b) The /proc/self/maps file contains a list of the virtual memory areas.
+     Both methods agree, except that on x86_64 systems, the value of
+     get_rusage_as_via_iterator() is 4 KB higher than
+     get_rusage_as_via_setrlimit().
+
+   MacOS X:
+     a) setrlimit with RLIMIT_AS succeeds but does not really work: The OS
+        ignores RLIMIT_AS. mmap() of a page always succeeds, therefore
+        get_rusage_as_via_setrlimit() is always 0.
+     b) The Mach based API works.
+
+   FreeBSD:
+     a) setrlimit with RLIMIT_AS works.
+     b) The /proc/self/maps file contains a list of the virtual memory areas.
+
+   NetBSD:
+     a) setrlimit with RLIMIT_AS works.
+     b) No VMA iteration API exists.
+
+   OpenBSD:
+     a) setrlimit exists, but RLIMIT_AS is not defined.
+     b) No VMA iteration API exists.
+
+   AIX:
+     a) setrlimit with RLIMIT_AS succeeds but does not really work: The OS
+        apparently ignores RLIMIT_AS. mmap() of a page always succeeds,
+        therefore get_rusage_as_via_setrlimit() is always 0.
+     b) No VMA iteration API exists.
+
+   HP-UX:
+     a) setrlimit with RLIMIT_AS works.
+     b) No VMA iteration API exists.
+
+   IRIX:
+     a) setrlimit with RLIMIT_AS works.
+     b) The /proc/$pid file supports ioctls PIOCNMAP and PIOCMAP.
+     Both methods agree,
+
+   OSF/1:
+     a) setrlimit with RLIMIT_AS works.
+     b) The /proc/$pid file supports ioctls PIOCNMAP and PIOCMAP.
+     The value returned by get_rusage_as_via_setrlimit() is 64 KB higher than
+     get_rusage_as_via_iterator().  It's not clear why.
+
+   Solaris:
+     a) setrlimit with RLIMIT_AS works.
+     b) No VMA iteration API exists.
+
+   Cygwin:
+     a) setrlimit with RLIMIT_AS always fails when the limit is < 0x80000000.
+        get_rusage_as_via_setrlimit() therefore produces a wrong value.
+     b) The /proc/$pid/maps file lists only the memory areas belonging to
+        the executable and shared libraries, not the anonymous memory.
+        But the native Win32 API works.
+
+   mingw:
+     a) There is no setrlimit function.
+     b) The native Win32 API works.
+
+   BeOS, Haiku:
+     a) On BeOS, there is no setrlimit function.
+        On Haiku, setrlimit exists. RLIMIT_AS is defined but unsupported.
+     b) There is a specific BeOS API: get_next_area_info().
+ */
+
+
+#include <errno.h> /* errno */
+#include <stdlib.h> /* size_t, abort */
+#include <fcntl.h> /* open, O_RDONLY */
+#include <unistd.h> /* getpagesize, read, close */
+
+
+/* System support for get_rusage_as_via_setrlimit().  */
+
+#if HAVE_SETRLIMIT
+# include <sys/time.h>
+# include <sys/resource.h> /* getrlimit, setrlimit */
+#endif
+
+/* Test whether mmap() and mprotect() are available.
+   We don't use HAVE_MMAP, because AC_FUNC_MMAP would not define it on HP-UX.
+   HAVE_MPROTECT is not enough, because mingw does not have mmap() but has an
+   mprotect() function in libgcc.a.  */
+#if HAVE_SYS_MMAN_H && HAVE_MPROTECT
+# include <fcntl.h>
+# include <sys/types.h>
+# include <sys/mman.h> /* mmap, munmap */
+/* Define MAP_FILE when it isn't otherwise.  */
+# ifndef MAP_FILE
+#  define MAP_FILE 0
+# endif
+#endif
+
+
+/* System support for get_rusage_as_via_iterator().  */
+
+#if defined __sgi || defined __osf__ /* IRIX, OSF/1 */
+# include <string.h> /* memcpy */
+# include <sys/types.h>
+# include <sys/procfs.h> /* PIOC*, prmap_t */
+#endif
+
+#if defined __APPLE__ && defined __MACH__ /* MacOS X */
+# include <mach/mach.h>
+#endif
+
+#if (defined _WIN32 || defined __WIN32__) || defined __CYGWIN__ /* Windows */
+# include <windows.h>
+#endif
+
+#if defined __BEOS__ /* BeOS */
+# include <OS.h>
+#endif
+
+
+#if HAVE_SETRLIMIT && defined RLIMIT_AS && HAVE_SYS_MMAN_H && HAVE_MPROTECT
+
+static inline uintptr_t
+get_rusage_as_via_setrlimit (void)
+{
+  uintptr_t result;
+
+  struct rlimit orig_limit;
+
+# if HAVE_MAP_ANONYMOUS
+  const int flags = MAP_ANONYMOUS | MAP_PRIVATE;
+  const int fd = -1;
+# else /* !HAVE_MAP_ANONYMOUS */
+  const int flags = MAP_FILE | MAP_PRIVATE;
+  int fd = open ("/dev/zero", O_RDONLY, 0666);
+  if (fd < 0)
+    return 0;
+# endif
+
+  /* Record the original limit.  */
+  if (getrlimit (RLIMIT_AS, &orig_limit) < 0)
+    {
+      result = 0;
+      goto done;
+    }
+
+  if (orig_limit.rlim_max != RLIM_INFINITY
+      && (orig_limit.rlim_cur == RLIM_INFINITY
+          || orig_limit.rlim_cur > orig_limit.rlim_max))
+    /* We may not be able to restore the current rlim_cur value.
+       So bail out.  */
+    {
+      result = 0;
+      goto done;
+    }
+
+  {
+    /* The granularity is a single page.  */
+    const size_t pagesize = getpagesize ();
+
+    uintptr_t low_bound = 0;
+    uintptr_t high_bound;
+
+    for (;;)
+      {
+        /* Here we know that the address space size is >= low_bound.  */
+        struct rlimit try_limit;
+        uintptr_t try_next = 2 * low_bound + pagesize;
+
+        if (try_next < low_bound)
+          /* Overflow.  */
+          try_next = ((uintptr_t) (~ 0) / pagesize) * pagesize;
+
+        /* There's no point in trying a value > orig_limit.rlim_max, as
+           setrlimit would fail anyway.  */
+        if (orig_limit.rlim_max != RLIM_INFINITY
+            && orig_limit.rlim_max < try_next)
+          try_next = orig_limit.rlim_max;
+
+        /* Avoid endless loop.  */
+        if (try_next == low_bound)
+          {
+            /* try_next could not be increased.  */
+            result = low_bound;
+            goto done;
+          }
+
+        try_limit.rlim_max = orig_limit.rlim_max;
+        try_limit.rlim_cur = try_next;
+        if (setrlimit (RLIMIT_AS, &try_limit) == 0)
+          {
+            /* Allocate a page of memory, to compare the current address space
+               size with try_limit.rlim_cur.  */
+            void *new_page =
+              mmap (NULL, pagesize, PROT_READ | PROT_WRITE, flags, fd, 0);
+
+            if (new_page != (void *)(-1))
+              {
+                /* The page could be added successfully.  Free it.  */
+                if (munmap (new_page, pagesize) < 0)
+                  abort ();
+                /* We know that the address space size is
+                   < try_limit.rlim_cur.  */
+                high_bound = try_next;
+                break;
+              }
+            else
+              {
+                /* We know that the address space size is
+                   >= try_limit.rlim_cur.  */
+                low_bound = try_next;
+              }
+          }
+        else
+          {
+            /* Here we expect only EINVAL, not EPERM.  */
+            if (errno != EINVAL)
+              abort ();
+            /* We know that the address space size is
+               >= try_limit.rlim_cur.  */
+            low_bound = try_next;
+          }
+      }
+
+    /* Here we know that the address space size is
+       >= low_bound and < high_bound.  */
+    while (high_bound - low_bound > pagesize)
+      {
+        struct rlimit try_limit;
+        uintptr_t try_next =
+          low_bound + (((high_bound - low_bound) / 2) / pagesize) * pagesize;
+
+        /* Here low_bound <= try_next < high_bound.  */
+        try_limit.rlim_max = orig_limit.rlim_max;
+        try_limit.rlim_cur = try_next;
+        if (setrlimit (RLIMIT_AS, &try_limit) == 0)
+          {
+            /* Allocate a page of memory, to compare the current address space
+               size with try_limit.rlim_cur.  */
+            void *new_page =
+              mmap (NULL, pagesize, PROT_READ | PROT_WRITE, flags, fd, 0);
+
+            if (new_page != (void *)(-1))
+              {
+                /* The page could be added successfully.  Free it.  */
+                if (munmap (new_page, pagesize) < 0)
+                  abort ();
+                /* We know that the address space size is
+                   < try_limit.rlim_cur.  */
+                high_bound = try_next;
+              }
+            else
+              {
+                /* We know that the address space size is
+                   >= try_limit.rlim_cur.  */
+                low_bound = try_next;
+              }
+          }
+        else
+          {
+            /* Here we expect only EINVAL, not EPERM.  */
+            if (errno != EINVAL)
+              abort ();
+            /* We know that the address space size is
+               >= try_limit.rlim_cur.  */
+            low_bound = try_next;
+          }
+      }
+
+    result = low_bound;
+  }
+
+  /* Restore the original rlim_cur value.  */
+  if (setrlimit (RLIMIT_AS, &orig_limit) < 0)
+    abort ();
+
+ done:
+# if !HAVE_MAP_ANONYMOUS
+  close (fd);
+# endif
+  return result;
+}
+
+#endif
+
+
+/* Support for reading text files in the /proc file system.  */
+
+#if defined __linux__ || defined __FreeBSD__ /* || defined __CYGWIN__ */
+
+/* Buffered read-only streams.
+   We cannot use <stdio.h> here, because fopen() calls malloc(), and a malloc()
+   call may call mmap() and thus pre-allocate available memory.  */
+
+struct rofile
+  {
+    int fd;
+    size_t position;
+    size_t filled;
+    int eof_seen;
+    char buffer[1024];
+  };
+
+/* Open a read-only file stream.  */
+static int
+rof_open (struct rofile *rof, const char *filename)
+{
+  int fd = open (filename, O_RDONLY);
+  if (fd < 0)
+    return -1;
+  rof->fd = fd;
+  rof->position = 0;
+  rof->filled = 0;
+  rof->eof_seen = 0;
+  return 0;
+}
+
+/* Return the next byte from a read-only file stream without consuming it,
+   or -1 at EOF.  */
+static int
+rof_peekchar (struct rofile *rof)
+{
+  if (rof->position == rof->filled)
+    {
+      if (rof->eof_seen)
+        return -1;
+      else
+        for (;;)
+          {
+            int n = read (rof->fd, rof->buffer, sizeof (rof->buffer));
+# ifdef EINTR
+            if (n < 0 && errno == EINTR)
+              continue;
+# endif
+            if (n <= 0)
+              {
+                rof->eof_seen = 1;
+                return -1;
+              }
+            rof->filled = n;
+            rof->position = 0;
+            break;
+          }
+    }
+  return (unsigned char) rof->buffer[rof->position];
+}
+
+/* Return the next byte from a read-only file stream, or -1 at EOF.  */
+static int
+rof_getchar (struct rofile *rof)
+{
+  int c = rof_peekchar (rof);
+  if (c >= 0)
+    rof->position++;
+  return c;
+}
+
+/* Parse an unsigned hexadecimal number from a read-only file stream.  */
+static int
+rof_scanf_lx (struct rofile *rof, unsigned long *valuep)
+{
+  unsigned long value = 0;
+  unsigned int numdigits = 0;
+  for (;;)
+    {
+      int c = rof_peekchar (rof);
+      if (c >= '0' && c <= '9')
+        value = (value << 4) + (c - '0');
+      else if (c >= 'A' && c <= 'F')
+        value = (value << 4) + (c - 'A' + 10);
+      else if (c >= 'a' && c <= 'f')
+        value = (value << 4) + (c - 'a' + 10);
+      else
+        break;
+      rof_getchar (rof);
+      numdigits++;
+    }
+  if (numdigits == 0)
+    return -1;
+  *valuep = value;
+  return 0;
+}
+
+/* Close a read-only file stream.  */
+static void
+rof_close (struct rofile *rof)
+{
+  close (rof->fd);
+}
+
+#endif
+
+
+static inline uintptr_t
+get_rusage_as_via_iterator (void)
+{
+#if defined __linux__ /* || defined __CYGWIN__ */
+
+  struct rofile rof;
+  int c;
+  unsigned long total;
+
+  /* Open the current process' maps file.  It describes one VMA per line.  */
+  if (rof_open (&rof, "/proc/self/maps") < 0)
+    return 0;
+
+  total = 0;
+  for (;;)
+    {
+      unsigned long start, end;
+
+      if (!(rof_scanf_lx (&rof, &start) >= 0
+            && rof_getchar (&rof) == '-'
+            && rof_scanf_lx (&rof, &end) >= 0))
+        break;
+      while (c = rof_getchar (&rof), c != -1 && c != '\n')
+        ;
+      total += end - start;
+    }
+  rof_close (&rof);
+  return total;
+
+#elif defined __FreeBSD__
+
+  struct rofile rof;
+  int c;
+  unsigned long total;
+
+  /* Open the current process' maps file.  It describes one VMA per line.  */
+  if (rof_open (&rof, "/proc/curproc/map") < 0)
+    return 0;
+
+  total = 0;
+  for (;;)
+    {
+      unsigned long start, end;
+
+      if (!(rof_getchar (&rof) == '0'
+            && rof_getchar (&rof) == 'x'
+            && rof_scanf_lx (&rof, &start) >= 0))
+        break;
+      while (c = rof_peekchar (&rof), c == ' ' || c == '\t')
+        rof_getchar (&rof);
+      if (!(rof_getchar (&rof) == '0'
+            && rof_getchar (&rof) == 'x'
+            && rof_scanf_lx (&rof, &end) >= 0))
+        break;
+      while (c = rof_getchar (&rof), c != -1 && c != '\n')
+        continue;
+      total += end - start;
+    }
+  rof_close (&rof);
+  return total;
+
+#elif defined __sgi || defined __osf__ /* IRIX, OSF/1 */
+
+  size_t pagesize;
+  char fnamebuf[6+10+1];
+  char *fname;
+  int fd;
+  int nmaps;
+  size_t memneed;
+# if HAVE_MAP_ANONYMOUS
+#  define zero_fd -1
+#  define map_flags MAP_ANONYMOUS
+# else
+  int zero_fd;
+#  define map_flags 0
+# endif
+  void *auxmap;
+  unsigned long auxmap_start;
+  unsigned long auxmap_end;
+  prmap_t* maps;
+  prmap_t* mp;
+  unsigned long total;
+
+  pagesize = getpagesize ();
+
+  /* Construct fname = sprintf (fnamebuf+i, "/proc/%u", getpid ()).  */
+  fname = fnamebuf + sizeof (fnamebuf) - 1;
+  *fname = '\0';
+  {
+    unsigned int value = getpid ();
+    do
+      *--fname = (value % 10) + '0';
+    while ((value = value / 10) > 0);
+  }
+  fname -= 6;
+  memcpy (fname, "/proc/", 6);
+
+  fd = open (fname, O_RDONLY);
+  if (fd < 0)
+    return 0;
+
+  if (ioctl (fd, PIOCNMAP, &nmaps) < 0)
+    goto fail2;
+
+  memneed = (nmaps + 10) * sizeof (prmap_t);
+  /* Allocate memneed bytes of memory.
+     We cannot use alloca here, because not much stack space is guaranteed.
+     We also cannot use malloc here, because a malloc() call may call mmap()
+     and thus pre-allocate available memory.
+     So use mmap(), and ignore the resulting VMA.  */
+  memneed = ((memneed - 1) / pagesize + 1) * pagesize;
+# if !HAVE_MAP_ANONYMOUS
+  zero_fd = open ("/dev/zero", O_RDONLY, 0644);
+  if (zero_fd < 0)
+    goto fail2;
+# endif
+  auxmap = (void *) mmap ((void *) 0, memneed, PROT_READ | PROT_WRITE,
+                          map_flags | MAP_PRIVATE, zero_fd, 0);
+# if !HAVE_MAP_ANONYMOUS
+  close (zero_fd);
+# endif
+  if (auxmap == (void *) -1)
+    goto fail2;
+  auxmap_start = (unsigned long) auxmap;
+  auxmap_end = auxmap_start + memneed;
+  maps = (prmap_t *) auxmap;
+
+  if (ioctl (fd, PIOCMAP, maps) < 0)
+    goto fail1;
+
+  total = 0;
+  for (mp = maps;;)
+    {
+      unsigned long start, end;
+
+      start = (unsigned long) mp->pr_vaddr;
+      end = start + mp->pr_size;
+      if (start == 0 && end == 0)
+        break;
+      mp++;
+      if (start <= auxmap_start && auxmap_end - 1 <= end - 1)
+        /* Consider [start,end-1] \ [auxmap_start,auxmap_end-1]
+           = [start,auxmap_start-1] u [auxmap_end,end-1].  */
+        total += (end - start) - memneed;
+      else
+        total += end - start;
+    }
+  munmap (auxmap, memneed);
+  close (fd);
+  return total;
+
+ fail1:
+  munmap (auxmap, memneed);
+ fail2:
+  close (fd);
+  return 0;
+
+#elif defined __APPLE__ && defined __MACH__ /* MacOS X */
+
+  task_t task = mach_task_self ();
+  vm_address_t address;
+  vm_size_t size;
+  vm_address_t total = 0;
+
+  for (address = VM_MIN_ADDRESS;; address += size)
+    {
+      int more;
+      mach_port_t object_name;
+      /* In MacOS X 10.5, the types vm_address_t, vm_offset_t, vm_size_t have
+         32 bits in 32-bit processes and 64 bits in 64-bit processes. Whereas
+         mach_vm_address_t and mach_vm_size_t are always 64 bits large.
+         MacOS X 10.5 has three vm_region like methods:
+           - vm_region. It has arguments that depend on whether the current
+             process is 32-bit or 64-bit. When linking dynamically, this
+             function exists only in 32-bit processes. Therefore we use it only
+             in 32-bit processes.
+           - vm_region_64. It has arguments that depend on whether the current
+             process is 32-bit or 64-bit. It interprets a flavor
+             VM_REGION_BASIC_INFO as VM_REGION_BASIC_INFO_64, which is
+             dangerous since 'struct vm_region_basic_info_64' is larger than
+             'struct vm_region_basic_info'; therefore let's write
+             VM_REGION_BASIC_INFO_64 explicitly.
+           - mach_vm_region. It has arguments that are 64-bit always. This
+             function is useful when you want to access the VM of a process
+             other than the current process.
+         In 64-bit processes, we could use vm_region_64 or mach_vm_region.
+         I choose vm_region_64 because it uses the same types as vm_region,
+         resulting in less conditional code.  */
+# if defined __ppc64__ || defined __x86_64__
+      struct vm_region_basic_info_64 info;
+      mach_msg_type_number_t info_count = VM_REGION_BASIC_INFO_COUNT_64;
+
+      more = (vm_region_64 (task, &address, &size, VM_REGION_BASIC_INFO_64,
+                            (vm_region_info_t)&info, &info_count, &object_name)
+              == KERN_SUCCESS);
+# else
+      struct vm_region_basic_info info;
+      mach_msg_type_number_t info_count = VM_REGION_BASIC_INFO_COUNT;
+
+      more = (vm_region (task, &address, &size, VM_REGION_BASIC_INFO,
+                         (vm_region_info_t)&info, &info_count, &object_name)
+              == KERN_SUCCESS);
+# endif
+      if (object_name != MACH_PORT_NULL)
+        mach_port_deallocate (mach_task_self (), object_name);
+      if (!more)
+        break;
+      total += size;
+    }
+  return total;
+
+#elif (defined _WIN32 || defined __WIN32__) || defined __CYGWIN__
+  /* Windows platform.  Use the native Windows API.  */
+
+  MEMORY_BASIC_INFORMATION info;
+  unsigned long address = 0;
+  unsigned long total = 0;
+
+  while (VirtualQuery ((void*)address, &info, sizeof(info)) == sizeof(info))
+    {
+      if (info.State != MEM_FREE)
+        total += info.RegionSize;
+      address = (unsigned long)info.BaseAddress + info.RegionSize;
+    }
+  return total;
+
+#elif defined __BEOS__
+  /* Use the BeOS specific API.  */
+
+  area_info info;
+  int32 cookie;
+  unsigned long total = 0;
+
+  cookie = 0;
+  while (get_next_area_info (0, &cookie, &info) == B_OK)
+    {
+      unsigned long start, end;
+
+      start = (unsigned long) info.address;
+      end = start + info.size;
+
+      total += end - start;
+    }
+  return total;
+
+#else
+
+  return 0;
+
+#endif
+}
+
+
+uintptr_t
+get_rusage_as (void)
+{
+#if (defined __APPLE__ && defined __MACH__) || defined _AIX || defined __CYGWIN__ /* MacOS X, AIX, Cygwin */
+  /* get_rusage_as_via_setrlimit() does not work.
+     Prefer get_rusage_as_via_iterator().  */
+  return get_rusage_as_via_iterator ();
+#elif HAVE_SETRLIMIT && defined RLIMIT_AS && HAVE_SYS_MMAN_H && HAVE_MPROTECT
+  /* Prefer get_rusage_as_via_setrlimit() if it succeeds,
+     because the caller may want to use the result with setrlimit().  */
+  uintptr_t result;
+
+  result = get_rusage_as_via_setrlimit ();
+  if (result == 0)
+    result = get_rusage_as_via_iterator ();
+  return result;
+#else
+  return get_rusage_as_via_iterator ();
+#endif
+}

new file mode 100644
--- /dev/null
+++ b/lib/resource-ext.h
@@ -0,0 +1,38 @@
+/* Extra functions for resource usage.
+   Copyright (C) 2011 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2011.
+
+   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.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef _RESOURCE_EXT_H
+#define _RESOURCE_EXT_H
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* Returns the amount of address space currently in use by the current
+   process, or zero if unknown.
+   This is the quantity which is limited by setrlimit(RLIMIT_AS,...).  */
+extern uintptr_t get_rusage_as (void);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _RESOURCE_EXT_H */

new file mode 100644
--- /dev/null
+++ b/modules/get-rusage-as
@@ -0,0 +1,32 @@
+Description:
+Getter for RLIMIT_AS: Returns the current address space size.
+
+Files:
+lib/resource-ext.h
+lib/get-rusage-as.c
+m4/mmap-anon.m4
+
+Depends-on:
+stdint
+unistd
+extensions
+getpagesize
+
+configure.ac:
+AC_REQUIRE([AC_C_INLINE])
+AC_CHECK_FUNCS_ONCE([setrlimit])
+gl_FUNC_MMAP_ANON
+AC_CHECK_HEADERS_ONCE([sys/mman.h])
+AC_CHECK_FUNCS_ONCE([mprotect])
+
+Makefile.am:
+lib_SOURCES += get-rusage-as.c
+
+Include:
+"resource-ext.h"
+
+License:
+GPL
+
+Maintainer:
+Bruno Haible