Implement SysV shared memory for GNU/Hurd.

2005-07-11  Marcus Brinkmann  <marcus@gnu.org>

        * hurd/Makefile (routines): Add sysvshm.
        (distribute): Add sysvshm.h.
        * hurd/sysvshm.h: New file.
        * hurd/sysvshm.c: New file.
        * sysdeps/mach/hurd/bits/stat.h (S_IMMAP0): New macro.
        (S_ISPARE): Unset the S_IMMAP0 flag.
        * sysdeps/mach/hurd/ftok.c: New file.
        * sysdeps/mach/hurd/shmat.c: New file.
        * sysdeps/mach/hurd/shmctl.c: New file.
        * sysdeps/mach/hurd/shmdt.c: New file.
        * sysdeps/mach/hurd/bits/posix_opt.h: Define _XOPEN_SHM to 1.

1 files changed, 96 insertions, 0 deletions

diff --git a/hurd/sysvshm.c b/hurd/sysvshm.c
new file mode 100644
index 0000000000..292cc01db4
--- /dev/null
+++ b/hurd/sysvshm.c
@@ -0,0 +1,96 @@
+/* Copyright (C) 2005 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stddef.h>
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <sys/stat.h>
+#include <sys/shm.h>
+
+
+/* Description of an shm attachment.  */
+struct sysvshm_attach
+{
+  /* Linked list.  */
+  struct sysvshm_attach *next;
+
+  /* Map address.  */
+  void *addr;
+
+  /* Map size.  */
+  size_t size;
+};
+
+/* List of attachments.  */
+static struct sysvshm_attach *attach_list;
+
+/* A lock to protect the linked list of shared memory attachments.  */
+static struct mutex sysvshm_lock = MUTEX_INITIALIZER;
+
+
+/* Adds a segment attachment.  */
+error_t
+__sysvshm_add (void *addr, size_t size)
+{
+  struct sysvshm_attach *shm;
+
+  shm = malloc (sizeof (*shm));
+  if (!shm)
+    return errno;
+
+  __mutex_lock (&sysvshm_lock);
+  shm->addr = addr;
+  shm->size = size;
+  shm->next = attach_list;
+  attach_list = shm;
+  __mutex_unlock (&sysvshm_lock);
+
+  return 0;
+}
+
+/* Removes a segment attachment.  Returns its size if found, or EINVAL
+   otherwise.  */
+error_t
+__sysvshm_remove (void *addr, size_t *size)
+{
+  struct sysvshm_attach *shm;
+  struct sysvshm_attach **pshm = &attach_list;
+
+  __mutex_lock (&sysvshm_lock);
+  shm = attach_list;
+  while (shm)
+    {
+      shm = *pshm;
+      if (shm->addr == addr)
+	{
+	  *pshm = shm->next;
+	  *size = shm->size;
+	  __mutex_unlock (&sysvshm_lock);
+	  return 0;
+	}
+      pshm = &shm->next;
+      shm = shm->next;
+    }
+  __mutex_unlock (&sysvshm_lock);
+  return EINVAL;
+}