1 files changed, 92 insertions, 0 deletions
diff --git a/libfshelp/get-identity.c b/libfshelp/get-identity.c
new file mode 100644
index 00000000..2dbd254c
--- /dev/null
+++ b/libfshelp/get-identity.c
@@ -0,0 +1,92 @@
+/* Helper function for io_identity
+   Copyright (C) 1996, 1999 Free Software Foundation, Inc.
+   Written by Michael I. Bushnell, p/BSG.
+
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd 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.
+
+   The GNU Hurd 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, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */
+
+
+#include <fshelp.h>
+#include <hurd/ports.h>
+#include <hurd/ihash.h>
+#include <stddef.h>
+#include <assert.h>
+
+static struct port_class *idclass = 0;
+static pthread_mutex_t idlock = PTHREAD_MUTEX_INITIALIZER;
+
+struct idspec
+{
+  struct port_info pi;
+  hurd_ihash_locp_t id_hashloc;
+};
+
+static struct hurd_ihash idhash
+  = HURD_IHASH_INITIALIZER (offsetof (struct idspec, id_hashloc));
+
+static void
+id_clean (void *cookie)
+{
+  struct idspec *i = cookie;
+  pthread_mutex_lock (&idlock);
+  hurd_ihash_locp_remove (&idhash, i->id_hashloc);
+  pthread_mutex_unlock (&idlock);
+}
+
+static void
+id_initialize ()
+{
+  assert (!idclass);
+  idclass = ports_create_class (id_clean, NULL);
+}
+
+error_t
+fshelp_get_identity (struct port_bucket *bucket,
+		     ino_t fileno,
+		     mach_port_t *pt)
+{
+  struct idspec *i;
+  error_t err = 0;
+
+  pthread_mutex_lock (&idlock);
+  if (!idclass)
+    id_initialize ();
+
+  i = hurd_ihash_find (&idhash, (hurd_ihash_key_t) fileno);
+  if (i == NULL)
+    {
+      err = ports_create_port (idclass, bucket, sizeof (struct idspec), &i);
+      if (err)
+        goto lose;
+      err = hurd_ihash_add (&idhash, (hurd_ihash_key_t) fileno, i);
+      if (err)
+        goto lose_port;
+
+      *pt = ports_get_right (i);
+      ports_port_deref (i);
+    }
+  else
+    *pt = ports_get_right (i);
+
+  /* Success!  */
+  goto lose;
+
+ lose_port:
+  ports_destroy_right (i);
+ lose:
+  pthread_mutex_unlock (&idlock);
+  return err;
+}