1 files changed, 156 insertions, 0 deletions
diff --git a/proc/hash.c b/proc/hash.c
new file mode 100644
index 00000000..e4dc5ffd
--- /dev/null
+++ b/proc/hash.c
@@ -0,0 +1,156 @@
+/* Hash table functions
+   Copyright (C) 1993, 1994, 1995, 1996, 1997 Free Software Foundation
+
+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 the GNU Hurd; see the file COPYING.  If not, write to
+the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+/* Written by Michael I. Bushnell.  */
+
+#include <mach.h>
+#include <stddef.h>
+#include <sys/types.h>
+#include <hurd/hurd_types.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/resource.h>
+
+#include "proc.h"
+#include <hurd/ihash.h>
+
+static struct hurd_ihash pghash
+  = HURD_IHASH_INITIALIZER (offsetof (struct pgrp, pg_hashloc));
+static struct hurd_ihash pidhash
+  = HURD_IHASH_INITIALIZER (offsetof (struct proc, p_pidhashloc));
+static struct hurd_ihash taskhash
+  = HURD_IHASH_INITIALIZER (offsetof (struct proc, p_taskhashloc));
+static struct hurd_ihash sidhash
+  = HURD_IHASH_INITIALIZER (offsetof (struct session, s_hashloc));
+
+
+/* Find the process corresponding to a given pid. */
+struct proc *
+pid_find (pid_t pid)
+{
+  struct proc *p;
+  p = hurd_ihash_find (&pidhash, pid);
+  return (!p || p->p_dead) ? 0 : p;
+}
+
+/* Find the process corresponding to a given pid.  Return it even if
+   it's dead. */
+struct proc *
+pid_find_allow_zombie (pid_t pid)
+{
+  return hurd_ihash_find (&pidhash, pid);
+}
+
+/* Find the process corresponding to a given task. */
+struct proc *
+task_find (task_t task)
+{
+  struct proc *p;
+  p = hurd_ihash_find (&taskhash, task) ? : add_tasks (task);
+  return (!p || p->p_dead) ? 0 : p;
+}
+
+/* Find the process corresponding to a given task, but
+   if we don't already know about it, just return 0. */
+struct proc *
+task_find_nocreate (task_t task)
+{
+  struct proc *p;
+  p = hurd_ihash_find (&taskhash, task);
+  return (!p || p->p_dead) ? 0 : p;
+}
+
+/* Find the process group corresponding to a given pgid. */
+struct pgrp *
+pgrp_find (pid_t pgid)
+{
+  return hurd_ihash_find (&pghash, pgid);
+}
+
+/* Find the session corresponding to a given sid. */
+struct session *
+session_find (pid_t sid)
+{
+  return hurd_ihash_find (&sidhash, sid);
+}
+
+/* Add a new process to the various hash tables. */
+void
+add_proc_to_hash (struct proc *p)
+{
+  hurd_ihash_add (&pidhash, p->p_pid, p);
+  hurd_ihash_add (&taskhash, p->p_task, p);
+}
+
+/* Add a new process group to the various hash tables. */
+void
+add_pgrp_to_hash (struct pgrp *pg)
+{
+  hurd_ihash_add (&pghash, pg->pg_pgid, pg);
+}
+
+/* Add a new session to the various hash tables. */
+void
+add_session_to_hash (struct session *s)
+{
+  hurd_ihash_add (&sidhash, s->s_sid, s);
+}
+
+/* Remove a process group from the various hash tables. */
+void
+remove_pgrp_from_hash (struct pgrp *pg)
+{
+  hurd_ihash_locp_remove (&pghash, pg->pg_hashloc);
+}
+
+/* Remove a process from the various hash tables. */
+void
+remove_proc_from_hash (struct proc *p)
+{
+  hurd_ihash_locp_remove (&pidhash, p->p_pidhashloc);
+  hurd_ihash_locp_remove (&taskhash, p->p_taskhashloc);
+}
+
+/* Remove a session from the various hash tables. */
+void
+remove_session_from_hash (struct session *s)
+{
+  hurd_ihash_locp_remove (&sidhash, s->s_hashloc);
+}
+
+/* Call function FUN of two args for each process.  FUN's first arg is
+   the process, its second arg is ARG. */
+void
+prociterate (void (*fun) (struct proc *, void *), void *arg)
+{
+  HURD_IHASH_ITERATE (&pidhash, value)
+    {
+      struct proc *p = value;
+      if (!p->p_dead)
+	(*fun)(p, arg);
+    }
+}
+
+/* Tell if a pid is available for use */
+int
+pidfree (pid_t pid)
+{
+  return (!pid_find_allow_zombie (pid)
+	  && !pgrp_find (pid) && !session_find (pid));
+}