Initial revision

1 files changed, 159 insertions, 0 deletions

diff --git a/libps/context.c b/libps/context.c
new file mode 100644
index 00000000..67b63ced
--- /dev/null
+++ b/libps/context.c
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+/* The type ps_context_t, for per-procserver and somewhat global state.
+
+   Copyright (C) 1995 Free Software Foundation, Inc.
+
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+
+   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 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., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include <hurd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+
+#include "ps.h"
+#include "common.h"
+
+/* ---------------------------------------------------------------- */
+
+/* Returns in PC a new ps_context_t for the proc server SERVER.  If a memory
+   allocation error occurs, ENOMEM is returned, otherwise 0.  */
+error_t
+ps_context_create(process_t server, ps_context_t *pc)
+{
+  error_t err_procs, err_ttys, err_ttys_by_cttyid, err_users;
+
+  *pc = NEW(struct ps_context);
+  if (*pc == NULL)
+    return ENOMEM;
+
+  (*pc)->server = server;
+  err_procs = ihash_create(&(*pc)->procs);
+  err_ttys = ihash_create(&(*pc)->ttys);
+  err_ttys_by_cttyid = ihash_create(&(*pc)->ttys_by_cttyid);
+  err_users = ihash_create(&(*pc)->users);
+
+  if (err_procs || err_ttys || err_ttys_by_cttyid)
+    /* Some allocation error occurred, backout any successful ones and fail. */
+    {
+      if (!err_procs) ihash_free((*pc)->procs);
+      if (!err_users) ihash_free((*pc)->users);
+      if (!err_ttys)  ihash_free((*pc)->ttys);
+      if (!err_ttys_by_cttyid) ihash_free((*pc)->ttys_by_cttyid);
+      free(*pc);
+      return ENOMEM;
+    }
+
+  ihash_set_cleanup((*pc)->procs,
+		    (void (*)(void *, void *arg))_proc_stat_free,
+		    NULL);
+  ihash_set_cleanup((*pc)->ttys,
+		    (void (*)(void *, void *arg))ps_tty_free,
+		    NULL);
+  ihash_set_cleanup((*pc)->users,
+		    (void (*)(void *, void *arg))ps_user_free,
+		    NULL);
+
+  return 0;
+}
+
+/* Frees PC and any resources it consumes.  */
+void
+ps_context_free(ps_context_t pc)
+{
+  ihash_free(pc->procs);
+  ihash_free(pc->procs);
+  free(pc);
+}
+
+/* ---------------------------------------------------------------- */
+
+/* Return the value in HT indexed by the key ID.  If it doesn't exist create
+   it by calling CREATE with ID and a return location pointer as arguments
+   (CREATE should return either an error-code or 0 if no error occurs), and
+   cache it in HT.  */
+static error_t
+lookup(int id, ihash_t ht, error_t (*create)(int id, void **), void **value)
+{
+  *value = ihash_find(ht, id);
+  if (*value == NULL)
+    {
+      error_t err = create(id, value);
+      if (err)
+	return err;
+      ihash_add(ht, id, *value, NULL);
+    }
+  return 0;
+}
+
+/* Find a proc_stat_t for the process referred to by PID, and return it in
+   PS.  If an error occurs, it is returned, otherwise 0.  */
+error_t
+ps_context_find_proc_stat(ps_context_t pc, int pid, proc_stat_t *ps)
+{
+  error_t create(int pid, void **value)
+    {
+      return _proc_stat_create(pid, pc, (proc_stat_t *)value);
+    }
+  return lookup(pid, pc->procs, create, (void **)ps);
+}
+
+/* Find a ps_tty_t for the terminal referred to by the port TTY_PORT, and
+   return it in TTY.  If an error occurs, it is returned, otherwise 0.  */
+error_t
+ps_context_find_tty(ps_context_t pc, int tty_port, ps_tty_t *tty)
+{
+  return lookup(tty_port,
+		pc->ttys,
+		(error_t (*)(int id, void **result))ps_tty_create,
+		(void **)tty);
+}
+
+/* Find a ps_tty_t for the terminal referred to by the ctty id port
+   CTTYID_PORT, and return it in TTY.  If an error occurs, it is returned,
+   otherwise 0.  */
+error_t
+ps_context_find_tty_by_cttyid(ps_context_t pc, int cttyid_port, ps_tty_t *tty)
+{
+  error_t create(int cttyid_port, void **value)
+    {
+      if (cttyid_port == MACH_PORT_NULL)
+	{
+	  *value = 0;
+	  return 0;
+	}
+      else
+	{
+	  int tty_port;
+	  error_t err = termctty_open_terminal(cttyid_port, 0, &tty_port);
+	  if (err)
+	    return err;
+	  else
+	    return ps_context_find_tty(pc, tty_port, (ps_tty_t *)value);
+	}
+    }
+
+  return lookup(cttyid_port, pc->ttys, create, (void **)tty);
+}
+
+/* Find a ps_user_t for the user referred to by UID, and return it in U.  */
+error_t
+ps_context_find_user(ps_context_t pc, int uid, ps_user_t *u)
+{
+  return lookup(uid,
+		pc->users,
+		(error_t (*)(int id, void **result))ps_user_create,
+		(void **)u);
+}