1 files changed, 314 insertions, 0 deletions

diff --git a/proc/wait.c b/proc/wait.c
new file mode 100644
index 00000000..a801c99b
--- /dev/null
+++ b/proc/wait.c
@@ -0,0 +1,314 @@
+/* Implementation of wait
+   Copyright (C) 1994 Free Software Foundation
+
+   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 <mach.h>
+#include <sys/types.h>
+#include <hurd/hurd_types.h>
+#include <sys/resource.h>
+
+#include "proc.h"
+
+#include <signal.h>
+#include <string.h>
+#include <sys/wait.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <assert.h>
+
+#include "proc_S.h"
+#include "process_reply.h"
+#include "msg.h"
+#include "interrupt_S.h"
+
+#include <mach/mig_errors.h>
+
+struct zombie 
+{
+  struct zombie *next;
+  pid_t pid, pgrp;
+  struct proc *parent;
+  int exit_status;
+  struct rusage ru;
+};
+
+static struct zombie *zombie_list;
+
+/* A process is dying.  Check if the parent is waiting for us to exit;
+   if so wake it up, otherwise, enter us as a zombie. */
+void
+alert_parent (struct proc *p)
+{
+  struct zombie *z;
+  
+  /* Don't allow init to exit */
+  assert (p->p_parent);
+
+  if (!p->p_exiting)
+    p->p_status = W_EXITCODE (0, SIGKILL);
+
+  if (p->p_parent->p_waiting)
+    {
+      struct wait_c *w = &p->p_parent->p_continuation.wait_c;
+      if (w->pid == p->p_pid || w->pid == -p->p_pgrp->pg_pgid || w->pid == 0)
+	{
+	  struct rusage ru;
+      
+	  bzero (&ru, sizeof (struct rusage));
+	  proc_wait_reply (w->reply_port, w->reply_port_type, 0,
+			   p->p_status, ru, p->p_pid);
+	  p->p_parent->p_waiting = 0;
+	  return;
+	}
+    }
+
+  z = malloc (sizeof (struct zombie));
+      
+  z->pid = p->p_pid;
+  z->pgrp = p->p_pgrp->pg_pgid;
+  z->parent = p->p_parent;
+  z->exit_status = p->p_status;
+  bzero (&z->ru, sizeof (struct rusage));
+  z->next = zombie_list;
+  zombie_list = z;
+}
+
+/* Process P is exiting.  Find all the zombies who claim P as their parent
+   and make them claim startup_proc as their parent; then wake it
+   up if appropriate. */
+void
+reparent_zombies (struct proc *p)
+{
+  struct zombie *z, *prevz;
+  struct wait_c *w = &startup_proc->p_continuation.wait_c;
+  int initwoken = 0;
+  
+  for (z = zombie_list, prevz = 0; z; prevz = z, z = z->next)
+    {
+      if (z->parent != p)
+	continue;
+      z->parent = startup_proc;
+
+      if (initwoken || !startup_proc->p_waiting)
+	continue;
+
+      if (w->pid == z->pid || w->pid == -z->pgrp || w->pid == 0)
+	{
+	  proc_wait_reply (w->reply_port, w->reply_port_type, 0,
+			   z->exit_status, z->ru, z->pid);
+	  startup_proc->p_waiting = 0;
+	  (prevz ? prevz->next : zombie_list) = z->next;
+	  free (z);
+	  initwoken = 1;
+	}
+    }
+}
+
+/* Cause the pending wait operation of process P to immediately
+   return. */
+void
+abort_wait (struct proc *p)
+{
+  struct wait_c *w = &p->p_continuation.wait_c;
+  struct rusage ru;
+
+  proc_wait_reply (w->reply_port, w->reply_port_type, EINTR,
+		   0, ru, 0);
+  p->p_waiting = 0;
+}
+
+/* Implement proc_wait as described in <hurd/proc.defs>. */
+error_t
+S_proc_wait (struct proc *p,
+	   mach_port_t reply_port,
+	   mach_msg_type_name_t reply_port_type,
+	   pid_t pid,
+	   int options,
+	   int *status,
+	   struct rusage *ru,
+	   pid_t *pid_status)
+{
+  struct wait_c *w;
+  struct zombie *z, *prevz;
+  
+  for (z = zombie_list, prevz = 0; z; prevz = z, z = z->next)
+    {
+      if (z->parent == p
+	  && (pid == z->pid || pid == -z->pgrp || pid == 0))
+	{
+	  *status = z->exit_status;
+	  bzero (ru, sizeof (struct rusage));
+	  *pid_status = z->pid;
+	  (prevz ? prevz->next : zombie_list) = z->next;
+	  free (z);
+	  return 0;
+	}
+    }
+
+  /* See if we can satisfy the request with a stopped
+     child; also check for invalid arguments here. */
+  if (!p->p_ochild) 
+    return ESRCH;
+  
+  if (pid > 0)
+    {
+      struct proc *child = pid_find (pid);
+      if (!child || child->p_parent != p)
+	return ESRCH;
+      if (child->p_stopped && !child->p_waited
+	  && ((options & WUNTRACED) || child->p_traced))
+	{
+	  child->p_waited = 1;
+	  *status = child->p_status;
+	  bzero (ru, sizeof (struct rusage));
+	  *pid_status = pid;
+	  return 0;
+	}
+    }
+  else
+    {
+      struct proc *child;
+      int had_a_match = !pid;
+
+      for (child = p->p_ochild; child; child = child->p_sib)
+	{
+	  if (child->p_pgrp->pg_pgid == -pid)
+	    had_a_match = 1;
+	  if (child->p_stopped && !child->p_waited
+	      && ((options & WUNTRACED) || child->p_traced))
+	    {
+	      child->p_waited = 1;
+	      *status = child->p_status;
+	      bzero (ru, sizeof (struct rusage));
+	      *pid_status = child->p_pid;
+	      return 0;
+	    }
+	}
+      if (!had_a_match)
+	return ESRCH;
+    }
+  
+  if (options & WNOHANG)
+    return EWOULDBLOCK;
+  
+  p->p_waiting = 1;
+  w = &p->p_continuation.wait_c;
+  w->reply_port = reply_port;
+  w->reply_port_type = reply_port_type;
+  w->pid = pid;
+  w->options = options;
+  return MIG_NO_REPLY;
+}
+
+/* Implement proc_mark_stop as described in <hurd/prco.defs>. */
+error_t
+S_proc_mark_stop (struct proc *p,
+	       int signo)
+{
+  p->p_stopped = 1;
+  p->p_status = W_STOPCODE (signo);
+  p->p_waited = 0;
+  
+  /* Don't allow init to stop */
+  assert (p->p_parent);
+  
+  if (p->p_parent->p_waiting)
+    {
+      struct wait_c *w = &p->p_parent->p_continuation.wait_c;
+      if (((w->options & WUNTRACED) || p->p_traced)
+	  && (w->pid == p->p_pid || w->pid == p->p_pgrp->pg_pgid
+	      || w->pid == 0))
+	{
+	  struct rusage ru;
+	  bzero (&ru, sizeof (struct rusage));
+	  proc_wait_reply (w->reply_port, w->reply_port_type, 0,
+			   p->p_status, ru, p->p_pid);
+	  p->p_parent->p_waiting = 0;
+	  p->p_waited = 1;
+	}
+    }
+
+  if (!p->p_parent->p_nostopcld)
+    nowait_sig_post (p->p_parent->p_msgport, SIGCHLD, p->p_parent->p_task);
+
+  return 0;
+}
+
+/* Implement proc_mark_exit as described in <hurd/proc.defs>. */
+error_t
+S_proc_mark_exit (struct proc *p,
+		int status)
+{
+  if (WIFSTOPPED (status))
+    return EINVAL;
+  
+  p->p_exiting = 1;
+  p->p_status = status;
+  return 0;
+}
+
+/* Implement proc_mark_cont as described in <hurd/proc.defs>. */
+error_t
+S_proc_mark_cont (struct proc *p)
+{
+  p->p_stopped = 0;
+  return 0;
+}
+
+/* Implement proc_mark_traced as described in <hurd/proc.defs>. */
+error_t
+S_proc_mark_traced (struct proc *p)
+{
+  p->p_traced = 1;
+  return 0;
+}
+
+/* Implement proc_mark_nostopchild as described in <hurd/proc.defs>. */
+error_t
+S_proc_mark_nostopchild (struct proc *p,
+		       int value)
+{
+  p->p_nostopcld = !! value;
+  return 0;
+}
+
+/* Return 1 if pid is in use by a zombie. */
+int
+zombie_check_pid (pid_t pid)
+{
+  struct zombie *z;
+  for (z = zombie_list; z; z = z->next)
+    if (z->pid == pid || -z->pid == pid)
+      return 1;
+  return 0;
+}
+
+/* Implement interrupt_operation as described in <hurd/interrupt.defs>. */
+error_t
+interrupt_operation (mach_port_t object)
+{
+  struct proc *p = reqport_find (object);
+  
+  if (!p)
+    return EOPNOTSUPP;
+  
+  if (p->p_waiting)
+    abort_wait (p);
+  else if (p->p_msgportwait)
+    abort_getmsgport (p);
+
+  return 0;
+}