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-rw-r--r--sysdeps/mach/hurd/sigsuspend.c81
1 files changed, 81 insertions, 0 deletions
diff --git a/sysdeps/mach/hurd/sigsuspend.c b/sysdeps/mach/hurd/sigsuspend.c
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+++ b/sysdeps/mach/hurd/sigsuspend.c
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+/* Copyright (C) 1991, 1992, 1993, 1994, 1995 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 Library General Public License as
+published by the Free Software Foundation; either version 2 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <ansidecl.h>
+#include <errno.h>
+#include <hurd.h>
+#include <hurd/signal.h>
+#include <hurd/msg.h>
+
+/* Change the set of blocked signals to SET,
+   wait until a signal arrives, and restore the set of blocked signals.  */
+int
+DEFUN(sigsuspend, (set), CONST sigset_t *set)
+{
+  struct hurd_sigstate *ss;
+  sigset_t newmask, oldmask, pending;
+  mach_port_t wait;
+  mach_msg_header_t msg;
+
+  if (set != NULL)
+    /* Crash before locking.  */
+    newmask = *set;
+
+  /* Get a fresh port we will wait on.  */
+  wait = __mach_reply_port ();
+
+  ss = _hurd_self_sigstate ();
+
+  __spin_lock (&ss->lock);
+
+  oldmask = ss->blocked;
+  if (set != NULL)
+    /* Change to the new blocked signal mask.  */
+    ss->blocked = newmask & ~_SIG_CANT_MASK;
+
+  /* Notice if any pending signals just became unblocked.  */
+  pending = ss->pending & ~ss->blocked;
+
+  /* Tell the signal thread to message us when a signal arrives.  */
+  ss->suspended = wait;
+  __spin_unlock (&ss->lock);
+
+  if (pending)
+    /* Tell the signal thread to check for pending signals.  */
+    __msg_sig_post (_hurd_msgport, 0, __mach_task_self ());
+
+  /* Wait for the signal thread's message.  */
+  __mach_msg (&msg, MACH_RCV_MSG, 0, sizeof (msg), wait,
+	      MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+  __mach_port_destroy (__mach_task_self (), wait);
+
+  __spin_lock (&ss->lock);
+  ss->blocked = oldmask;	/* Restore the old mask.  */
+  pending = ss->pending & ~ss->blocked;	/* Again check for pending signals.  */
+  __spin_unlock (&ss->lock);
+
+  if (pending)
+    /* Tell the signal thread to check for pending signals.  */
+    __msg_sig_post (_hurd_msgport, 0, __mach_task_self ());
+    
+  /* We've been interrupted!  And a good thing, too.
+     Otherwise we'd never return.
+     That's right; this function always returns an error.  */
+  errno = EINTR;
+  return -1;
+}