Mon Aug 14 16:51:13 1995 Roland McGrath <roland@churchy.gnu.ai.mit.edu>

* hurd/thread-cancel.c: New file.
	* sysdeps/mach/hurd/i386/trampoline.c (_hurd_setup_sighandler): In
 	rpc_wait case, frob mach_msg args to set timeout on receive.
	(_hurdsig_rcv_interrupted_p): Function removed.
	* sysdeps/mach/hurd/alpha/trampoline.c: Likewise.
	* sysdeps/mach/hurd/hppa/trampoline.c: Likewise.
	* sysdeps/mach/hurd/mips/trampoline.c: Likewise.
	* hurd/intr-msg.c: New file.
	* hurd/hurd/signal.h (struct hurd_sigstate): New member `cancel'.
	(_hurdsig_rcv_interrupted_p): Declaration removed.
	(HURD_EINTR_RPC): Macro removed.
	(_hurd_longjmp_thread_state, _hurd_interrupted_rpc_timeout): Declare
	these.
	* hurd/intr-rpc.h: New file.
	* hurd/intr-rpc.defs: Just import intr-rpc.h.
	* hurd/hurdsig.c (_hurd_interrupted_rpc_timeout): New variable.
	(interrupted_reply_port_location): Take new flag arg; only catch
	faults if it's set.
	(abort_rpcs): Rename to _hurdsig_abort_rpcs; take same new flag arg.
	No longer use _hurdsig_rcv_interrupted_p; instead compare PC to
 	&_hurd_intr_rpc_msg_in_trap.  If before it, mutate state to simulate
 	MACH_SEND_INTERRUPTED return; on it, interrupt the operation.  All
 	callers changed.
	* hurd/hurd.h (hurd_thread_cancel, hurd_check_cancel): Declare these.
	* hurd/Makefile (distribute): Remove intr-rpc.awk.
	(sig): Add thread-cancel.
	(transform-user-stub, transform-user-stub-output): Variables removed.
	* sysdeps/mach/hurd/dl-sysdep.c: Change all RPCs from
 	`__hurd_intr_rpc_*' to `__*'.
	(_hurd_intr_rpc_mach_msg): New function.
	(_hurd_thread_sigstate): Function removed.
	* sysdeps/mach/hurd/ioctl.c: Use _hurd_intr_rpc_mach_msg function,
 	instead of __mach_msg inside HURD_EINTR_RPC macro.

	* sysdeps/generic/morecore.c [__GNU_LIBRARY__]: Declare `__sbrk'
 	to take ptrdiff_t arg.

	* sysdeps/mach/hurd/fork.c: Remove _hurd_longjmp_thread_state decl.

	* sysdeps/mach/hurd/kill.c (kill_pid): Don't make `inline'.

	* libc-symbols.h [GCC >= 2.7] (strong_alias, weak_symbol,
 	weak_alias): Use `extern' storage class.

hurd/thread-cancel.c

@@ -0,0 +1,86 @@
+/* Thread cancellation support.
+Copyright (C) 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 <hurd/signal.h>
+#include <hurd/interrupt.h>
+#include <assert.h>
+#include <thread_state.h>
+
+
+/* See hurdsig.c.  */
+extern mach_port_t _hurdsig_abort_rpcs (struct hurd_sigstate *ss,
+					int signo, int sigthread, 
+					struct machine_thread_all_state *,
+					int *state_change,
+					mach_port_t *reply_port,
+					mach_msg_type_name_t reply_port_type,
+					int untraced);
+
+error_t
+hurd_thread_cancel (thread_t thread)
+{
+  struct hurd_sigstate *ss = _hurd_thread_sigstate (thread);
+  struct machine_thread_all_state state;
+  int state_change;
+  error_t err;
+
+  if (! ss)
+    return EINVAL;
+
+  __spin_lock (&ss->lock);
+  assert (! ss->critical_section);
+  ss->critical_section = 1;
+  err = __thread_suspend (thread);
+  __spin_unlock (&ss->lock);
+
+  if (! err)
+    {
+      /* Set the flag telling the thread its operation is being cancelled.  */
+      ss->cancel = 1;
+
+      /* Interrupt any interruptible RPC now in progress.  */
+      state.set = 0;
+      _hurdsig_abort_rpcs (ss, 0, 0, &state, &state_change, NULL, 0, 0);
+      if (state_change) 
+	err = __thread_set_state (thread, MACHINE_THREAD_STATE_FLAVOR,
+				  (natural_t *) &state.basic,
+				  MACHINE_THREAD_STATE_COUNT);
+
+      __thread_resume (thread);
+    }
+
+  _hurd_critical_section_unlock (ss);
+  return err;
+}
+
+
+int
+hurd_check_cancel (void)
+{
+  struct hurd_sigstate *ss = _hurd_self_sigstate ();
+  int cancel;
+
+  __spin_lock (&ss->lock);
+  assert (! ss->critical_section);
+  cancel = ss->cancel;
+  ss->cancel = 0;
+  __spin_unlock (&ss->lock);
+
+  return cancel;
+}