* gdb_usleep.h, gdb_usleep.c: New files.

* Makefile.in (SFILES): Add gdb_usleep.c.
            (HFILES_NO_SRCDIR): Add gdb_usleep.h.
            (COMMON_OBS): Add gdb_usleep.o.
            * ser-unix.c (hardwire_send_break): Replace call to gdb_select
            by call to gdb_usleep.

gdb/gdb_usleep.h

@@ -0,0 +1,30 @@
+/* Copyright (C) 2009 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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 3 of the License, 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, see <http://www.gnu.org/licenses/>.  */
+
+#if !defined(GDB_USLEEP_H)
+#define GDB_USLEEP_H
+
+/* Suspend execution for USEC microseconds.
+
+   Limitation: If a signal is raised during the delay, gdb_usleep
+   might return earlier than requested.
+
+   It returns 0 on success or -1 on error.  */
+extern int gdb_usleep (int usect);
+
+#endif /* !defined(GDB_USLEEP_H) */
+