* poll.cc: New file. Implement `poll' system call.

* include/poll.h: Ditto.
        * include/sys/poll.h: Ditto.
        * Makefile.in: Add poll.o as dependency.
        * cygwin.din: Add poll and _poll symbols.

winsup/cygwin/include/sys/poll.h

@@ -0,0 +1,43 @@
+/* sys/poll.h
+
+   Copyright 2000 Cygnus Solutions.
+
+   This file is part of Cygwin.
+
+   This software is a copyrighted work licensed under the terms of the
+   Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
+   details. */
+
+#ifndef _SYS_POLL_H
+#define _SYS_POLL_H
+
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+#define POLLIN  1       /* Set if data to read. */
+#define POLLPRI 2       /* Set if urgent data to read. */
+#define POLLOUT 4       /* Set if writing data wouldn't block. */
+#define POLLERR   8     /* An error occured, not used by Cygwin. */
+#define POLLHUP  16     /* Shutdown or close happened. */
+#define POLLNVAL 32     /* Invalid file descriptor. */
+
+#define NPOLLFILE 64    /* Number of canonical fd's in one call to poll(). */
+
+/* The following values are defined by XPG4. */
+#define POLLRDNORM POLLIN
+#define POLLRDBAND POLLPRI
+#define POLLWRNORM POLLOUT
+#define POLLWRBAND POLLOUT
+
+struct pollfd {
+  int fd;
+  short events;
+  short revents;
+};
+
+extern int poll __P ((struct pollfd *fds, unsigned int nfds, int timeout));
+
+__END_DECLS
+
+#endif /* _SYS_POLL_H */