Add io_select_timeout to the io interface

This change fixes a problem that can occur with non-blocking (and also
blocking for very short times) select/poll calls. The problem occurs because
the timeout is implemented at the client side. For a non-blocking call, this
means that (depending on the code path taken in the C library) the client
could get a timeout without a full RPC round-trip to the server. Moving the
implementation of the timeout to the servers guarantees a full round-trip,
and correct results for non-blocking calls.

The modifications in this change depend on the availability of the recently
added pthread_hurd_cond_timedwait_np function in libpthread.

* boot/boot.c (io_select_common): New static function.
(S_io_select): Use io_select_common.
(S_io_select_timeout): New function which makes use of io_select_common.
* console-client/kbd-repeat.c (repeater_select): Add a timeout parameter.
* console-client/pc-mouse.c (repeater_select): Likewise.
* console-client/trans.c (io_select_common): New static function.
(netfs_S_io_select): Use io_select_common.
(netfs_S_io_select_timeout): New function which makes use of io_select_common.
* console-client/trans.h (struct consnode): Add a timeout parameter.
* hurd/io.defs (io_select_timeout): New MIG routine.
* hurd/io_reply.defs (io_select_timeout_reply): New MIG simpleroutine.
* hurd/io_request.defs (io_select_timeout_request): Likewise.
* libdiskfs/io-select.c (diskfs_S_io_select_timeout): New function.
* libnetfs/io-select.c (netfs_S_io_select_timeout): Likewise.
* libpipe/pipe.c (pipe_pair_select): Add a timeout parameter.
* libpipe/pipe.h (pipe_select_readable): Likewise.
(pipe_select_writable): Likewise.
(pipe_pair_select): Likewise.
* libpipe/pq.h: Include <hurd/hurd_types.h>.
* libtrivfs/io-select.c (trivfs_S_io_select_timeout): New function.
* pfinet/glue-include/linux/sched.h: Include <errno.h>.
(interruptible_sleep_on): Function removed, replaced with ...
(interruptible_sleep_on_timeout): New function.
(schedule): Update to use interruptible_sleep_on_timeout.
(schedule_timeout): Likewise.
* pfinet/io-ops.c (io_select_common): New static function.
(S_io_select): Use io_select_common.
(S_io_select_timeout): New function which makes use of io_select_common.
* pfinet/tunnel.c (io_select_common): New static function.
(trivfs_S_io_select): Use io_select_common.
(trivfs_S_io_select_timeout): New function which makes use of io_select_common.
* pflocal/connq.c (connq_listen): Replace noblock with a timeout parameter.
* pflocal/connq.h: Include <hurd/hurd_types.h>.
(connq_listen): Update declaration to replace noblock with a timeout parameter.
* pflocal/io.c (io_select_common): New static function.
(S_io_select): Use io_select_common.
(S_io_select_timeout): New function which makes use of io_select_common.
* pflocal/socket.c (S_socket_accept): Update call to connq_listen to match new
declaration.
* storeio/io.c (trivfs_S_io_select_timeout): New function.
* term/ptyio.c (pty_io_select): Add a timeout parameter.
* term/term.h (pty_io_select): Likewise.
* term/users.c (io_select_common): New static function.
(trivfs_S_io_select): Use io_select_common.
(trivfs_S_io_select_timeout): New function which makes use of io_select_common.
* trans/fifo.c (io_select_common): New static function.
(trivfs_S_io_select): Use io_select_common.
(trivfs_S_io_select_timeout): New function which makes use of io_select_common.
* trans/firmlink.c (trivfs_S_io_select_timeout): New function.
* trans/new-fifo.c (io_select_common): New static function.
(trivfs_S_io_select): Use io_select_common.
(trivfs_S_io_select_timeout): New function which makes use of io_select_common.
* trans/null.c (trivfs_S_io_select_timeout): New function.
* trans/streamio.c (io_select_common): New static function.
(trivfs_S_io_select): Use io_select_common.
(trivfs_S_io_select_timeout): New function which makes use of io_select_common.

3 files changed, 22 insertions, 0 deletions

diff --git a/hurd/io.defs b/hurd/io.defs
index 9119b05b..ba0b8077 100644
--- a/hurd/io.defs
+++ b/hurd/io.defs
@@ -320,3 +320,14 @@ routine io_identity (
    on the specified object.  */
 routine io_revoke (
 	io_object: io_t RPTLAST);
+
+/* INTR */
+routine io_select_timeout (
+	io_object: io_t;
+#if defined (REPLY_PORTS) || defined (IO_SELECT_REPLY_PORT)
+	replyport reply: sreply_port_t;
+#else
+	ureplyport reply: mach_port_make_send_t;
+#endif
+	timeout: timespec_t;
+	inout select_type: int);
diff --git a/hurd/io_reply.defs b/hurd/io_reply.defs
index ffc4e752..eee68244 100644
--- a/hurd/io_reply.defs
+++ b/hurd/io_reply.defs
@@ -175,3 +175,8 @@ simpleroutine io_identity_reply (
 simpleroutine io_revoke_reply (
 	reply: reply_port_t;
 	RETURN_CODE_ARG);
+
+simpleroutine io_select_timeout_reply (
+	reply: reply_port_t;
+	RETURN_CODE_ARG;
+	select_result: int);
diff --git a/hurd/io_request.defs b/hurd/io_request.defs
index a3e775aa..0d5e36dd 100644
--- a/hurd/io_request.defs
+++ b/hurd/io_request.defs
@@ -172,3 +172,9 @@ simpleroutine io_identity_request (
 simpleroutine io_revoke_request (
 		io_object: io_t;
 		reply: reply_port_t);
+
+simpleroutine io_select_timeout_request (
+		io_object: io_t;
+		ureplyport reply: mach_port_make_send_t;
+		timeout: timespec_t;
+		select_type: int);