From 8cd75c4d6b229bb4e3de9264466731e3a32e0133 Mon Sep 17 00:00:00 2001 From: Richard Braun Date: Tue, 26 Feb 2013 22:24:47 +0100 Subject: 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 . * libtrivfs/io-select.c (trivfs_S_io_select_timeout): New function. * pfinet/glue-include/linux/sched.h: Include . (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 . (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. --- term/users.c | 43 +++++++++++++++++++++++++++++++++++-------- 1 file changed, 35 insertions(+), 8 deletions(-) (limited to 'term/users.c') diff --git a/term/users.c b/term/users.c index 9fc1dc23..529693e8 100644 --- a/term/users.c +++ b/term/users.c @@ -2002,17 +2002,17 @@ trivfs_S_io_async (struct trivfs_protid *cred, return 0; } -error_t -trivfs_S_io_select (struct trivfs_protid *cred, - mach_port_t reply, - mach_msg_type_name_t reply_type, - int *type) +static error_t +io_select_common (struct trivfs_protid *cred, + mach_port_t reply, + mach_msg_type_name_t reply_type, + struct timespec *tsp, int *type) { if (!cred) return EOPNOTSUPP; if (cred->pi.class == pty_class) - return pty_io_select (cred, reply, type); + return pty_io_select (cred, reply, tsp, type); if ((cred->po->openmodes & O_READ) == 0) *type &= ~SELECT_READ; @@ -2024,6 +2024,8 @@ trivfs_S_io_select (struct trivfs_protid *cred, while (1) { int available = 0; + error_t err = 0; + if ((*type & SELECT_READ) && qsize (inputq)) available |= SELECT_READ; if ((*type & SELECT_WRITE) && qavail (outputq)) @@ -2032,16 +2034,41 @@ trivfs_S_io_select (struct trivfs_protid *cred, if (available == 0) { ports_interrupt_self_on_port_death (cred, reply); - if (pthread_hurd_cond_wait_np (&select_alert, &global_lock) == 0) + err = pthread_hurd_cond_timedwait_np (&select_alert, &global_lock, + tsp); + if (!err) continue; } *type = available; pthread_mutex_unlock (&global_lock); - return available ? 0 : EINTR; + + if (err == ETIMEDOUT) + err = 0; + + return err; } } +error_t +trivfs_S_io_select (struct trivfs_protid *cred, + mach_port_t reply, + mach_msg_type_name_t reply_type, + int *type) +{ + return io_select_common (cred, reply, reply_type, NULL, type); +} + +error_t +trivfs_S_io_select_timeout (struct trivfs_protid *cred, + mach_port_t reply, + mach_msg_type_name_t reply_type, + struct timespec ts, + int *type) +{ + return io_select_common (cred, reply, reply_type, &ts, type); +} + kern_return_t trivfs_S_io_map (struct trivfs_protid *cred, mach_port_t reply, -- cgit v1.2.3