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. --- libpipe/pipe.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) (limited to 'libpipe/pipe.c') diff --git a/libpipe/pipe.c b/libpipe/pipe.c index dd306f60..1ddaf126 100644 --- a/libpipe/pipe.c +++ b/libpipe/pipe.c @@ -209,7 +209,7 @@ void _pipe_no_writers (struct pipe *pipe) this function (unlike most pipe functions). */ error_t pipe_pair_select (struct pipe *rpipe, struct pipe *wpipe, - int *select_type, int data_only) + struct timespec *tsp, int *select_type, int data_only) { error_t err = 0; @@ -218,13 +218,13 @@ pipe_pair_select (struct pipe *rpipe, struct pipe *wpipe, if (*select_type == SELECT_READ) { pthread_mutex_lock (&rpipe->lock); - err = pipe_select_readable (rpipe, data_only); + err = pipe_select_readable (rpipe, tsp, data_only); pthread_mutex_unlock (&rpipe->lock); } else if (*select_type == SELECT_WRITE) { pthread_mutex_lock (&wpipe->lock); - err = pipe_select_writable (wpipe); + err = pipe_select_writable (wpipe, tsp); pthread_mutex_unlock (&wpipe->lock); } else @@ -260,8 +260,8 @@ pipe_pair_select (struct pipe *rpipe, struct pipe *wpipe, pthread_mutex_unlock (&rpipe->lock); pthread_mutex_unlock (&wpipe->lock); } - if (pthread_hurd_cond_wait_np (&pending_select.cond, lock)) - err = EINTR; + err = pthread_hurd_cond_timedwait_np (&pending_select.cond, lock, + tsp); if (rpipe != wpipe) { pthread_mutex_lock (&rpipe->lock); @@ -295,6 +295,12 @@ pipe_pair_select (struct pipe *rpipe, struct pipe *wpipe, pthread_mutex_unlock (lock); } + if (err == ETIMEDOUT) + { + err = 0; + *select_type = 0; + } + return err; } -- cgit v1.2.3