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. --- pflocal/connq.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) (limited to 'pflocal/connq.c') diff --git a/pflocal/connq.c b/pflocal/connq.c index ab2b3a55..d88711e3 100644 --- a/pflocal/connq.c +++ b/pflocal/connq.c @@ -141,16 +141,19 @@ connq_destroy (struct connq *cq) /* ---------------------------------------------------------------- */ /* Return a connection request on CQ. If SOCK is NULL, the request is - left in the queue. If NOBLOCK is true, EWOULDBLOCK is returned - when there are no immediate connections available. */ + left in the queue. If TIMEOUT denotes a value of 0, EWOULDBLOCK is + returned when there are no immediate connections available. + Otherwise this value is used to limit the wait duration. If TIMEOUT + is NULL, the wait duration isn't bounded. */ error_t -connq_listen (struct connq *cq, int noblock, struct sock **sock) +connq_listen (struct connq *cq, struct timespec *tsp, struct sock **sock) { error_t err = 0; pthread_mutex_lock (&cq->lock); - if (noblock && cq->count == 0 && cq->num_connectors == 0) + if (tsp && tsp->tv_sec == 0 && tsp->tv_nsec == 0 && cq->count == 0 + && cq->num_connectors == 0) { pthread_mutex_unlock (&cq->lock); return EWOULDBLOCK; @@ -176,12 +179,14 @@ connq_listen (struct connq *cq, int noblock, struct sock **sock) pthread_cond_signal (&cq->connectors); do - if (pthread_hurd_cond_wait_np (&cq->listeners, &cq->lock)) + { + err = pthread_hurd_cond_timedwait_np (&cq->listeners, &cq->lock, tsp); + if (err) { cq->num_listeners--; - err = EINTR; goto out; } + } while (cq->count == 0); } -- cgit v1.2.3