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. --- pfinet/glue-include/linux/sched.h | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) (limited to 'pfinet/glue-include') diff --git a/pfinet/glue-include/linux/sched.h b/pfinet/glue-include/linux/sched.h index aea6c47a..26ab10a8 100644 --- a/pfinet/glue-include/linux/sched.h +++ b/pfinet/glue-include/linux/sched.h @@ -8,6 +8,7 @@ #include #include #include +#include #include "mapped-time.h" @@ -92,12 +93,13 @@ capable(int cap) extern pthread_mutex_t global_lock; -static inline void -interruptible_sleep_on (struct wait_queue **p) +static inline int +interruptible_sleep_on_timeout (struct wait_queue **p, struct timespec *tsp) { pthread_cond_t **condp = (void *) p, *c; int isroot; struct wait_queue **next_wait; + error_t err; c = *condp; if (c == 0) @@ -111,12 +113,13 @@ interruptible_sleep_on (struct wait_queue **p) isroot = current->isroot; /* This is our context that needs switched. */ next_wait = current->next_wait; /* This too, for multiple schedule calls. */ current->next_wait = 0; - if (pthread_hurd_cond_wait_np (c, &global_lock)) + err = pthread_hurd_cond_timedwait_np(c, &global_lock, tsp); + if (err == EINTR) current->signal = 1; /* We got cancelled, mark it for later. */ current->isroot = isroot; /* Switch back to our context. */ current->next_wait = next_wait; + return (err == ETIMEDOUT); } -#define sleep_on interruptible_sleep_on static inline void wake_up_interruptible (struct wait_queue **p) @@ -146,7 +149,7 @@ static inline void schedule (void) { assert (current->next_wait); - interruptible_sleep_on (current->next_wait); + interruptible_sleep_on_timeout (current->next_wait, NULL); } static inline void @@ -171,7 +174,7 @@ schedule_timeout (long timeout) timer.function = process_schedule_timeout; add_timer (&timer); - interruptible_sleep_on (&sleep); + interruptible_sleep_on_timeout (&sleep, NULL); if (signal_pending (current)) { /* We were canceled. */ -- cgit v1.2.3