diff options
| author | Andrew Morton <akpm@osdl.org> | 2004-04-11 22:54:29 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2004-04-11 22:54:29 -0700 |
| commit | 0301b50bb63dd4149019b1fdb5fc7b168c6c12f7 (patch) | |
| tree | 54de4334388427c0f11adfa615d0eb91c20e7363 /ipc | |
| parent | be94d44e818a56406016111fc48a1084b9f8e435 (diff) | |
| download | history-0301b50bb63dd4149019b1fdb5fc7b168c6c12f7.tar.gz | |
[PATCH] posix message queues: linux-specific poll extension
From: Manfred Spraul <manfred@colorfullife.com>
Linux specific extension: make the message queue identifiers pollable. It's
simple and could be useful.
Diffstat (limited to 'ipc')
| -rw-r--r-- | ipc/mqueue.c | 27 |
1 files changed, 24 insertions, 3 deletions
diff --git a/ipc/mqueue.c b/ipc/mqueue.c index 4de24971867580..4755a6040e3249 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -251,6 +251,24 @@ static int mqueue_flush_file(struct file *filp) return 0; } +static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab) +{ + struct mqueue_inode_info *info = MQUEUE_I(filp->f_dentry->d_inode); + int retval = 0; + + poll_wait(filp, &info->wait_q, poll_tab); + + spin_lock(&info->lock); + if (info->attr.mq_curmsgs) + retval = POLLIN | POLLRDNORM; + + if (info->attr.mq_curmsgs < info->attr.mq_maxmsg) + retval |= POLLOUT | POLLWRNORM; + spin_unlock(&info->lock); + + return retval; +} + /* Adds current to info->e_wait_q[sr] before element with smaller prio */ static void wq_add(struct mqueue_inode_info *info, int sr, struct ext_wait_queue *ewp) @@ -376,11 +394,11 @@ static void __do_notify(struct mqueue_inode_info *info) &sig_i, info->notify_owner); } else if (info->notify.sigev_notify == SIGEV_THREAD) { info->notify_filp->private_data = (void*)NP_WOKENUP; - wake_up(&info->wait_q); } /* after notification unregisters process */ info->notify_owner = 0; } + wake_up(&info->wait_q); } static long prepare_timeout(const struct timespec __user *u_arg) @@ -712,9 +730,11 @@ static inline void pipelined_receive(struct mqueue_inode_info *info) { struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND); - if (!sender) + if (!sender) { + /* for poll */ + wake_up_interruptible(&info->wait_q); return; - + } msg_insert(sender->msg, info); list_del(&sender->list); sender->state = STATE_PENDING; @@ -1039,6 +1059,7 @@ static struct inode_operations mqueue_dir_inode_operations = { static struct file_operations mqueue_file_operations = { .flush = mqueue_flush_file, + .poll = mqueue_poll_file, }; static struct file_operations mqueue_notify_fops = { |