* Reworked the select support:
- The io_context additionally stores a table of lists of select_infos,
which enables it to deselect events of a pending select() when
closing a FD. This prevents a race condition potentially causing a
write to stale memory.
- The opaque selectsync* passed to FSs is now actually a select_info*.
This was necessary, since the FDs deselect() hook (unlike the
select() hook) doesn't take a "ref" argument and deselecting a
single info (e.g. caused by a premature close()) was not possible.
The select() hook's "ref" argument has become superfluous.
- It should now be relatively easy to implement a poll_on_steroids()
that can also wait for objects other than FDs (e.g. semaphores,
ports, threads etc.).
* Set/reset the signal mask in common_select(). This makes pselect()
work as required.
* Reorganized vfs_resize_fd_table().
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22391 a95241bf-73f2-0310-859d-f6bbb57e9c96