poll will return true until the semaphore is blocked again, but before the
semaphore is blocked, poll returns false.
We do this by maintaining another queue of "released" processes in
struct irix_usema_rec. Unblocking causes the waiting process record to be
moved to the released queue, and poll check for the process in this released
queue.
a SIGSEGV when sigaction(2) is used before a fork(2) and a signal is received
in the child.
- we now nearly correctly emulate PR_TERMCHILD in prctl(2). (the perfect
emulation would not send a SIGHUP if the parent is killed)
return the number of processes waiting on the semaphore. We now maintiain
a count of waiting processes.
- Blocked processes are unblocked "first in, first out". We now have a
queue of waiting processes on a asemaphores, so that we can wakeup the
first blocked process.
Problems:
- We now have a lot of dynamic memory allocation, it may be a bit slow.
- Nothing is SMP safe for now. We need to add locks.
- On close, we forget about a semaphore, which is incorrect. One process
can close its fd attached on a semaphore, but other processes would carry
on using it. Since any process can join a shared arena, this is not an
easy thing to solve.
- A lot of usema/usync functionnalities are still to be discovered.
successfully emulates a few test program that use poll semaphores,
including the attach-to-file-descriptor-and-select feature.
There are a few issues:
1) at least one ioctl need to set retval. We handle this in irix_sys_ioctl()
by replacing the data argument by a pointer to a strucutre in the stackgap
that carries the real data and retval. The underlying ioctl methods can
therefore retreive both data and retval.
2) usemaclone is a cloning device: each time it is open, it creates a new
context, and ioctl operation on each open file descriptor will lead to
different behavior. This functionnality is available in NetBSD through the
devvp branch. This first implementation does not use devvp yet, but this
should be done later. Currently, we create a new vnode, and we provide our
own vnode operations. Some operation are applied to the cloned vnode, others
are applied to the original vnode. The v_data field is used to hold a
reference to the original vnode so that we can work on it.
3) at least the setattr vnode operation needs some customisation: IRIX
libc relies on the fact that fchmod on /dev/usema will return 0 in case
of failure.
than current one; this is expected (even documented) behaviour of the
new system call
This fixes the endless loop when reading directories on NFS, though
applications won't see all directory entries due to different problem.
Fix by Matthias Scheler and Charles Hannum.
lst_ino to __lst_ino and lst_ino64 to lst_ino, and define
LINUX_STAT64_HAS_BROKEN_ST_INO. Only assign __lst_ino if this define
is present.
This fixes compile on powerpc archs, and hence port-powerpc/16893.
host:port pair through SO_REUSEADDR even if the address is not a
multicast-address. Effectively, this means that we should use
SO_REUSEPORT when SO_REUSEADDR is set (from the linux process)
to allow Linux applications to not exit with EADDRINUSE.
(Previously erraneously applied to 1.5 branch; approved for
proper location by thorpej)
eeh