Access to the thread's flags and state is protected by
_thread_critical_enter/exit(). When a thread is signaled with a condition
its state must be protected by locking it and disabling
signals before it is taken of the waiters' queue.
Move the implementation of pthread_cond_signal() and pthread_cond_broadcast()
into one function, cond_signal(). Its behaviour is determined by the
last argument, int broadcast. If this is set to 1 it will remove all
waiters, otherwise it will wake up only the first waiter thread.
Remove an extraneous call to pthread_testcancel().
Approved by: re/blanket libthr
that take the address of a struct pthread as their first argument.
_spin[un]lock() just become wrappers arround these two functions.
These new functions are for use in situations where curthread can't be
used. One example is _thread_retire(), where we invalidate the array index
curthread uses to get its pointer..
Approved by: re/blanket libthr
Prevent one thread from messing up another thread's saved signal
mask by saving it in struct pthread instead of leaving it as a
global variable. D'oh!
Approved by: re/blanket libthr
in thr_private.h
o Lock down the ldt_entries array and ldt_free, which points to
the next free slot. As noted in the comments, it's necessary
to special case the initial_thread because %gs is not setup
for it yet. This is ok because that early in the program there
won't be any reentrancy issues anyways.
Approved by: re/blanket libthr
When in either the mutex or cond queue we notice that the thread
is already on one of the queues, don't just simply abort(). Print
out the thread's identifiers and what queue it was on.
Approved by: markm/mentor, re/blanket libthr
is the *only* remaining thread in the application, in which case we
should not core dump, and instead exit gracefully.
Approved by: markm/mentor, re/blanket libthr
of pthread_cond_timedwait() is moved into cond_wait_common().
Pthread_cond_wait() and pthread_cond_timedwait() are now wrappers around
this function. Previously, the former called the latter with the abstime
pointing to 0 time. This violated Posix semantics should an application
have reason to call it with that argument because instead or returning
immediately it would have waited indefinitely for the cv to be signaled.
Approved by: markm/mentor, re/blanket libthr
Reviewed by: jeff
respect to other threads and signal handlers by moving to
the _thread_critical_enter/exit functions.
o Introduce an static function, testcancel(), that is used by
the other functions in this module. This allows it to make
locking assumptions that the top-level functions can't.
o Rework the code flow a bit to reduce indentation levels.
Approved by: markm/mentor, re/blanket libthr
Reviewed by: jeff
Note that the tp register (r13) is reserved as the TLS pointer in
the same way that that gp register (r1) is reserved as the global
pointer. This implementation uses the tp register to point to the
thread structure used by the threads implementation. This is not
in violation with the runtime specification provided the TLS is
a fixed distance from the thread structure. This is only an issue
when code used the __thread keyword to create TLS. This is not
supported at the moment.
libthr. No changes were made to libpthread by request of deischen,
who will soon commit a real implementation for that library.
PR: standards/50848
Submitted by: Sergey A. Osokin <osa@freebsd.org.ru>
MFC after: 1 week
as curthread in the new context, so that it will be set automatically when
the thread is switched to. This fixes a race where we'd run for a little
while with curthread unset in _thread_start.
Reviewed by: jeff
_get_curthread(). This is similar to the kernel's curthread. Doing
this saves stack overhead and is more convenient to the programmer.
- Pass the pointer to the newly created thread to _thread_init().
- Remove _get_curthread_slow().
This was changed because originally we were blocking on the umtx and
allowing the kernel to do the queueing. It was decided that the
lib should queue and start the threads in the order it decides and the
umtx code would just be used like spinlocks.
