diff options
Diffstat (limited to 'lib/libkse/thread/thr_join.c')
-rw-r--r-- | lib/libkse/thread/thr_join.c | 160 |
1 files changed, 65 insertions, 95 deletions
diff --git a/lib/libkse/thread/thr_join.c b/lib/libkse/thread/thr_join.c index c2e7cec..38cc8b3 100644 --- a/lib/libkse/thread/thr_join.c +++ b/lib/libkse/thread/thr_join.c @@ -41,121 +41,91 @@ int _pthread_join(pthread_t pthread, void **thread_return) { struct pthread *curthread = _get_curthread(); - int ret = 0; - pthread_t thread; + int ret = 0; - _thread_enter_cancellation_point(); + _thr_enter_cancellation_point(curthread); /* Check if the caller has specified an invalid thread: */ - if (pthread == NULL || pthread->magic != PTHREAD_MAGIC) { + if (pthread == NULL || pthread->magic != THR_MAGIC) { /* Invalid thread: */ - _thread_leave_cancellation_point(); - return(EINVAL); + _thr_leave_cancellation_point(curthread); + return (EINVAL); } /* Check if the caller has specified itself: */ if (pthread == curthread) { /* Avoid a deadlock condition: */ - _thread_leave_cancellation_point(); - return(EDEADLK); + _thr_leave_cancellation_point(curthread); + return (EDEADLK); } /* - * Lock the garbage collector mutex to ensure that the garbage - * collector is not using the dead thread list. + * Find the thread in the list of active threads or in the + * list of dead threads: */ - if (pthread_mutex_lock(&_gc_mutex) != 0) - PANIC("Cannot lock gc mutex"); - - /* - * Defer signals to protect the thread list from access - * by the signal handler: - */ - _thread_kern_sig_defer(); - - /* - * Unlock the garbage collector mutex, now that the garbage collector - * can't be run: - */ - if (pthread_mutex_unlock(&_gc_mutex) != 0) - PANIC("Cannot lock gc mutex"); - - /* - * Search for the specified thread in the list of active threads. This - * is done manually here rather than calling _find_thread() because - * the searches in _thread_list and _dead_list (as well as setting up - * join/detach state) have to be done atomically. - */ - TAILQ_FOREACH(thread, &_thread_list, tle) { - if (thread == pthread) - break; - } - if (thread == NULL) { - /* - * Search for the specified thread in the list of dead threads: - */ - TAILQ_FOREACH(thread, &_dead_list, dle) { - if (thread == pthread) - break; - } + if ((ret = _thr_ref_add(curthread, pthread, /*include dead*/1)) != 0) { + /* Return an error: */ + _thr_leave_cancellation_point(curthread); + return (ESRCH); } - /* Check if the thread was not found or has been detached: */ - if (thread == NULL || - ((pthread->attr.flags & PTHREAD_DETACHED) != 0)) { - /* Undefer and handle pending signals, yielding if necessary: */ - _thread_kern_sig_undefer(); - - /* Return an error: */ + /* Check if this thread has been detached: */ + if ((pthread->attr.flags & PTHREAD_DETACHED) != 0) { + /* Remove the reference and return an error: */ + _thr_ref_delete(curthread, pthread); ret = ESRCH; - - } else if (pthread->joiner != NULL) { - /* Undefer and handle pending signals, yielding if necessary: */ - _thread_kern_sig_undefer(); - - /* Multiple joiners are not supported. */ - ret = ENOTSUP; - - /* Check if the thread is not dead: */ - } else if (pthread->state != PS_DEAD) { - /* Set the running thread to be the joiner: */ - pthread->joiner = curthread; - - /* Keep track of which thread we're joining to: */ - curthread->join_status.thread = pthread; - - while (curthread->join_status.thread == pthread) { - /* Schedule the next thread: */ - _thread_kern_sched_state(PS_JOIN, __FILE__, __LINE__); - } - - /* - * The thread return value and error are set by the thread we're - * joining to when it exits or detaches: - */ - ret = curthread->join_status.error; - if ((ret == 0) && (thread_return != NULL)) - *thread_return = curthread->join_status.ret; } else { - /* - * The thread exited (is dead) without being detached, and no - * thread has joined it. - */ - - /* Check if the return value is required: */ - if (thread_return != NULL) { - /* Return the thread's return value: */ - *thread_return = pthread->ret; + /* Lock the target thread while checking its state. */ + THR_SCHED_LOCK(curthread, pthread); + if ((pthread->state == PS_DEAD) || + ((pthread->flags & THR_FLAGS_EXITING) != 0)) { + if (thread_return != NULL) + /* Return the thread's return value: */ + *thread_return = pthread->ret; + + /* Unlock the thread and remove the reference. */ + THR_SCHED_UNLOCK(curthread, pthread); + _thr_ref_delete(curthread, pthread); } + else if (pthread->joiner != NULL) { + /* Unlock the thread and remove the reference. */ + THR_SCHED_UNLOCK(curthread, pthread); + _thr_ref_delete(curthread, pthread); - /* Make the thread collectable by the garbage collector. */ - pthread->attr.flags |= PTHREAD_DETACHED; - - /* Undefer and handle pending signals, yielding if necessary: */ - _thread_kern_sig_undefer(); + /* Multiple joiners are not supported. */ + ret = ENOTSUP; + } + else { + /* Set the running thread to be the joiner: */ + pthread->joiner = curthread; + + /* Keep track of which thread we're joining to: */ + curthread->join_status.thread = pthread; + + /* Unlock the thread and remove the reference. */ + THR_SCHED_UNLOCK(curthread, pthread); + _thr_ref_delete(curthread, pthread); + + THR_SCHED_LOCK(curthread, curthread); + if (curthread->join_status.thread == pthread) + THR_SET_STATE(curthread, PS_JOIN); + THR_SCHED_UNLOCK(curthread, curthread); + + while (curthread->join_status.thread == pthread) { + /* Schedule the next thread: */ + _thr_sched_switch(curthread); + } + + /* + * The thread return value and error are set by the + * thread we're joining to when it exits or detaches: + */ + ret = curthread->join_status.error; + if ((ret == 0) && (thread_return != NULL)) + *thread_return = curthread->join_status.ret; + } } - - _thread_leave_cancellation_point(); + _thr_leave_cancellation_point(curthread); /* Return the completion status: */ return (ret); |