static void
thread_start(void *arg)
{
struct pthread *curthread = (struct pthread *)arg;
tls_set_tcb(curthread->tcb);
/* Thread was created with all signals blocked, unblock them. */
__sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL);
THR_LOCK(curthread);
THR_UNLOCK(curthread);
if (curthread->flags & THR_FLAGS_NEED_SUSPEND)
_thr_suspend_check(curthread);
_nmalloc_thr_init();
/* Run the current thread's start routine with argument: */
_pthread_exit(curthread->start_routine(curthread->arg));
/* This point should never be reached. */
PANIC("Thread has resumed after exit");
}
/*
* Threaded process initialization.
*
* This is only called under two conditions:
*
* 1) Some thread routines have detected that the library hasn't yet
* been initialized (_thr_initial == NULL && curthread == NULL), or
*
* 2) An explicit call to reinitialize after a fork (indicated
* by curthread != NULL)
*/
void
_libpthread_init(struct pthread *curthread)
{
int fd, first = 0;
sigset_t sigset, oldset;
/* Check if this function has already been called: */
if ((_thr_initial != NULL) && (curthread == NULL))
/* Only initialize the threaded application once. */
return;
/*
* Check for the special case of this process running as
* or in place of init as pid = 1:
*/
if ((_thr_pid = getpid()) == 1) {
/*
* Setup a new session for this process which is
* assumed to be running as root.
*/
if (setsid() == -1)
PANIC("Can't set session ID");
if (revoke(_PATH_CONSOLE) != 0)
PANIC("Can't revoke console");
if ((fd = __sys_open(_PATH_CONSOLE, O_RDWR)) < 0)
PANIC("Can't open console");
if (setlogin("root") == -1)
PANIC("Can't set login to root");
if (__sys_ioctl(fd, TIOCSCTTY, NULL) == -1)
PANIC("Can't set controlling terminal");
}
/* Initialize pthread private data. */
init_private();
/* Set the initial thread. */
if (curthread == NULL) {
first = 1;
/* Create and initialize the initial thread. */
curthread = _thr_alloc(NULL);
if (curthread == NULL)
PANIC("Can't allocate initial thread");
init_main_thread(curthread);
}
/*
* Add the thread to the thread list queue.
*/
THR_LIST_ADD(curthread);
_thread_active_threads = 1;
/* Setup the thread specific data */
tls_set_tcb(curthread->tcb);
if (first) {
SIGFILLSET(sigset);
__sys_sigprocmask(SIG_SETMASK, &sigset, &oldset);
_thr_signal_init();
_thr_initial = curthread;
SIGDELSET(oldset, SIGCANCEL);
__sys_sigprocmask(SIG_SETMASK, &oldset, NULL);
if (td_eventismember(&_thread_event_mask, TD_CREATE))
_thr_report_creation(curthread, curthread);
}
}
static inline int
mutex_unlock_common(pthread_mutex_t * mutex, int add_reference)
{
struct pthread *curthread = _get_curthread();
int ret = 0;
if (mutex == NULL || *mutex == NULL) {
ret = EINVAL;
} else {
/*
* Defer signals to protect the scheduling queues from
* access by the signal handler:
*/
_thread_kern_sig_defer();
/* Lock the mutex structure: */
_SPINLOCK(&(*mutex)->lock);
/* Process according to mutex type: */
switch ((*mutex)->m_protocol) {
/* Default POSIX mutex: */
case PTHREAD_PRIO_NONE:
/*
* Check if the running thread is not the owner of the
* mutex:
*/
if ((*mutex)->m_owner != curthread) {
/*
* Return an invalid argument error for no
* owner and a permission error otherwise:
*/
ret = (*mutex)->m_owner == NULL ? EINVAL : EPERM;
}
else if (((*mutex)->m_type == PTHREAD_MUTEX_RECURSIVE) &&
((*mutex)->m_data.m_count > 0)) {
/* Decrement the count: */
(*mutex)->m_data.m_count--;
} else {
/*
* Clear the count in case this is recursive
* mutex.
*/
(*mutex)->m_data.m_count = 0;
/* Remove the mutex from the threads queue. */
_MUTEX_ASSERT_IS_OWNED(*mutex);
TAILQ_REMOVE(&(*mutex)->m_owner->mutexq,
(*mutex), m_qe);
_MUTEX_INIT_LINK(*mutex);
/*
* Get the next thread from the queue of
* threads waiting on the mutex:
*/
if (((*mutex)->m_owner =
mutex_queue_deq(*mutex)) != NULL) {
/* Make the new owner runnable: */
PTHREAD_NEW_STATE((*mutex)->m_owner,
PS_RUNNING);
/*
* Add the mutex to the threads list of
* owned mutexes:
*/
TAILQ_INSERT_TAIL(&(*mutex)->m_owner->mutexq,
(*mutex), m_qe);
/*
* The owner is no longer waiting for
* this mutex:
*/
(*mutex)->m_owner->data.mutex = NULL;
}
}
break;
/* POSIX priority inheritence mutex: */
case PTHREAD_PRIO_INHERIT:
/*
* Check if the running thread is not the owner of the
* mutex:
*/
if ((*mutex)->m_owner != curthread) {
/*
* Return an invalid argument error for no
* owner and a permission error otherwise:
*/
ret = (*mutex)->m_owner == NULL ? EINVAL : EPERM;
}
else if (((*mutex)->m_type == PTHREAD_MUTEX_RECURSIVE) &&
((*mutex)->m_data.m_count > 0)) {
/* Decrement the count: */
(*mutex)->m_data.m_count--;
} else {
/*
* Clear the count in case this is recursive
* mutex.
*/
(*mutex)->m_data.m_count = 0;
/*
* Restore the threads inherited priority and
* recompute the active priority (being careful
* not to override changes in the threads base
* priority subsequent to locking the mutex).
*/
curthread->inherited_priority =
(*mutex)->m_saved_prio;
curthread->active_priority =
MAX(curthread->inherited_priority,
curthread->base_priority);
/*
* This thread now owns one less priority mutex.
*/
curthread->priority_mutex_count--;
/* Remove the mutex from the threads queue. */
_MUTEX_ASSERT_IS_OWNED(*mutex);
TAILQ_REMOVE(&(*mutex)->m_owner->mutexq,
(*mutex), m_qe);
_MUTEX_INIT_LINK(*mutex);
/*
* Get the next thread from the queue of threads
* waiting on the mutex:
*/
if (((*mutex)->m_owner =
mutex_queue_deq(*mutex)) == NULL)
/* This mutex has no priority. */
(*mutex)->m_prio = 0;
else {
/*
* Track number of priority mutexes owned:
*/
(*mutex)->m_owner->priority_mutex_count++;
/*
* Add the mutex to the threads list
* of owned mutexes:
*/
TAILQ_INSERT_TAIL(&(*mutex)->m_owner->mutexq,
(*mutex), m_qe);
/*
* The owner is no longer waiting for
* this mutex:
*/
(*mutex)->m_owner->data.mutex = NULL;
/*
* Set the priority of the mutex. Since
* our waiting threads are in descending
* priority order, the priority of the
* mutex becomes the active priority of
* the thread we just dequeued.
*/
(*mutex)->m_prio =
(*mutex)->m_owner->active_priority;
/*
* Save the owning threads inherited
* priority:
*/
(*mutex)->m_saved_prio =
(*mutex)->m_owner->inherited_priority;
/*
* The owning threads inherited priority
* now becomes his active priority (the
* priority of the mutex).
*/
(*mutex)->m_owner->inherited_priority =
(*mutex)->m_prio;
/*
* Make the new owner runnable:
*/
PTHREAD_NEW_STATE((*mutex)->m_owner,
PS_RUNNING);
}
}
break;
/* POSIX priority ceiling mutex: */
case PTHREAD_PRIO_PROTECT:
/*
* Check if the running thread is not the owner of the
* mutex:
*/
if ((*mutex)->m_owner != curthread) {
/*
* Return an invalid argument error for no
* owner and a permission error otherwise:
*/
ret = (*mutex)->m_owner == NULL ? EINVAL : EPERM;
}
else if (((*mutex)->m_type == PTHREAD_MUTEX_RECURSIVE) &&
((*mutex)->m_data.m_count > 0)) {
/* Decrement the count: */
(*mutex)->m_data.m_count--;
} else {
/*
* Clear the count in case this is recursive
* mutex.
*/
(*mutex)->m_data.m_count = 0;
/*
* Restore the threads inherited priority and
* recompute the active priority (being careful
* not to override changes in the threads base
* priority subsequent to locking the mutex).
*/
curthread->inherited_priority =
(*mutex)->m_saved_prio;
curthread->active_priority =
MAX(curthread->inherited_priority,
curthread->base_priority);
/*
* This thread now owns one less priority mutex.
*/
curthread->priority_mutex_count--;
/* Remove the mutex from the threads queue. */
_MUTEX_ASSERT_IS_OWNED(*mutex);
TAILQ_REMOVE(&(*mutex)->m_owner->mutexq,
(*mutex), m_qe);
_MUTEX_INIT_LINK(*mutex);
/*
* Enter a loop to find a waiting thread whose
* active priority will not cause a ceiling
* violation:
*/
while ((((*mutex)->m_owner =
mutex_queue_deq(*mutex)) != NULL) &&
((*mutex)->m_owner->active_priority >
(*mutex)->m_prio)) {
/*
* Either the mutex ceiling priority
* been lowered and/or this threads
* priority has been raised subsequent
* to this thread being queued on the
* waiting list.
*/
tls_set_tcb((*mutex)->m_owner->tcb);
errno = EINVAL;
tls_set_tcb(curthread->tcb);
PTHREAD_NEW_STATE((*mutex)->m_owner,
PS_RUNNING);
/*
* The thread is no longer waiting for
* this mutex:
*/
(*mutex)->m_owner->data.mutex = NULL;
}
/* Check for a new owner: */
if ((*mutex)->m_owner != NULL) {
/*
* Track number of priority mutexes owned:
*/
(*mutex)->m_owner->priority_mutex_count++;
/*
* Add the mutex to the threads list
* of owned mutexes:
*/
TAILQ_INSERT_TAIL(&(*mutex)->m_owner->mutexq,
(*mutex), m_qe);
/*
* The owner is no longer waiting for
* this mutex:
*/
(*mutex)->m_owner->data.mutex = NULL;
/*
* Save the owning threads inherited
* priority:
*/
(*mutex)->m_saved_prio =
(*mutex)->m_owner->inherited_priority;
/*
* The owning thread inherits the
* ceiling priority of the mutex and
* executes at that priority:
*/
(*mutex)->m_owner->inherited_priority =
(*mutex)->m_prio;
(*mutex)->m_owner->active_priority =
(*mutex)->m_prio;
/*
* Make the new owner runnable:
*/
PTHREAD_NEW_STATE((*mutex)->m_owner,
PS_RUNNING);
}
}
break;
/* Trap invalid mutex types: */
default:
/* Return an invalid argument error: */
ret = EINVAL;
break;
}
if ((ret == 0) && (add_reference != 0)) {
/* Increment the reference count: */
(*mutex)->m_refcount++;
}
/* Unlock the mutex structure: */
_SPINUNLOCK(&(*mutex)->lock);
/*
* Undefer and handle pending signals, yielding if
* necessary:
*/
_thread_kern_sig_undefer();
}
/* Return the completion status: */
return (ret);
}
