int
_sem_post(sem_t *sem)
{
int retval;
_SEM_CHECK_VALIDITY(sem);
/*
* sem_post() is required to be safe to call from within signal
* handlers. Thus, we must defer signals.
*/
_thread_kern_sig_defer();
pthread_mutex_lock(&(*sem)->lock);
(*sem)->count++;
if ((*sem)->nwaiters > 0)
pthread_cond_signal(&(*sem)->gtzero);
pthread_mutex_unlock(&(*sem)->lock);
_thread_kern_sig_undefer();
retval = 0;
RETURN:
return retval;
}
/*
* Validate the signal number and thread. If valid process the signal.
*/
int
pthread_kill(pthread_t pthread, int sig)
{
int ret;
if (sig >= 0 && sig < NSIG) {
ret = _find_thread(pthread);
if (ret == 0 && sig != 0) {
if (_thread_sigact[sig - 1].sa_handler != SIG_IGN) {
_thread_kern_sig_defer();
if (pthread->state == PS_SIGWAIT &&
sigismember(pthread->data.sigwait, sig)) {
PTHREAD_NEW_STATE(pthread,PS_RUNNING);
pthread->signo = sig;
} else {
_thread_kill_siginfo(sig);
_thread_signal(pthread,sig);
}
_thread_kern_sig_undefer();
}
}
} else
ret = EINVAL;
return ret;
}
void
_mutex_lock_backout(pthread_t pthread)
{
struct pthread_mutex *mutex;
/*
* Defer signals to protect the scheduling queues from
* access by the signal handler:
*/
_thread_kern_sig_defer();
if ((pthread->flags & PTHREAD_FLAGS_IN_MUTEXQ) != 0) {
mutex = pthread->data.mutex;
/* Lock the mutex structure: */
_SPINLOCK(&mutex->lock);
mutex_queue_remove(mutex, pthread);
/* This thread is no longer waiting for the mutex: */
pthread->data.mutex = NULL;
/* Unlock the mutex structure: */
_SPINUNLOCK(&mutex->lock);
}
/*
* Undefer and handle pending signals, yielding if
* necessary:
*/
_thread_kern_sig_undefer();
}
int
_pthread_detach(pthread_t pthread)
{
int rval = 0;
/* Check for invalid calling parameters: */
if (pthread == NULL || pthread->magic != PTHREAD_MAGIC)
/* Return an invalid argument error: */
rval = EINVAL;
/* Check if the thread has not been detached: */
else if ((pthread->attr.flags & PTHREAD_DETACHED) == 0) {
/* Flag the thread as detached: */
pthread->attr.flags |= PTHREAD_DETACHED;
/*
* Defer signals to protect the scheduling queues from
* access by the signal handler:
*/
_thread_kern_sig_defer();
/* Check if there is a joiner: */
if (pthread->joiner != NULL) {
struct pthread *joiner = pthread->joiner;
/* Make the thread runnable: */
PTHREAD_NEW_STATE(joiner, PS_RUNNING);
/* Set the return value for the woken thread: */
joiner->join_status.error = ESRCH;
joiner->join_status.ret = NULL;
joiner->join_status.thread = NULL;
/*
* Disconnect the joiner from the thread being detached:
*/
pthread->joiner = NULL;
}
/*
* Undefer and handle pending signals, yielding if a
* scheduling signal occurred while in the critical region.
*/
_thread_kern_sig_undefer();
} else
/* Return an error: */
rval = EINVAL;
/* Return the completion status: */
return (rval);
}
/*
* Note: a thread calling wait4 may have its state changed to waiting
* until awakened by a signal. Also note that system(3), for example,
* blocks SIGCHLD and calls waitpid (which calls wait4). If the process
* started by system(3) doesn't finish before this function is called the
* function will never awaken -- system(3) also ignores SIGINT and SIGQUIT.
*
* Thus always unmask SIGCHLD here.
*/
pid_t
wait4(pid_t pid, int *istat, int options, struct rusage * rusage)
{
struct pthread *curthread = _get_curthread();
pid_t ret;
sigset_t mask, omask;
/* This is a cancellation point: */
_thread_enter_cancellation_point();
_thread_kern_sig_defer();
sigemptyset(&mask);
sigaddset(&mask, SIGCHLD);
sigprocmask(SIG_UNBLOCK, &mask, &omask);
/* Perform a non-blocking wait4 syscall: */
while ((ret = _thread_sys_wait4(pid, istat, options | WNOHANG, rusage)) == 0 && (options & WNOHANG) == 0) {
/* Reset the interrupted operation flag: */
curthread->interrupted = 0;
/* Schedule the next thread while this one waits: */
_thread_kern_sched_state(PS_WAIT_WAIT, __FILE__, __LINE__);
/* Check if this call was interrupted by a signal: */
if (curthread->interrupted) {
errno = EINTR;
ret = -1;
break;
}
}
sigprocmask(SIG_SETMASK, &omask, NULL);
_thread_kern_sig_undefer();
/* No longer in a cancellation point: */
_thread_leave_cancellation_point();
return (ret);
}
void
_cond_wait_backout(pthread_t pthread)
{
pthread_cond_t cond;
cond = pthread->data.cond;
if (cond != NULL) {
/*
* Defer signals to protect the scheduling queues
* from access by the signal handler:
*/
_thread_kern_sig_defer();
/* Lock the condition variable structure: */
_SPINLOCK(&cond->lock);
/* Process according to condition variable type: */
switch (cond->c_type) {
/* Fast condition variable: */
case COND_TYPE_FAST:
cond_queue_remove(cond, pthread);
/* Check for no more waiters: */
if (TAILQ_FIRST(&cond->c_queue) == NULL)
cond->c_mutex = NULL;
break;
default:
break;
}
/* Unlock the condition variable structure: */
_SPINUNLOCK(&cond->lock);
/*
* Undefer and handle pending signals, yielding if
* necessary:
*/
_thread_kern_sig_undefer();
}
}
int
getsockopt(int fd, int level, int optname, void *optval, socklen_t *optlen)
{
int ret;
struct fd_table_entry *entry;
ret = _thread_fd_table_init(fd, FD_INIT_UNKNOWN, NULL);
if (ret == 0) {
entry = _thread_fd_table[fd];
_thread_kern_sig_defer();
if (entry->state == FD_ENTRY_OPEN) {
ret = _thread_sys_getsockopt(fd, level, optname, optval, optlen);
} else {
ret = -1;
errno = EBADF;
}
_thread_kern_sig_undefer();
}
return ret;
}
int
_pthread_cond_broadcast(pthread_cond_t * cond)
{
int rval = 0;
pthread_t pthread;
if (cond == NULL)
rval = EINVAL;
/*
* If the condition variable is statically initialized, perform dynamic
* initialization.
*/
else if (*cond != NULL || (rval = pthread_cond_init(cond, NULL)) == 0) {
/*
* Defer signals to protect the scheduling queues
* from access by the signal handler:
*/
_thread_kern_sig_defer();
/* Lock the condition variable structure: */
_SPINLOCK(&(*cond)->lock);
/* Process according to condition variable type: */
switch ((*cond)->c_type) {
/* Fast condition variable: */
case COND_TYPE_FAST:
/* Increment the sequence number: */
(*cond)->c_seqno++;
/*
* Enter a loop to bring all threads off the
* condition queue:
*/
while ((pthread = cond_queue_deq(*cond)) != NULL) {
/*
* Wake up the signaled thread:
*/
PTHREAD_NEW_STATE(pthread, PS_RUNNING);
}
/* There are no more waiting threads: */
(*cond)->c_mutex = NULL;
break;
/* Trap invalid condition variable types: */
default:
/* Return an invalid argument error: */
rval = EINVAL;
break;
}
/* Unlock the condition variable structure: */
_SPINUNLOCK(&(*cond)->lock);
/*
* Undefer and handle pending signals, yielding if
* necessary:
*/
_thread_kern_sig_undefer();
}
/* Return the completion status: */
return (rval);
}
int
_pthread_create(pthread_t *thread, const pthread_attr_t *attr,
void *(*start_routine) (void *), void *arg)
{
struct pthread *curthread = _get_curthread();
struct itimerval itimer;
int f_gc = 0;
int ret = 0;
pthread_t gc_thread;
pthread_t new_thread;
pthread_attr_t pattr;
void *stack;
if (thread == NULL)
return (EINVAL);
/*
* Locking functions in libc are required when there are
* threads other than the initial thread.
*/
__isthreaded = 1;
/* Allocate memory for the thread structure: */
if ((new_thread = (pthread_t) malloc(sizeof(struct pthread))) == NULL) {
/* Insufficient memory to create a thread: */
ret = EAGAIN;
} else {
/* Check if default thread attributes are required: */
if (attr == NULL || *attr == NULL) {
/* Use the default thread attributes: */
pattr = &pthread_attr_default;
} else {
pattr = *attr;
}
/* Check if a stack was specified in the thread attributes: */
if ((stack = pattr->stackaddr_attr) != NULL) {
}
/* Allocate memory for a default-size stack: */
else if (pattr->stacksize_attr == PTHREAD_STACK_DEFAULT) {
struct stack *spare_stack;
/* Allocate or re-use a default-size stack. */
/*
* Use the garbage collector mutex for synchronization
* of the spare stack list.
*/
if (pthread_mutex_lock(&_gc_mutex) != 0)
PANIC("Cannot lock gc mutex");
if ((spare_stack = SLIST_FIRST(&_stackq)) != NULL) {
/* Use the spare stack. */
SLIST_REMOVE_HEAD(&_stackq, qe);
/* Unlock the garbage collector mutex. */
if (pthread_mutex_unlock(&_gc_mutex) != 0)
PANIC("Cannot unlock gc mutex");
stack = sizeof(struct stack)
+ (void *) spare_stack
- PTHREAD_STACK_DEFAULT;
} else {
/* Allocate a new stack. */
stack = _next_stack + PTHREAD_STACK_GUARD;
/*
* Even if stack allocation fails, we don't want
* to try to use this location again, so
* unconditionally decrement _next_stack. Under
* normal operating conditions, the most likely
* reason for an mmap() error is a stack
* overflow of the adjacent thread stack.
*/
_next_stack -= (PTHREAD_STACK_DEFAULT
+ PTHREAD_STACK_GUARD);
/* Unlock the garbage collector mutex. */
if (pthread_mutex_unlock(&_gc_mutex) != 0)
PANIC("Cannot unlock gc mutex");
/* Stack: */
if (mmap(stack, PTHREAD_STACK_DEFAULT,
PROT_READ | PROT_WRITE, MAP_STACK,
-1, 0) == MAP_FAILED) {
ret = EAGAIN;
free(new_thread);
}
}
}
/*
* The user wants a stack of a particular size. Lets hope they
* really know what they want, and simply malloc the stack.
*/
else if ((stack = (void *) malloc(pattr->stacksize_attr))
== NULL) {
/* Insufficient memory to create a thread: */
ret = EAGAIN;
free(new_thread);
}
/* Check for errors: */
if (ret != 0) {
} else {
/* Initialise the thread structure: */
memset(new_thread, 0, sizeof(struct pthread));
new_thread->tcb = _libc_allocate_tls();
if (new_thread->tcb == NULL)
PANIC("Cannot allocate TLS and TCB");
new_thread->slice_usec = -1;
new_thread->stack = stack;
new_thread->start_routine = start_routine;
new_thread->arg = arg;
new_thread->cancelflags = PTHREAD_CANCEL_ENABLE |
PTHREAD_CANCEL_DEFERRED;
/*
* Write a magic value to the thread structure
* to help identify valid ones:
*/
new_thread->magic = PTHREAD_MAGIC;
/* Initialise the thread for signals: */
new_thread->sigmask = curthread->sigmask;
new_thread->sigmask_seqno = 0;
/* Initialize the signal frame: */
new_thread->curframe = NULL;
/* Initialise the jump buffer: */
_setjmp(new_thread->ctx.jb);
/*
* Set up new stack frame so that it looks like it
* returned from a longjmp() to the beginning of
* _thread_start().
*/
SET_RETURN_ADDR_JB(new_thread->ctx.jb, _thread_start);
/* The stack starts high and builds down: */
SET_STACK_JB(new_thread->ctx.jb,
(long)new_thread->stack + pattr->stacksize_attr
- sizeof(double));
/* Copy the thread attributes: */
memcpy(&new_thread->attr, pattr, sizeof(struct pthread_attr));
/*
* Check if this thread is to inherit the scheduling
* attributes from its parent:
*/
if (new_thread->attr.flags & PTHREAD_INHERIT_SCHED) {
/* Copy the scheduling attributes: */
new_thread->base_priority =
curthread->base_priority &
~PTHREAD_SIGNAL_PRIORITY;
new_thread->attr.prio =
curthread->base_priority &
~PTHREAD_SIGNAL_PRIORITY;
new_thread->attr.sched_policy =
curthread->attr.sched_policy;
} else {
/*
* Use just the thread priority, leaving the
* other scheduling attributes as their
* default values:
*/
new_thread->base_priority =
new_thread->attr.prio;
}
new_thread->active_priority = new_thread->base_priority;
new_thread->inherited_priority = 0;
/* Initialize joiner to NULL (no joiner): */
new_thread->joiner = NULL;
/* Initialize the mutex queue: */
TAILQ_INIT(&new_thread->mutexq);
/* Initialise hooks in the thread structure: */
new_thread->specific_data = NULL;
new_thread->cleanup = NULL;
new_thread->flags = 0;
new_thread->poll_data.nfds = 0;
new_thread->poll_data.fds = NULL;
new_thread->continuation = NULL;
/*
* Defer signals to protect the scheduling queues
* from access by the signal handler:
*/
_thread_kern_sig_defer();
/*
* Initialise the unique id which GDB uses to
* track threads.
*/
new_thread->uniqueid = next_uniqueid++;
/*
* Check if the garbage collector thread
* needs to be started.
*/
f_gc = (TAILQ_FIRST(&_thread_list) == _thread_initial);
/* Add the thread to the linked list of all threads: */
TAILQ_INSERT_HEAD(&_thread_list, new_thread, tle);
if (pattr->suspend == PTHREAD_CREATE_SUSPENDED) {
new_thread->flags |= PTHREAD_FLAGS_SUSPENDED;
new_thread->state = PS_SUSPENDED;
} else {
new_thread->state = PS_RUNNING;
PTHREAD_PRIOQ_INSERT_TAIL(new_thread);
}
/*
* Undefer and handle pending signals, yielding
* if necessary.
*/
_thread_kern_sig_undefer();
/* Return a pointer to the thread structure: */
(*thread) = new_thread;
if (f_gc != 0) {
/* Install the scheduling timer: */
itimer.it_interval.tv_sec = 0;
itimer.it_interval.tv_usec = _clock_res_usec;
itimer.it_value = itimer.it_interval;
if (setitimer(_ITIMER_SCHED_TIMER, &itimer,
NULL) != 0)
PANIC("Cannot set interval timer");
}
/* Schedule the new user thread: */
_thread_kern_sched(NULL);
/*
* Start a garbage collector thread
* if necessary.
*/
if (f_gc && pthread_create(&gc_thread,NULL,
_thread_gc,NULL) != 0)
PANIC("Can't create gc thread");
}
}
/* Return the status: */
return (ret);
}
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);
}
int
_pthread_mutex_lock(pthread_mutex_t * mutex)
{
struct pthread *curthread = _get_curthread();
int ret = 0;
if (_thread_initial == NULL)
_thread_init();
if (mutex == NULL)
return (EINVAL);
/*
* If the mutex is statically initialized, perform the dynamic
* initialization:
*/
if ((*mutex == NULL) &&
((ret = init_static(mutex)) != 0))
return (ret);
/* Reset the interrupted flag: */
curthread->interrupted = 0;
/*
* Enter a loop waiting to become the mutex owner. We need a
* loop in case the waiting thread is interrupted by a signal
* to execute a signal handler. It is not (currently) possible
* to remain in the waiting queue while running a handler.
* Instead, the thread is interrupted and backed out of the
* waiting queue prior to executing the signal handler.
*/
do {
/*
* Defer signals to protect the scheduling queues from
* access by the signal handler:
*/
_thread_kern_sig_defer();
/* Lock the mutex structure: */
_SPINLOCK(&(*mutex)->lock);
/*
* If the mutex was statically allocated, properly
* initialize the tail queue.
*/
if (((*mutex)->m_flags & MUTEX_FLAGS_INITED) == 0) {
TAILQ_INIT(&(*mutex)->m_queue);
(*mutex)->m_flags |= MUTEX_FLAGS_INITED;
_MUTEX_INIT_LINK(*mutex);
}
/* Process according to mutex type: */
switch ((*mutex)->m_protocol) {
/* Default POSIX mutex: */
case PTHREAD_PRIO_NONE:
if ((*mutex)->m_owner == NULL) {
/* Lock the mutex for this thread: */
(*mutex)->m_owner = curthread;
/* Add to the list of owned mutexes: */
_MUTEX_ASSERT_NOT_OWNED(*mutex);
TAILQ_INSERT_TAIL(&curthread->mutexq,
(*mutex), m_qe);
} else if ((*mutex)->m_owner == curthread)
ret = mutex_self_lock(*mutex);
else {
/*
* Join the queue of threads waiting to lock
* the mutex:
*/
mutex_queue_enq(*mutex, curthread);
/*
* Keep a pointer to the mutex this thread
* is waiting on:
*/
curthread->data.mutex = *mutex;
/*
* Unlock the mutex structure and schedule the
* next thread:
*/
_thread_kern_sched_state_unlock(PS_MUTEX_WAIT,
&(*mutex)->lock, __FILE__, __LINE__);
/* Lock the mutex structure again: */
_SPINLOCK(&(*mutex)->lock);
}
break;
/* POSIX priority inheritence mutex: */
case PTHREAD_PRIO_INHERIT:
/* Check if this mutex is not locked: */
if ((*mutex)->m_owner == NULL) {
/* Lock the mutex for this thread: */
(*mutex)->m_owner = curthread;
/* Track number of priority mutexes owned: */
curthread->priority_mutex_count++;
/*
* The mutex takes on attributes of the
* running thread when there are no waiters.
*/
(*mutex)->m_prio = curthread->active_priority;
(*mutex)->m_saved_prio =
curthread->inherited_priority;
curthread->inherited_priority =
(*mutex)->m_prio;
/* Add to the list of owned mutexes: */
_MUTEX_ASSERT_NOT_OWNED(*mutex);
TAILQ_INSERT_TAIL(&curthread->mutexq,
(*mutex), m_qe);
} else if ((*mutex)->m_owner == curthread)
ret = mutex_self_lock(*mutex);
else {
/*
* Join the queue of threads waiting to lock
* the mutex:
*/
mutex_queue_enq(*mutex, curthread);
/*
* Keep a pointer to the mutex this thread
* is waiting on:
*/
curthread->data.mutex = *mutex;
if (curthread->active_priority >
(*mutex)->m_prio)
/* Adjust priorities: */
mutex_priority_adjust(*mutex);
/*
* Unlock the mutex structure and schedule the
* next thread:
*/
_thread_kern_sched_state_unlock(PS_MUTEX_WAIT,
&(*mutex)->lock, __FILE__, __LINE__);
/* Lock the mutex structure again: */
_SPINLOCK(&(*mutex)->lock);
}
break;
/* POSIX priority protection mutex: */
case PTHREAD_PRIO_PROTECT:
/* Check for a priority ceiling violation: */
if (curthread->active_priority > (*mutex)->m_prio)
ret = EINVAL;
/* Check if this mutex is not locked: */
else if ((*mutex)->m_owner == NULL) {
/*
* Lock the mutex for the running
* thread:
*/
(*mutex)->m_owner = curthread;
/* Track number of priority mutexes owned: */
curthread->priority_mutex_count++;
/*
* The running thread inherits the ceiling
* priority of the mutex and executes at that
* priority:
*/
curthread->active_priority = (*mutex)->m_prio;
(*mutex)->m_saved_prio =
curthread->inherited_priority;
curthread->inherited_priority =
(*mutex)->m_prio;
/* Add to the list of owned mutexes: */
_MUTEX_ASSERT_NOT_OWNED(*mutex);
TAILQ_INSERT_TAIL(&curthread->mutexq,
(*mutex), m_qe);
} else if ((*mutex)->m_owner == curthread)
ret = mutex_self_lock(*mutex);
else {
/*
* Join the queue of threads waiting to lock
* the mutex:
*/
mutex_queue_enq(*mutex, curthread);
/*
* Keep a pointer to the mutex this thread
* is waiting on:
*/
curthread->data.mutex = *mutex;
/* Clear any previous error: */
errno = 0;
/*
* Unlock the mutex structure and schedule the
* next thread:
*/
_thread_kern_sched_state_unlock(PS_MUTEX_WAIT,
&(*mutex)->lock, __FILE__, __LINE__);
/* Lock the mutex structure again: */
_SPINLOCK(&(*mutex)->lock);
/*
* The threads priority may have changed while
* waiting for the mutex causing a ceiling
* violation.
*/
ret = errno;
errno = 0;
}
break;
/* Trap invalid mutex types: */
default:
/* Return an invalid argument error: */
ret = EINVAL;
break;
}
/*
* Check to see if this thread was interrupted and
* is still in the mutex queue of waiting threads:
*/
if (curthread->interrupted != 0)
mutex_queue_remove(*mutex, curthread);
/* Unlock the mutex structure: */
_SPINUNLOCK(&(*mutex)->lock);
/*
* Undefer and handle pending signals, yielding if
* necessary:
*/
_thread_kern_sig_undefer();
} while (((*mutex)->m_owner != curthread) && (ret == 0) &&
(curthread->interrupted == 0));
if (curthread->interrupted != 0 &&
curthread->continuation != NULL)
curthread->continuation((void *) curthread);
/* Return the completion status: */
return (ret);
}
int
_pthread_mutex_trylock(pthread_mutex_t * mutex)
{
struct pthread *curthread = _get_curthread();
int ret = 0;
if (mutex == NULL)
ret = EINVAL;
/*
* If the mutex is statically initialized, perform the dynamic
* initialization:
*/
else if (*mutex != NULL || (ret = init_static(mutex)) == 0) {
/*
* Defer signals to protect the scheduling queues from
* access by the signal handler:
*/
_thread_kern_sig_defer();
/* Lock the mutex structure: */
_SPINLOCK(&(*mutex)->lock);
/*
* If the mutex was statically allocated, properly
* initialize the tail queue.
*/
if (((*mutex)->m_flags & MUTEX_FLAGS_INITED) == 0) {
TAILQ_INIT(&(*mutex)->m_queue);
_MUTEX_INIT_LINK(*mutex);
(*mutex)->m_flags |= MUTEX_FLAGS_INITED;
}
/* Process according to mutex type: */
switch ((*mutex)->m_protocol) {
/* Default POSIX mutex: */
case PTHREAD_PRIO_NONE:
/* Check if this mutex is not locked: */
if ((*mutex)->m_owner == NULL) {
/* Lock the mutex for the running thread: */
(*mutex)->m_owner = curthread;
/* Add to the list of owned mutexes: */
_MUTEX_ASSERT_NOT_OWNED(*mutex);
TAILQ_INSERT_TAIL(&curthread->mutexq,
(*mutex), m_qe);
} else if ((*mutex)->m_owner == curthread)
ret = mutex_self_trylock(*mutex);
else
/* Return a busy error: */
ret = EBUSY;
break;
/* POSIX priority inheritence mutex: */
case PTHREAD_PRIO_INHERIT:
/* Check if this mutex is not locked: */
if ((*mutex)->m_owner == NULL) {
/* Lock the mutex for the running thread: */
(*mutex)->m_owner = curthread;
/* Track number of priority mutexes owned: */
curthread->priority_mutex_count++;
/*
* The mutex takes on the attributes of the
* running thread when there are no waiters.
*/
(*mutex)->m_prio = curthread->active_priority;
(*mutex)->m_saved_prio =
curthread->inherited_priority;
/* Add to the list of owned mutexes: */
_MUTEX_ASSERT_NOT_OWNED(*mutex);
TAILQ_INSERT_TAIL(&curthread->mutexq,
(*mutex), m_qe);
} else if ((*mutex)->m_owner == curthread)
ret = mutex_self_trylock(*mutex);
else
/* Return a busy error: */
ret = EBUSY;
break;
/* POSIX priority protection mutex: */
case PTHREAD_PRIO_PROTECT:
/* Check for a priority ceiling violation: */
if (curthread->active_priority > (*mutex)->m_prio)
ret = EINVAL;
/* Check if this mutex is not locked: */
else if ((*mutex)->m_owner == NULL) {
/* Lock the mutex for the running thread: */
(*mutex)->m_owner = curthread;
/* Track number of priority mutexes owned: */
curthread->priority_mutex_count++;
/*
* The running thread inherits the ceiling
* priority of the mutex and executes at that
* priority.
*/
curthread->active_priority = (*mutex)->m_prio;
(*mutex)->m_saved_prio =
curthread->inherited_priority;
curthread->inherited_priority =
(*mutex)->m_prio;
/* Add to the list of owned mutexes: */
_MUTEX_ASSERT_NOT_OWNED(*mutex);
TAILQ_INSERT_TAIL(&curthread->mutexq,
(*mutex), m_qe);
} else if ((*mutex)->m_owner == curthread)
ret = mutex_self_trylock(*mutex);
else
/* Return a busy error: */
ret = EBUSY;
break;
/* Trap invalid mutex types: */
default:
/* Return an invalid argument error: */
ret = EINVAL;
break;
}
/* 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);
}
int
_pthread_create(pthread_t *thread, const pthread_attr_t *attr,
void *(*start_routine) (void *), void *arg)
{
struct pthread *curthread = _get_curthread();
struct itimerval itimer;
int f_gc = 0;
int ret = 0;
pthread_t gc_thread;
pthread_t new_thread;
pthread_attr_t pattr;
void *stack;
#if !defined(__ia64__)
u_long stackp;
#endif
if (thread == NULL)
return(EINVAL);
/*
* Locking functions in libc are required when there are
* threads other than the initial thread.
*/
__isthreaded = 1;
/* Allocate memory for the thread structure: */
if ((new_thread = (pthread_t) malloc(sizeof(struct pthread))) == NULL) {
/* Insufficient memory to create a thread: */
ret = EAGAIN;
} else {
/* Check if default thread attributes are required: */
if (attr == NULL || *attr == NULL) {
/* Use the default thread attributes: */
pattr = &_pthread_attr_default;
} else {
pattr = *attr;
}
/* Check if a stack was specified in the thread attributes: */
if ((stack = pattr->stackaddr_attr) != NULL) {
}
/* Allocate a stack: */
else {
stack = _thread_stack_alloc(pattr->stacksize_attr,
pattr->guardsize_attr);
if (stack == NULL) {
ret = EAGAIN;
free(new_thread);
}
}
/* Check for errors: */
if (ret != 0) {
} else {
/* Initialise the thread structure: */
memset(new_thread, 0, sizeof(struct pthread));
new_thread->slice_usec = -1;
new_thread->stack = stack;
new_thread->start_routine = start_routine;
new_thread->arg = arg;
new_thread->cancelflags = PTHREAD_CANCEL_ENABLE |
PTHREAD_CANCEL_DEFERRED;
/*
* Write a magic value to the thread structure
* to help identify valid ones:
*/
new_thread->magic = PTHREAD_MAGIC;
/* Initialise the thread for signals: */
new_thread->sigmask = curthread->sigmask;
new_thread->sigmask_seqno = 0;
/* Initialize the signal frame: */
new_thread->curframe = NULL;
/* Initialise the jump buffer: */
_setjmp(new_thread->ctx.jb);
/*
* Set up new stack frame so that it looks like it
* returned from a longjmp() to the beginning of
* _thread_start().
*/
SET_RETURN_ADDR_JB(new_thread->ctx.jb, _thread_start);
#if !defined(__ia64__)
stackp = (long)new_thread->stack + pattr->stacksize_attr - sizeof(double);
#if defined(__amd64__)
stackp &= ~0xFUL;
#endif
/* The stack starts high and builds down: */
SET_STACK_JB(new_thread->ctx.jb, stackp);
#else
SET_STACK_JB(new_thread->ctx.jb,
(long)new_thread->stack, pattr->stacksize_attr);
#endif
/* Copy the thread attributes: */
memcpy(&new_thread->attr, pattr, sizeof(struct pthread_attr));
/*
* Check if this thread is to inherit the scheduling
* attributes from its parent:
*/
if (new_thread->attr.flags & PTHREAD_INHERIT_SCHED) {
/* Copy the scheduling attributes: */
new_thread->base_priority =
curthread->base_priority &
~PTHREAD_SIGNAL_PRIORITY;
new_thread->attr.prio =
curthread->base_priority &
~PTHREAD_SIGNAL_PRIORITY;
new_thread->attr.sched_policy =
curthread->attr.sched_policy;
} else {
/*
* Use just the thread priority, leaving the
* other scheduling attributes as their
* default values:
*/
new_thread->base_priority =
new_thread->attr.prio;
}
new_thread->active_priority = new_thread->base_priority;
new_thread->inherited_priority = 0;
/* Initialize joiner to NULL (no joiner): */
new_thread->joiner = NULL;
/* Initialize the mutex queue: */
TAILQ_INIT(&new_thread->mutexq);
/* Initialise hooks in the thread structure: */
new_thread->specific = NULL;
new_thread->cleanup = NULL;
new_thread->flags = 0;
new_thread->poll_data.nfds = 0;
new_thread->poll_data.fds = NULL;
new_thread->continuation = NULL;
/*
* Defer signals to protect the scheduling queues
* from access by the signal handler:
*/
_thread_kern_sig_defer();
/*
* Initialise the unique id which GDB uses to
* track threads.
*/
new_thread->uniqueid = next_uniqueid++;
/*
* Check if the garbage collector thread
* needs to be started.
*/
f_gc = (TAILQ_FIRST(&_thread_list) == _thread_initial);
/* Add the thread to the linked list of all threads: */
TAILQ_INSERT_HEAD(&_thread_list, new_thread, tle);
if (pattr->suspend == PTHREAD_CREATE_SUSPENDED) {
new_thread->flags |= PTHREAD_FLAGS_SUSPENDED;
new_thread->state = PS_SUSPENDED;
} else {
new_thread->state = PS_RUNNING;
PTHREAD_PRIOQ_INSERT_TAIL(new_thread);
}
/*
* Undefer and handle pending signals, yielding
* if necessary.
*/
_thread_kern_sig_undefer();
/* Return a pointer to the thread structure: */
(*thread) = new_thread;
if (f_gc != 0) {
/* Install the scheduling timer: */
itimer.it_interval.tv_sec = 0;
itimer.it_interval.tv_usec = _clock_res_usec;
itimer.it_value = itimer.it_interval;
if (setitimer(_ITIMER_SCHED_TIMER, &itimer,
NULL) != 0)
PANIC("Cannot set interval timer");
}
/* Schedule the new user thread: */
_thread_kern_sched(NULL);
/*
* Start a garbage collector thread
* if necessary.
*/
if (f_gc && _pthread_create(&gc_thread, NULL,
_thread_gc, NULL) != 0)
PANIC("Can't create gc thread");
}
}
/* Return the status: */
return (ret);
}
void
funlockfile(FILE * fp)
{
int idx = file_idx(fp);
struct file_lock *p;
/*
* Defer signals to protect the scheduling queues from
* access by the signal handler:
*/
_thread_kern_sig_defer();
/* Lock the hash table: */
_SPINLOCK(&hash_lock);
/*
* Get a pointer to the lock for the file and check that
* the running thread is the one with the lock:
*/
if ((p = find_lock(idx, fp)) != NULL &&
p->owner == _thread_run) {
/*
* Check if this thread has locked the FILE
* more than once:
*/
if (p->count > 1)
/*
* Decrement the count of the number of
* times the running thread has locked this
* file:
*/
p->count--;
else {
/*
* The running thread will release the
* lock now:
*/
p->count = 0;
/* Get the new owner of the lock: */
if ((p->owner = TAILQ_FIRST(&p->l_head)) != NULL) {
/* Pop the thread off the queue: */
TAILQ_REMOVE(&p->l_head,p->owner,qe);
/*
* This is the first lock for the new
* owner:
*/
p->count = 1;
/* Allow the new owner to run: */
PTHREAD_NEW_STATE(p->owner,PS_RUNNING);
}
}
}
/* Unlock the hash table: */
_SPINUNLOCK(&hash_lock);
/*
* Undefer and handle pending signals, yielding if
* necessary:
*/
_thread_kern_sig_undefer();
}