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This commit is contained in:
mtm 2003-05-12 10:34:01 +00:00
parent f6f3e2ff8f
commit 100c8a533a
3 changed files with 181 additions and 263 deletions
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50
lib/libthr/thread/thr_kern.c
View File

@ -51,6 +51,56 @@
static sigset_t restore;
void
_thread_critical_enter(pthread_t pthread)
{
sigset_t set;
sigset_t sav;
/*
* Block all signals.
*/
SIGFILLSET(set);
/*
* We can not use the global 'restore' set until after we have
* acquired the giant lock.
*/
_SPINLOCK(&pthread->lock);
if (__sys_sigprocmask(SIG_SETMASK, &set, &sav)) {
_thread_printf(STDERR_FILENO, "Critical Enter: sig err %d\n",
errno);
abort();
}
restore = sav;
}
void
_thread_critical_exit(pthread_t pthread)
{
sigset_t set;
int error;
/*
* restore is protected by giant. We could restore our signal state
* incorrectly if someone else set restore between unlocking giant
* and restoring the signal mask. To avoid this we cache a copy prior
* to the unlock.
*/
set = restore;
/*
* Restore signals.
*/
if (__sys_sigprocmask(SIG_SETMASK, &set, NULL)) {
_thread_printf(STDERR_FILENO, "Critical Exit: sig err %d\n",
errno);
abort();
}
_SPINUNLOCK(&pthread->lock);
}
void
GIANT_LOCK(pthread_t pthread)
{

392
lib/libthr/thread/thr_mutex.c
View File

@ -62,6 +62,8 @@
/*
* Prototypes
*/
static int get_muncontested(pthread_mutex_t, int);
static void get_mcontested(pthread_mutex_t);
static inline int mutex_self_trylock(pthread_mutex_t);
static inline int mutex_self_lock(pthread_mutex_t);
static inline int mutex_unlock_common(pthread_mutex_t *, int);
@ -297,138 +299,6 @@ init_static_private(pthread_mutex_t *mutex)
return (ret);
}
static int
mutex_trylock_common(pthread_mutex_t *mutex)
{
int ret = 0;
PTHREAD_ASSERT((mutex != NULL) && (*mutex != NULL),
"Uninitialized mutex in pthread_mutex_trylock_basic");
/*
* Defer signals to protect the scheduling queues from
* access by the signal handler:
*/
/* _thread_kern_sig_defer(); XXXThr */
/* 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_mutex_trylock(pthread_mutex_t *mutex)
{
@ -442,7 +312,7 @@ __pthread_mutex_trylock(pthread_mutex_t *mutex)
* initialization:
*/
else if ((*mutex != NULL) || (ret = init_static(mutex)) == 0)
ret = mutex_trylock_common(mutex);
ret = mutex_lock_common(mutex, 1);
return (ret);
}
@ -460,15 +330,17 @@ _pthread_mutex_trylock(pthread_mutex_t *mutex)
* initialization marking the mutex private (delete safe):
*/
else if ((*mutex != NULL) || (ret = init_static_private(mutex)) == 0)
ret = mutex_trylock_common(mutex);
ret = mutex_lock_common(mutex, 1);
return (ret);
}
static int
mutex_lock_common(pthread_mutex_t * mutex)
mutex_lock_common(pthread_mutex_t * mutex, int nonblock)
{
int ret = 0;
int ret, error, inCancel;
ret = error = inCancel = 0;
PTHREAD_ASSERT((mutex != NULL) && (*mutex != NULL),
"Uninitialized mutex in mutex_lock_common");
@ -505,51 +377,20 @@ mutex_lock_common(pthread_mutex_t * mutex)
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:
*/
/* XXX Sched lock. */
PTHREAD_SET_STATE(curthread, PS_MUTEX_WAIT);
_SPINUNLOCK(&(*mutex)->lock);
_thread_suspend(curthread, NULL);
/* Lock the mutex structure again: */
_SPINLOCK(&(*mutex)->lock);
}
if ((error = get_muncontested(*mutex, nonblock)) == -1)
if (nonblock) {
ret = EBUSY;
break;
} else {
get_mcontested(*mutex);
}
else
ret = error;
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;
if ((error = get_muncontested(*mutex, nonblock)) == 0) {
/* Track number of priority mutexes owned: */
curthread->priority_mutex_count++;
@ -562,43 +403,20 @@ mutex_lock_common(pthread_mutex_t * mutex)
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;
} else if (error == -1) {
if (nonblock) {
ret = EBUSY;
break;
} else {
get_mcontested(*mutex);
}
if (curthread->active_priority >
(*mutex)->m_prio)
/* Adjust priorities: */
mutex_priority_adjust(*mutex);
/*
* Unlock the mutex structure and schedule the
* next thread:
*/
/* XXX Sched lock. */
PTHREAD_SET_STATE(curthread, PS_MUTEX_WAIT);
_SPINUNLOCK(&(*mutex)->lock);
_thread_suspend(curthread, NULL);
/* Lock the mutex structure again: */
_SPINLOCK(&(*mutex)->lock);
} else {
ret = error;
}
break;
@ -608,14 +426,7 @@ mutex_lock_common(pthread_mutex_t * mutex)
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;
if ((error = get_muncontested(*mutex, nonblock)) == 0) {
/* Track number of priority mutexes owned: */
curthread->priority_mutex_count++;
@ -629,40 +440,16 @@ mutex_lock_common(pthread_mutex_t * mutex)
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;
} else if (error == -1) {
if (nonblock) {
ret = EBUSY;
break;
}
/* Clear any previous error: */
curthread->error = 0;
/*
* Unlock the mutex structure and schedule the
* next thread:
*/
/* XXX Sched lock. */
PTHREAD_SET_STATE(curthread, PS_MUTEX_WAIT);
_SPINUNLOCK(&(*mutex)->lock);
_thread_suspend(curthread, NULL);
/* Lock the mutex structure again: */
_SPINLOCK(&(*mutex)->lock);
get_mcontested(*mutex);
/*
* The threads priority may have changed while
@ -671,6 +458,8 @@ mutex_lock_common(pthread_mutex_t * mutex)
*/
ret = curthread->error;
curthread->error = 0;
} else {
ret = error;
}
break;
@ -685,8 +474,11 @@ mutex_lock_common(pthread_mutex_t * mutex)
* Check to see if this thread was interrupted and
* is still in the mutex queue of waiting threads:
*/
if (curthread->cancelflags & PTHREAD_CANCELLING)
mutex_queue_remove(*mutex, curthread);
if (curthread->cancelflags & PTHREAD_CANCELLING) {
if (!nonblock)
mutex_queue_remove(*mutex, curthread);
inCancel=1;
}
/* Unlock the mutex structure: */
_SPINUNLOCK(&(*mutex)->lock);
@ -696,7 +488,7 @@ mutex_lock_common(pthread_mutex_t * mutex)
* necessary:
*/
/* _thread_kern_sig_undefer(); */
if (curthread->cancelflags & PTHREAD_CANCELLING) {
if (inCancel) {
pthread_testcancel();
PANIC("Canceled thread came back.\n");
}
@ -722,7 +514,7 @@ __pthread_mutex_lock(pthread_mutex_t *mutex)
* initialization:
*/
else if ((*mutex != NULL) || ((ret = init_static(mutex)) == 0))
ret = mutex_lock_common(mutex);
ret = mutex_lock_common(mutex, 0);
return (ret);
}
@ -743,7 +535,7 @@ _pthread_mutex_lock(pthread_mutex_t *mutex)
* initialization marking it private (delete safe):
*/
else if ((*mutex != NULL) || ((ret = init_static_private(mutex)) == 0))
ret = mutex_lock_common(mutex);
ret = mutex_lock_common(mutex, 0);
return (ret);
}
@ -890,7 +682,9 @@ mutex_unlock_common(pthread_mutex_t * mutex, int add_reference)
/*
* Get the next thread from the queue of
* threads waiting on the mutex:
* threads waiting on the mutex. The deq
* function will have already locked it
* for us.
*/
if (((*mutex)->m_owner =
mutex_queue_deq(*mutex)) != NULL) {
@ -911,6 +705,7 @@ mutex_unlock_common(pthread_mutex_t * mutex, int add_reference)
* this mutex:
*/
(*mutex)->m_owner->data.mutex = NULL;
_thread_critical_exit((*mutex)->m_owner);
}
}
break;
@ -964,7 +759,8 @@ mutex_unlock_common(pthread_mutex_t * mutex, int add_reference)
/*
* Get the next thread from the queue of threads
* waiting on the mutex:
* waiting on the mutex. It will already be
* locked for us.
*/
if (((*mutex)->m_owner =
mutex_queue_deq(*mutex)) == NULL)
@ -1020,6 +816,8 @@ mutex_unlock_common(pthread_mutex_t * mutex, int add_reference)
/* XXXTHR sched lock. */
PTHREAD_NEW_STATE((*mutex)->m_owner,
PS_RUNNING);
_thread_critical_exit((*mutex)->m_owner);
}
}
break;
@ -1074,7 +872,7 @@ mutex_unlock_common(pthread_mutex_t * mutex, int add_reference)
/*
* Enter a loop to find a waiting thread whose
* active priority will not cause a ceiling
* violation:
* violation. It will already be locked for us.
*/
while ((((*mutex)->m_owner =
mutex_queue_deq(*mutex)) != NULL) &&
@ -1095,6 +893,8 @@ mutex_unlock_common(pthread_mutex_t * mutex, int add_reference)
* this mutex:
*/
(*mutex)->m_owner->data.mutex = NULL;
_thread_critical_exit((*mutex)->m_owner);
}
/* Check for a new owner: */
@ -1140,6 +940,8 @@ mutex_unlock_common(pthread_mutex_t * mutex, int add_reference)
/* XXXTHR sched lock. */
PTHREAD_NEW_STATE((*mutex)->m_owner,
PS_RUNNING);
_thread_critical_exit((*mutex)->m_owner);
}
}
break;
@ -1472,31 +1274,36 @@ _mutex_lock_backout(pthread_t pthread)
* 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);
/* XXX - Necessary to obey lock order */
_SPINLOCK(&pthread->lock);
mutex = pthread->data.mutex;
_SPINUNLOCK(&pthread->lock);
_SPINLOCK(&mutex->lock);
_thread_critical_enter(pthread);
if ((pthread->flags & PTHREAD_FLAGS_IN_MUTEXQ) != 0) {
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(); */
_thread_critical_exit(pthread);
_SPINUNLOCK(&mutex->lock);
}
/*
* Dequeue a waiting thread from the head of a mutex queue in descending
* priority order.
* priority order. This funtion will return with the thread locked.
*/
static inline pthread_t
mutex_queue_deq(pthread_mutex_t mutex)
@ -1504,6 +1311,7 @@ mutex_queue_deq(pthread_mutex_t mutex)
pthread_t pthread;
while ((pthread = TAILQ_FIRST(&mutex->m_queue)) != NULL) {
_thread_critical_enter(pthread);
TAILQ_REMOVE(&mutex->m_queue, pthread, sqe);
pthread->flags &= ~PTHREAD_FLAGS_IN_MUTEXQ;
@ -1514,6 +1322,8 @@ mutex_queue_deq(pthread_mutex_t mutex)
if ((pthread->cancelflags & PTHREAD_CANCELLING) == 0 &&
pthread->state == PS_MUTEX_WAIT)
break;
else
_thread_critical_exit(pthread);
}
return (pthread);
@ -1556,3 +1366,59 @@ mutex_queue_enq(pthread_mutex_t mutex, pthread_t pthread)
pthread->flags |= PTHREAD_FLAGS_IN_MUTEXQ;
}
/*
* Returns with the lock owned and on the threads mutexq if
* it is currently unowned. Returns 1, otherwise.
*/
static int
get_muncontested(pthread_mutex_t mutexp, int nonblock)
{
if (mutexp->m_owner != NULL && mutexp->m_owner != curthread)
return (-1);
else if (mutexp->m_owner == curthread)
if (nonblock)
return (mutex_self_trylock(mutexp));
else
return (mutex_self_lock(mutexp));
/*
* The mutex belongs to this thread now. Mark it as
* such. Add it to the list of mutexes owned by this
* thread.
*/
mutexp->m_owner = curthread;
_MUTEX_ASSERT_NOT_OWNED(mutexp);
TAILQ_INSERT_TAIL(&curthread->mutexq, mutexp, m_qe);
return (0);
}
/*
* Returns with the lock owned and on the thread's mutexq. If
* the mutex is currently owned by another thread it will sleep
* until it is available.
*/
static void
get_mcontested(pthread_mutex_t mutexp)
{
_thread_critical_enter(curthread);
/*
* Put this thread on the mutex's list of waiting threads.
* The lock on the thread ensures atomic (as far as other
* threads are concerned) setting of the thread state with
* it's status on the mutex queue.
*/
do {
mutex_queue_enq(mutexp, curthread);
PTHREAD_SET_STATE(curthread, PS_MUTEX_WAIT);
curthread->data.mutex = mutexp;
_thread_critical_exit(curthread);
_SPINUNLOCK(&mutexp->lock);
_thread_suspend(curthread, NULL);
_SPINLOCK(&mutexp->lock);
_thread_critical_enter(curthread);
} while ((curthread->flags & PTHREAD_FLAGS_IN_MUTEXQ) != 0);
_thread_critical_exit(curthread);
}

2
lib/libthr/thread/thr_private.h
View File

@ -727,6 +727,8 @@ void _thread_enter_cancellation_point(void);
void _thread_leave_cancellation_point(void);
void _thread_cancellation_point(void);
int _thread_suspend(pthread_t thread, struct timespec *abstime);
void _thread_critical_enter(pthread_t);
void _thread_critical_exit(pthread_t);
/* #include <sys/aio.h> */
#ifdef _SYS_AIO_H_