/*
* Lock a location for the running thread. Yield to allow other
* threads to run if this thread is blocked because the lock is
* not available. Note that this function does not sleep. It
* assumes that the lock will be available very soon.
*
* This function checks if the running thread has already locked the
* location, warns if this occurs and creates a thread dump before
* returning.
*/
void
_spinlock_debug(spinlock_t *lck, char *fname, int lineno)
{
struct pthread *curthread = _get_curthread();
int cnt = 0;
/*
* Try to grab the lock and loop if another thread grabs
* it before we do.
*/
while(_atomic_lock(&lck->access_lock)) {
cnt++;
if (cnt > 100) {
char str[256];
snprintf(str, sizeof(str), "%s - Warning: Thread %p attempted to lock %p from %s (%d) was left locked from %s (%d)\n", _getprogname(), curthread, lck, fname, lineno, lck->fname, lck->lineno);
__sys_extpwrite(2, str, strlen(str), O_FBLOCKING, -1);
__sleep(1);
cnt = 0;
}
/* Block the thread until the lock. */
curthread->data.spinlock = lck;
_thread_kern_sched_state(PS_SPINBLOCK, fname, lineno);
}
/* The running thread now owns the lock: */
lck->lock_owner = (long) curthread;
lck->fname = fname;
lck->lineno = lineno;
}
/*
* internal support functions
*/
void
_spinlock(_spinlock_lock_t *lock)
{
while (_atomic_lock(lock))
pthread_yield();
}
/*
* Lock a location for the running thread. Yield to allow other
* threads to run if this thread is blocked because the lock is
* not available. Note that this function does not sleep. It
* assumes that the lock will be available very soon.
*/
void
_spinlock(spinlock_t *lck)
{
struct pthread *curthread = _get_curthread();
/*
* Try to grab the lock and loop if another thread grabs
* it before we do.
*/
while(_atomic_lock(&lck->access_lock)) {
/* Block the thread until the lock. */
curthread->data.spinlock = lck;
_thread_kern_sched_state(PS_SPINBLOCK, __FILE__, __LINE__);
}
/* The running thread now owns the lock: */
lck->lock_owner = (long) curthread;
}