optimize out useless default-attribute object in pthread_create

This commit is contained in:
Rich Felker 2011-05-07 23:39:48 -04:00
commit 11e4b92556

View file

@ -61,10 +61,10 @@ weak_alias(dummy, __pthread_tsd_size);
int pthread_create(pthread_t *res, const pthread_attr_t *attr, void *(*entry)(void *), void *arg)
{
int ret;
size_t size, guard;
size_t size = DEFAULT_STACK_SIZE + DEFAULT_GUARD_SIZE;
size_t guard = DEFAULT_GUARD_SIZE;
struct pthread *self = pthread_self(), *new;
unsigned char *map, *stack, *tsd;
const pthread_attr_t default_attr = { 0 };
if (!self) return ENOSYS;
if (!libc.threaded) {
@ -72,9 +72,10 @@ int pthread_create(pthread_t *res, const pthread_attr_t *attr, void *(*entry)(vo
libc.threaded = 1;
}
if (!attr) attr = &default_attr;
guard = ROUND(attr->_a_guardsize + DEFAULT_GUARD_SIZE);
size = guard + ROUND(attr->_a_stacksize + DEFAULT_STACK_SIZE);
if (attr) {
guard = ROUND(attr->_a_guardsize + DEFAULT_GUARD_SIZE);
size = guard + ROUND(attr->_a_stacksize + DEFAULT_STACK_SIZE);
}
size += __pthread_tsd_size;
map = mmap(0, size, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_ANON, -1, 0);
if (!map) return EAGAIN;
@ -90,8 +91,7 @@ int pthread_create(pthread_t *res, const pthread_attr_t *attr, void *(*entry)(vo
new->start_arg = arg;
new->self = new;
new->tsd = (void *)tsd;
new->detached = attr->_a_detach;
new->attr = *attr;
if (attr) new->detached = attr->_a_detach;
new->unblock_cancel = self->cancel;
memcpy(new->tlsdesc, self->tlsdesc, sizeof new->tlsdesc);
new->tlsdesc[1] = (uintptr_t)new;