DISPATCH_NOINLINE
_os_object_t
_os_object_retain(_os_object_t obj)
{
int xref_cnt = _os_object_xrefcnt_inc(obj);
if (slowpath(xref_cnt <= 0)) {
_OS_OBJECT_CLIENT_CRASH("Resurrection of an object");
}
return obj;
}
bool
_os_object_allows_weak_reference(_os_object_t obj)
{
int xref_cnt = obj->os_obj_xref_cnt;
if (slowpath(xref_cnt == -1)) {
return false;
}
if (slowpath(xref_cnt < -1)) {
_OS_OBJECT_CLIENT_CRASH("Over-release of an object");
}
return true;
}
DISPATCH_NOINLINE
void
_os_object_release(_os_object_t obj)
{
int xref_cnt = _os_object_xrefcnt_dec(obj);
if (fastpath(xref_cnt >= 0)) {
return;
}
if (slowpath(xref_cnt < -1)) {
_OS_OBJECT_CLIENT_CRASH("Over-release of an object");
}
return _os_object_xref_dispose(obj);
}
DISPATCH_NOINLINE
_os_object_t
_os_object_retain_with_resurrect(_os_object_t obj)
{
int xref_cnt = _os_object_xrefcnt_inc(obj);
if (slowpath(xref_cnt < 0)) {
_OS_OBJECT_CLIENT_CRASH("Resurrection of an overreleased object");
}
if (slowpath(xref_cnt == 0)) {
_os_object_retain_internal(obj);
}
return obj;
}
DISPATCH_NOINLINE
_os_object_t
_os_object_retain(_os_object_t obj)
{
int xref_cnt = obj->os_obj_xref_cnt;
if (slowpath(xref_cnt == _OS_OBJECT_GLOBAL_REFCNT)) {
return obj; // global object
}
xref_cnt = dispatch_atomic_inc2o(obj, os_obj_xref_cnt, relaxed);
if (slowpath(xref_cnt <= 0)) {
_OS_OBJECT_CLIENT_CRASH("Resurrection of an object");
}
return obj;
}
DISPATCH_NOINLINE
void
_os_object_release(_os_object_t obj)
{
int xref_cnt = obj->os_obj_xref_cnt;
if (slowpath(xref_cnt == _OS_OBJECT_GLOBAL_REFCNT)) {
return; // global object
}
xref_cnt = dispatch_atomic_dec2o(obj, os_obj_xref_cnt, relaxed);
if (fastpath(xref_cnt >= 0)) {
return;
}
if (slowpath(xref_cnt < -1)) {
_OS_OBJECT_CLIENT_CRASH("Over-release of an object");
}
return _os_object_xref_dispose(obj);
}
bool
_os_object_retain_weak(_os_object_t obj)
{
int xref_cnt = obj->os_obj_xref_cnt;
if (slowpath(xref_cnt == _OS_OBJECT_GLOBAL_REFCNT)) {
return true; // global object
}
retry:
if (slowpath(xref_cnt == -1)) {
return false;
}
if (slowpath(xref_cnt < -1)) {
goto overrelease;
}
if (slowpath(!dispatch_atomic_cmpxchgvw2o(obj, os_obj_xref_cnt, xref_cnt,
xref_cnt + 1, &xref_cnt, relaxed))) {
goto retry;
}
return true;
overrelease:
_OS_OBJECT_CLIENT_CRASH("Over-release of an object");
}
static voucher_t
_voucher_find_and_retain(mach_voucher_t kv)
{
voucher_t v;
if (!kv) return NULL;
_vouchers_lock_lock();
TAILQ_FOREACH(v, _vouchers_head(kv), v_list) {
if (v->v_ipc_kvoucher == kv) {
int xref_cnt = os_atomic_inc2o(v, os_obj_xref_cnt, relaxed);
_dispatch_voucher_debug("retain -> %d", v, xref_cnt + 1);
if (slowpath(xref_cnt < 0)) {
_dispatch_voucher_debug("over-release", v);
_OS_OBJECT_CLIENT_CRASH("Voucher over-release");
}
if (xref_cnt == 0) {
// resurrection: raced with _voucher_remove
(void)os_atomic_inc2o(v, os_obj_ref_cnt, relaxed);
}
break;
}
}
_vouchers_lock_unlock();
return v;
}
