void
dispatch_resume(dispatch_object_t dou)
{
DISPATCH_OBJECT_TFB(_dispatch_objc_resume, dou);
// Global objects cannot be suspended or resumed. This also has the
// side effect of saturating the suspend count of an object and
// guarding against resuming due to overflow.
if (slowpath(dou._do->do_ref_cnt == DISPATCH_OBJECT_GLOBAL_REFCNT) ||
slowpath(dx_type(dou._do) == DISPATCH_QUEUE_ROOT_TYPE)) {
return;
}
// Check the previous value of the suspend count. If the previous
// value was a single suspend interval, the object should be resumed.
// If the previous value was less than the suspend interval, the object
// has been over-resumed.
unsigned int suspend_cnt = dispatch_atomic_sub_orig2o(dou._do,
do_suspend_cnt, DISPATCH_OBJECT_SUSPEND_INTERVAL, relaxed);
if (fastpath(suspend_cnt > DISPATCH_OBJECT_SUSPEND_INTERVAL)) {
// Balancing the retain() done in suspend() for rdar://8181908
return _dispatch_release(dou._do);
}
if (fastpath(suspend_cnt == DISPATCH_OBJECT_SUSPEND_INTERVAL)) {
return _dispatch_resume_slow(dou);
}
DISPATCH_CLIENT_CRASH("Over-resume of an object");
}
static void
_dispatch_apply_redirect(void *ctxt)
{
dispatch_apply_t da = (dispatch_apply_t)ctxt;
uint32_t da_width = 2 * (da->da_thr_cnt - 1);
dispatch_queue_t dq = da->da_queue, rq = dq, tq;
do {
uint32_t running = dispatch_atomic_add2o(rq, dq_running, da_width);
uint32_t width = rq->dq_width;
if (slowpath(running > width)) {
uint32_t excess = width > 1 ? running - width : da_width;
for (tq = dq; 1; tq = tq->do_targetq) {
(void)dispatch_atomic_sub2o(tq, dq_running, excess);
if (tq == rq) {
break;
}
}
da_width -= excess;
if (slowpath(!da_width)) {
return _dispatch_apply_serial(da);
}
da->da_thr_cnt -= excess / 2;
}
rq = rq->do_targetq;
} while (slowpath(rq->do_targetq));
_dispatch_apply_f2(rq, da, _dispatch_apply3);
do {
(void)dispatch_atomic_sub2o(dq, dq_running, da_width);
dq = dq->do_targetq;
} while (slowpath(dq->do_targetq));
}
void
dispatch_set_finalizer_f(dispatch_object_t dou, dispatch_function_t finalizer)
{
DISPATCH_OBJECT_TFB(_dispatch_objc_set_finalizer_f, dou, finalizer);
if (slowpath(dou._do->do_ref_cnt == DISPATCH_OBJECT_GLOBAL_REFCNT) ||
slowpath(dx_type(dou._do) == DISPATCH_QUEUE_ROOT_TYPE)) {
return;
}
dou._do->do_finalizer = finalizer;
}
void
dispatch_set_context(dispatch_object_t dou, void *context)
{
DISPATCH_OBJECT_TFB(_dispatch_objc_set_context, dou, context);
if (slowpath(dou._do->do_ref_cnt == DISPATCH_OBJECT_GLOBAL_REFCNT) ||
slowpath(dx_type(dou._do) == DISPATCH_QUEUE_ROOT_TYPE)) {
return;
}
dou._do->do_ctxt = context;
}
void *
dispatch_get_context(dispatch_object_t dou)
{
DISPATCH_OBJECT_TFB(_dispatch_objc_get_context, dou);
if (slowpath(dou._do->do_ref_cnt == DISPATCH_OBJECT_GLOBAL_REFCNT) ||
slowpath(dx_type(dou._do) == DISPATCH_QUEUE_ROOT_TYPE)) {
return NULL;
}
return dou._do->do_ctxt;
}
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
_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;
}
void
dispatch_group_leave(dispatch_group_t dg)
{
dispatch_semaphore_t dsema = (dispatch_semaphore_t)dg;
dispatch_atomic_release_barrier();
long value = dispatch_atomic_inc2o(dsema, dsema_value);
if (slowpath(value == LONG_MIN)) {
DISPATCH_CLIENT_CRASH("Unbalanced call to dispatch_group_leave()");
}
if (slowpath(value == dsema->dsema_orig)) {
(void)_dispatch_group_wake(dsema);
}
}
void
dispatch_suspend(dispatch_object_t dou)
{
DISPATCH_OBJECT_TFB(_dispatch_objc_suspend, dou);
if (slowpath(dou._do->do_ref_cnt == DISPATCH_OBJECT_GLOBAL_REFCNT) ||
slowpath(dx_type(dou._do) == DISPATCH_QUEUE_ROOT_TYPE)) {
return;
}
// rdar://8181908 explains why we need to do an internal retain at every
// suspension.
(void)dispatch_atomic_add2o(dou._do, do_suspend_cnt,
DISPATCH_OBJECT_SUSPEND_INTERVAL, relaxed);
_dispatch_retain(dou._do);
}
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;
}
ssize_t IOPoller::_Poll(int timeout){
assert(epoll_fd);
int32_t n, mode;
struct epoll_event *ev;
//TODO: dedicated thread always blocks but others should not
n = epoll_wait(epoll_fd, events, MAXEVENTS, timeout);
if (n == -1) {
if (errno != EINTR) {
return (-1);
}
return (0);
}
//timeout
if(n == 0 ) return 0;
for(int i = 0; i < n; i++) {
ev = &events[i];
if(slowpath(ev->events == 0))
continue;
mode = 0;
if(ev->events & (EPOLLIN|EPOLLRDHUP|EPOLLHUP|EPOLLERR))
mode |= IOHandler::UT_IOREAD;
if(ev->events & (EPOLLOUT|EPOLLHUP|EPOLLERR))
mode |= IOHandler::UT_IOWRITE;
if(fastpath(mode))
ioh.PollReady( *(PollData*) ev->data.ptr , mode);
}
return n;
}
void kThread::initializeMainUT(bool isDefaultKT) {
/*
* if defaultKT, then create a stack for mainUT.
* kernel thread's stack is assigned to initUT.
*/
if (slowpath(isDefaultKT)) {
mainUT = uThread::create(defaultStackSize);
/*
* can't use mainUT->start as mainUT should not end up in
* the Ready Queue. Thus, the stack pointer shoud be initiated
* directly.
*/
mainUT->stackPointer = (vaddr) stackInit(mainUT->stackPointer, (ptr_t) uThread::invoke,
(ptr_t) kThread::defaultRun, (void*)this, nullptr, nullptr); //Initialize the thread context
mainUT->state = uThread::State::READY;
} else {
/*
* Default function takes up the default kernel thread's
* stack pointer and run from there
*/
mainUT = uThread::createMainUT(*localCluster);
currentUT = mainUT;
mainUT->state = uThread::State::RUNNING;
}
//Default uThreads are not being counted
uThread::totalNumberofUTs--;
}
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);
}
dispatch_source_t
dispatch_source_create(dispatch_source_type_t type,
uintptr_t handle,
uintptr_t mask,
dispatch_queue_t q)
{
dispatch_source_t ds = NULL;
static char source_label[sizeof(ds->dq_label)] = "source";
// input validation
if (type == NULL || (mask & ~type->mask)) {
goto out_bad;
}
ds = calloc(1ul, sizeof(struct dispatch_source_s));
if (slowpath(!ds)) {
goto out_bad;
}
// Initialize as a queue first, then override some settings below.
_dispatch_queue_init((dispatch_queue_t)ds);
memcpy(ds->dq_label, source_label, sizeof(source_label));
// Dispatch Object
ds->do_vtable = &_dispatch_source_kevent_vtable;
ds->do_ref_cnt++; // the reference the manger queue holds
ds->do_suspend_cnt = DISPATCH_OBJECT_SUSPEND_INTERVAL;
// do_targetq will be retained below, past point of no-return
ds->do_targetq = q;
if (slowpath(!type->init(ds, type, handle, mask, q))) {
goto out_bad;
}
dispatch_assert(!(ds->ds_is_level && ds->ds_is_adder));
#if DISPATCH_DEBUG
dispatch_debug(as_do(ds), __FUNCTION__);
#endif
_dispatch_retain(as_do(ds->do_targetq));
return ds;
out_bad:
free(ds);
return NULL;
}
void
_dispatch_dispose(dispatch_object_t dou)
{
if (slowpath(dou._do->do_next != DISPATCH_OBJECT_LISTLESS)) {
DISPATCH_CRASH("Release while enqueued");
}
dx_dispose(dou._do);
return _dispatch_dealloc(dou);
}
unsigned long
_os_object_retain_count(_os_object_t obj)
{
int xref_cnt = obj->os_obj_xref_cnt;
if (slowpath(xref_cnt == _OS_OBJECT_GLOBAL_REFCNT)) {
return ULONG_MAX; // global object
}
return (unsigned long)(xref_cnt + 1);
}
int IOPoller::_Close(int fd){
struct epoll_event ev;
int res;
res = epoll_ctl(epoll_fd, EPOLL_CTL_DEL, fd, &ev);
if(slowpath(res < 0 && errno != 2))
std::cerr<< "EPOLL DEL ERROR: " << errno << std::endl;
return res;
}
DISPATCH_ALLOC_NOINLINE
static void
_dispatch_alloc_continuation_free(dispatch_continuation_t c)
{
bitmap_t *b, *s;
unsigned int b_idx, idx;
get_maps_and_indices_for_continuation(c, &s, &b_idx, &b, &idx);
bool bitmap_now_empty = bitmap_clear_bit(b, idx, CLEAR_EXCLUSIVELY);
if (slowpath(s)) {
(void)bitmap_clear_bit(s, b_idx, CLEAR_NONEXCLUSIVELY);
}
// We only try to madvise(2) pages outside of the first page.
// (Allocations in the first page do not have a supermap entry.)
if (slowpath(bitmap_now_empty) && slowpath(s)) {
return _dispatch_alloc_maybe_madvise_page(c);
}
}
void
_dispatch_thread_semaphore_wait(_dispatch_thread_semaphore_t sema)
{
#if USE_MACH_SEM
semaphore_t s4 = (semaphore_t)sema;
kern_return_t kr;
do {
kr = semaphore_wait(s4);
} while (slowpath(kr == KERN_ABORTED));
DISPATCH_SEMAPHORE_VERIFY_KR(kr);
#elif USE_POSIX_SEM
int ret;
do {
ret = sem_wait((sem_t *) sema);
} while (slowpath(ret != 0));
DISPATCH_SEMAPHORE_VERIFY_RET(ret);
#endif
}
void
_dispatch_put_thread_semaphore(_dispatch_thread_semaphore_t sema)
{
_dispatch_thread_semaphore_t old_sema = (_dispatch_thread_semaphore_t)
_dispatch_thread_getspecific(dispatch_sema4_key);
_dispatch_thread_setspecific(dispatch_sema4_key, (void*)sema);
if (slowpath(old_sema)) {
return _dispatch_thread_semaphore_dispose(old_sema);
}
}
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;
}
int IOPoller::_Open(int fd, PollData &pd){
struct epoll_event ev;
ev.events = EPOLLIN|EPOLLOUT|EPOLLRDHUP|EPOLLET;
ev.data.ptr = (void*)&pd;
int res = epoll_ctl(epoll_fd,EPOLL_CTL_ADD, fd, &ev);
if(slowpath(res < 0))
std::cerr<< "EPOLL ADD ERROR: " << errno << std::endl;
return res;
}
_dispatch_thread_semaphore_t
_dispatch_get_thread_semaphore(void)
{
_dispatch_thread_semaphore_t sema = (_dispatch_thread_semaphore_t)
_dispatch_thread_getspecific(dispatch_sema4_key);
if (slowpath(!sema)) {
return _dispatch_thread_semaphore_create();
}
_dispatch_thread_setspecific(dispatch_sema4_key, NULL);
return sema;
}
// Base address of page, or NULL if this page shouldn't be madvise()d
DISPATCH_ALWAYS_INLINE_NDEBUG DISPATCH_CONST
static void *
madvisable_page_base_for_continuation(dispatch_continuation_t c)
{
if (fastpath(continuation_is_in_first_page(c))) {
return NULL;
}
void *page_base = (void *)((uintptr_t)c & ~(uintptr_t)PAGE_MASK);
#if DISPATCH_DEBUG
struct dispatch_magazine_s *m = magazine_for_continuation(c);
if (slowpath(page_base < (void *)&m->conts)) {
DISPATCH_CRASH("madvisable continuation too low");
}
if (slowpath(page_base > (void *)&m->conts[SUPERMAPS_PER_MAGAZINE-1]
[BITMAPS_PER_SUPERMAP-1][CONTINUATIONS_PER_BITMAP-1])) {
DISPATCH_CRASH("madvisable continuation too high");
}
#endif
return page_base;
}
static void
_voucher_insert(voucher_t v)
{
mach_voucher_t kv = v->v_ipc_kvoucher;
if (!kv) return;
_vouchers_lock_lock();
if (slowpath(_TAILQ_IS_ENQUEUED(v, v_list))) {
_dispatch_voucher_debug("corruption", v);
DISPATCH_CLIENT_CRASH(v->v_list.tqe_prev, "Voucher corruption");
}
TAILQ_INSERT_TAIL(_vouchers_head(kv), v, v_list);
_vouchers_lock_unlock();
}
long
dispatch_semaphore_signal(dispatch_semaphore_t dsema)
{
dispatch_atomic_release_barrier();
long value = dispatch_atomic_inc2o(dsema, dsema_value);
if (fastpath(value > 0)) {
return 0;
}
if (slowpath(value == LONG_MIN)) {
DISPATCH_CLIENT_CRASH("Unbalanced call to dispatch_semaphore_signal()");
}
return _dispatch_semaphore_signal_slow(dsema);
}
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
void
_os_object_release_internal(_os_object_t obj)
{
int ref_cnt = obj->os_obj_ref_cnt;
if (slowpath(ref_cnt == _OS_OBJECT_GLOBAL_REFCNT)) {
return; // global object
}
ref_cnt = dispatch_atomic_dec2o(obj, os_obj_ref_cnt, relaxed);
if (fastpath(ref_cnt >= 0)) {
return;
}
if (slowpath(ref_cnt < -1)) {
DISPATCH_CRASH("Over-release of an object");
}
#if DISPATCH_DEBUG
if (slowpath(obj->os_obj_xref_cnt >= 0)) {
DISPATCH_CRASH("Release while external references exist");
}
#endif
return _os_object_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");
}
void
_dispatch_xref_dispose(dispatch_object_t dou)
{
if (slowpath(DISPATCH_OBJECT_SUSPENDED(dou._do))) {
// Arguments for and against this assert are within 6705399
DISPATCH_CLIENT_CRASH("Release of a suspended object");
}
#if !USE_OBJC
if (dx_type(dou._do) == DISPATCH_SOURCE_KEVENT_TYPE) {
_dispatch_source_xref_dispose(dou._ds);
} else if (dou._dq->do_vtable == DISPATCH_VTABLE(queue_runloop)) {
_dispatch_runloop_queue_xref_dispose(dou._dq);
}
return _dispatch_release(dou._os_obj);
#endif
}
