#include "internal.h"
#if HAVE_MACH
#include "protocol.h"
#endif
#if (!HAVE_PTHREAD_WORKQUEUES || DISPATCH_DEBUG) && \
!defined(DISPATCH_ENABLE_THREAD_POOL)
#define DISPATCH_ENABLE_THREAD_POOL 1
#endif
static void _dispatch_cache_cleanup(void *value);
static void _dispatch_async_f_redirect(dispatch_queue_t dq,
dispatch_continuation_t dc);
static void _dispatch_queue_cleanup(void *ctxt);
static bool _dispatch_queue_wakeup_global(dispatch_queue_t dq);
static void _dispatch_queue_drain(dispatch_queue_t dq);
static inline _dispatch_thread_semaphore_t
_dispatch_queue_drain_one_barrier_sync(dispatch_queue_t dq);
static void _dispatch_worker_thread2(void *context);
#if DISPATCH_ENABLE_THREAD_POOL
static void *_dispatch_worker_thread(void *context);
static int _dispatch_pthread_sigmask(int how, sigset_t *set, sigset_t *oset);
#endif
static bool _dispatch_mgr_wakeup(dispatch_queue_t dq);
static dispatch_queue_t _dispatch_mgr_thread(dispatch_queue_t dq);
#if DISPATCH_COCOA_COMPAT
static unsigned int _dispatch_worker_threads;
static dispatch_once_t _dispatch_main_q_port_pred;
static mach_port_t main_q_port;
static void _dispatch_main_q_port_init(void *ctxt);
static void _dispatch_queue_wakeup_main(void);
static void _dispatch_main_queue_drain(void);
#endif
#pragma mark -
#pragma mark dispatch_queue_vtable
const struct dispatch_queue_vtable_s _dispatch_queue_vtable = {
.do_type = DISPATCH_QUEUE_TYPE,
.do_kind = "queue",
.do_dispose = _dispatch_queue_dispose,
.do_invoke = NULL,
.do_probe = (void *)dummy_function_r0,
.do_debug = dispatch_queue_debug,
};
static const struct dispatch_queue_vtable_s _dispatch_queue_root_vtable = {
.do_type = DISPATCH_QUEUE_GLOBAL_TYPE,
.do_kind = "global-queue",
.do_debug = dispatch_queue_debug,
.do_probe = _dispatch_queue_wakeup_global,
};
static const struct dispatch_queue_vtable_s _dispatch_queue_mgr_vtable = {
.do_type = DISPATCH_QUEUE_MGR_TYPE,
.do_kind = "mgr-queue",
.do_invoke = _dispatch_mgr_thread,
.do_debug = dispatch_queue_debug,
.do_probe = _dispatch_mgr_wakeup,
};
#pragma mark -
#pragma mark dispatch_root_queue
#if HAVE_PTHREAD_WORKQUEUES
static const int _dispatch_root_queue_wq_priorities[] = {
[DISPATCH_ROOT_QUEUE_IDX_LOW_PRIORITY] = WORKQ_LOW_PRIOQUEUE,
[DISPATCH_ROOT_QUEUE_IDX_LOW_OVERCOMMIT_PRIORITY] = WORKQ_LOW_PRIOQUEUE,
[DISPATCH_ROOT_QUEUE_IDX_DEFAULT_PRIORITY] = WORKQ_DEFAULT_PRIOQUEUE,
[DISPATCH_ROOT_QUEUE_IDX_DEFAULT_OVERCOMMIT_PRIORITY] =
WORKQ_DEFAULT_PRIOQUEUE,
[DISPATCH_ROOT_QUEUE_IDX_HIGH_PRIORITY] = WORKQ_HIGH_PRIOQUEUE,
[DISPATCH_ROOT_QUEUE_IDX_HIGH_OVERCOMMIT_PRIORITY] = WORKQ_HIGH_PRIOQUEUE,
[DISPATCH_ROOT_QUEUE_IDX_BACKGROUND_PRIORITY] = WORKQ_BG_PRIOQUEUE,
[DISPATCH_ROOT_QUEUE_IDX_BACKGROUND_OVERCOMMIT_PRIORITY] =
WORKQ_BG_PRIOQUEUE,
};
#endif
#if DISPATCH_ENABLE_THREAD_POOL
static struct dispatch_semaphore_s _dispatch_thread_mediator[] = {
[DISPATCH_ROOT_QUEUE_IDX_LOW_PRIORITY] = {
.do_vtable = &_dispatch_semaphore_vtable,
.do_ref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_xref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
},
[DISPATCH_ROOT_QUEUE_IDX_LOW_OVERCOMMIT_PRIORITY] = {
.do_vtable = &_dispatch_semaphore_vtable,
.do_ref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_xref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
},
[DISPATCH_ROOT_QUEUE_IDX_DEFAULT_PRIORITY] = {
.do_vtable = &_dispatch_semaphore_vtable,
.do_ref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_xref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
},
[DISPATCH_ROOT_QUEUE_IDX_DEFAULT_OVERCOMMIT_PRIORITY] = {
.do_vtable = &_dispatch_semaphore_vtable,
.do_ref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_xref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
},
[DISPATCH_ROOT_QUEUE_IDX_HIGH_PRIORITY] = {
.do_vtable = &_dispatch_semaphore_vtable,
.do_ref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_xref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
},
[DISPATCH_ROOT_QUEUE_IDX_HIGH_OVERCOMMIT_PRIORITY] = {
.do_vtable = &_dispatch_semaphore_vtable,
.do_ref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_xref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
},
[DISPATCH_ROOT_QUEUE_IDX_BACKGROUND_PRIORITY] = {
.do_vtable = &_dispatch_semaphore_vtable,
.do_ref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_xref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
},
[DISPATCH_ROOT_QUEUE_IDX_BACKGROUND_OVERCOMMIT_PRIORITY] = {
.do_vtable = &_dispatch_semaphore_vtable,
.do_ref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_xref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
},
};
#endif
#define MAX_THREAD_COUNT 255
struct dispatch_root_queue_context_s {
#if HAVE_PTHREAD_WORKQUEUES
pthread_workqueue_t dgq_kworkqueue;
#endif
uint32_t dgq_pending;
#if DISPATCH_ENABLE_THREAD_POOL
uint32_t dgq_thread_pool_size;
dispatch_semaphore_t dgq_thread_mediator;
#endif
};
static struct dispatch_root_queue_context_s _dispatch_root_queue_contexts[] = {
[DISPATCH_ROOT_QUEUE_IDX_LOW_PRIORITY] = {
#if DISPATCH_ENABLE_THREAD_POOL
.dgq_thread_mediator = &_dispatch_thread_mediator[
DISPATCH_ROOT_QUEUE_IDX_LOW_PRIORITY],
.dgq_thread_pool_size = MAX_THREAD_COUNT,
#endif
},
[DISPATCH_ROOT_QUEUE_IDX_LOW_OVERCOMMIT_PRIORITY] = {
#if DISPATCH_ENABLE_THREAD_POOL
.dgq_thread_mediator = &_dispatch_thread_mediator[
DISPATCH_ROOT_QUEUE_IDX_LOW_OVERCOMMIT_PRIORITY],
.dgq_thread_pool_size = MAX_THREAD_COUNT,
#endif
},
[DISPATCH_ROOT_QUEUE_IDX_DEFAULT_PRIORITY] = {
#if DISPATCH_ENABLE_THREAD_POOL
.dgq_thread_mediator = &_dispatch_thread_mediator[
DISPATCH_ROOT_QUEUE_IDX_DEFAULT_PRIORITY],
.dgq_thread_pool_size = MAX_THREAD_COUNT,
#endif
},
[DISPATCH_ROOT_QUEUE_IDX_DEFAULT_OVERCOMMIT_PRIORITY] = {
#if DISPATCH_ENABLE_THREAD_POOL
.dgq_thread_mediator = &_dispatch_thread_mediator[
DISPATCH_ROOT_QUEUE_IDX_DEFAULT_OVERCOMMIT_PRIORITY],
.dgq_thread_pool_size = MAX_THREAD_COUNT,
#endif
},
[DISPATCH_ROOT_QUEUE_IDX_HIGH_PRIORITY] = {
#if DISPATCH_ENABLE_THREAD_POOL
.dgq_thread_mediator = &_dispatch_thread_mediator[
DISPATCH_ROOT_QUEUE_IDX_HIGH_PRIORITY],
.dgq_thread_pool_size = MAX_THREAD_COUNT,
#endif
},
[DISPATCH_ROOT_QUEUE_IDX_HIGH_OVERCOMMIT_PRIORITY] = {
#if DISPATCH_ENABLE_THREAD_POOL
.dgq_thread_mediator = &_dispatch_thread_mediator[
DISPATCH_ROOT_QUEUE_IDX_HIGH_OVERCOMMIT_PRIORITY],
.dgq_thread_pool_size = MAX_THREAD_COUNT,
#endif
},
[DISPATCH_ROOT_QUEUE_IDX_BACKGROUND_PRIORITY] = {
#if DISPATCH_ENABLE_THREAD_POOL
.dgq_thread_mediator = &_dispatch_thread_mediator[
DISPATCH_ROOT_QUEUE_IDX_BACKGROUND_PRIORITY],
.dgq_thread_pool_size = MAX_THREAD_COUNT,
#endif
},
[DISPATCH_ROOT_QUEUE_IDX_BACKGROUND_OVERCOMMIT_PRIORITY] = {
#if DISPATCH_ENABLE_THREAD_POOL
.dgq_thread_mediator = &_dispatch_thread_mediator[
DISPATCH_ROOT_QUEUE_IDX_BACKGROUND_OVERCOMMIT_PRIORITY],
.dgq_thread_pool_size = MAX_THREAD_COUNT,
#endif
},
};
DISPATCH_CACHELINE_ALIGN
struct dispatch_queue_s _dispatch_root_queues[] = {
[DISPATCH_ROOT_QUEUE_IDX_LOW_PRIORITY] = {
.do_vtable = &_dispatch_queue_root_vtable,
.do_ref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_xref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_suspend_cnt = DISPATCH_OBJECT_SUSPEND_LOCK,
.do_ctxt = &_dispatch_root_queue_contexts[
DISPATCH_ROOT_QUEUE_IDX_LOW_PRIORITY],
.dq_label = "com.apple.root.low-priority",
.dq_running = 2,
.dq_width = UINT32_MAX,
.dq_serialnum = 4,
},
[DISPATCH_ROOT_QUEUE_IDX_LOW_OVERCOMMIT_PRIORITY] = {
.do_vtable = &_dispatch_queue_root_vtable,
.do_ref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_xref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_suspend_cnt = DISPATCH_OBJECT_SUSPEND_LOCK,
.do_ctxt = &_dispatch_root_queue_contexts[
DISPATCH_ROOT_QUEUE_IDX_LOW_OVERCOMMIT_PRIORITY],
.dq_label = "com.apple.root.low-overcommit-priority",
.dq_running = 2,
.dq_width = UINT32_MAX,
.dq_serialnum = 5,
},
[DISPATCH_ROOT_QUEUE_IDX_DEFAULT_PRIORITY] = {
.do_vtable = &_dispatch_queue_root_vtable,
.do_ref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_xref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_suspend_cnt = DISPATCH_OBJECT_SUSPEND_LOCK,
.do_ctxt = &_dispatch_root_queue_contexts[
DISPATCH_ROOT_QUEUE_IDX_DEFAULT_PRIORITY],
.dq_label = "com.apple.root.default-priority",
.dq_running = 2,
.dq_width = UINT32_MAX,
.dq_serialnum = 6,
},
[DISPATCH_ROOT_QUEUE_IDX_DEFAULT_OVERCOMMIT_PRIORITY] = {
.do_vtable = &_dispatch_queue_root_vtable,
.do_ref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_xref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_suspend_cnt = DISPATCH_OBJECT_SUSPEND_LOCK,
.do_ctxt = &_dispatch_root_queue_contexts[
DISPATCH_ROOT_QUEUE_IDX_DEFAULT_OVERCOMMIT_PRIORITY],
.dq_label = "com.apple.root.default-overcommit-priority",
.dq_running = 2,
.dq_width = UINT32_MAX,
.dq_serialnum = 7,
},
[DISPATCH_ROOT_QUEUE_IDX_HIGH_PRIORITY] = {
.do_vtable = &_dispatch_queue_root_vtable,
.do_ref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_xref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_suspend_cnt = DISPATCH_OBJECT_SUSPEND_LOCK,
.do_ctxt = &_dispatch_root_queue_contexts[
DISPATCH_ROOT_QUEUE_IDX_HIGH_PRIORITY],
.dq_label = "com.apple.root.high-priority",
.dq_running = 2,
.dq_width = UINT32_MAX,
.dq_serialnum = 8,
},
[DISPATCH_ROOT_QUEUE_IDX_HIGH_OVERCOMMIT_PRIORITY] = {
.do_vtable = &_dispatch_queue_root_vtable,
.do_ref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_xref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_suspend_cnt = DISPATCH_OBJECT_SUSPEND_LOCK,
.do_ctxt = &_dispatch_root_queue_contexts[
DISPATCH_ROOT_QUEUE_IDX_HIGH_OVERCOMMIT_PRIORITY],
.dq_label = "com.apple.root.high-overcommit-priority",
.dq_running = 2,
.dq_width = UINT32_MAX,
.dq_serialnum = 9,
},
[DISPATCH_ROOT_QUEUE_IDX_BACKGROUND_PRIORITY] = {
.do_vtable = &_dispatch_queue_root_vtable,
.do_ref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_xref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_suspend_cnt = DISPATCH_OBJECT_SUSPEND_LOCK,
.do_ctxt = &_dispatch_root_queue_contexts[
DISPATCH_ROOT_QUEUE_IDX_BACKGROUND_PRIORITY],
.dq_label = "com.apple.root.background-priority",
.dq_running = 2,
.dq_width = UINT32_MAX,
.dq_serialnum = 10,
},
[DISPATCH_ROOT_QUEUE_IDX_BACKGROUND_OVERCOMMIT_PRIORITY] = {
.do_vtable = &_dispatch_queue_root_vtable,
.do_ref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_xref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_suspend_cnt = DISPATCH_OBJECT_SUSPEND_LOCK,
.do_ctxt = &_dispatch_root_queue_contexts[
DISPATCH_ROOT_QUEUE_IDX_BACKGROUND_OVERCOMMIT_PRIORITY],
.dq_label = "com.apple.root.background-overcommit-priority",
.dq_running = 2,
.dq_width = UINT32_MAX,
.dq_serialnum = 11,
},
};
DISPATCH_CACHELINE_ALIGN
struct dispatch_queue_s _dispatch_mgr_q = {
.do_vtable = &_dispatch_queue_mgr_vtable,
.do_ref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_xref_cnt = DISPATCH_OBJECT_GLOBAL_REFCNT,
.do_suspend_cnt = DISPATCH_OBJECT_SUSPEND_LOCK,
.do_targetq = &_dispatch_root_queues[
DISPATCH_ROOT_QUEUE_IDX_HIGH_OVERCOMMIT_PRIORITY],
.dq_label = "com.apple.libdispatch-manager",
.dq_width = 1,
.dq_serialnum = 2,
};
dispatch_queue_t
dispatch_get_global_queue(long priority, unsigned long flags)
{
if (flags & ~DISPATCH_QUEUE_OVERCOMMIT) {
return NULL;
}
return _dispatch_get_root_queue(priority,
flags & DISPATCH_QUEUE_OVERCOMMIT);
}
dispatch_queue_t
dispatch_get_current_queue(void)
{
return _dispatch_queue_get_current() ?: _dispatch_get_root_queue(0, true);
}
#pragma mark -
#pragma mark dispatch_init
static void
_dispatch_hw_config_init(void)
{
_dispatch_hw_config.cc_max_active = _dispatch_get_activecpu();
_dispatch_hw_config.cc_max_logical = _dispatch_get_logicalcpu_max();
_dispatch_hw_config.cc_max_physical = _dispatch_get_physicalcpu_max();
}
static inline bool
_dispatch_root_queues_init_workq(void)
{
bool result = false;
#if HAVE_PTHREAD_WORKQUEUES
#if DISPATCH_ENABLE_THREAD_POOL
if (slowpath(getenv("LIBDISPATCH_DISABLE_KWQ"))) return result;
#endif
int i, r;
pthread_workqueue_attr_t pwq_attr;
r = pthread_workqueue_attr_init_np(&pwq_attr);
(void)dispatch_assume_zero(r);
for (i = 0; i < DISPATCH_ROOT_QUEUE_COUNT; i++) {
pthread_workqueue_t pwq = NULL;
const int prio = _dispatch_root_queue_wq_priorities[i];
r = pthread_workqueue_attr_setqueuepriority_np(&pwq_attr, prio);
(void)dispatch_assume_zero(r);
r = pthread_workqueue_attr_setovercommit_np(&pwq_attr, i & 1);
(void)dispatch_assume_zero(r);
r = pthread_workqueue_create_np(&pwq, &pwq_attr);
(void)dispatch_assume_zero(r);
result = result || dispatch_assume(pwq);
_dispatch_root_queue_contexts[i].dgq_kworkqueue = pwq;
}
r = pthread_workqueue_attr_destroy_np(&pwq_attr);
(void)dispatch_assume_zero(r);
#endif // HAVE_PTHREAD_WORKQUEUES
return result;
}
static inline void
_dispatch_root_queues_init_thread_pool(void)
{
#if DISPATCH_ENABLE_THREAD_POOL
int i;
for (i = 0; i < DISPATCH_ROOT_QUEUE_COUNT; i++) {
#if TARGET_OS_EMBEDDED
if (!(i & 1)) {
_dispatch_root_queue_contexts[i].dgq_thread_pool_size =
_dispatch_hw_config.cc_max_active;
}
#endif
#if USE_MACH_SEM
kern_return_t kr = semaphore_create(mach_task_self(),
&_dispatch_thread_mediator[i].dsema_port, SYNC_POLICY_LIFO, 0);
DISPATCH_VERIFY_MIG(kr);
(void)dispatch_assume_zero(kr);
(void)dispatch_assume(_dispatch_thread_mediator[i].dsema_port);
#elif USE_POSIX_SEM
int ret = sem_init(&_dispatch_thread_mediator[i].dsema_sem, 0, 0);
(void)dispatch_assume_zero(ret);
#endif
}
#else
DISPATCH_CRASH("Thread pool creation failed");
#endif // DISPATCH_ENABLE_THREAD_POOL
}
static void
_dispatch_root_queues_init(void *context DISPATCH_UNUSED)
{
if (!_dispatch_root_queues_init_workq()) {
_dispatch_root_queues_init_thread_pool();
}
}
#define countof(x) (sizeof(x) / sizeof(x[0]))
DISPATCH_EXPORT DISPATCH_NOTHROW
void
libdispatch_init(void)
{
dispatch_assert(DISPATCH_QUEUE_PRIORITY_COUNT == 4);
dispatch_assert(DISPATCH_ROOT_QUEUE_COUNT == 8);
dispatch_assert(DISPATCH_QUEUE_PRIORITY_LOW ==
-DISPATCH_QUEUE_PRIORITY_HIGH);
dispatch_assert(countof(_dispatch_root_queues) ==
DISPATCH_ROOT_QUEUE_COUNT);
dispatch_assert(countof(_dispatch_root_queue_contexts) ==
DISPATCH_ROOT_QUEUE_COUNT);
#if HAVE_PTHREAD_WORKQUEUES
dispatch_assert(countof(_dispatch_root_queue_wq_priorities) ==
DISPATCH_ROOT_QUEUE_COUNT);
#endif
#if DISPATCH_ENABLE_THREAD_POOL
dispatch_assert(countof(_dispatch_thread_mediator) ==
DISPATCH_ROOT_QUEUE_COUNT);
#endif
dispatch_assert(sizeof(struct dispatch_source_s) ==
sizeof(struct dispatch_queue_s) - DISPATCH_QUEUE_CACHELINE_PAD);
#if DISPATCH_DEBUG
dispatch_assert(sizeof(struct dispatch_queue_s) % DISPATCH_CACHELINE_SIZE
== 0);
#endif
_dispatch_thread_key_create(&dispatch_queue_key, _dispatch_queue_cleanup);
_dispatch_thread_key_create(&dispatch_sema4_key,
(void (*)(void *))_dispatch_thread_semaphore_dispose);
_dispatch_thread_key_create(&dispatch_cache_key, _dispatch_cache_cleanup);
_dispatch_thread_key_create(&dispatch_io_key, NULL);
_dispatch_thread_key_create(&dispatch_apply_key, NULL);
#if DISPATCH_PERF_MON
_dispatch_thread_key_create(&dispatch_bcounter_key, NULL);
#endif
#if DISPATCH_USE_RESOLVERS // rdar://problem/8541707
_dispatch_main_q.do_vtable = &_dispatch_queue_vtable;
_dispatch_main_q.do_targetq = &_dispatch_root_queues[
DISPATCH_ROOT_QUEUE_IDX_DEFAULT_OVERCOMMIT_PRIORITY];
_dispatch_data_empty.do_vtable = &_dispatch_data_vtable;
#endif
_dispatch_thread_setspecific(dispatch_queue_key, &_dispatch_main_q);
#if DISPATCH_USE_PTHREAD_ATFORK
(void)dispatch_assume_zero(pthread_atfork(dispatch_atfork_prepare,
dispatch_atfork_parent, dispatch_atfork_child));
#endif
_dispatch_hw_config_init();
}
DISPATCH_EXPORT DISPATCH_NOTHROW
void
dispatch_atfork_child(void)
{
void *crash = (void *)0x100;
size_t i;
if (_dispatch_safe_fork) {
return;
}
_dispatch_main_q.dq_items_head = crash;
_dispatch_main_q.dq_items_tail = crash;
_dispatch_mgr_q.dq_items_head = crash;
_dispatch_mgr_q.dq_items_tail = crash;
for (i = 0; i < DISPATCH_ROOT_QUEUE_COUNT; i++) {
_dispatch_root_queues[i].dq_items_head = crash;
_dispatch_root_queues[i].dq_items_tail = crash;
}
}
#pragma mark -
#pragma mark dispatch_queue_t
unsigned long _dispatch_queue_serial_numbers = 12;
dispatch_queue_t
dispatch_queue_create(const char *label, dispatch_queue_attr_t attr)
{
dispatch_queue_t dq;
size_t label_len;
if (!label) {
label = "";
}
label_len = strlen(label);
if (label_len < (DISPATCH_QUEUE_MIN_LABEL_SIZE - 1)) {
label_len = (DISPATCH_QUEUE_MIN_LABEL_SIZE - 1);
}
dq = calloc(1ul, sizeof(struct dispatch_queue_s) -
DISPATCH_QUEUE_MIN_LABEL_SIZE - DISPATCH_QUEUE_CACHELINE_PAD +
label_len + 1);
if (slowpath(!dq)) {
return dq;
}
_dispatch_queue_init(dq);
strcpy(dq->dq_label, label);
if (fastpath(!attr)) {
return dq;
}
if (fastpath(attr == DISPATCH_QUEUE_CONCURRENT)) {
dq->dq_width = UINT32_MAX;
dq->do_targetq = _dispatch_get_root_queue(0, false);
} else {
dispatch_debug_assert(!attr, "Invalid attribute");
}
return dq;
}
void
_dispatch_queue_dispose(dispatch_queue_t dq)
{
if (slowpath(dq == _dispatch_queue_get_current())) {
DISPATCH_CRASH("Release of a queue by itself");
}
if (slowpath(dq->dq_items_tail)) {
DISPATCH_CRASH("Release of a queue while items are enqueued");
}
dq->dq_items_tail = (void *)0x200;
dispatch_queue_t dqsq = dispatch_atomic_xchg2o(dq, dq_specific_q,
(void *)0x200);
if (dqsq) {
_dispatch_release(dqsq);
}
_dispatch_dispose(dq);
}
const char *
dispatch_queue_get_label(dispatch_queue_t dq)
{
return dq->dq_label;
}
static void
_dispatch_queue_set_width2(void *ctxt)
{
int w = (int)(intptr_t)ctxt; uint32_t tmp;
dispatch_queue_t dq = _dispatch_queue_get_current();
if (w == 1 || w == 0) {
dq->dq_width = 1;
return;
}
if (w > 0) {
tmp = w;
} else switch (w) {
case DISPATCH_QUEUE_WIDTH_MAX_PHYSICAL_CPUS:
tmp = _dispatch_hw_config.cc_max_physical;
break;
case DISPATCH_QUEUE_WIDTH_ACTIVE_CPUS:
tmp = _dispatch_hw_config.cc_max_active;
break;
default:
case DISPATCH_QUEUE_WIDTH_MAX_LOGICAL_CPUS:
tmp = _dispatch_hw_config.cc_max_logical;
break;
}
dq->dq_width = tmp * 2;
}
void
dispatch_queue_set_width(dispatch_queue_t dq, long width)
{
if (slowpath(dq->do_ref_cnt == DISPATCH_OBJECT_GLOBAL_REFCNT)) {
return;
}
dispatch_barrier_async_f(dq, (void*)(intptr_t)width,
_dispatch_queue_set_width2);
}
static void
_dispatch_set_target_queue2(void *ctxt)
{
dispatch_queue_t prev_dq, dq = _dispatch_queue_get_current();
prev_dq = dq->do_targetq;
dq->do_targetq = ctxt;
_dispatch_release(prev_dq);
}
void
dispatch_set_target_queue(dispatch_object_t dou, dispatch_queue_t dq)
{
dispatch_queue_t prev_dq;
unsigned long type;
if (slowpath(dou._do->do_xref_cnt == DISPATCH_OBJECT_GLOBAL_REFCNT)) {
return;
}
type = dx_type(dou._do) & _DISPATCH_META_TYPE_MASK;
if (slowpath(!dq)) {
bool is_concurrent_q = (type == _DISPATCH_QUEUE_TYPE &&
slowpath(dou._dq->dq_width > 1));
dq = _dispatch_get_root_queue(0, !is_concurrent_q);
}
switch(type) {
case _DISPATCH_QUEUE_TYPE:
case _DISPATCH_SOURCE_TYPE:
_dispatch_retain(dq);
return dispatch_barrier_async_f(dou._dq, dq,
_dispatch_set_target_queue2);
case _DISPATCH_IO_TYPE:
return _dispatch_io_set_target_queue(dou._dchannel, dq);
default:
_dispatch_retain(dq);
dispatch_atomic_store_barrier();
prev_dq = dispatch_atomic_xchg2o(dou._do, do_targetq, dq);
if (prev_dq) _dispatch_release(prev_dq);
return;
}
}
void
dispatch_set_current_target_queue(dispatch_queue_t dq)
{
dispatch_queue_t queue = _dispatch_queue_get_current();
if (slowpath(!queue)) {
DISPATCH_CLIENT_CRASH("SPI not called from a queue");
}
if (slowpath(queue->do_xref_cnt == DISPATCH_OBJECT_GLOBAL_REFCNT)) {
DISPATCH_CLIENT_CRASH("SPI not supported on this queue");
}
if (slowpath(queue->dq_width != 1)) {
DISPATCH_CLIENT_CRASH("SPI not called from a serial queue");
}
if (slowpath(!dq)) {
dq = _dispatch_get_root_queue(0, true);
}
_dispatch_retain(dq);
_dispatch_set_target_queue2(dq);
}
#pragma mark -
#pragma mark dispatch_queue_specific
struct dispatch_queue_specific_queue_s {
DISPATCH_STRUCT_HEADER(dispatch_queue_specific_queue_s,
dispatch_queue_specific_queue_vtable_s);
DISPATCH_QUEUE_HEADER;
union {
char _dqsq_pad[DISPATCH_QUEUE_MIN_LABEL_SIZE];
struct {
char dq_label[16];
TAILQ_HEAD(dispatch_queue_specific_head_s,
dispatch_queue_specific_s) dqsq_contexts;
};
};
};
DISPATCH_DECL(dispatch_queue_specific_queue);
static void
_dispatch_queue_specific_queue_dispose(dispatch_queue_specific_queue_t dqsq);
struct dispatch_queue_specific_queue_vtable_s {
DISPATCH_VTABLE_HEADER(dispatch_queue_specific_queue_s);
};
static const struct dispatch_queue_specific_queue_vtable_s
_dispatch_queue_specific_queue_vtable = {
.do_type = DISPATCH_QUEUE_SPECIFIC_TYPE,
.do_kind = "queue-context",
.do_dispose = _dispatch_queue_specific_queue_dispose,
.do_invoke = NULL,
.do_probe = (void *)dummy_function_r0,
.do_debug = (void *)dispatch_queue_debug,
};
struct dispatch_queue_specific_s {
const void *dqs_key;
void *dqs_ctxt;
dispatch_function_t dqs_destructor;
TAILQ_ENTRY(dispatch_queue_specific_s) dqs_list;
};
DISPATCH_DECL(dispatch_queue_specific);
static void
_dispatch_queue_specific_queue_dispose(dispatch_queue_specific_queue_t dqsq)
{
dispatch_queue_specific_t dqs, tmp;
TAILQ_FOREACH_SAFE(dqs, &dqsq->dqsq_contexts, dqs_list, tmp) {
if (dqs->dqs_destructor) {
dispatch_async_f(_dispatch_get_root_queue(
DISPATCH_QUEUE_PRIORITY_DEFAULT, false), dqs->dqs_ctxt,
dqs->dqs_destructor);
}
free(dqs);
}
_dispatch_queue_dispose((dispatch_queue_t)dqsq);
}
static void
_dispatch_queue_init_specific(dispatch_queue_t dq)
{
dispatch_queue_specific_queue_t dqsq;
dqsq = calloc(1ul, sizeof(struct dispatch_queue_specific_queue_s));
_dispatch_queue_init((dispatch_queue_t)dqsq);
dqsq->do_vtable = &_dispatch_queue_specific_queue_vtable;
dqsq->do_xref_cnt = 0;
dqsq->do_targetq = _dispatch_get_root_queue(DISPATCH_QUEUE_PRIORITY_HIGH,
true);
dqsq->dq_width = UINT32_MAX;
strlcpy(dqsq->dq_label, "queue-specific", sizeof(dqsq->dq_label));
TAILQ_INIT(&dqsq->dqsq_contexts);
dispatch_atomic_store_barrier();
if (slowpath(!dispatch_atomic_cmpxchg2o(dq, dq_specific_q, NULL, dqsq))) {
_dispatch_release((dispatch_queue_t)dqsq);
}
}
static void
_dispatch_queue_set_specific(void *ctxt)
{
dispatch_queue_specific_t dqs, dqsn = ctxt;
dispatch_queue_specific_queue_t dqsq =
(dispatch_queue_specific_queue_t)_dispatch_queue_get_current();
TAILQ_FOREACH(dqs, &dqsq->dqsq_contexts, dqs_list) {
if (dqs->dqs_key == dqsn->dqs_key) {
if (dqs->dqs_destructor) {
dispatch_async_f(_dispatch_get_root_queue(
DISPATCH_QUEUE_PRIORITY_DEFAULT, false), dqs->dqs_ctxt,
dqs->dqs_destructor);
}
if (dqsn->dqs_ctxt) {
dqs->dqs_ctxt = dqsn->dqs_ctxt;
dqs->dqs_destructor = dqsn->dqs_destructor;
} else {
TAILQ_REMOVE(&dqsq->dqsq_contexts, dqs, dqs_list);
free(dqs);
}
return free(dqsn);
}
}
TAILQ_INSERT_TAIL(&dqsq->dqsq_contexts, dqsn, dqs_list);
}
DISPATCH_NOINLINE
void
dispatch_queue_set_specific(dispatch_queue_t dq, const void *key,
void *ctxt, dispatch_function_t destructor)
{
if (slowpath(!key)) {
return;
}
dispatch_queue_specific_t dqs;
dqs = calloc(1, sizeof(struct dispatch_queue_specific_s));
dqs->dqs_key = key;
dqs->dqs_ctxt = ctxt;
dqs->dqs_destructor = destructor;
if (slowpath(!dq->dq_specific_q)) {
_dispatch_queue_init_specific(dq);
}
dispatch_barrier_async_f(dq->dq_specific_q, dqs,
_dispatch_queue_set_specific);
}
static void
_dispatch_queue_get_specific(void *ctxt)
{
void **ctxtp = ctxt;
void *key = *ctxtp;
dispatch_queue_specific_queue_t dqsq =
(dispatch_queue_specific_queue_t)_dispatch_queue_get_current();
dispatch_queue_specific_t dqs;
TAILQ_FOREACH(dqs, &dqsq->dqsq_contexts, dqs_list) {
if (dqs->dqs_key == key) {
*ctxtp = dqs->dqs_ctxt;
return;
}
}
*ctxtp = NULL;
}
DISPATCH_NOINLINE
void *
dispatch_queue_get_specific(dispatch_queue_t dq, const void *key)
{
if (slowpath(!key)) {
return NULL;
}
void *ctxt = NULL;
if (fastpath(dq->dq_specific_q)) {
ctxt = (void *)key;
dispatch_sync_f(dq->dq_specific_q, &ctxt, _dispatch_queue_get_specific);
}
return ctxt;
}
DISPATCH_NOINLINE
void *
dispatch_get_specific(const void *key)
{
if (slowpath(!key)) {
return NULL;
}
void *ctxt = NULL;
dispatch_queue_t dq = _dispatch_queue_get_current();
while (slowpath(dq)) {
if (slowpath(dq->dq_specific_q)) {
ctxt = (void *)key;
dispatch_sync_f(dq->dq_specific_q, &ctxt,
_dispatch_queue_get_specific);
if (ctxt) break;
}
dq = dq->do_targetq;
}
return ctxt;
}
#pragma mark -
#pragma mark dispatch_queue_debug
size_t
_dispatch_queue_debug_attr(dispatch_queue_t dq, char* buf, size_t bufsiz)
{
dispatch_queue_t target = dq->do_targetq;
return snprintf(buf, bufsiz, "target = %s[%p], width = 0x%x, "
"running = 0x%x, barrier = %d ", target ? target->dq_label : "",
target, dq->dq_width / 2, dq->dq_running / 2, dq->dq_running & 1);
}
size_t
dispatch_queue_debug(dispatch_queue_t dq, char* buf, size_t bufsiz)
{
size_t offset = 0;
offset += snprintf(&buf[offset], bufsiz - offset, "%s[%p] = { ",
dq->dq_label, dq);
offset += _dispatch_object_debug_attr(dq, &buf[offset], bufsiz - offset);
offset += _dispatch_queue_debug_attr(dq, &buf[offset], bufsiz - offset);
offset += snprintf(&buf[offset], bufsiz - offset, "}");
return offset;
}
#if DISPATCH_DEBUG
void
dispatch_debug_queue(dispatch_queue_t dq, const char* str) {
if (fastpath(dq)) {
dispatch_debug(dq, "%s", str);
} else {
_dispatch_log("queue[NULL]: %s", str);
}
}
#endif
#if DISPATCH_PERF_MON
static OSSpinLock _dispatch_stats_lock;
static size_t _dispatch_bad_ratio;
static struct {
uint64_t time_total;
uint64_t count_total;
uint64_t thread_total;
} _dispatch_stats[65];
static void
_dispatch_queue_merge_stats(uint64_t start)
{
uint64_t avg, delta = _dispatch_absolute_time() - start;
unsigned long count, bucket;
count = (size_t)_dispatch_thread_getspecific(dispatch_bcounter_key);
_dispatch_thread_setspecific(dispatch_bcounter_key, NULL);
if (count) {
avg = delta / count;
bucket = flsll(avg);
} else {
bucket = 0;
}
OSSpinLockLock(&_dispatch_stats_lock);
_dispatch_stats[bucket].time_total += delta;
_dispatch_stats[bucket].count_total += count;
_dispatch_stats[bucket].thread_total++;
OSSpinLockUnlock(&_dispatch_stats_lock);
}
#endif
#pragma mark -
#pragma mark dispatch_continuation_t
static malloc_zone_t *_dispatch_ccache_zone;
static void
_dispatch_ccache_init(void *context DISPATCH_UNUSED)
{
_dispatch_ccache_zone = malloc_create_zone(0, 0);
dispatch_assert(_dispatch_ccache_zone);
malloc_set_zone_name(_dispatch_ccache_zone, "DispatchContinuations");
}
static dispatch_continuation_t
_dispatch_continuation_alloc_from_heap(void)
{
static dispatch_once_t pred;
dispatch_continuation_t dc;
dispatch_once_f(&pred, NULL, _dispatch_ccache_init);
while (!(dc = fastpath(malloc_zone_calloc(_dispatch_ccache_zone, 1,
ROUND_UP_TO_CACHELINE_SIZE(sizeof(*dc)))))) {
sleep(1);
}
return dc;
}
DISPATCH_ALWAYS_INLINE
static inline dispatch_continuation_t
_dispatch_continuation_alloc_cacheonly(void)
{
dispatch_continuation_t dc;
dc = fastpath(_dispatch_thread_getspecific(dispatch_cache_key));
if (dc) {
_dispatch_thread_setspecific(dispatch_cache_key, dc->do_next);
}
return dc;
}
static void
_dispatch_force_cache_cleanup(void)
{
dispatch_continuation_t dc;
dc = _dispatch_thread_getspecific(dispatch_cache_key);
if (dc) {
_dispatch_thread_setspecific(dispatch_cache_key, NULL);
_dispatch_cache_cleanup(dc);
}
}
DISPATCH_NOINLINE
static void
_dispatch_cache_cleanup(void *value)
{
dispatch_continuation_t dc, next_dc = value;
while ((dc = next_dc)) {
next_dc = dc->do_next;
malloc_zone_free(_dispatch_ccache_zone, dc);
}
}
DISPATCH_ALWAYS_INLINE
static inline void
_dispatch_continuation_free(dispatch_continuation_t dc)
{
dispatch_continuation_t prev_dc;
prev_dc = _dispatch_thread_getspecific(dispatch_cache_key);
dc->do_next = prev_dc;
_dispatch_thread_setspecific(dispatch_cache_key, dc);
}
DISPATCH_ALWAYS_INLINE_NDEBUG
static inline void
_dispatch_continuation_redirect(dispatch_queue_t dq, dispatch_object_t dou)
{
dispatch_continuation_t dc = dou._dc;
_dispatch_trace_continuation_pop(dq, dou);
(void)dispatch_atomic_add2o(dq, dq_running, 2);
if (!DISPATCH_OBJ_IS_VTABLE(dc) &&
(long)dc->do_vtable & DISPATCH_OBJ_SYNC_SLOW_BIT) {
dispatch_atomic_barrier();
_dispatch_thread_semaphore_signal(
(_dispatch_thread_semaphore_t)dc->dc_ctxt);
} else {
_dispatch_async_f_redirect(dq, dc);
}
}
DISPATCH_ALWAYS_INLINE_NDEBUG
static inline void
_dispatch_continuation_pop(dispatch_object_t dou)
{
dispatch_continuation_t dc = dou._dc;
dispatch_group_t dg;
_dispatch_trace_continuation_pop(_dispatch_queue_get_current(), dou);
if (DISPATCH_OBJ_IS_VTABLE(dou._do)) {
return _dispatch_queue_invoke(dou._dq);
}
if ((long)dc->do_vtable & DISPATCH_OBJ_ASYNC_BIT) {
_dispatch_continuation_free(dc);
}
if ((long)dc->do_vtable & DISPATCH_OBJ_GROUP_BIT) {
dg = dc->dc_group;
} else {
dg = NULL;
}
_dispatch_client_callout(dc->dc_ctxt, dc->dc_func);
if (dg) {
dispatch_group_leave(dg);
_dispatch_release(dg);
}
}
#pragma mark -
#pragma mark dispatch_barrier_async
DISPATCH_NOINLINE
static void
_dispatch_barrier_async_f_slow(dispatch_queue_t dq, void *ctxt,
dispatch_function_t func)
{
dispatch_continuation_t dc = _dispatch_continuation_alloc_from_heap();
dc->do_vtable = (void *)(DISPATCH_OBJ_ASYNC_BIT | DISPATCH_OBJ_BARRIER_BIT);
dc->dc_func = func;
dc->dc_ctxt = ctxt;
_dispatch_queue_push(dq, dc);
}
DISPATCH_NOINLINE
void
dispatch_barrier_async_f(dispatch_queue_t dq, void *ctxt,
dispatch_function_t func)
{
dispatch_continuation_t dc;
dc = fastpath(_dispatch_continuation_alloc_cacheonly());
if (!dc) {
return _dispatch_barrier_async_f_slow(dq, ctxt, func);
}
dc->do_vtable = (void *)(DISPATCH_OBJ_ASYNC_BIT | DISPATCH_OBJ_BARRIER_BIT);
dc->dc_func = func;
dc->dc_ctxt = ctxt;
_dispatch_queue_push(dq, dc);
}
#ifdef __BLOCKS__
void
dispatch_barrier_async(dispatch_queue_t dq, void (^work)(void))
{
dispatch_barrier_async_f(dq, _dispatch_Block_copy(work),
_dispatch_call_block_and_release);
}
#endif
#pragma mark -
#pragma mark dispatch_async
static void
_dispatch_async_f_redirect_invoke(void *_ctxt)
{
struct dispatch_continuation_s *dc = _ctxt;
struct dispatch_continuation_s *other_dc = dc->dc_data[1];
dispatch_queue_t old_dq, dq = dc->dc_data[0], rq;
old_dq = _dispatch_thread_getspecific(dispatch_queue_key);
_dispatch_thread_setspecific(dispatch_queue_key, dq);
_dispatch_continuation_pop(other_dc);
_dispatch_thread_setspecific(dispatch_queue_key, old_dq);
rq = dq->do_targetq;
while (slowpath(rq->do_targetq) && rq != old_dq) {
if (dispatch_atomic_sub2o(rq, dq_running, 2) == 0) {
_dispatch_wakeup(rq);
}
rq = rq->do_targetq;
}
if (dispatch_atomic_sub2o(dq, dq_running, 2) == 0) {
_dispatch_wakeup(dq);
}
_dispatch_release(dq);
}
DISPATCH_NOINLINE
static void
_dispatch_async_f2_slow(dispatch_queue_t dq, dispatch_continuation_t dc)
{
_dispatch_wakeup(dq);
_dispatch_queue_push(dq, dc);
}
DISPATCH_NOINLINE
static void
_dispatch_async_f_redirect(dispatch_queue_t dq,
dispatch_continuation_t other_dc)
{
dispatch_continuation_t dc;
dispatch_queue_t rq;
_dispatch_retain(dq);
dc = fastpath(_dispatch_continuation_alloc_cacheonly());
if (!dc) {
dc = _dispatch_continuation_alloc_from_heap();
}
dc->do_vtable = (void *)DISPATCH_OBJ_ASYNC_BIT;
dc->dc_func = _dispatch_async_f_redirect_invoke;
dc->dc_ctxt = dc;
dc->dc_data[0] = dq;
dc->dc_data[1] = other_dc;
rq = dq->do_targetq;
while (slowpath(rq->do_targetq)) {
uint32_t running;
if (slowpath(rq->dq_items_tail) ||
slowpath(DISPATCH_OBJECT_SUSPENDED(rq)) ||
slowpath(rq->dq_width == 1)) {
break;
}
running = dispatch_atomic_add2o(rq, dq_running, 2) - 2;
if (slowpath(running & 1) || slowpath(running + 2 > rq->dq_width)) {
if (slowpath(dispatch_atomic_sub2o(rq, dq_running, 2) == 0)) {
return _dispatch_async_f2_slow(rq, dc);
}
break;
}
rq = rq->do_targetq;
}
_dispatch_queue_push(rq, dc);
}
DISPATCH_NOINLINE
static void
_dispatch_async_f2(dispatch_queue_t dq, dispatch_continuation_t dc)
{
uint32_t running;
bool locked;
do {
if (slowpath(dq->dq_items_tail)
|| slowpath(DISPATCH_OBJECT_SUSPENDED(dq))) {
break;
}
running = dispatch_atomic_add2o(dq, dq_running, 2);
if (slowpath(running > dq->dq_width)) {
if (slowpath(dispatch_atomic_sub2o(dq, dq_running, 2) == 0)) {
return _dispatch_async_f2_slow(dq, dc);
}
break;
}
locked = running & 1;
if (fastpath(!locked)) {
return _dispatch_async_f_redirect(dq, dc);
}
locked = dispatch_atomic_sub2o(dq, dq_running, 2) & 1;
} while (!locked);
_dispatch_queue_push(dq, dc);
}
DISPATCH_NOINLINE
static void
_dispatch_async_f_slow(dispatch_queue_t dq, void *ctxt,
dispatch_function_t func)
{
dispatch_continuation_t dc = _dispatch_continuation_alloc_from_heap();
dc->do_vtable = (void *)DISPATCH_OBJ_ASYNC_BIT;
dc->dc_func = func;
dc->dc_ctxt = ctxt;
if (dq->do_targetq) {
return _dispatch_async_f2(dq, dc);
}
_dispatch_queue_push(dq, dc);
}
DISPATCH_NOINLINE
void
dispatch_async_f(dispatch_queue_t dq, void *ctxt, dispatch_function_t func)
{
dispatch_continuation_t dc;
if (dq->dq_width == 1) {
return dispatch_barrier_async_f(dq, ctxt, func);
}
dc = fastpath(_dispatch_continuation_alloc_cacheonly());
if (!dc) {
return _dispatch_async_f_slow(dq, ctxt, func);
}
dc->do_vtable = (void *)DISPATCH_OBJ_ASYNC_BIT;
dc->dc_func = func;
dc->dc_ctxt = ctxt;
if (dq->do_targetq) {
return _dispatch_async_f2(dq, dc);
}
_dispatch_queue_push(dq, dc);
}
#ifdef __BLOCKS__
void
dispatch_async(dispatch_queue_t dq, void (^work)(void))
{
dispatch_async_f(dq, _dispatch_Block_copy(work),
_dispatch_call_block_and_release);
}
#endif
#pragma mark -
#pragma mark dispatch_group_async
DISPATCH_NOINLINE
void
dispatch_group_async_f(dispatch_group_t dg, dispatch_queue_t dq, void *ctxt,
dispatch_function_t func)
{
dispatch_continuation_t dc;
_dispatch_retain(dg);
dispatch_group_enter(dg);
dc = fastpath(_dispatch_continuation_alloc_cacheonly());
if (!dc) {
dc = _dispatch_continuation_alloc_from_heap();
}
dc->do_vtable = (void *)(DISPATCH_OBJ_ASYNC_BIT | DISPATCH_OBJ_GROUP_BIT);
dc->dc_func = func;
dc->dc_ctxt = ctxt;
dc->dc_group = dg;
if (dq->dq_width != 1 && dq->do_targetq) {
return _dispatch_async_f2(dq, dc);
}
_dispatch_queue_push(dq, dc);
}
#ifdef __BLOCKS__
void
dispatch_group_async(dispatch_group_t dg, dispatch_queue_t dq,
dispatch_block_t db)
{
dispatch_group_async_f(dg, dq, _dispatch_Block_copy(db),
_dispatch_call_block_and_release);
}
#endif
#pragma mark -
#pragma mark dispatch_function_invoke
DISPATCH_ALWAYS_INLINE
static inline void
_dispatch_function_invoke(dispatch_queue_t dq, void *ctxt,
dispatch_function_t func)
{
dispatch_queue_t old_dq = _dispatch_thread_getspecific(dispatch_queue_key);
_dispatch_thread_setspecific(dispatch_queue_key, dq);
_dispatch_client_callout(ctxt, func);
_dispatch_workitem_inc();
_dispatch_thread_setspecific(dispatch_queue_key, old_dq);
}
struct dispatch_function_recurse_s {
dispatch_queue_t dfr_dq;
void* dfr_ctxt;
dispatch_function_t dfr_func;
};
static void
_dispatch_function_recurse_invoke(void *ctxt)
{
struct dispatch_function_recurse_s *dfr = ctxt;
_dispatch_function_invoke(dfr->dfr_dq, dfr->dfr_ctxt, dfr->dfr_func);
}
DISPATCH_ALWAYS_INLINE
static inline void
_dispatch_function_recurse(dispatch_queue_t dq, void *ctxt,
dispatch_function_t func)
{
struct dispatch_function_recurse_s dfr = {
.dfr_dq = dq,
.dfr_func = func,
.dfr_ctxt = ctxt,
};
dispatch_sync_f(dq->do_targetq, &dfr, _dispatch_function_recurse_invoke);
}
#pragma mark -
#pragma mark dispatch_barrier_sync
struct dispatch_barrier_sync_slow_s {
DISPATCH_CONTINUATION_HEADER(dispatch_barrier_sync_slow_s);
};
struct dispatch_barrier_sync_slow2_s {
dispatch_queue_t dbss2_dq;
#if DISPATCH_COCOA_COMPAT
dispatch_function_t dbss2_func;
void *dbss2_ctxt;
#endif
_dispatch_thread_semaphore_t dbss2_sema;
};
static void
_dispatch_barrier_sync_f_slow_invoke(void *ctxt)
{
struct dispatch_barrier_sync_slow2_s *dbss2 = ctxt;
dispatch_assert(dbss2->dbss2_dq == _dispatch_queue_get_current());
#if DISPATCH_COCOA_COMPAT
if (dbss2->dbss2_dq == &_dispatch_main_q && pthread_main_np()) {
dbss2->dbss2_func(dbss2->dbss2_ctxt);
dbss2->dbss2_func = NULL;
dispatch_atomic_barrier();
_dispatch_thread_semaphore_signal(dbss2->dbss2_sema);
return;
}
#endif
(void)dispatch_atomic_add2o(dbss2->dbss2_dq, do_suspend_cnt,
DISPATCH_OBJECT_SUSPEND_INTERVAL);
(void)dispatch_atomic_add2o(dbss2->dbss2_dq, dq_running, 2);
dispatch_atomic_barrier();
_dispatch_thread_semaphore_signal(dbss2->dbss2_sema);
}
DISPATCH_NOINLINE
static void
_dispatch_barrier_sync_f_slow(dispatch_queue_t dq, void *ctxt,
dispatch_function_t func)
{
struct dispatch_barrier_sync_slow2_s dbss2 = {
.dbss2_dq = dq,
#if DISPATCH_COCOA_COMPAT
.dbss2_func = func,
.dbss2_ctxt = ctxt,
#endif
.dbss2_sema = _dispatch_get_thread_semaphore(),
};
struct dispatch_barrier_sync_slow_s dbss = {
.do_vtable = (void *)(DISPATCH_OBJ_BARRIER_BIT |
DISPATCH_OBJ_SYNC_SLOW_BIT),
.dc_func = _dispatch_barrier_sync_f_slow_invoke,
.dc_ctxt = &dbss2,
};
_dispatch_queue_push(dq, (void *)&dbss);
_dispatch_thread_semaphore_wait(dbss2.dbss2_sema);
_dispatch_put_thread_semaphore(dbss2.dbss2_sema);
#if DISPATCH_COCOA_COMPAT
if (dbss2.dbss2_func == NULL) {
return;
}
#endif
dispatch_atomic_acquire_barrier();
if (slowpath(dq->do_targetq) && slowpath(dq->do_targetq->do_targetq)) {
_dispatch_function_recurse(dq, ctxt, func);
} else {
_dispatch_function_invoke(dq, ctxt, func);
}
dispatch_atomic_release_barrier();
if (fastpath(dq->do_suspend_cnt < 2 * DISPATCH_OBJECT_SUSPEND_INTERVAL)) {
while (slowpath(dq->dq_running > 2)) {
_dispatch_hardware_pause();
}
_dispatch_thread_semaphore_t sema;
sema = _dispatch_queue_drain_one_barrier_sync(dq);
if (sema) {
_dispatch_thread_semaphore_signal(sema);
return;
}
}
(void)dispatch_atomic_sub2o(dq, do_suspend_cnt,
DISPATCH_OBJECT_SUSPEND_INTERVAL);
if (slowpath(dispatch_atomic_sub2o(dq, dq_running, 2) == 0)) {
_dispatch_wakeup(dq);
}
}
DISPATCH_NOINLINE
static void
_dispatch_barrier_sync_f2(dispatch_queue_t dq)
{
if (!slowpath(DISPATCH_OBJECT_SUSPENDED(dq))) {
_dispatch_thread_semaphore_t sema;
sema = _dispatch_queue_drain_one_barrier_sync(dq);
if (sema) {
(void)dispatch_atomic_add2o(dq, do_suspend_cnt,
DISPATCH_OBJECT_SUSPEND_INTERVAL);
(void)dispatch_atomic_inc2o(dq, dq_running);
_dispatch_thread_semaphore_signal(sema);
return;
}
}
if (slowpath(dispatch_atomic_dec2o(dq, dq_running) == 0)) {
_dispatch_wakeup(dq);
}
}
DISPATCH_NOINLINE
static void
_dispatch_barrier_sync_f_invoke(dispatch_queue_t dq, void *ctxt,
dispatch_function_t func)
{
dispatch_atomic_acquire_barrier();
_dispatch_function_invoke(dq, ctxt, func);
dispatch_atomic_release_barrier();
if (slowpath(dq->dq_items_tail)) {
return _dispatch_barrier_sync_f2(dq);
}
if (slowpath(dispatch_atomic_dec2o(dq, dq_running) == 0)) {
_dispatch_wakeup(dq);
}
}
DISPATCH_NOINLINE
static void
_dispatch_barrier_sync_f_recurse(dispatch_queue_t dq, void *ctxt,
dispatch_function_t func)
{
dispatch_atomic_acquire_barrier();
_dispatch_function_recurse(dq, ctxt, func);
dispatch_atomic_release_barrier();
if (slowpath(dq->dq_items_tail)) {
return _dispatch_barrier_sync_f2(dq);
}
if (slowpath(dispatch_atomic_dec2o(dq, dq_running) == 0)) {
_dispatch_wakeup(dq);
}
}
DISPATCH_NOINLINE
void
dispatch_barrier_sync_f(dispatch_queue_t dq, void *ctxt,
dispatch_function_t func)
{
if (slowpath(dq->dq_items_tail) || slowpath(DISPATCH_OBJECT_SUSPENDED(dq))){
return _dispatch_barrier_sync_f_slow(dq, ctxt, func);
}
if (slowpath(!dispatch_atomic_cmpxchg2o(dq, dq_running, 0, 1))) {
return _dispatch_barrier_sync_f_slow(dq, ctxt, func);
}
if (slowpath(dq->do_targetq->do_targetq)) {
return _dispatch_barrier_sync_f_recurse(dq, ctxt, func);
}
_dispatch_barrier_sync_f_invoke(dq, ctxt, func);
}
#ifdef __BLOCKS__
#if DISPATCH_COCOA_COMPAT
DISPATCH_NOINLINE
static void
_dispatch_barrier_sync_slow(dispatch_queue_t dq, void (^work)(void))
{
if (dispatch_begin_thread_4GC) {
dispatch_block_t block = _dispatch_Block_copy(work);
return dispatch_barrier_sync_f(dq, block,
_dispatch_call_block_and_release);
}
struct Block_basic *bb = (void *)work;
dispatch_barrier_sync_f(dq, work, (dispatch_function_t)bb->Block_invoke);
}
#endif
void
dispatch_barrier_sync(dispatch_queue_t dq, void (^work)(void))
{
#if DISPATCH_COCOA_COMPAT
if (slowpath(dq == &_dispatch_main_q)) {
return _dispatch_barrier_sync_slow(dq, work);
}
#endif
struct Block_basic *bb = (void *)work;
dispatch_barrier_sync_f(dq, work, (dispatch_function_t)bb->Block_invoke);
}
#endif
#pragma mark -
#pragma mark dispatch_sync
DISPATCH_NOINLINE
static void
_dispatch_sync_f_slow(dispatch_queue_t dq, void *ctxt, dispatch_function_t func)
{
_dispatch_thread_semaphore_t sema = _dispatch_get_thread_semaphore();
struct dispatch_sync_slow_s {
DISPATCH_CONTINUATION_HEADER(dispatch_sync_slow_s);
} dss = {
.do_vtable = (void*)DISPATCH_OBJ_SYNC_SLOW_BIT,
.dc_ctxt = (void*)sema,
};
_dispatch_queue_push(dq, (void *)&dss);
_dispatch_thread_semaphore_wait(sema);
_dispatch_put_thread_semaphore(sema);
if (slowpath(dq->do_targetq->do_targetq)) {
_dispatch_function_recurse(dq, ctxt, func);
} else {
_dispatch_function_invoke(dq, ctxt, func);
}
if (slowpath(dispatch_atomic_sub2o(dq, dq_running, 2) == 0)) {
_dispatch_wakeup(dq);
}
}
DISPATCH_NOINLINE
static void
_dispatch_sync_f_slow2(dispatch_queue_t dq, void *ctxt,
dispatch_function_t func)
{
if (slowpath(dispatch_atomic_sub2o(dq, dq_running, 2) == 0)) {
_dispatch_wakeup(dq);
}
_dispatch_sync_f_slow(dq, ctxt, func);
}
DISPATCH_NOINLINE
static void
_dispatch_sync_f_invoke(dispatch_queue_t dq, void *ctxt,
dispatch_function_t func)
{
_dispatch_function_invoke(dq, ctxt, func);
if (slowpath(dispatch_atomic_sub2o(dq, dq_running, 2) == 0)) {
_dispatch_wakeup(dq);
}
}
DISPATCH_NOINLINE
static void
_dispatch_sync_f_recurse(dispatch_queue_t dq, void *ctxt,
dispatch_function_t func)
{
_dispatch_function_recurse(dq, ctxt, func);
if (slowpath(dispatch_atomic_sub2o(dq, dq_running, 2) == 0)) {
_dispatch_wakeup(dq);
}
}
DISPATCH_NOINLINE
static void
_dispatch_sync_f2(dispatch_queue_t dq, void *ctxt, dispatch_function_t func)
{
if (slowpath(dq->dq_items_tail) || slowpath(DISPATCH_OBJECT_SUSPENDED(dq))){
return _dispatch_sync_f_slow(dq, ctxt, func);
}
if (slowpath(dispatch_atomic_add2o(dq, dq_running, 2) & 1)) {
return _dispatch_sync_f_slow2(dq, ctxt, func);
}
if (slowpath(dq->do_targetq->do_targetq)) {
return _dispatch_sync_f_recurse(dq, ctxt, func);
}
_dispatch_sync_f_invoke(dq, ctxt, func);
}
DISPATCH_NOINLINE
void
dispatch_sync_f(dispatch_queue_t dq, void *ctxt, dispatch_function_t func)
{
if (fastpath(dq->dq_width == 1)) {
return dispatch_barrier_sync_f(dq, ctxt, func);
}
if (slowpath(!dq->do_targetq)) {
(void)dispatch_atomic_add2o(dq, dq_running, 2);
return _dispatch_sync_f_invoke(dq, ctxt, func);
}
_dispatch_sync_f2(dq, ctxt, func);
}
#ifdef __BLOCKS__
#if DISPATCH_COCOA_COMPAT
DISPATCH_NOINLINE
static void
_dispatch_sync_slow(dispatch_queue_t dq, void (^work)(void))
{
if (dispatch_begin_thread_4GC) {
dispatch_block_t block = _dispatch_Block_copy(work);
return dispatch_sync_f(dq, block, _dispatch_call_block_and_release);
}
struct Block_basic *bb = (void *)work;
dispatch_sync_f(dq, work, (dispatch_function_t)bb->Block_invoke);
}
#endif
void
dispatch_sync(dispatch_queue_t dq, void (^work)(void))
{
#if DISPATCH_COCOA_COMPAT
if (slowpath(dq == &_dispatch_main_q)) {
return _dispatch_sync_slow(dq, work);
}
#endif
struct Block_basic *bb = (void *)work;
dispatch_sync_f(dq, work, (dispatch_function_t)bb->Block_invoke);
}
#endif
#pragma mark -
#pragma mark dispatch_after
struct _dispatch_after_time_s {
void *datc_ctxt;
void (*datc_func)(void *);
dispatch_source_t ds;
};
static void
_dispatch_after_timer_callback(void *ctxt)
{
struct _dispatch_after_time_s *datc = ctxt;
dispatch_assert(datc->datc_func);
_dispatch_client_callout(datc->datc_ctxt, datc->datc_func);
dispatch_source_t ds = datc->ds;
free(datc);
dispatch_source_cancel(ds); dispatch_release(ds);
}
DISPATCH_NOINLINE
void
dispatch_after_f(dispatch_time_t when, dispatch_queue_t queue, void *ctxt,
dispatch_function_t func)
{
uint64_t delta;
struct _dispatch_after_time_s *datc = NULL;
dispatch_source_t ds;
if (when == DISPATCH_TIME_FOREVER) {
#if DISPATCH_DEBUG
DISPATCH_CLIENT_CRASH(
"dispatch_after_f() called with 'when' == infinity");
#endif
return;
}
delta = _dispatch_timeout(when);
if (delta == 0) {
return dispatch_async_f(queue, ctxt, func);
}
ds = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, queue);
dispatch_assert(ds);
datc = malloc(sizeof(*datc));
dispatch_assert(datc);
datc->datc_ctxt = ctxt;
datc->datc_func = func;
datc->ds = ds;
dispatch_set_context(ds, datc);
dispatch_source_set_event_handler_f(ds, _dispatch_after_timer_callback);
dispatch_source_set_timer(ds, when, DISPATCH_TIME_FOREVER, 0);
dispatch_resume(ds);
}
#ifdef __BLOCKS__
void
dispatch_after(dispatch_time_t when, dispatch_queue_t queue,
dispatch_block_t work)
{
if (when == DISPATCH_TIME_FOREVER) {
#if DISPATCH_DEBUG
DISPATCH_CLIENT_CRASH(
"dispatch_after() called with 'when' == infinity");
#endif
return;
}
dispatch_after_f(when, queue, _dispatch_Block_copy(work),
_dispatch_call_block_and_release);
}
#endif
#pragma mark -
#pragma mark dispatch_wakeup
DISPATCH_NOINLINE
void
_dispatch_queue_push_list_slow(dispatch_queue_t dq,
struct dispatch_object_s *obj)
{
_dispatch_retain(dq);
dq->dq_items_head = obj;
_dispatch_wakeup(dq);
_dispatch_release(dq);
}
dispatch_queue_t
_dispatch_wakeup(dispatch_object_t dou)
{
dispatch_queue_t tq;
if (slowpath(DISPATCH_OBJECT_SUSPENDED(dou._do))) {
return NULL;
}
if (!dx_probe(dou._do) && !dou._dq->dq_items_tail) {
return NULL;
}
if (!dispatch_atomic_cmpxchg2o(dou._do, do_suspend_cnt, 0,
DISPATCH_OBJECT_SUSPEND_LOCK)) {
#if DISPATCH_COCOA_COMPAT
if (dou._dq == &_dispatch_main_q) {
_dispatch_queue_wakeup_main();
}
#endif
return NULL;
}
_dispatch_retain(dou._do);
tq = dou._do->do_targetq;
_dispatch_queue_push(tq, dou._do);
return tq; }
#if DISPATCH_COCOA_COMPAT
DISPATCH_NOINLINE
void
_dispatch_queue_wakeup_main(void)
{
kern_return_t kr;
dispatch_once_f(&_dispatch_main_q_port_pred, NULL,
_dispatch_main_q_port_init);
kr = _dispatch_send_wakeup_main_thread(main_q_port, 0);
switch (kr) {
case MACH_SEND_TIMEOUT:
case MACH_SEND_TIMED_OUT:
case MACH_SEND_INVALID_DEST:
break;
default:
(void)dispatch_assume_zero(kr);
break;
}
_dispatch_safe_fork = false;
}
#endif
static bool
_dispatch_queue_wakeup_global(dispatch_queue_t dq)
{
static dispatch_once_t pred;
struct dispatch_root_queue_context_s *qc = dq->do_ctxt;
int r;
if (!dq->dq_items_tail) {
return false;
}
_dispatch_safe_fork = false;
dispatch_debug_queue(dq, __PRETTY_FUNCTION__);
dispatch_once_f(&pred, NULL, _dispatch_root_queues_init);
#if HAVE_PTHREAD_WORKQUEUES
#if DISPATCH_ENABLE_THREAD_POOL
if (qc->dgq_kworkqueue)
#endif
{
if (dispatch_atomic_cmpxchg2o(qc, dgq_pending, 0, 1)) {
pthread_workitem_handle_t wh;
unsigned int gen_cnt;
_dispatch_debug("requesting new worker thread");
r = pthread_workqueue_additem_np(qc->dgq_kworkqueue,
_dispatch_worker_thread2, dq, &wh, &gen_cnt);
(void)dispatch_assume_zero(r);
} else {
_dispatch_debug("work thread request still pending on global "
"queue: %p", dq);
}
goto out;
}
#endif // HAVE_PTHREAD_WORKQUEUES
#if DISPATCH_ENABLE_THREAD_POOL
if (dispatch_semaphore_signal(qc->dgq_thread_mediator)) {
goto out;
}
pthread_t pthr;
int t_count;
do {
t_count = qc->dgq_thread_pool_size;
if (!t_count) {
_dispatch_debug("The thread pool is full: %p", dq);
goto out;
}
} while (!dispatch_atomic_cmpxchg2o(qc, dgq_thread_pool_size, t_count,
t_count - 1));
while ((r = pthread_create(&pthr, NULL, _dispatch_worker_thread, dq))) {
if (r != EAGAIN) {
(void)dispatch_assume_zero(r);
}
sleep(1);
}
r = pthread_detach(pthr);
(void)dispatch_assume_zero(r);
#endif // DISPATCH_ENABLE_THREAD_POOL
out:
return false;
}
#pragma mark -
#pragma mark dispatch_queue_drain
DISPATCH_NOINLINE
void
_dispatch_queue_invoke(dispatch_queue_t dq)
{
if (!slowpath(DISPATCH_OBJECT_SUSPENDED(dq)) &&
fastpath(dispatch_atomic_cmpxchg2o(dq, dq_running, 0, 1))) {
dispatch_atomic_acquire_barrier();
dispatch_queue_t otq = dq->do_targetq, tq = NULL;
_dispatch_queue_drain(dq);
if (dq->do_vtable->do_invoke) {
tq = dx_invoke(dq);
} else if (slowpath(otq != dq->do_targetq)) {
tq = dq->do_targetq;
}
dispatch_atomic_release_barrier();
(void)dispatch_atomic_dec2o(dq, dq_running);
if (tq) {
return _dispatch_queue_push(tq, dq);
}
}
dq->do_next = DISPATCH_OBJECT_LISTLESS;
if (!dispatch_atomic_sub2o(dq, do_suspend_cnt,
DISPATCH_OBJECT_SUSPEND_LOCK)) {
if (dq->dq_running == 0) {
_dispatch_wakeup(dq); }
}
_dispatch_release(dq); }
static void
_dispatch_queue_drain(dispatch_queue_t dq)
{
dispatch_queue_t orig_tq, old_dq;
old_dq = _dispatch_thread_getspecific(dispatch_queue_key);
struct dispatch_object_s *dc = NULL, *next_dc = NULL;
bool check_tq = (dx_type(dq) != DISPATCH_SOURCE_KEVENT_TYPE);
orig_tq = dq->do_targetq;
_dispatch_thread_setspecific(dispatch_queue_key, dq);
while (dq->dq_items_tail) {
while (!(dc = fastpath(dq->dq_items_head))) {
_dispatch_hardware_pause();
}
dq->dq_items_head = NULL;
do {
next_dc = fastpath(dc->do_next);
if (!next_dc &&
!dispatch_atomic_cmpxchg2o(dq, dq_items_tail, dc, NULL)) {
while (!(next_dc = fastpath(dc->do_next))) {
_dispatch_hardware_pause();
}
}
if (DISPATCH_OBJECT_SUSPENDED(dq)) {
goto out;
}
if (dq->dq_running > dq->dq_width) {
goto out;
}
if (slowpath(orig_tq != dq->do_targetq) && check_tq) {
goto out;
}
if (fastpath(dq->dq_width == 1)) {
_dispatch_continuation_pop(dc);
_dispatch_workitem_inc();
} else if (!DISPATCH_OBJ_IS_VTABLE(dc) &&
(long)dc->do_vtable & DISPATCH_OBJ_BARRIER_BIT) {
if (dq->dq_running > 1) {
goto out;
}
_dispatch_continuation_pop(dc);
_dispatch_workitem_inc();
} else {
_dispatch_continuation_redirect(dq, dc);
}
} while ((dc = next_dc));
}
out:
if (slowpath(dc)) {
if (!next_dc &&
!dispatch_atomic_cmpxchg2o(dq, dq_items_tail, NULL, dc)) {
while (!(next_dc = fastpath(dq->dq_items_head))) {
_dispatch_hardware_pause();
}
dc->do_next = next_dc;
}
dq->dq_items_head = dc;
}
_dispatch_thread_setspecific(dispatch_queue_key, old_dq);
}
static void
_dispatch_queue_serial_drain_till_empty(dispatch_queue_t dq)
{
#if DISPATCH_PERF_MON
uint64_t start = _dispatch_absolute_time();
#endif
_dispatch_queue_drain(dq);
#if DISPATCH_PERF_MON
_dispatch_queue_merge_stats(start);
#endif
_dispatch_force_cache_cleanup();
}
#if DISPATCH_COCOA_COMPAT
void
_dispatch_main_queue_drain(void)
{
dispatch_queue_t dq = &_dispatch_main_q;
if (!dq->dq_items_tail) {
return;
}
struct dispatch_main_queue_drain_marker_s {
DISPATCH_CONTINUATION_HEADER(dispatch_main_queue_drain_marker_s);
} marker = {
.do_vtable = NULL,
};
struct dispatch_object_s *dmarker = (void*)▮
_dispatch_queue_push_notrace(dq, dmarker);
#if DISPATCH_PERF_MON
uint64_t start = _dispatch_absolute_time();
#endif
dispatch_queue_t old_dq = _dispatch_thread_getspecific(dispatch_queue_key);
_dispatch_thread_setspecific(dispatch_queue_key, dq);
struct dispatch_object_s *dc = NULL, *next_dc = NULL;
while (dq->dq_items_tail) {
while (!(dc = fastpath(dq->dq_items_head))) {
_dispatch_hardware_pause();
}
dq->dq_items_head = NULL;
do {
next_dc = fastpath(dc->do_next);
if (!next_dc &&
!dispatch_atomic_cmpxchg2o(dq, dq_items_tail, dc, NULL)) {
while (!(next_dc = fastpath(dc->do_next))) {
_dispatch_hardware_pause();
}
}
if (dc == dmarker) {
if (next_dc) {
dq->dq_items_head = next_dc;
_dispatch_queue_wakeup_main();
}
goto out;
}
_dispatch_continuation_pop(dc);
_dispatch_workitem_inc();
} while ((dc = next_dc));
}
dispatch_assert(dc);
out:
_dispatch_thread_setspecific(dispatch_queue_key, old_dq);
#if DISPATCH_PERF_MON
_dispatch_queue_merge_stats(start);
#endif
_dispatch_force_cache_cleanup();
}
#endif
DISPATCH_ALWAYS_INLINE_NDEBUG
static inline _dispatch_thread_semaphore_t
_dispatch_queue_drain_one_barrier_sync(dispatch_queue_t dq)
{
struct dispatch_object_s *dc, *next_dc;
dc = dq->dq_items_head;
if (slowpath(!dc) || DISPATCH_OBJ_IS_VTABLE(dc) || ((long)dc->do_vtable &
(DISPATCH_OBJ_BARRIER_BIT | DISPATCH_OBJ_SYNC_SLOW_BIT)) !=
(DISPATCH_OBJ_BARRIER_BIT | DISPATCH_OBJ_SYNC_SLOW_BIT)) {
return 0;
}
next_dc = fastpath(dc->do_next);
dq->dq_items_head = next_dc;
if (!next_dc && !dispatch_atomic_cmpxchg2o(dq, dq_items_tail, dc, NULL)) {
while (!(next_dc = fastpath(dc->do_next))) {
_dispatch_hardware_pause();
}
dq->dq_items_head = next_dc;
}
_dispatch_trace_continuation_pop(dq, dc);
_dispatch_workitem_inc();
struct dispatch_barrier_sync_slow_s *dbssp = (void *)dc;
struct dispatch_barrier_sync_slow2_s *dbss2p = dbssp->dc_ctxt;
return dbss2p->dbss2_sema;
}
static struct dispatch_object_s *
_dispatch_queue_concurrent_drain_one(dispatch_queue_t dq)
{
struct dispatch_object_s *head, *next, *const mediator = (void *)~0ul;
head = dispatch_atomic_xchg2o(dq, dq_items_head, mediator);
if (slowpath(head == NULL)) {
(void)dispatch_atomic_cmpxchg2o(dq, dq_items_head, mediator, NULL);
_dispatch_debug("no work on global work queue");
return NULL;
}
if (slowpath(head == mediator)) {
_dispatch_debug("Contention on queue: %p", dq);
_dispatch_queue_wakeup_global(dq);
#if DISPATCH_PERF_MON
dispatch_atomic_inc(&_dispatch_bad_ratio);
#endif
return NULL;
}
next = fastpath(head->do_next);
if (slowpath(!next)) {
dq->dq_items_head = NULL;
if (dispatch_atomic_cmpxchg2o(dq, dq_items_tail, head, NULL)) {
goto out;
}
while (!(next = head->do_next)) {
_dispatch_hardware_pause();
}
}
dq->dq_items_head = next;
_dispatch_queue_wakeup_global(dq);
out:
return head;
}
#pragma mark -
#pragma mark dispatch_worker_thread
static void
_dispatch_worker_thread2(void *context)
{
struct dispatch_object_s *item;
dispatch_queue_t dq = context;
struct dispatch_root_queue_context_s *qc = dq->do_ctxt;
if (_dispatch_thread_getspecific(dispatch_queue_key)) {
DISPATCH_CRASH("Premature thread recycling");
}
_dispatch_thread_setspecific(dispatch_queue_key, dq);
qc->dgq_pending = 0;
#if DISPATCH_COCOA_COMPAT
(void)dispatch_atomic_inc(&_dispatch_worker_threads);
if (dispatch_begin_thread_4GC) {
dispatch_begin_thread_4GC();
}
void *pool = _dispatch_begin_NSAutoReleasePool();
#endif
#if DISPATCH_PERF_MON
uint64_t start = _dispatch_absolute_time();
#endif
while ((item = fastpath(_dispatch_queue_concurrent_drain_one(dq)))) {
_dispatch_continuation_pop(item);
}
#if DISPATCH_PERF_MON
_dispatch_queue_merge_stats(start);
#endif
#if DISPATCH_COCOA_COMPAT
_dispatch_end_NSAutoReleasePool(pool);
dispatch_end_thread_4GC();
if (!dispatch_atomic_dec(&_dispatch_worker_threads) &&
dispatch_no_worker_threads_4GC) {
dispatch_no_worker_threads_4GC();
}
#endif
_dispatch_thread_setspecific(dispatch_queue_key, NULL);
_dispatch_force_cache_cleanup();
}
#if DISPATCH_ENABLE_THREAD_POOL
static void *
_dispatch_worker_thread(void *context)
{
dispatch_queue_t dq = context;
struct dispatch_root_queue_context_s *qc = dq->do_ctxt;
sigset_t mask;
int r;
r = sigfillset(&mask);
(void)dispatch_assume_zero(r);
r = _dispatch_pthread_sigmask(SIG_BLOCK, &mask, NULL);
(void)dispatch_assume_zero(r);
do {
_dispatch_worker_thread2(context);
} while (dispatch_semaphore_wait(qc->dgq_thread_mediator,
dispatch_time(0, 65ull * NSEC_PER_SEC)) == 0);
(void)dispatch_atomic_inc2o(qc, dgq_thread_pool_size);
if (dq->dq_items_tail) {
_dispatch_queue_wakeup_global(dq);
}
return NULL;
}
int
_dispatch_pthread_sigmask(int how, sigset_t *set, sigset_t *oset)
{
int r;
r = sigdelset(set, SIGILL);
(void)dispatch_assume_zero(r);
r = sigdelset(set, SIGTRAP);
(void)dispatch_assume_zero(r);
#if HAVE_DECL_SIGEMT
r = sigdelset(set, SIGEMT);
(void)dispatch_assume_zero(r);
#endif
r = sigdelset(set, SIGFPE);
(void)dispatch_assume_zero(r);
r = sigdelset(set, SIGBUS);
(void)dispatch_assume_zero(r);
r = sigdelset(set, SIGSEGV);
(void)dispatch_assume_zero(r);
r = sigdelset(set, SIGSYS);
(void)dispatch_assume_zero(r);
r = sigdelset(set, SIGPIPE);
(void)dispatch_assume_zero(r);
return pthread_sigmask(how, set, oset);
}
#endif
#pragma mark -
#pragma mark dispatch_main_queue
static bool _dispatch_program_is_probably_callback_driven;
#if DISPATCH_COCOA_COMPAT
static void
_dispatch_main_q_port_init(void *ctxt DISPATCH_UNUSED)
{
kern_return_t kr;
kr = mach_port_allocate(mach_task_self(), MACH_PORT_RIGHT_RECEIVE,
&main_q_port);
DISPATCH_VERIFY_MIG(kr);
(void)dispatch_assume_zero(kr);
kr = mach_port_insert_right(mach_task_self(), main_q_port, main_q_port,
MACH_MSG_TYPE_MAKE_SEND);
DISPATCH_VERIFY_MIG(kr);
(void)dispatch_assume_zero(kr);
_dispatch_program_is_probably_callback_driven = true;
_dispatch_safe_fork = false;
}
mach_port_t
_dispatch_get_main_queue_port_4CF(void)
{
dispatch_once_f(&_dispatch_main_q_port_pred, NULL,
_dispatch_main_q_port_init);
return main_q_port;
}
static bool main_q_is_draining;
DISPATCH_NOINLINE
static void
_dispatch_queue_set_mainq_drain_state(bool arg)
{
main_q_is_draining = arg;
}
void
_dispatch_main_queue_callback_4CF(mach_msg_header_t *msg DISPATCH_UNUSED)
{
if (main_q_is_draining) {
return;
}
_dispatch_queue_set_mainq_drain_state(true);
_dispatch_main_queue_drain();
_dispatch_queue_set_mainq_drain_state(false);
}
#endif
void
dispatch_main(void)
{
#if HAVE_PTHREAD_MAIN_NP
if (pthread_main_np()) {
#endif
_dispatch_program_is_probably_callback_driven = true;
pthread_exit(NULL);
DISPATCH_CRASH("pthread_exit() returned");
#if HAVE_PTHREAD_MAIN_NP
}
DISPATCH_CLIENT_CRASH("dispatch_main() must be called on the main thread");
#endif
}
DISPATCH_NOINLINE DISPATCH_NORETURN
static void
_dispatch_sigsuspend(void)
{
static const sigset_t mask;
#if DISPATCH_COCOA_COMPAT
(void)dispatch_atomic_dec(&_dispatch_worker_threads);
#endif
for (;;) {
sigsuspend(&mask);
}
}
DISPATCH_NORETURN
static void
_dispatch_sig_thread(void *ctxt DISPATCH_UNUSED)
{
_dispatch_clear_stack(0);
_dispatch_sigsuspend();
}
DISPATCH_NOINLINE
static void
_dispatch_queue_cleanup2(void)
{
(void)dispatch_atomic_dec(&_dispatch_main_q.dq_running);
if (dispatch_atomic_sub(&_dispatch_main_q.do_suspend_cnt,
DISPATCH_OBJECT_SUSPEND_LOCK) == 0) {
_dispatch_wakeup(&_dispatch_main_q);
}
if (_dispatch_program_is_probably_callback_driven) {
dispatch_async_f(_dispatch_get_root_queue(0, false), NULL,
_dispatch_sig_thread);
sleep(1); }
#if DISPATCH_COCOA_COMPAT
dispatch_once_f(&_dispatch_main_q_port_pred, NULL,
_dispatch_main_q_port_init);
mach_port_t mp = main_q_port;
kern_return_t kr;
main_q_port = 0;
if (mp) {
kr = mach_port_deallocate(mach_task_self(), mp);
DISPATCH_VERIFY_MIG(kr);
(void)dispatch_assume_zero(kr);
kr = mach_port_mod_refs(mach_task_self(), mp, MACH_PORT_RIGHT_RECEIVE,
-1);
DISPATCH_VERIFY_MIG(kr);
(void)dispatch_assume_zero(kr);
}
#endif
}
static void
_dispatch_queue_cleanup(void *ctxt)
{
if (ctxt == &_dispatch_main_q) {
return _dispatch_queue_cleanup2();
}
DISPATCH_CRASH("Premature thread exit while a dispatch queue is running");
}
#pragma mark -
#pragma mark dispatch_manager_queue
static unsigned int _dispatch_select_workaround;
static fd_set _dispatch_rfds;
static fd_set _dispatch_wfds;
static void **_dispatch_rfd_ptrs;
static void **_dispatch_wfd_ptrs;
static int _dispatch_kq;
static void
_dispatch_get_kq_init(void *context DISPATCH_UNUSED)
{
static const struct kevent kev = {
.ident = 1,
.filter = EVFILT_USER,
.flags = EV_ADD|EV_CLEAR,
};
_dispatch_kq = kqueue();
_dispatch_safe_fork = false;
if (_dispatch_kq == -1) {
DISPATCH_CLIENT_CRASH("kqueue() create failed: "
"probably out of file descriptors");
} else if (dispatch_assume(_dispatch_kq < FD_SETSIZE)) {
FD_SET(_dispatch_kq, &_dispatch_rfds);
}
(void)dispatch_assume_zero(kevent(_dispatch_kq, &kev, 1, NULL, 0, NULL));
_dispatch_queue_push(_dispatch_mgr_q.do_targetq, &_dispatch_mgr_q);
}
static int
_dispatch_get_kq(void)
{
static dispatch_once_t pred;
dispatch_once_f(&pred, NULL, _dispatch_get_kq_init);
return _dispatch_kq;
}
long
_dispatch_update_kq(const struct kevent *kev)
{
struct kevent kev_copy = *kev;
kev_copy.flags |= EV_RECEIPT;
if (_dispatch_select_workaround && (kev_copy.flags & EV_DELETE)) {
switch (kev_copy.filter) {
case EVFILT_READ:
if (kev_copy.ident < FD_SETSIZE &&
FD_ISSET((int)kev_copy.ident, &_dispatch_rfds)) {
FD_CLR((int)kev_copy.ident, &_dispatch_rfds);
_dispatch_rfd_ptrs[kev_copy.ident] = 0;
(void)dispatch_atomic_dec(&_dispatch_select_workaround);
return 0;
}
break;
case EVFILT_WRITE:
if (kev_copy.ident < FD_SETSIZE &&
FD_ISSET((int)kev_copy.ident, &_dispatch_wfds)) {
FD_CLR((int)kev_copy.ident, &_dispatch_wfds);
_dispatch_wfd_ptrs[kev_copy.ident] = 0;
(void)dispatch_atomic_dec(&_dispatch_select_workaround);
return 0;
}
break;
default:
break;
}
}
int rval = kevent(_dispatch_get_kq(), &kev_copy, 1, &kev_copy, 1, NULL);
if (rval == -1) {
(void)dispatch_assume_zero(errno);
return errno;
}
if ((kev->flags & (EV_DISABLE|EV_DELETE)) ||
!(kev->flags & (EV_ADD|EV_ENABLE))) {
return 0;
}
switch (kev_copy.data) {
case 0:
return 0;
case EBADF:
break;
default:
switch (kev_copy.filter) {
case EVFILT_READ:
if (dispatch_assume(kev_copy.ident < FD_SETSIZE)) {
if (!_dispatch_rfd_ptrs) {
_dispatch_rfd_ptrs = calloc(FD_SETSIZE, sizeof(void*));
}
_dispatch_rfd_ptrs[kev_copy.ident] = kev_copy.udata;
FD_SET((int)kev_copy.ident, &_dispatch_rfds);
(void)dispatch_atomic_inc(&_dispatch_select_workaround);
_dispatch_debug("select workaround used to read fd %d: 0x%lx",
(int)kev_copy.ident, (long)kev_copy.data);
return 0;
}
break;
case EVFILT_WRITE:
if (dispatch_assume(kev_copy.ident < FD_SETSIZE)) {
if (!_dispatch_wfd_ptrs) {
_dispatch_wfd_ptrs = calloc(FD_SETSIZE, sizeof(void*));
}
_dispatch_wfd_ptrs[kev_copy.ident] = kev_copy.udata;
FD_SET((int)kev_copy.ident, &_dispatch_wfds);
(void)dispatch_atomic_inc(&_dispatch_select_workaround);
_dispatch_debug("select workaround used to write fd %d: 0x%lx",
(int)kev_copy.ident, (long)kev_copy.data);
return 0;
}
break;
default:
_dispatch_source_drain_kevent(&kev_copy);
break;
}
break;
}
return kev_copy.data;
}
static bool
_dispatch_mgr_wakeup(dispatch_queue_t dq)
{
static const struct kevent kev = {
.ident = 1,
.filter = EVFILT_USER,
.fflags = NOTE_TRIGGER,
};
_dispatch_debug("waking up the _dispatch_mgr_q: %p", dq);
_dispatch_update_kq(&kev);
return false;
}
static void
_dispatch_mgr_thread2(struct kevent *kev, size_t cnt)
{
size_t i;
for (i = 0; i < cnt; i++) {
if (kev[i].filter == EVFILT_USER) {
_dispatch_queue_serial_drain_till_empty(&_dispatch_mgr_q);
} else {
_dispatch_source_drain_kevent(&kev[i]);
}
}
}
#if DISPATCH_USE_VM_PRESSURE && DISPATCH_USE_MALLOC_VM_PRESSURE_SOURCE
static dispatch_source_t _dispatch_malloc_vm_pressure_source;
static void
_dispatch_malloc_vm_pressure_handler(void *context DISPATCH_UNUSED)
{
malloc_zone_pressure_relief(0,0);
}
static void
_dispatch_malloc_vm_pressure_setup(void)
{
_dispatch_malloc_vm_pressure_source = dispatch_source_create(
DISPATCH_SOURCE_TYPE_VM, 0, DISPATCH_VM_PRESSURE,
_dispatch_get_root_queue(0, true));
dispatch_source_set_event_handler_f(_dispatch_malloc_vm_pressure_source,
_dispatch_malloc_vm_pressure_handler);
dispatch_resume(_dispatch_malloc_vm_pressure_source);
}
#else
#define _dispatch_malloc_vm_pressure_setup()
#endif
DISPATCH_NOINLINE DISPATCH_NORETURN
static void
_dispatch_mgr_invoke(void)
{
static const struct timespec timeout_immediately = { 0, 0 };
struct timespec timeout;
const struct timespec *timeoutp;
struct timeval sel_timeout, *sel_timeoutp;
fd_set tmp_rfds, tmp_wfds;
struct kevent kev[1];
int k_cnt, err, i, r;
_dispatch_thread_setspecific(dispatch_queue_key, &_dispatch_mgr_q);
#if DISPATCH_COCOA_COMPAT
(void)dispatch_atomic_dec(&_dispatch_worker_threads);
#endif
_dispatch_malloc_vm_pressure_setup();
for (;;) {
_dispatch_run_timers();
timeoutp = _dispatch_get_next_timer_fire(&timeout);
if (_dispatch_select_workaround) {
FD_COPY(&_dispatch_rfds, &tmp_rfds);
FD_COPY(&_dispatch_wfds, &tmp_wfds);
if (timeoutp) {
sel_timeout.tv_sec = timeoutp->tv_sec;
sel_timeout.tv_usec = (typeof(sel_timeout.tv_usec))
(timeoutp->tv_nsec / 1000u);
sel_timeoutp = &sel_timeout;
} else {
sel_timeoutp = NULL;
}
r = select(FD_SETSIZE, &tmp_rfds, &tmp_wfds, NULL, sel_timeoutp);
if (r == -1) {
err = errno;
if (err != EBADF) {
if (err != EINTR) {
(void)dispatch_assume_zero(err);
}
continue;
}
for (i = 0; i < FD_SETSIZE; i++) {
if (i == _dispatch_kq) {
continue;
}
if (!FD_ISSET(i, &_dispatch_rfds) && !FD_ISSET(i,
&_dispatch_wfds)) {
continue;
}
r = dup(i);
if (r != -1) {
close(r);
} else {
if (FD_ISSET(i, &_dispatch_rfds)) {
FD_CLR(i, &_dispatch_rfds);
_dispatch_rfd_ptrs[i] = 0;
(void)dispatch_atomic_dec(
&_dispatch_select_workaround);
}
if (FD_ISSET(i, &_dispatch_wfds)) {
FD_CLR(i, &_dispatch_wfds);
_dispatch_wfd_ptrs[i] = 0;
(void)dispatch_atomic_dec(
&_dispatch_select_workaround);
}
}
}
continue;
}
if (r > 0) {
for (i = 0; i < FD_SETSIZE; i++) {
if (i == _dispatch_kq) {
continue;
}
if (FD_ISSET(i, &tmp_rfds)) {
FD_CLR(i, &_dispatch_rfds); EV_SET(&kev[0], i, EVFILT_READ,
EV_ADD|EV_ENABLE|EV_DISPATCH, 0, 1,
_dispatch_rfd_ptrs[i]);
_dispatch_rfd_ptrs[i] = 0;
(void)dispatch_atomic_dec(&_dispatch_select_workaround);
_dispatch_mgr_thread2(kev, 1);
}
if (FD_ISSET(i, &tmp_wfds)) {
FD_CLR(i, &_dispatch_wfds); EV_SET(&kev[0], i, EVFILT_WRITE,
EV_ADD|EV_ENABLE|EV_DISPATCH, 0, 1,
_dispatch_wfd_ptrs[i]);
_dispatch_wfd_ptrs[i] = 0;
(void)dispatch_atomic_dec(&_dispatch_select_workaround);
_dispatch_mgr_thread2(kev, 1);
}
}
}
timeoutp = &timeout_immediately;
}
k_cnt = kevent(_dispatch_kq, NULL, 0, kev, sizeof(kev) / sizeof(kev[0]),
timeoutp);
err = errno;
switch (k_cnt) {
case -1:
if (err == EBADF) {
DISPATCH_CLIENT_CRASH("Do not close random Unix descriptors");
}
if (err != EINTR) {
(void)dispatch_assume_zero(err);
}
continue;
default:
_dispatch_mgr_thread2(kev, (size_t)k_cnt);
case 0:
_dispatch_force_cache_cleanup();
continue;
}
}
}
DISPATCH_NORETURN
static dispatch_queue_t
_dispatch_mgr_thread(dispatch_queue_t dq DISPATCH_UNUSED)
{
_dispatch_clear_stack(2048);
_dispatch_mgr_invoke();
}