| /* |
| * Copyright (c) 2008-2013 Apple Inc. All rights reserved. |
| * |
| * @APPLE_APACHE_LICENSE_HEADER_START@ |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| * @APPLE_APACHE_LICENSE_HEADER_END@ |
| */ |
| |
| /* |
| * IMPORTANT: This header file describes INTERNAL interfaces to libdispatch |
| * which are subject to change in future releases of Mac OS X. Any applications |
| * relying on these interfaces WILL break. |
| */ |
| |
| #ifndef __DISPATCH_INLINE_INTERNAL__ |
| #define __DISPATCH_INLINE_INTERNAL__ |
| |
| #ifndef __DISPATCH_INDIRECT__ |
| #error "Please #include <dispatch/dispatch.h> instead of this file directly." |
| #include <dispatch/base.h> // for HeaderDoc |
| #endif |
| |
| #if DISPATCH_USE_CLIENT_CALLOUT |
| |
| DISPATCH_NOTHROW void |
| _dispatch_client_callout(void *ctxt, dispatch_function_t f); |
| DISPATCH_NOTHROW void |
| _dispatch_client_callout2(void *ctxt, size_t i, void (*f)(void *, size_t)); |
| #if HAVE_MACH |
| DISPATCH_NOTHROW void |
| _dispatch_client_callout3(void *ctxt, dispatch_mach_reason_t reason, |
| dispatch_mach_msg_t dmsg, dispatch_mach_async_reply_callback_t f); |
| DISPATCH_NOTHROW void |
| _dispatch_client_callout4(void *ctxt, dispatch_mach_reason_t reason, |
| dispatch_mach_msg_t dmsg, mach_error_t error, |
| dispatch_mach_handler_function_t f); |
| #endif // HAVE_MACH |
| |
| #else // !DISPATCH_USE_CLIENT_CALLOUT |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_client_callout(void *ctxt, dispatch_function_t f) |
| { |
| return f(ctxt); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_client_callout2(void *ctxt, size_t i, void (*f)(void *, size_t)) |
| { |
| return f(ctxt, i); |
| } |
| |
| #if HAVE_MACH |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_client_callout3(void *ctxt, dispatch_mach_reason_t reason, |
| dispatch_mach_msg_t dmsg, dispatch_mach_async_reply_callback_t f) |
| { |
| return f(ctxt, reason, dmsg); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_client_callout4(void *ctxt, dispatch_mach_reason_t reason, |
| dispatch_mach_msg_t dmsg, mach_error_t error, |
| dispatch_mach_handler_function_t f) |
| { |
| return f(ctxt, reason, dmsg, error); |
| } |
| #endif // HAVE_MACH |
| |
| #endif // !DISPATCH_USE_CLIENT_CALLOUT |
| |
| #pragma mark - |
| #pragma mark _os_object_t & dispatch_object_t |
| #if DISPATCH_PURE_C |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_object_has_vtable(dispatch_object_t dou) |
| { |
| uintptr_t dc_flags = dou._dc->dc_flags; |
| |
| // vtables are pointers far away from the low page in memory |
| return dc_flags > 0xffful; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_object_is_continuation(dispatch_object_t dou) |
| { |
| if (_dispatch_object_has_vtable(dou)) { |
| return dx_metatype(dou._do) == _DISPATCH_CONTINUATION_TYPE; |
| } |
| return true; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_object_has_type(dispatch_object_t dou, unsigned long type) |
| { |
| return _dispatch_object_has_vtable(dou) && dx_type(dou._do) == type; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_object_is_redirection(dispatch_object_t dou) |
| { |
| return _dispatch_object_has_type(dou, |
| DISPATCH_CONTINUATION_TYPE(ASYNC_REDIRECT)); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_object_is_barrier(dispatch_object_t dou) |
| { |
| dispatch_queue_flags_t dq_flags; |
| |
| if (!_dispatch_object_has_vtable(dou)) { |
| return (dou._dc->dc_flags & DISPATCH_OBJ_BARRIER_BIT); |
| } |
| switch (dx_metatype(dou._do)) { |
| case _DISPATCH_QUEUE_TYPE: |
| case _DISPATCH_SOURCE_TYPE: |
| dq_flags = os_atomic_load2o(dou._dq, dq_atomic_flags, relaxed); |
| return dq_flags & DQF_BARRIER_BIT; |
| default: |
| return false; |
| } |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_object_is_sync_waiter(dispatch_object_t dou) |
| { |
| if (_dispatch_object_has_vtable(dou)) { |
| return false; |
| } |
| return (dou._dc->dc_flags & DISPATCH_OBJ_SYNC_WAITER_BIT); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_object_is_sync_waiter_non_barrier(dispatch_object_t dou) |
| { |
| if (_dispatch_object_has_vtable(dou)) { |
| return false; |
| } |
| return ((dou._dc->dc_flags & |
| (DISPATCH_OBJ_BARRIER_BIT | DISPATCH_OBJ_SYNC_WAITER_BIT)) == |
| (DISPATCH_OBJ_SYNC_WAITER_BIT)); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline _os_object_t |
| _os_object_retain_internal_inline(_os_object_t obj) |
| { |
| int ref_cnt = _os_object_refcnt_inc(obj); |
| if (unlikely(ref_cnt <= 0)) { |
| _OS_OBJECT_CLIENT_CRASH("Resurrection of an object"); |
| } |
| return obj; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _os_object_release_internal_inline_no_dispose(_os_object_t obj) |
| { |
| int ref_cnt = _os_object_refcnt_dec(obj); |
| if (likely(ref_cnt >= 0)) { |
| return; |
| } |
| if (ref_cnt == 0) { |
| _OS_OBJECT_CLIENT_CRASH("Unexpected release of an object"); |
| } |
| _OS_OBJECT_CLIENT_CRASH("Over-release of an object"); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _os_object_release_internal_inline(_os_object_t obj) |
| { |
| int ref_cnt = _os_object_refcnt_dec(obj); |
| if (likely(ref_cnt >= 0)) { |
| return; |
| } |
| if (unlikely(ref_cnt < -1)) { |
| _OS_OBJECT_CLIENT_CRASH("Over-release of an object"); |
| } |
| #if DISPATCH_DEBUG |
| int xref_cnt = obj->os_obj_xref_cnt; |
| if (unlikely(xref_cnt >= 0)) { |
| DISPATCH_INTERNAL_CRASH(xref_cnt, |
| "Release while external references exist"); |
| } |
| #endif |
| // _os_object_refcnt_dispose_barrier() is in _os_object_dispose() |
| return _os_object_dispose(obj); |
| } |
| |
| DISPATCH_ALWAYS_INLINE_NDEBUG |
| static inline void |
| _dispatch_retain(dispatch_object_t dou) |
| { |
| (void)_os_object_retain_internal_inline(dou._os_obj); |
| } |
| |
| DISPATCH_ALWAYS_INLINE_NDEBUG |
| static inline void |
| _dispatch_release(dispatch_object_t dou) |
| { |
| _os_object_release_internal_inline(dou._os_obj); |
| } |
| |
| DISPATCH_ALWAYS_INLINE_NDEBUG |
| static inline void |
| _dispatch_release_tailcall(dispatch_object_t dou) |
| { |
| _os_object_release_internal(dou._os_obj); |
| } |
| |
| DISPATCH_ALWAYS_INLINE DISPATCH_NONNULL_ALL |
| static inline void |
| _dispatch_object_set_target_queue_inline(dispatch_object_t dou, |
| dispatch_queue_t tq) |
| { |
| _dispatch_retain(tq); |
| tq = os_atomic_xchg2o(dou._do, do_targetq, tq, release); |
| if (tq) _dispatch_release(tq); |
| _dispatch_object_debug(dou._do, "%s", __func__); |
| } |
| |
| #endif // DISPATCH_PURE_C |
| #pragma mark - |
| #pragma mark dispatch_thread |
| #if DISPATCH_PURE_C |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_thread_context_t |
| _dispatch_thread_context_find(const void *key) |
| { |
| dispatch_thread_context_t dtc = |
| _dispatch_thread_getspecific(dispatch_context_key); |
| while (dtc) { |
| if (dtc->dtc_key == key) { |
| return dtc; |
| } |
| dtc = dtc->dtc_prev; |
| } |
| return NULL; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_thread_context_push(dispatch_thread_context_t ctxt) |
| { |
| ctxt->dtc_prev = _dispatch_thread_getspecific(dispatch_context_key); |
| _dispatch_thread_setspecific(dispatch_context_key, ctxt); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_thread_context_pop(dispatch_thread_context_t ctxt) |
| { |
| dispatch_assert(_dispatch_thread_getspecific(dispatch_context_key) == ctxt); |
| _dispatch_thread_setspecific(dispatch_context_key, ctxt->dtc_prev); |
| } |
| |
| typedef struct dispatch_thread_frame_iterator_s { |
| dispatch_queue_t dtfi_queue; |
| dispatch_thread_frame_t dtfi_frame; |
| } *dispatch_thread_frame_iterator_t; |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_thread_frame_iterate_start(dispatch_thread_frame_iterator_t it) |
| { |
| _dispatch_thread_getspecific_pair( |
| dispatch_queue_key, (void **)&it->dtfi_queue, |
| dispatch_frame_key, (void **)&it->dtfi_frame); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_thread_frame_iterate_next(dispatch_thread_frame_iterator_t it) |
| { |
| dispatch_thread_frame_t dtf = it->dtfi_frame; |
| dispatch_queue_t dq = it->dtfi_queue; |
| |
| if (dtf) { |
| dispatch_queue_t tq = dq->do_targetq; |
| if (tq) { |
| // redirections, dispatch_sync and dispatch_trysync_f may skip |
| // frames, so we need to simulate seeing the missing links |
| it->dtfi_queue = tq; |
| if (dq == dtf->dtf_queue) { |
| it->dtfi_frame = dtf->dtf_prev; |
| } |
| } else { |
| it->dtfi_queue = dtf->dtf_queue; |
| it->dtfi_frame = dtf->dtf_prev; |
| } |
| } else if (dq) { |
| it->dtfi_queue = dq->do_targetq; |
| } |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_thread_frame_find_queue(dispatch_queue_t dq) |
| { |
| struct dispatch_thread_frame_iterator_s it; |
| |
| _dispatch_thread_frame_iterate_start(&it); |
| while (it.dtfi_queue) { |
| if (it.dtfi_queue == dq) { |
| return true; |
| } |
| _dispatch_thread_frame_iterate_next(&it); |
| } |
| return false; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_thread_frame_t |
| _dispatch_thread_frame_get_current(void) |
| { |
| return _dispatch_thread_getspecific(dispatch_frame_key); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_thread_frame_save_state(dispatch_thread_frame_t dtf) |
| { |
| _dispatch_thread_getspecific_packed_pair( |
| dispatch_queue_key, dispatch_frame_key, (void **)&dtf->dtf_queue); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_thread_frame_push(dispatch_thread_frame_t dtf, dispatch_queue_t dq) |
| { |
| _dispatch_thread_frame_save_state(dtf); |
| _dispatch_thread_setspecific_pair(dispatch_queue_key, dq, |
| dispatch_frame_key, dtf); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_thread_frame_push_and_rebase(dispatch_thread_frame_t dtf, |
| dispatch_queue_t dq, dispatch_thread_frame_t new_base) |
| { |
| _dispatch_thread_frame_save_state(dtf); |
| _dispatch_thread_setspecific_pair(dispatch_queue_key, dq, |
| dispatch_frame_key, new_base); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_thread_frame_pop(dispatch_thread_frame_t dtf) |
| { |
| _dispatch_thread_setspecific_packed_pair( |
| dispatch_queue_key, dispatch_frame_key, (void **)&dtf->dtf_queue); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_queue_t |
| _dispatch_thread_frame_stash(dispatch_thread_frame_t dtf) |
| { |
| _dispatch_thread_getspecific_pair( |
| dispatch_queue_key, (void **)&dtf->dtf_queue, |
| dispatch_frame_key, (void **)&dtf->dtf_prev); |
| _dispatch_thread_frame_pop(dtf->dtf_prev); |
| return dtf->dtf_queue; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_thread_frame_unstash(dispatch_thread_frame_t dtf) |
| { |
| _dispatch_thread_frame_pop(dtf); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline int |
| _dispatch_wqthread_override_start_check_owner(mach_port_t thread, |
| dispatch_qos_t qos, mach_port_t *ulock_addr) |
| { |
| #if HAVE_PTHREAD_WORKQUEUE_QOS |
| if (!_dispatch_set_qos_class_enabled) return 0; |
| return _pthread_workqueue_override_start_direct_check_owner(thread, |
| _dispatch_qos_to_pp(qos), ulock_addr); |
| #else |
| (void)thread; (void)qos; (void)ulock_addr; |
| return 0; |
| #endif |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_wqthread_override_start(mach_port_t thread, dispatch_qos_t qos) |
| { |
| #if HAVE_PTHREAD_WORKQUEUE_QOS |
| if (!_dispatch_set_qos_class_enabled) return; |
| (void)_pthread_workqueue_override_start_direct(thread, |
| _dispatch_qos_to_pp(qos)); |
| #else |
| (void)thread; (void)qos; |
| #endif |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_wqthread_override_reset(void) |
| { |
| #if HAVE_PTHREAD_WORKQUEUE_QOS |
| if (!_dispatch_set_qos_class_enabled) return; |
| (void)_pthread_workqueue_override_reset(); |
| #endif |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_thread_override_start(mach_port_t thread, pthread_priority_t pp, |
| void *resource) |
| { |
| #if HAVE_PTHREAD_WORKQUEUE_QOS |
| if (!_dispatch_set_qos_class_enabled) return; |
| (void)_pthread_qos_override_start_direct(thread, pp, resource); |
| #else |
| (void)thread; (void)pp; (void)resource; |
| #endif |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_thread_override_end(mach_port_t thread, void *resource) |
| { |
| #if HAVE_PTHREAD_WORKQUEUE_QOS |
| if (!_dispatch_set_qos_class_enabled) return; |
| (void)_pthread_qos_override_end_direct(thread, resource); |
| #else |
| (void)thread; (void)resource; |
| #endif |
| } |
| |
| #endif // DISPATCH_PURE_C |
| #pragma mark - |
| #pragma mark dispatch_queue_t state accessors |
| #if DISPATCH_PURE_C |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_queue_flags_t |
| _dispatch_queue_atomic_flags(dispatch_queue_t dq) |
| { |
| return os_atomic_load2o(dq, dq_atomic_flags, relaxed); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_queue_flags_t |
| _dispatch_queue_atomic_flags_set(dispatch_queue_t dq, |
| dispatch_queue_flags_t bits) |
| { |
| return os_atomic_or2o(dq, dq_atomic_flags, bits, relaxed); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_queue_flags_t |
| _dispatch_queue_atomic_flags_set_and_clear_orig(dispatch_queue_t dq, |
| dispatch_queue_flags_t add_bits, dispatch_queue_flags_t clr_bits) |
| { |
| dispatch_queue_flags_t oflags, nflags; |
| os_atomic_rmw_loop2o(dq, dq_atomic_flags, oflags, nflags, relaxed, { |
| nflags = (oflags | add_bits) & ~clr_bits; |
| }); |
| return oflags; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_queue_flags_t |
| _dispatch_queue_atomic_flags_set_and_clear(dispatch_queue_t dq, |
| dispatch_queue_flags_t add_bits, dispatch_queue_flags_t clr_bits) |
| { |
| dispatch_queue_flags_t oflags, nflags; |
| os_atomic_rmw_loop2o(dq, dq_atomic_flags, oflags, nflags, relaxed, { |
| nflags = (oflags | add_bits) & ~clr_bits; |
| }); |
| return nflags; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_queue_flags_t |
| _dispatch_queue_atomic_flags_set_orig(dispatch_queue_t dq, |
| dispatch_queue_flags_t bits) |
| { |
| return os_atomic_or_orig2o(dq, dq_atomic_flags, bits, relaxed); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_queue_flags_t |
| _dispatch_queue_atomic_flags_clear(dispatch_queue_t dq, |
| dispatch_queue_flags_t bits) |
| { |
| return os_atomic_and2o(dq, dq_atomic_flags, ~bits, relaxed); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_queue_is_thread_bound(dispatch_queue_t dq) |
| { |
| return _dispatch_queue_atomic_flags(dq) & DQF_THREAD_BOUND; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_queue_cannot_trysync(dispatch_queue_t dq) |
| { |
| return _dispatch_queue_atomic_flags(dq) & DQF_CANNOT_TRYSYNC; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_queue_label_needs_free(dispatch_queue_t dq) |
| { |
| return _dispatch_queue_atomic_flags(dq) & DQF_LABEL_NEEDS_FREE; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_invoke_flags_t |
| _dispatch_queue_autorelease_frequency(dispatch_queue_t dq) |
| { |
| const unsigned long factor = |
| DISPATCH_INVOKE_AUTORELEASE_ALWAYS / DQF_AUTORELEASE_ALWAYS; |
| dispatch_static_assert(factor > 0); |
| |
| dispatch_queue_flags_t qaf = _dispatch_queue_atomic_flags(dq); |
| |
| qaf &= _DQF_AUTORELEASE_MASK; |
| return (dispatch_invoke_flags_t)qaf * factor; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_invoke_flags_t |
| _dispatch_queue_merge_autorelease_frequency(dispatch_queue_t dq, |
| dispatch_invoke_flags_t flags) |
| { |
| dispatch_invoke_flags_t qaf = _dispatch_queue_autorelease_frequency(dq); |
| |
| if (qaf) { |
| flags &= ~_DISPATCH_INVOKE_AUTORELEASE_MASK; |
| flags |= qaf; |
| } |
| return flags; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_queue_is_legacy(dispatch_queue_t dq) |
| { |
| return _dispatch_queue_atomic_flags(dq) & DQF_LEGACY; |
| } |
| |
| #endif // DISPATCH_PURE_C |
| #ifndef __cplusplus |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline uint32_t |
| _dq_state_suspend_cnt(uint64_t dq_state) |
| { |
| return (uint32_t)(dq_state / DISPATCH_QUEUE_SUSPEND_INTERVAL); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dq_state_has_side_suspend_cnt(uint64_t dq_state) |
| { |
| return dq_state & DISPATCH_QUEUE_HAS_SIDE_SUSPEND_CNT; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline uint32_t |
| _dq_state_extract_width_bits(uint64_t dq_state) |
| { |
| dq_state &= DISPATCH_QUEUE_WIDTH_MASK; |
| return (uint32_t)(dq_state >> DISPATCH_QUEUE_WIDTH_SHIFT); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline uint32_t |
| _dq_state_available_width(uint64_t dq_state) |
| { |
| uint32_t full = DISPATCH_QUEUE_WIDTH_FULL; |
| if (likely(!(dq_state & DISPATCH_QUEUE_WIDTH_FULL_BIT))) { |
| return full - _dq_state_extract_width_bits(dq_state); |
| } |
| return 0; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline uint32_t |
| _dq_state_used_width(uint64_t dq_state, uint16_t dq_width) |
| { |
| uint32_t full = DISPATCH_QUEUE_WIDTH_FULL; |
| uint32_t width = _dq_state_extract_width_bits(dq_state); |
| |
| if (dq_state & DISPATCH_QUEUE_PENDING_BARRIER) { |
| // DISPATCH_QUEUE_PENDING_BARRIER means (dq_width - 1) of the used width |
| // is pre-reservation that we want to ignore |
| return width - (full - dq_width) - (dq_width - 1); |
| } |
| return width - (full - dq_width); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dq_state_is_suspended(uint64_t dq_state) |
| { |
| return dq_state >= DISPATCH_QUEUE_NEEDS_ACTIVATION; |
| } |
| #define DISPATCH_QUEUE_IS_SUSPENDED(x) \ |
| _dq_state_is_suspended(os_atomic_load2o(x, dq_state, relaxed)) |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dq_state_is_inactive(uint64_t dq_state) |
| { |
| return dq_state & DISPATCH_QUEUE_INACTIVE; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dq_state_needs_activation(uint64_t dq_state) |
| { |
| return dq_state & DISPATCH_QUEUE_NEEDS_ACTIVATION; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dq_state_is_in_barrier(uint64_t dq_state) |
| { |
| return dq_state & DISPATCH_QUEUE_IN_BARRIER; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dq_state_has_available_width(uint64_t dq_state) |
| { |
| return !(dq_state & DISPATCH_QUEUE_WIDTH_FULL_BIT); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dq_state_has_pending_barrier(uint64_t dq_state) |
| { |
| return dq_state & DISPATCH_QUEUE_PENDING_BARRIER; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dq_state_is_dirty(uint64_t dq_state) |
| { |
| return dq_state & DISPATCH_QUEUE_DIRTY; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dq_state_is_enqueued(uint64_t dq_state) |
| { |
| return dq_state & DISPATCH_QUEUE_ENQUEUED; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dq_state_received_override(uint64_t dq_state) |
| { |
| return dq_state & DISPATCH_QUEUE_RECEIVED_OVERRIDE; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_qos_t |
| _dq_state_max_qos(uint64_t dq_state) |
| { |
| dq_state &= DISPATCH_QUEUE_MAX_QOS_MASK; |
| return (dispatch_qos_t)(dq_state >> DISPATCH_QUEUE_MAX_QOS_SHIFT); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline uint64_t |
| _dq_state_from_qos(dispatch_qos_t qos) |
| { |
| return (uint64_t)(qos) << DISPATCH_QUEUE_MAX_QOS_SHIFT; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline uint64_t |
| _dq_state_merge_qos(uint64_t dq_state, dispatch_qos_t qos) |
| { |
| uint64_t qos_bits = _dq_state_from_qos(qos); |
| if ((dq_state & DISPATCH_QUEUE_MAX_QOS_MASK) < qos_bits) { |
| dq_state &= ~DISPATCH_QUEUE_MAX_QOS_MASK; |
| dq_state |= qos_bits | DISPATCH_QUEUE_RECEIVED_OVERRIDE; |
| } |
| return dq_state; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_lock_owner |
| _dq_state_drain_owner(uint64_t dq_state) |
| { |
| return _dispatch_lock_owner((dispatch_lock)dq_state); |
| } |
| #define DISPATCH_QUEUE_DRAIN_OWNER(dq) \ |
| _dq_state_drain_owner(os_atomic_load2o(dq, dq_state, relaxed)) |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dq_state_drain_pended(uint64_t dq_state) |
| { |
| return (dq_state & DISPATCH_QUEUE_DRAIN_PENDED); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dq_state_drain_locked_by(uint64_t dq_state, uint32_t owner) |
| { |
| if (_dq_state_drain_pended(dq_state)) { |
| return false; |
| } |
| return _dq_state_drain_owner(dq_state) == owner; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dq_state_drain_locked(uint64_t dq_state) |
| { |
| return (dq_state & DISPATCH_QUEUE_DRAIN_OWNER_MASK) != 0; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dq_state_has_waiters(uint64_t dq_state) |
| { |
| return _dispatch_lock_has_waiters((dispatch_lock)dq_state); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dq_state_is_sync_runnable(uint64_t dq_state) |
| { |
| return dq_state < DISPATCH_QUEUE_IN_BARRIER; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dq_state_is_runnable(uint64_t dq_state) |
| { |
| return dq_state < DISPATCH_QUEUE_WIDTH_FULL_BIT; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dq_state_should_wakeup(uint64_t dq_state) |
| { |
| return _dq_state_is_runnable(dq_state) && |
| !_dq_state_is_enqueued(dq_state) && |
| !_dq_state_drain_locked(dq_state); |
| } |
| |
| #endif // __cplusplus |
| #pragma mark - |
| #pragma mark dispatch_queue_t state machine |
| #ifndef __cplusplus |
| |
| static inline pthread_priority_t _dispatch_get_priority(void); |
| static inline dispatch_priority_t _dispatch_get_basepri(void); |
| static inline dispatch_qos_t _dispatch_get_basepri_override_qos_floor(void); |
| static inline void _dispatch_set_basepri_override_qos(dispatch_qos_t qos); |
| static inline void _dispatch_reset_basepri(dispatch_priority_t dbp); |
| static inline dispatch_priority_t _dispatch_set_basepri(dispatch_priority_t dbp); |
| |
| static inline bool _dispatch_queue_need_override_retain( |
| dispatch_queue_class_t dqu, dispatch_qos_t qos); |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_queue_xref_dispose(struct dispatch_queue_s *dq) |
| { |
| uint64_t dq_state = os_atomic_load2o(dq, dq_state, relaxed); |
| if (unlikely(_dq_state_is_suspended(dq_state))) { |
| long state = (long)dq_state; |
| if (sizeof(long) < sizeof(uint64_t)) state = (long)(dq_state >> 32); |
| if (unlikely(_dq_state_is_inactive(dq_state))) { |
| // Arguments for and against this assert are within 6705399 |
| DISPATCH_CLIENT_CRASH(state, "Release of an inactive object"); |
| } |
| DISPATCH_CLIENT_CRASH(dq_state, "Release of a suspended object"); |
| } |
| os_atomic_or2o(dq, dq_atomic_flags, DQF_RELEASED, relaxed); |
| } |
| |
| #endif |
| #if DISPATCH_PURE_C |
| |
| // Note to later developers: ensure that any initialization changes are |
| // made for statically allocated queues (i.e. _dispatch_main_q). |
| static inline void |
| _dispatch_queue_init(dispatch_queue_t dq, dispatch_queue_flags_t dqf, |
| uint16_t width, bool inactive) |
| { |
| uint64_t dq_state = DISPATCH_QUEUE_STATE_INIT_VALUE(width); |
| |
| if (inactive) { |
| dq_state += DISPATCH_QUEUE_INACTIVE + DISPATCH_QUEUE_NEEDS_ACTIVATION; |
| dq_state += DLOCK_OWNER_INVALID; |
| dq->do_ref_cnt++; // rdar://8181908 see _dispatch_queue_resume |
| } |
| dq->do_next = (struct dispatch_queue_s *)DISPATCH_OBJECT_LISTLESS; |
| dqf |= DQF_WIDTH(width); |
| os_atomic_store2o(dq, dq_atomic_flags, dqf, relaxed); |
| dq->dq_state = dq_state; |
| dq->dq_serialnum = |
| os_atomic_inc_orig(&_dispatch_queue_serial_numbers, relaxed); |
| } |
| |
| /* Used by: |
| * - _dispatch_queue_set_target_queue |
| * - changing dispatch source handlers |
| * |
| * Tries to prevent concurrent wakeup of an inactive queue by suspending it. |
| */ |
| DISPATCH_ALWAYS_INLINE DISPATCH_WARN_RESULT |
| static inline bool |
| _dispatch_queue_try_inactive_suspend(dispatch_queue_t dq) |
| { |
| uint64_t old_state, new_state; |
| |
| (void)os_atomic_rmw_loop2o(dq, dq_state, old_state, new_state, relaxed, { |
| if (unlikely(!_dq_state_is_inactive(old_state))) { |
| os_atomic_rmw_loop_give_up(return false); |
| } |
| new_state = old_state + DISPATCH_QUEUE_SUSPEND_INTERVAL; |
| }); |
| if (unlikely(!_dq_state_is_suspended(old_state) || |
| _dq_state_has_side_suspend_cnt(old_state))) { |
| // Crashing here means that 128+ dispatch_suspend() calls have been |
| // made on an inactive object and then dispatch_set_target_queue() or |
| // dispatch_set_*_handler() has been called. |
| // |
| // We don't want to handle the side suspend count in a codepath that |
| // needs to be fast. |
| DISPATCH_CLIENT_CRASH(dq, "Too many calls to dispatch_suspend() " |
| "prior to calling dispatch_set_target_queue() " |
| "or dispatch_set_*_handler()"); |
| } |
| return true; |
| } |
| |
| #define _dispatch_queue_should_override_self(dq_state, qos) \ |
| unlikely(qos < _dq_state_max_qos(dq_state)) |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_qos_t |
| _dispatch_queue_override_self(uint64_t dq_state) |
| { |
| dispatch_qos_t qos = _dq_state_max_qos(dq_state); |
| _dispatch_wqthread_override_start(_dispatch_tid_self(), qos); |
| // ensure that the root queue sees |
| // that this thread was overridden. |
| _dispatch_set_basepri_override_qos(qos); |
| return qos; |
| } |
| |
| /* Used by: |
| * - _dispatch_queue_class_invoke (normal path) |
| * - _dispatch_queue_override_invoke (stealer) |
| * |
| * Initial state must be { sc:0, ib:0, qf:0, dl:0 } |
| * Final state forces { dl:self, qf:1, d: 0 } |
| * ib:1 is forced when the width acquired is equivalent to the barrier width |
| */ |
| DISPATCH_ALWAYS_INLINE DISPATCH_WARN_RESULT |
| static inline uint64_t |
| _dispatch_queue_drain_try_lock(dispatch_queue_t dq, |
| dispatch_invoke_flags_t flags, uint64_t *dq_state) |
| { |
| uint64_t pending_barrier_width = |
| (dq->dq_width - 1) * DISPATCH_QUEUE_WIDTH_INTERVAL; |
| uint64_t xor_owner_and_set_full_width = |
| _dispatch_tid_self() | DISPATCH_QUEUE_WIDTH_FULL_BIT; |
| uint64_t clear_enqueued_bit, old_state, new_state; |
| |
| if (flags & DISPATCH_INVOKE_STEALING) { |
| clear_enqueued_bit = 0; |
| } else { |
| clear_enqueued_bit = DISPATCH_QUEUE_ENQUEUED; |
| } |
| |
| dispatch_qos_t oq_floor = _dispatch_get_basepri_override_qos_floor(); |
| retry: |
| os_atomic_rmw_loop2o(dq, dq_state, old_state, new_state, acquire, { |
| new_state = old_state; |
| new_state ^= clear_enqueued_bit; |
| if (likely(_dq_state_is_runnable(old_state) && |
| !_dq_state_drain_locked(old_state))) { |
| if (_dispatch_queue_should_override_self(old_state, oq_floor)) { |
| os_atomic_rmw_loop_give_up({ |
| oq_floor = _dispatch_queue_override_self(old_state); |
| goto retry; |
| }); |
| } |
| // |
| // Only keep the HAS_WAITER, MAX_QOS and ENQUEUED (if stealing) bits |
| // In particular acquiring the drain lock clears the DIRTY and |
| // RECEIVED_OVERRIDE |
| // |
| new_state &= DISPATCH_QUEUE_DRAIN_PRESERVED_BITS_MASK; |
| // |
| // For the NOWAITERS_BIT case, the thread identity |
| // has NOWAITERS_BIT set, and NOWAITERS_BIT was kept above, |
| // so the xor below flips the NOWAITERS_BIT to 0 as expected. |
| // |
| // For the non inverted WAITERS_BIT case, WAITERS_BIT is not set in |
| // the thread identity, and the xor leaves the bit alone. |
| // |
| new_state ^= xor_owner_and_set_full_width; |
| if (_dq_state_has_pending_barrier(old_state) || |
| old_state + pending_barrier_width < |
| DISPATCH_QUEUE_WIDTH_FULL_BIT) { |
| new_state |= DISPATCH_QUEUE_IN_BARRIER; |
| } |
| } else if (!clear_enqueued_bit) { |
| os_atomic_rmw_loop_give_up(break); |
| } |
| }); |
| |
| if (dq_state) *dq_state = new_state; |
| if (likely(_dq_state_is_runnable(old_state) && |
| !_dq_state_drain_locked(old_state))) { |
| new_state &= DISPATCH_QUEUE_IN_BARRIER | DISPATCH_QUEUE_WIDTH_FULL_BIT; |
| old_state &= DISPATCH_QUEUE_WIDTH_MASK; |
| return new_state - old_state; |
| } |
| return 0; |
| } |
| |
| /* Used by _dispatch_barrier_{try,}sync |
| * |
| * Note, this fails if any of e:1 or dl!=0, but that allows this code to be a |
| * simple cmpxchg which is significantly faster on Intel, and makes a |
| * significant difference on the uncontended codepath. |
| * |
| * See discussion for DISPATCH_QUEUE_DIRTY in queue_internal.h |
| * |
| * Initial state must be `completely idle` |
| * Final state forces { ib:1, qf:1, w:0 } |
| */ |
| DISPATCH_ALWAYS_INLINE DISPATCH_WARN_RESULT |
| static inline bool |
| _dispatch_queue_try_acquire_barrier_sync(dispatch_queue_t dq, uint32_t tid) |
| { |
| uint64_t value = DISPATCH_QUEUE_WIDTH_FULL_BIT | DISPATCH_QUEUE_IN_BARRIER; |
| value |= tid; |
| |
| return os_atomic_cmpxchg2o(dq, dq_state, |
| DISPATCH_QUEUE_STATE_INIT_VALUE(dq->dq_width), value, acquire); |
| } |
| |
| /* Used by _dispatch_sync for root queues and some drain codepaths |
| * |
| * Root queues have no strict orderning and dispatch_sync() always goes through. |
| * Drain is the sole setter of `dl` hence can use this non failing version of |
| * _dispatch_queue_try_acquire_sync(). |
| * |
| * Final state: { w += 1 } |
| */ |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_queue_reserve_sync_width(dispatch_queue_t dq) |
| { |
| (void)os_atomic_add2o(dq, dq_state, |
| DISPATCH_QUEUE_WIDTH_INTERVAL, relaxed); |
| } |
| |
| /* Used by _dispatch_sync on non-serial queues |
| * |
| * Initial state must be { sc:0, ib:0, pb:0, d:0 } |
| * Final state: { w += 1 } |
| */ |
| DISPATCH_ALWAYS_INLINE DISPATCH_WARN_RESULT |
| static inline bool |
| _dispatch_queue_try_reserve_sync_width(dispatch_queue_t dq) |
| { |
| uint64_t old_state, new_state; |
| |
| // <rdar://problem/24738102&24743140> reserving non barrier width |
| // doesn't fail if only the ENQUEUED bit is set (unlike its barrier width |
| // equivalent), so we have to check that this thread hasn't enqueued |
| // anything ahead of this call or we can break ordering |
| if (unlikely(dq->dq_items_tail)) { |
| return false; |
| } |
| |
| return os_atomic_rmw_loop2o(dq, dq_state, old_state, new_state, relaxed, { |
| if (unlikely(!_dq_state_is_sync_runnable(old_state)) || |
| _dq_state_is_dirty(old_state) || |
| _dq_state_has_pending_barrier(old_state)) { |
| os_atomic_rmw_loop_give_up(return false); |
| } |
| new_state = old_state + DISPATCH_QUEUE_WIDTH_INTERVAL; |
| }); |
| } |
| |
| /* Used by _dispatch_apply_redirect |
| * |
| * Try to acquire at most da_width and returns what could be acquired, |
| * possibly 0 |
| */ |
| DISPATCH_ALWAYS_INLINE DISPATCH_WARN_RESULT |
| static inline uint32_t |
| _dispatch_queue_try_reserve_apply_width(dispatch_queue_t dq, uint32_t da_width) |
| { |
| uint64_t old_state, new_state; |
| uint32_t width; |
| |
| (void)os_atomic_rmw_loop2o(dq, dq_state, old_state, new_state, relaxed, { |
| width = _dq_state_available_width(old_state); |
| if (unlikely(!width)) { |
| os_atomic_rmw_loop_give_up(return 0); |
| } |
| if (width > da_width) { |
| width = da_width; |
| } |
| new_state = old_state + width * DISPATCH_QUEUE_WIDTH_INTERVAL; |
| }); |
| return width; |
| } |
| |
| /* Used by _dispatch_apply_redirect |
| * |
| * Release width acquired by _dispatch_queue_try_acquire_width |
| */ |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_queue_relinquish_width(dispatch_queue_t dq, uint32_t da_width) |
| { |
| (void)os_atomic_sub2o(dq, dq_state, |
| da_width * DISPATCH_QUEUE_WIDTH_INTERVAL, relaxed); |
| } |
| |
| /* Used by target-queue recursing code |
| * |
| * Initial state must be { sc:0, ib:0, qf:0, pb:0, d:0 } |
| * Final state: { w += 1 } |
| */ |
| DISPATCH_ALWAYS_INLINE DISPATCH_WARN_RESULT |
| static inline bool |
| _dispatch_queue_try_acquire_async(dispatch_queue_t dq) |
| { |
| uint64_t old_state, new_state; |
| |
| return os_atomic_rmw_loop2o(dq, dq_state, old_state, new_state, acquire, { |
| if (unlikely(!_dq_state_is_runnable(old_state) || |
| _dq_state_is_dirty(old_state) || |
| _dq_state_has_pending_barrier(old_state))) { |
| os_atomic_rmw_loop_give_up(return false); |
| } |
| new_state = old_state + DISPATCH_QUEUE_WIDTH_INTERVAL; |
| }); |
| } |
| |
| /* Used by concurrent drain |
| * |
| * Either acquires the full barrier width, in which case the Final state is: |
| * { ib:1 qf:1 pb:0 d:0 } |
| * Or if there isn't enough width prepare the queue with the PENDING_BARRIER bit |
| * { ib:0 pb:1 d:0} |
| * |
| * This always clears the dirty bit as we know for sure we shouldn't reevaluate |
| * the state machine here |
| */ |
| DISPATCH_ALWAYS_INLINE DISPATCH_WARN_RESULT |
| static inline bool |
| _dispatch_queue_try_upgrade_full_width(dispatch_queue_t dq, uint64_t owned) |
| { |
| uint64_t old_state, new_state; |
| uint64_t pending_barrier_width = DISPATCH_QUEUE_PENDING_BARRIER + |
| (dq->dq_width - 1) * DISPATCH_QUEUE_WIDTH_INTERVAL; |
| |
| os_atomic_rmw_loop2o(dq, dq_state, old_state, new_state, acquire, { |
| new_state = old_state - owned; |
| if (likely(!_dq_state_has_pending_barrier(old_state))) { |
| new_state += pending_barrier_width; |
| } |
| if (likely(_dq_state_is_runnable(new_state))) { |
| new_state += DISPATCH_QUEUE_WIDTH_INTERVAL; |
| new_state += DISPATCH_QUEUE_IN_BARRIER; |
| new_state -= DISPATCH_QUEUE_PENDING_BARRIER; |
| } |
| new_state &= ~DISPATCH_QUEUE_DIRTY; |
| }); |
| return new_state & DISPATCH_QUEUE_IN_BARRIER; |
| } |
| |
| /* Used at the end of Drainers |
| * |
| * This adjusts the `owned` width when the next continuation is already known |
| * to account for its barrierness. |
| */ |
| DISPATCH_ALWAYS_INLINE |
| static inline uint64_t |
| _dispatch_queue_adjust_owned(dispatch_queue_t dq, uint64_t owned, |
| struct dispatch_object_s *next_dc) |
| { |
| uint64_t reservation; |
| |
| if (unlikely(dq->dq_width > 1)) { |
| if (next_dc && _dispatch_object_is_barrier(next_dc)) { |
| reservation = DISPATCH_QUEUE_PENDING_BARRIER; |
| reservation += (dq->dq_width - 1) * DISPATCH_QUEUE_WIDTH_INTERVAL; |
| owned -= reservation; |
| } |
| } |
| return owned; |
| } |
| |
| /* Used at the end of Drainers |
| * |
| * Unlocking fails if the DIRTY bit is seen (and the queue is not suspended). |
| * In that case, only the DIRTY bit is cleared. The DIRTY bit is therefore used |
| * as a signal to renew the drain lock instead of releasing it. |
| * |
| * Successful unlock forces { dl:0, d:!done, qo:0 } and gives back `owned` |
| */ |
| DISPATCH_ALWAYS_INLINE DISPATCH_WARN_RESULT |
| static inline bool |
| _dispatch_queue_drain_try_unlock(dispatch_queue_t dq, uint64_t owned, bool done) |
| { |
| uint64_t old_state = os_atomic_load2o(dq, dq_state, relaxed); |
| uint64_t new_state; |
| |
| os_atomic_rmw_loop2o(dq, dq_state, old_state, new_state, release, { |
| new_state = old_state - owned; |
| if (unlikely(_dq_state_is_suspended(new_state))) { |
| #ifdef DLOCK_NOWAITERS_BIT |
| new_state = new_state | DISPATCH_QUEUE_DRAIN_OWNER_MASK; |
| #else |
| new_state = new_state | DLOCK_OWNER_INVALID; |
| #endif |
| new_state |= DISPATCH_QUEUE_DIRTY; |
| } else if (unlikely(_dq_state_is_dirty(old_state))) { |
| os_atomic_rmw_loop_give_up({ |
| // just renew the drain lock with an acquire barrier, to see |
| // what the enqueuer that set DIRTY has done. |
| // the xor generates better assembly as DISPATCH_QUEUE_DIRTY |
| // is already in a register |
| os_atomic_xor2o(dq, dq_state, DISPATCH_QUEUE_DIRTY, acquire); |
| return false; |
| }); |
| } else if (likely(done)) { |
| new_state &= ~DISPATCH_QUEUE_DRAIN_UNLOCK_MASK; |
| new_state &= ~DISPATCH_QUEUE_RECEIVED_OVERRIDE; |
| new_state &= ~DISPATCH_QUEUE_MAX_QOS_MASK; |
| } else { |
| new_state = DISPATCH_QUEUE_DRAIN_UNLOCK(new_state); |
| new_state |= DISPATCH_QUEUE_DIRTY; |
| } |
| }); |
| |
| if (_dq_state_received_override(old_state)) { |
| // Ensure that the root queue sees that this thread was overridden. |
| _dispatch_set_basepri_override_qos(_dq_state_max_qos(old_state)); |
| } |
| return true; |
| } |
| |
| /* Used to transfer the drain lock to a next thread, because it is known |
| * and that the dirty-head check isn't needed. |
| * |
| * This releases `owned`, clears DIRTY, and handles overrides when seen. |
| */ |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_queue_drain_transfer_lock(dispatch_queue_t dq, |
| uint64_t owned, dispatch_object_t dou) |
| { |
| uint64_t old_state, new_state; |
| mach_port_t next_owner = 0; |
| if (dou._dc->dc_flags & DISPATCH_OBJ_BARRIER_BIT) { |
| next_owner = (mach_port_t)dou._dc->dc_data; |
| } |
| |
| #ifdef DLOCK_NOWAITERS_BIT |
| // The NOWAITERS_BIT state must not change through the transfer. It means |
| // that if next_owner is 0 the bit must be flipped in the rmw_loop below, |
| // and if next_owner is set, then the bit must be left unchanged. |
| // |
| // - when next_owner is 0, the xor below sets NOWAITERS_BIT in next_owner, |
| // which causes the second xor to flip the bit as expected. |
| // - if next_owner is not 0, it has the NOWAITERS_BIT set, so we have to |
| // clear it so that the second xor leaves the NOWAITERS_BIT alone. |
| next_owner ^= DLOCK_NOWAITERS_BIT; |
| #endif |
| os_atomic_rmw_loop2o(dq, dq_state, old_state, new_state, release, { |
| new_state = old_state - owned; |
| // same as DISPATCH_QUEUE_DRAIN_UNLOCK |
| // but we want to be more efficient wrt the WAITERS_BIT |
| new_state &= ~DISPATCH_QUEUE_DRAIN_OWNER_MASK; |
| new_state &= ~DISPATCH_QUEUE_DRAIN_PENDED; |
| new_state &= ~DISPATCH_QUEUE_RECEIVED_OVERRIDE; |
| new_state &= ~DISPATCH_QUEUE_DIRTY; |
| new_state ^= next_owner; |
| }); |
| if (_dq_state_received_override(old_state)) { |
| // Ensure that the root queue sees that this thread was overridden. |
| _dispatch_set_basepri_override_qos(_dq_state_max_qos(old_state)); |
| } |
| } |
| |
| /* Used to forcefully unlock the drain lock, bypassing the dirty bit check. |
| * This usually is followed by a wakeup to re-evaluate the state machine |
| * of the queue/source. |
| * |
| * This releases `owned`, clears DIRTY, and handles overrides when seen. |
| */ |
| DISPATCH_ALWAYS_INLINE |
| static inline uint64_t |
| _dispatch_queue_drain_unlock(dispatch_queue_t dq, uint64_t owned) |
| { |
| uint64_t old_state, new_state; |
| |
| os_atomic_rmw_loop2o(dq, dq_state, old_state, new_state, release, { |
| new_state = old_state - owned; |
| // same as DISPATCH_QUEUE_DRAIN_UNLOCK |
| // but we want to be more efficient wrt the WAITERS_BIT |
| #ifdef DLOCK_NOWAITERS_BIT |
| new_state ^= DLOCK_NOWAITERS_BIT; |
| #endif |
| new_state &= ~DISPATCH_QUEUE_DRAIN_OWNER_MASK; |
| new_state &= ~DISPATCH_QUEUE_DRAIN_PENDED; |
| new_state &= ~DISPATCH_QUEUE_RECEIVED_OVERRIDE; |
| }); |
| |
| if (_dq_state_received_override(old_state)) { |
| // Ensure that the root queue sees that this thread was overridden. |
| _dispatch_set_basepri_override_qos(_dq_state_max_qos(old_state)); |
| } |
| return old_state; |
| } |
| |
| #pragma mark - |
| #pragma mark os_mpsc_queue |
| |
| // type_t * {volatile,const,_Atomic,...} -> type_t * |
| // type_t[] -> type_t * |
| #define os_unqualified_pointer_type(expr) \ |
| typeof(typeof(*(expr)) *) |
| |
| #define os_mpsc_node_type(q, _ns) \ |
| os_unqualified_pointer_type((q)->_ns##_head) |
| |
| // |
| // Multi Producer calls, can be used safely concurrently |
| // |
| |
| // Returns true when the queue was empty and the head must be set |
| #define os_mpsc_push_update_tail_list(q, _ns, head, tail, _o_next) ({ \ |
| os_mpsc_node_type(q, _ns) _head = (head), _tail = (tail), _prev; \ |
| _tail->_o_next = NULL; \ |
| _prev = os_atomic_xchg2o((q), _ns##_tail, _tail, release); \ |
| if (likely(_prev)) { \ |
| os_atomic_store2o(_prev, _o_next, _head, relaxed); \ |
| } \ |
| (_prev == NULL); \ |
| }) |
| |
| // Returns true when the queue was empty and the head must be set |
| #define os_mpsc_push_update_tail(q, _ns, o, _o_next) ({ \ |
| os_mpsc_node_type(q, _ns) _o = (o); \ |
| os_mpsc_push_update_tail_list(q, _ns, _o, _o, _o_next); \ |
| }) |
| |
| #define os_mpsc_push_update_head(q, _ns, o) ({ \ |
| os_atomic_store2o((q), _ns##_head, o, relaxed); \ |
| }) |
| |
| // |
| // Single Consumer calls, can NOT be used safely concurrently |
| // |
| |
| #define os_mpsc_get_head(q, _ns) \ |
| _dispatch_wait_until(os_atomic_load2o(q, _ns##_head, dependency)) |
| |
| #define os_mpsc_get_next(_n, _o_next) \ |
| _dispatch_wait_until(os_atomic_load2o(_n, _o_next, dependency)) |
| |
| #define os_mpsc_pop_head(q, _ns, head, _o_next) ({ \ |
| typeof(q) _q = (q); \ |
| os_mpsc_node_type(_q, _ns) _head = (head), _n; \ |
| _n = os_atomic_load2o(_head, _o_next, dependency); \ |
| os_atomic_store2o(_q, _ns##_head, _n, relaxed); \ |
| /* 22708742: set tail to NULL with release, so that NULL write */ \ |
| /* to head above doesn't clobber head from concurrent enqueuer */ \ |
| if (unlikely(!_n && \ |
| !os_atomic_cmpxchg2o(_q, _ns##_tail, _head, NULL, release))) { \ |
| _n = os_mpsc_get_next(_head, _o_next); \ |
| os_atomic_store2o(_q, _ns##_head, _n, relaxed); \ |
| } \ |
| _n; \ |
| }) |
| |
| #define os_mpsc_undo_pop_head(q, _ns, head, next, _o_next) ({ \ |
| typeof(q) _q = (q); \ |
| os_mpsc_node_type(_q, _ns) _head = (head), _n = (next); \ |
| if (unlikely(!_n && \ |
| !os_atomic_cmpxchg2o(_q, _ns##_tail, NULL, _head, relaxed))) { \ |
| _n = os_mpsc_get_head(q, _ns); \ |
| os_atomic_store2o(_head, _o_next, _n, relaxed); \ |
| } \ |
| os_atomic_store2o(_q, _ns##_head, _head, relaxed); \ |
| }) |
| |
| #define os_mpsc_capture_snapshot(q, _ns, tail) ({ \ |
| typeof(q) _q = (q); \ |
| os_mpsc_node_type(_q, _ns) _head = os_mpsc_get_head(q, _ns); \ |
| os_atomic_store2o(_q, _ns##_head, NULL, relaxed); \ |
| /* 22708742: set tail to NULL with release, so that NULL write */ \ |
| /* to head above doesn't clobber head from concurrent enqueuer */ \ |
| *(tail) = os_atomic_xchg2o(_q, _ns##_tail, NULL, release); \ |
| _head; \ |
| }) |
| |
| #define os_mpsc_pop_snapshot_head(head, tail, _o_next) ({ \ |
| os_unqualified_pointer_type(head) _head = (head), _n = NULL; \ |
| if (_head != (tail)) { \ |
| _n = os_mpsc_get_next(_head, _o_next); \ |
| }; \ |
| _n; }) |
| |
| #define os_mpsc_prepend(q, _ns, head, tail, _o_next) ({ \ |
| typeof(q) _q = (q); \ |
| os_mpsc_node_type(_q, _ns) _head = (head), _tail = (tail), _n; \ |
| os_atomic_store2o(_tail, _o_next, NULL, relaxed); \ |
| if (unlikely(!os_atomic_cmpxchg2o(_q, _ns##_tail, NULL, _tail, release))) { \ |
| _n = os_mpsc_get_head(q, _ns); \ |
| os_atomic_store2o(_tail, _o_next, _n, relaxed); \ |
| } \ |
| os_atomic_store2o(_q, _ns##_head, _head, relaxed); \ |
| }) |
| |
| #pragma mark - |
| #pragma mark dispatch_queue_t tq lock |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_queue_sidelock_trylock(dispatch_queue_t dq, dispatch_qos_t qos) |
| { |
| dispatch_lock_owner owner; |
| if (_dispatch_unfair_lock_trylock(&dq->dq_sidelock, &owner)) { |
| return true; |
| } |
| _dispatch_wqthread_override_start_check_owner(owner, qos, |
| &dq->dq_sidelock.dul_lock); |
| return false; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_queue_sidelock_lock(dispatch_queue_t dq) |
| { |
| return _dispatch_unfair_lock_lock(&dq->dq_sidelock); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_queue_sidelock_tryunlock(dispatch_queue_t dq) |
| { |
| if (_dispatch_unfair_lock_tryunlock(&dq->dq_sidelock)) { |
| return true; |
| } |
| // Ensure that the root queue sees that this thread was overridden. |
| // Since we don't know which override QoS was used, use MAINTENANCE |
| // as a marker for _dispatch_reset_basepri_override() |
| _dispatch_set_basepri_override_qos(DISPATCH_QOS_MAINTENANCE); |
| return false; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_queue_sidelock_unlock(dispatch_queue_t dq) |
| { |
| if (_dispatch_unfair_lock_unlock_had_failed_trylock(&dq->dq_sidelock)) { |
| // Ensure that the root queue sees that this thread was overridden. |
| // Since we don't know which override QoS was used, use MAINTENANCE |
| // as a marker for _dispatch_reset_basepri_override() |
| _dispatch_set_basepri_override_qos(DISPATCH_QOS_MAINTENANCE); |
| } |
| } |
| |
| #pragma mark - |
| #pragma mark dispatch_queue_t misc |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_queue_t |
| _dispatch_queue_get_current(void) |
| { |
| return (dispatch_queue_t)_dispatch_thread_getspecific(dispatch_queue_key); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_queue_set_current(dispatch_queue_t dq) |
| { |
| _dispatch_thread_setspecific(dispatch_queue_key, dq); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline struct dispatch_object_s* |
| _dispatch_queue_head(dispatch_queue_t dq) |
| { |
| return os_mpsc_get_head(dq, dq_items); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline struct dispatch_object_s* |
| _dispatch_queue_next(dispatch_queue_t dq, struct dispatch_object_s *dc) |
| { |
| return os_mpsc_pop_head(dq, dq_items, dc, do_next); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_queue_push_update_tail(dispatch_queue_t dq, |
| struct dispatch_object_s *tail) |
| { |
| // if we crash here with a value less than 0x1000, then we are |
| // at a known bug in client code. for example, see |
| // _dispatch_queue_dispose or _dispatch_atfork_child |
| return os_mpsc_push_update_tail(dq, dq_items, tail, do_next); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_queue_push_update_tail_list(dispatch_queue_t dq, |
| struct dispatch_object_s *head, struct dispatch_object_s *tail) |
| { |
| // if we crash here with a value less than 0x1000, then we are |
| // at a known bug in client code. for example, see |
| // _dispatch_queue_dispose or _dispatch_atfork_child |
| return os_mpsc_push_update_tail_list(dq, dq_items, head, tail, do_next); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_queue_push_update_head(dispatch_queue_t dq, |
| struct dispatch_object_s *head) |
| { |
| os_mpsc_push_update_head(dq, dq_items, head); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_root_queue_push_inline(dispatch_queue_t dq, dispatch_object_t _head, |
| dispatch_object_t _tail, unsigned int n) |
| { |
| struct dispatch_object_s *head = _head._do, *tail = _tail._do; |
| if (unlikely(_dispatch_queue_push_update_tail_list(dq, head, tail))) { |
| _dispatch_queue_push_update_head(dq, head); |
| return _dispatch_global_queue_poke(dq, n); |
| } |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_queue_push_inline(dispatch_queue_t dq, dispatch_object_t _tail, |
| dispatch_qos_t qos) |
| { |
| struct dispatch_object_s *tail = _tail._do; |
| dispatch_wakeup_flags_t flags = 0; |
| // If we are going to call dx_wakeup(), the queue must be retained before |
| // the item we're pushing can be dequeued, which means: |
| // - before we exchange the tail if we may have to override |
| // - before we set the head if we made the queue non empty. |
| // Otherwise, if preempted between one of these and the call to dx_wakeup() |
| // the blocks submitted to the queue may release the last reference to the |
| // queue when invoked by _dispatch_queue_drain. <rdar://problem/6932776> |
| bool overriding = _dispatch_queue_need_override_retain(dq, qos); |
| if (unlikely(_dispatch_queue_push_update_tail(dq, tail))) { |
| if (!overriding) _dispatch_retain(dq); |
| _dispatch_queue_push_update_head(dq, tail); |
| flags = DISPATCH_WAKEUP_CONSUME | DISPATCH_WAKEUP_FLUSH; |
| } else if (overriding) { |
| flags = DISPATCH_WAKEUP_CONSUME | DISPATCH_WAKEUP_OVERRIDING; |
| } else { |
| return; |
| } |
| return dx_wakeup(dq, qos, flags); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_priority_t |
| _dispatch_root_queue_identity_assume(dispatch_queue_t assumed_rq) |
| { |
| dispatch_priority_t old_dbp = _dispatch_get_basepri(); |
| dispatch_assert(dx_type(assumed_rq) == DISPATCH_QUEUE_GLOBAL_ROOT_TYPE); |
| _dispatch_reset_basepri(assumed_rq->dq_priority); |
| _dispatch_queue_set_current(assumed_rq); |
| return old_dbp; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_root_queue_allows_wlh_for_queue(dispatch_queue_t rq, |
| dispatch_queue_class_t dqu) |
| { |
| // This will discard: |
| // - queues already tagged with the global wlh |
| // - concurrent queues (width != 1) |
| // - non overcommit queues, which includes pthread root queues. |
| return dqu._dq->dq_wlh != DISPATCH_WLH_GLOBAL && dqu._dq->dq_width == 1 && |
| (rq->dq_priority & DISPATCH_PRIORITY_FLAG_OVERCOMMIT); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_wlh_t |
| _dispatch_root_queue_wlh_for_queue(dispatch_queue_t rq, |
| dispatch_queue_class_t dqu) |
| { |
| if (likely(_dispatch_root_queue_allows_wlh_for_queue(rq, dqu))) { |
| return (dispatch_wlh_t)dqu._dq; |
| } |
| return DISPATCH_WLH_GLOBAL; |
| } |
| |
| typedef dispatch_queue_wakeup_target_t |
| _dispatch_queue_class_invoke_handler_t(dispatch_object_t, |
| dispatch_invoke_context_t dic, dispatch_invoke_flags_t, |
| uint64_t *owned); |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_queue_class_invoke(dispatch_object_t dou, |
| dispatch_invoke_context_t dic, dispatch_invoke_flags_t flags, |
| _dispatch_queue_class_invoke_handler_t invoke) |
| { |
| dispatch_queue_t dq = dou._dq; |
| dispatch_queue_wakeup_target_t tq = DISPATCH_QUEUE_WAKEUP_NONE; |
| uint64_t dq_state, to_unlock = 0; |
| bool owning = !(flags & DISPATCH_INVOKE_STEALING); |
| bool overriding = (flags & DISPATCH_INVOKE_OVERRIDING); |
| |
| // When called from a plain _dispatch_queue_drain: |
| // overriding = false |
| // owning = true |
| // |
| // When called from an override continuation: |
| // overriding = true |
| // owning depends on whether the override embedded the queue or steals |
| DISPATCH_COMPILER_CAN_ASSUME(owning || overriding); |
| |
| if (likely(owning)) { |
| dq->do_next = DISPATCH_OBJECT_LISTLESS; |
| } |
| to_unlock = _dispatch_queue_drain_try_lock(dq, flags, &dq_state); |
| if (likely(to_unlock)) { |
| dispatch_priority_t old_dbp; |
| if (!(flags & DISPATCH_INVOKE_MANAGER_DRAIN)) { |
| if (unlikely(overriding)) { |
| _dispatch_object_debug(dq, "stolen onto thread 0x%x, 0x%x", |
| _dispatch_tid_self(), _dispatch_get_basepri()); |
| } |
| old_dbp = _dispatch_set_basepri(dq->dq_priority); |
| dispatch_wlh_t wlh = _dispatch_get_wlh(); |
| if (unlikely(dq->dq_wlh != wlh)) { |
| if (unlikely(dq->dq_wlh)) { |
| _dispatch_ktrace3(DISPATCH_PERF_wlh_change, dq, |
| dq->dq_wlh, wlh); |
| if (!(_dispatch_queue_atomic_flags_set_orig(dq, |
| DQF_WLH_CHANGED) & DQF_WLH_CHANGED)) { |
| _dispatch_bug_deprecated("Changing target queue " |
| "hierarchy after object has started executing"); |
| } |
| } |
| dq->dq_wlh = wlh; |
| #if DISPATCH_ENFORCE_STATIC_WLH_HIERARCHY |
| _dispatch_queue_atomic_flags_clear(dq, DQF_LEGACY); |
| #endif |
| } |
| } else { |
| old_dbp = 0; |
| } |
| |
| flags = _dispatch_queue_merge_autorelease_frequency(dq, flags); |
| attempt_running_slow_head: |
| tq = invoke(dq, dic, flags, &to_unlock); |
| dispatch_assert(tq != DISPATCH_QUEUE_WAKEUP_TARGET); |
| if (unlikely(tq != DISPATCH_QUEUE_WAKEUP_NONE && |
| tq != DISPATCH_QUEUE_WAKEUP_WAIT_FOR_EVENT)) { |
| // Either dc is set, which is a deferred invoke case |
| // |
| // or only tq is and it means a reenqueue is required, because of: |
| // a retarget, a suspension, or a width change. |
| // |
| // In both cases, we want to bypass the check for DIRTY. |
| // That may cause us to leave DIRTY in place but all drain lock |
| // acquirers clear it |
| } else if (!_dispatch_queue_drain_try_unlock(dq, to_unlock, |
| tq == DISPATCH_QUEUE_WAKEUP_NONE)) { |
| tq = _dispatch_queue_get_current(); |
| if (dx_hastypeflag(tq, QUEUE_ROOT) || !owning) { |
| goto attempt_running_slow_head; |
| } |
| } else { |
| to_unlock = 0; |
| tq = NULL; |
| } |
| if (!(flags & DISPATCH_INVOKE_MANAGER_DRAIN)) { |
| _dispatch_reset_basepri(old_dbp); |
| } |
| } |
| if (likely(owning)) { |
| _dispatch_introspection_queue_item_complete(dq); |
| } |
| |
| if (tq && dic->dic_deferred) { |
| return _dispatch_queue_drain_deferred_invoke(dq, dic, flags, to_unlock); |
| } |
| |
| if (tq) { |
| uint64_t old_state, new_state; |
| |
| os_atomic_rmw_loop2o(dq, dq_state, old_state, new_state, release, { |
| new_state = DISPATCH_QUEUE_DRAIN_UNLOCK(old_state - to_unlock); |
| new_state |= DISPATCH_QUEUE_DIRTY; |
| if (_dq_state_should_wakeup(new_state)) { |
| // drain was not interupted for suspension |
| // we will reenqueue right away, just put ENQUEUED back |
| new_state |= DISPATCH_QUEUE_ENQUEUED; |
| } |
| }); |
| if (_dq_state_received_override(old_state)) { |
| // Ensure that the root queue sees that this thread was overridden. |
| _dispatch_set_basepri_override_qos(_dq_state_max_qos(old_state)); |
| } |
| if ((old_state ^ new_state) & DISPATCH_QUEUE_ENQUEUED) { |
| return dx_push(tq, dq, _dq_state_max_qos(old_state)); |
| } |
| } |
| |
| return _dispatch_release_tailcall(dq); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_queue_class_probe(dispatch_queue_class_t dqu) |
| { |
| struct dispatch_object_s *tail; |
| // seq_cst wrt atomic store to dq_state <rdar://problem/14637483> |
| // seq_cst wrt atomic store to dq_flags <rdar://problem/22623242> |
| tail = os_atomic_load2o(dqu._oq, oq_items_tail, ordered); |
| return unlikely(tail != NULL); |
| } |
| |
| DISPATCH_ALWAYS_INLINE DISPATCH_CONST |
| static inline bool |
| _dispatch_is_in_root_queues_array(dispatch_queue_t dq) |
| { |
| return (dq >= _dispatch_root_queues) && |
| (dq < _dispatch_root_queues + _DISPATCH_ROOT_QUEUE_IDX_COUNT); |
| } |
| |
| DISPATCH_ALWAYS_INLINE DISPATCH_CONST |
| static inline dispatch_queue_t |
| _dispatch_get_root_queue(dispatch_qos_t qos, bool overcommit) |
| { |
| if (unlikely(qos == DISPATCH_QOS_UNSPECIFIED || qos > DISPATCH_QOS_MAX)) { |
| DISPATCH_CLIENT_CRASH(qos, "Corrupted priority"); |
| } |
| return &_dispatch_root_queues[2 * (qos - 1) + overcommit]; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_queue_set_bound_thread(dispatch_queue_t dq) |
| { |
| // Tag thread-bound queues with the owning thread |
| dispatch_assert(_dispatch_queue_is_thread_bound(dq)); |
| mach_port_t old_owner, self = _dispatch_tid_self(); |
| uint64_t dq_state = os_atomic_or_orig2o(dq, dq_state, self, relaxed); |
| if (unlikely(old_owner = _dq_state_drain_owner(dq_state))) { |
| DISPATCH_INTERNAL_CRASH(old_owner, "Queue bound twice"); |
| } |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_queue_clear_bound_thread(dispatch_queue_t dq) |
| { |
| uint64_t old_state, new_state; |
| |
| dispatch_assert(_dispatch_queue_is_thread_bound(dq)); |
| os_atomic_rmw_loop2o(dq, dq_state, old_state, new_state, relaxed, { |
| new_state = DISPATCH_QUEUE_DRAIN_UNLOCK(old_state); |
| }); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_pthread_root_queue_observer_hooks_t |
| _dispatch_get_pthread_root_queue_observer_hooks(void) |
| { |
| return _dispatch_thread_getspecific( |
| dispatch_pthread_root_queue_observer_hooks_key); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_set_pthread_root_queue_observer_hooks( |
| dispatch_pthread_root_queue_observer_hooks_t observer_hooks) |
| { |
| _dispatch_thread_setspecific(dispatch_pthread_root_queue_observer_hooks_key, |
| observer_hooks); |
| } |
| |
| #pragma mark - |
| #pragma mark dispatch_priority |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_priority_t |
| _dispatch_get_basepri(void) |
| { |
| #if HAVE_PTHREAD_WORKQUEUE_QOS |
| return (dispatch_priority_t)(uintptr_t)_dispatch_thread_getspecific( |
| dispatch_basepri_key); |
| #else |
| return 0; |
| #endif |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_reset_basepri(dispatch_priority_t dbp) |
| { |
| #if HAVE_PTHREAD_WORKQUEUE_QOS |
| dispatch_priority_t old_dbp = _dispatch_get_basepri(); |
| // If an inner-loop or'd in the override flag to the per-thread priority, |
| // it needs to be propagated up the chain. |
| dbp &= ~DISPATCH_PRIORITY_OVERRIDE_MASK; |
| dbp |= (old_dbp & DISPATCH_PRIORITY_OVERRIDE_MASK); |
| _dispatch_thread_setspecific(dispatch_basepri_key, (void*)(uintptr_t)dbp); |
| #else |
| (void)dbp; |
| #endif |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_qos_t |
| _dispatch_get_basepri_override_qos_floor(void) |
| { |
| dispatch_priority_t dbp = _dispatch_get_basepri(); |
| dispatch_qos_t qos = _dispatch_priority_qos(dbp); |
| dispatch_qos_t oqos = _dispatch_priority_override_qos(dbp); |
| dispatch_qos_t qos_floor = MAX(qos, oqos); |
| return qos_floor ? qos_floor : DISPATCH_QOS_SATURATED; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_set_basepri_override_qos(dispatch_qos_t qos) |
| { |
| #if HAVE_PTHREAD_WORKQUEUE_QOS |
| dispatch_priority_t dbp = _dispatch_get_basepri(); |
| if (_dispatch_priority_override_qos(dbp) >= qos) return; |
| dbp &= ~DISPATCH_PRIORITY_OVERRIDE_MASK; |
| dbp |= qos << DISPATCH_PRIORITY_OVERRIDE_SHIFT; |
| _dispatch_thread_setspecific(dispatch_basepri_key, (void*)(uintptr_t)dbp); |
| #else |
| (void)qos; |
| #endif |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_reset_basepri_override(void) |
| { |
| #if HAVE_PTHREAD_WORKQUEUE_QOS |
| dispatch_priority_t dbp = _dispatch_get_basepri(); |
| dispatch_qos_t oqos = _dispatch_priority_override_qos(dbp); |
| if (oqos) { |
| dbp &= ~DISPATCH_PRIORITY_OVERRIDE_MASK; |
| _dispatch_thread_setspecific(dispatch_basepri_key, (void*)(uintptr_t)dbp); |
| return oqos != DISPATCH_QOS_SATURATED; |
| } |
| #endif |
| return false; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_priority_t |
| _dispatch_set_basepri(dispatch_priority_t dbp) |
| { |
| #if HAVE_PTHREAD_WORKQUEUE_QOS |
| const dispatch_priority_t preserved_mask = |
| DISPATCH_PRIORITY_OVERRIDE_MASK | DISPATCH_PRIORITY_FLAG_OVERCOMMIT; |
| dispatch_priority_t old_dbp = _dispatch_get_basepri(); |
| if (old_dbp) { |
| dispatch_priority_t flags, defaultqueue, basepri; |
| flags = (dbp & DISPATCH_PRIORITY_FLAG_DEFAULTQUEUE); |
| defaultqueue = (old_dbp & DISPATCH_PRIORITY_FLAG_DEFAULTQUEUE); |
| basepri = old_dbp & DISPATCH_PRIORITY_REQUESTED_MASK; |
| dbp &= DISPATCH_PRIORITY_REQUESTED_MASK; |
| if (!dbp) { |
| flags = DISPATCH_PRIORITY_FLAG_INHERIT | defaultqueue; |
| dbp = basepri; |
| } else if (dbp < basepri && !defaultqueue) { // rdar://16349734 |
| dbp = basepri; |
| } |
| dbp |= flags | (old_dbp & preserved_mask); |
| } else { |
| dbp &= ~DISPATCH_PRIORITY_OVERRIDE_MASK; |
| } |
| _dispatch_thread_setspecific(dispatch_basepri_key, (void*)(uintptr_t)dbp); |
| return old_dbp; |
| #else |
| (void)dbp; |
| return 0; |
| #endif |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline pthread_priority_t |
| _dispatch_priority_adopt(pthread_priority_t pp, unsigned long flags) |
| { |
| #if HAVE_PTHREAD_WORKQUEUE_QOS |
| dispatch_priority_t inherited, defaultqueue, dbp = _dispatch_get_basepri(); |
| pthread_priority_t basepp = _dispatch_priority_to_pp_strip_flags(dbp); |
| bool enforce = (flags & DISPATCH_PRIORITY_ENFORCE) || |
| (pp & _PTHREAD_PRIORITY_ENFORCE_FLAG); |
| inherited = (dbp & DISPATCH_PRIORITY_FLAG_INHERIT); |
| defaultqueue = (dbp & DISPATCH_PRIORITY_FLAG_DEFAULTQUEUE); |
| pp &= ~_PTHREAD_PRIORITY_FLAGS_MASK; |
| |
| if (!pp) { |
| return basepp; |
| } else if (defaultqueue) { // rdar://16349734 |
| return pp; |
| } else if (pp < basepp) { |
| return basepp; |
| } else if (enforce || inherited) { |
| return pp; |
| } else { |
| return basepp; |
| } |
| #else |
| (void)pp; (void)flags; |
| return 0; |
| #endif |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_queue_priority_inherit_from_target(dispatch_queue_t dq, |
| dispatch_queue_t tq) |
| { |
| #if HAVE_PTHREAD_WORKQUEUE_QOS |
| const dispatch_priority_t rootqueue_flag = DISPATCH_PRIORITY_FLAG_ROOTQUEUE; |
| const dispatch_priority_t inherited_flag = DISPATCH_PRIORITY_FLAG_INHERIT; |
| const dispatch_priority_t defaultqueue_flag = |
| DISPATCH_PRIORITY_FLAG_DEFAULTQUEUE; |
| dispatch_priority_t pri = dq->dq_priority, tpri = tq->dq_priority; |
| |
| if ((!_dispatch_priority_qos(pri) || (pri & inherited_flag)) && |
| (tpri & rootqueue_flag)) { |
| if (tpri & defaultqueue_flag) { |
| dq->dq_priority = 0; |
| } else { |
| dq->dq_priority = (tpri & ~rootqueue_flag) | inherited_flag; |
| } |
| } |
| #else |
| (void)dq; (void)tq; |
| #endif |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_priority_t |
| _dispatch_priority_inherit_from_root_queue(dispatch_priority_t pri, |
| dispatch_queue_t rq) |
| { |
| #if HAVE_PTHREAD_WORKQUEUE_QOS |
| dispatch_priority_t p = pri & DISPATCH_PRIORITY_REQUESTED_MASK; |
| dispatch_priority_t rqp = rq->dq_priority & DISPATCH_PRIORITY_REQUESTED_MASK; |
| dispatch_priority_t defaultqueue = |
| rq->dq_priority & DISPATCH_PRIORITY_FLAG_DEFAULTQUEUE; |
| |
| if (!p || (!defaultqueue && p < rqp)) { |
| p = rqp | defaultqueue; |
| } |
| return p | (rq->dq_priority & DISPATCH_PRIORITY_FLAG_OVERCOMMIT); |
| #else |
| (void)rq; (void)pri; |
| return 0; |
| #endif |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline pthread_priority_t |
| _dispatch_get_priority(void) |
| { |
| #if HAVE_PTHREAD_WORKQUEUE_QOS |
| pthread_priority_t pp = (uintptr_t) |
| _dispatch_thread_getspecific(dispatch_priority_key); |
| return pp; |
| #else |
| return 0; |
| #endif |
| } |
| |
| #if HAVE_PTHREAD_WORKQUEUE_QOS |
| DISPATCH_ALWAYS_INLINE |
| static inline pthread_priority_t |
| _dispatch_priority_compute_update(pthread_priority_t pp) |
| { |
| dispatch_assert(pp != DISPATCH_NO_PRIORITY); |
| if (!_dispatch_set_qos_class_enabled) return 0; |
| // the priority in _dispatch_get_priority() only tracks manager-ness |
| // and overcommit, which is inherited from the current value for each update |
| // however if the priority had the NEEDS_UNBIND flag set we need to clear it |
| // the first chance we get |
| // |
| // the manager bit is invalid input, but we keep it to get meaningful |
| // assertions in _dispatch_set_priority_and_voucher_slow() |
| pp &= _PTHREAD_PRIORITY_EVENT_MANAGER_FLAG | ~_PTHREAD_PRIORITY_FLAGS_MASK; |
| pthread_priority_t cur_priority = _dispatch_get_priority(); |
| pthread_priority_t unbind = _PTHREAD_PRIORITY_NEEDS_UNBIND_FLAG; |
| pthread_priority_t overcommit = _PTHREAD_PRIORITY_OVERCOMMIT_FLAG; |
| if (unlikely(cur_priority & unbind)) { |
| // else we always need an update if the NEEDS_UNBIND flag is set |
| // the slow path in _dispatch_set_priority_and_voucher_slow() will |
| // adjust the priority further with the proper overcommitness |
| return pp ? pp : (cur_priority & ~unbind); |
| } else { |
| cur_priority &= ~overcommit; |
| } |
| if (unlikely(pp != cur_priority)) return pp; |
| return 0; |
| } |
| #endif |
| |
| DISPATCH_ALWAYS_INLINE DISPATCH_WARN_RESULT |
| static inline voucher_t |
| _dispatch_set_priority_and_voucher(pthread_priority_t pp, |
| voucher_t v, dispatch_thread_set_self_t flags) |
| { |
| #if HAVE_PTHREAD_WORKQUEUE_QOS |
| pp = _dispatch_priority_compute_update(pp); |
| if (likely(!pp)) { |
| if (v == DISPATCH_NO_VOUCHER) { |
| return DISPATCH_NO_VOUCHER; |
| } |
| if (likely(v == _voucher_get())) { |
| bool retained = flags & DISPATCH_VOUCHER_CONSUME; |
| if (flags & DISPATCH_VOUCHER_REPLACE) { |
| if (retained && v) _voucher_release_no_dispose(v); |
| v = DISPATCH_NO_VOUCHER; |
| } else { |
| if (!retained && v) _voucher_retain(v); |
| } |
| return v; |
| } |
| } |
| return _dispatch_set_priority_and_voucher_slow(pp, v, flags); |
| #else |
| (void)pp; (void)v; (void)flags; |
| return DISPATCH_NO_VOUCHER; |
| #endif |
| } |
| |
| DISPATCH_ALWAYS_INLINE DISPATCH_WARN_RESULT |
| static inline voucher_t |
| _dispatch_adopt_priority_and_set_voucher(pthread_priority_t pp, |
| voucher_t v, dispatch_thread_set_self_t flags) |
| { |
| pthread_priority_t p = 0; |
| if (pp != DISPATCH_NO_PRIORITY) { |
| p = _dispatch_priority_adopt(pp, flags); |
| } |
| return _dispatch_set_priority_and_voucher(p, v, flags); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_reset_priority_and_voucher(pthread_priority_t pp, voucher_t v) |
| { |
| if (pp == DISPATCH_NO_PRIORITY) pp = 0; |
| (void)_dispatch_set_priority_and_voucher(pp, v, |
| DISPATCH_VOUCHER_CONSUME | DISPATCH_VOUCHER_REPLACE); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_reset_voucher(voucher_t v, dispatch_thread_set_self_t flags) |
| { |
| flags |= DISPATCH_VOUCHER_CONSUME | DISPATCH_VOUCHER_REPLACE; |
| (void)_dispatch_set_priority_and_voucher(0, v, flags); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_queue_need_override(dispatch_queue_class_t dqu, dispatch_qos_t qos) |
| { |
| uint64_t dq_state = os_atomic_load2o(dqu._dq, dq_state, relaxed); |
| // dq_priority "override qos" contains the priority at which the queue |
| // is already running for thread-bound queues. |
| // For non thread-bound queues, the qos of the queue may not be observed |
| // when the first work item is dispatched synchronously. |
| return _dq_state_max_qos(dq_state) < qos && |
| _dispatch_priority_override_qos(dqu._dq->dq_priority) < qos; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_queue_need_override_retain(dispatch_queue_class_t dqu, |
| dispatch_qos_t qos) |
| { |
| if (_dispatch_queue_need_override(dqu, qos)) { |
| _os_object_retain_internal_inline(dqu._oq->_as_os_obj); |
| return true; |
| } |
| return false; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_qos_t |
| _dispatch_queue_override_qos(dispatch_queue_class_t dqu, dispatch_qos_t qos) |
| { |
| if (dqu._oq->oq_priority & DISPATCH_PRIORITY_FLAG_DEFAULTQUEUE) { |
| return qos; |
| } |
| // for asynchronous workitems, queue priority is the floor for overrides |
| return MAX(qos, _dispatch_priority_qos(dqu._oq->oq_priority)); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_qos_t |
| _dispatch_queue_reset_max_qos(dispatch_queue_class_t dqu) |
| { |
| uint64_t old_state, new_state; |
| os_atomic_rmw_loop2o(dqu._dq, dq_state, old_state, new_state, relaxed, { |
| new_state = old_state; |
| new_state &= ~DISPATCH_QUEUE_MAX_QOS_MASK; |
| new_state &= ~DISPATCH_QUEUE_RECEIVED_OVERRIDE; |
| if (old_state == new_state) { |
| os_atomic_rmw_loop_give_up(return DISPATCH_QOS_UNSPECIFIED); |
| } |
| }); |
| return _dq_state_max_qos(old_state); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline pthread_priority_t |
| _dispatch_priority_propagate(void) |
| { |
| #if HAVE_PTHREAD_WORKQUEUE_QOS |
| pthread_priority_t pp = _dispatch_get_priority(); |
| pp &= ~_PTHREAD_PRIORITY_FLAGS_MASK; |
| if (pp > _dispatch_qos_to_pp(DISPATCH_QOS_USER_INITIATED)) { |
| // Cap QOS for propagation at user-initiated <rdar://16681262&16998036> |
| return _dispatch_qos_to_pp(DISPATCH_QOS_USER_INITIATED); |
| } |
| return pp; |
| #else |
| return 0; |
| #endif |
| } |
| |
| // including maintenance |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_is_background_thread(void) |
| { |
| #if HAVE_PTHREAD_WORKQUEUE_QOS |
| pthread_priority_t pp = _dispatch_get_priority(); |
| return _dispatch_qos_is_background(_dispatch_qos_from_pp(pp)); |
| #else |
| return false; |
| #endif |
| } |
| |
| #pragma mark - |
| #pragma mark dispatch_wlh_t |
| |
| static inline dispatch_wlh_t |
| _dispatch_queue_class_compute_wlh(dispatch_queue_class_t dqu) |
| { |
| // TODO: combine with _dispatch_source_compute_kevent_priority |
| dispatch_queue_t dq = dqu._dq; |
| dispatch_queue_t tq = dq->do_targetq; |
| |
| while (unlikely(!dx_hastypeflag(tq, QUEUE_ROOT))) { |
| if (tq->dq_wlh) { |
| return tq->dq_wlh; |
| } |
| dispatch_assert(!_dispatch_queue_is_thread_bound(tq)); |
| if (unlikely(DISPATCH_QUEUE_IS_SUSPENDED(tq))) { |
| // this queue may not be activated yet, so the queue graph may not |
| // have stabilized yet |
| return NULL; |
| } |
| if (unlikely(_dispatch_queue_is_legacy(tq))) { |
| if (!_dispatch_is_in_root_queues_array(tq->do_targetq)) { |
| // we're not allowed to dereference tq->do_targetq |
| return NULL; |
| } |
| } |
| dq = tq; |
| tq = dq->do_targetq; |
| } |
| dispatch_assert(tq->dq_wlh); |
| return _dispatch_root_queue_wlh_for_queue(tq, dq); |
| } |
| |
| static inline void |
| _dispatch_queue_class_record_wlh_hierarchy(dispatch_queue_class_t dqu, |
| dispatch_wlh_t wlh) |
| { |
| dispatch_queue_t dq = dqu._dq; |
| dispatch_queue_t tq = dq->do_targetq; |
| |
| dispatch_assert(wlh); |
| dispatch_assert(!dq->dq_wlh); |
| dq->dq_wlh = wlh; |
| #if DISPATCH_ENFORCE_STATIC_WLH_HIERARCHY |
| _dispatch_queue_atomic_flags_clear(dq, DQF_LEGACY); |
| #endif |
| while (unlikely(!dx_hastypeflag(tq, QUEUE_ROOT))) { |
| if (tq->dq_wlh) { |
| return; |
| } |
| tq->dq_wlh = wlh; |
| #if DISPATCH_ENFORCE_STATIC_WLH_HIERARCHY |
| _dispatch_queue_atomic_flags_set_and_clear(tq, DQF_TARGETED,DQF_LEGACY); |
| #else |
| _dispatch_queue_atomic_flags_set(tq, DQF_TARGETED); |
| #endif |
| tq = tq->do_targetq; |
| } |
| } |
| |
| #pragma mark - |
| #pragma mark dispatch_block_t |
| |
| #ifdef __BLOCKS__ |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_block_has_private_data(const dispatch_block_t block) |
| { |
| extern void (*_dispatch_block_special_invoke)(void*); |
| return (_dispatch_Block_invoke(block) == _dispatch_block_special_invoke); |
| } |
| |
| DISPATCH_ALWAYS_INLINE DISPATCH_WARN_RESULT |
| static inline bool |
| _dispatch_block_invoke_should_set_priority(dispatch_block_flags_t flags) |
| { |
| if (flags & DISPATCH_BLOCK_HAS_PRIORITY) { |
| return (flags & DISPATCH_BLOCK_ENFORCE_QOS_CLASS) || |
| !(flags & DISPATCH_BLOCK_INHERIT_QOS_CLASS); |
| } |
| return false; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_block_private_data_t |
| _dispatch_block_get_data(const dispatch_block_t db) |
| { |
| if (!_dispatch_block_has_private_data(db)) { |
| return NULL; |
| } |
| // Keep in sync with _dispatch_block_create implementation |
| uint8_t *x = (uint8_t *)db; |
| // x points to base of struct Block_layout |
| x += sizeof(struct Block_layout); |
| // x points to base of captured dispatch_block_private_data_s object |
| dispatch_block_private_data_t dbpd = (dispatch_block_private_data_t)x; |
| if (dbpd->dbpd_magic != DISPATCH_BLOCK_PRIVATE_DATA_MAGIC) { |
| DISPATCH_CLIENT_CRASH(dbpd->dbpd_magic, |
| "Corruption of dispatch block object"); |
| } |
| return dbpd; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline pthread_priority_t |
| _dispatch_block_get_priority(const dispatch_block_t db) |
| { |
| dispatch_block_private_data_t dbpd = _dispatch_block_get_data(db); |
| return dbpd ? dbpd->dbpd_priority : 0; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_block_flags_t |
| _dispatch_block_get_flags(const dispatch_block_t db) |
| { |
| dispatch_block_private_data_t dbpd = _dispatch_block_get_data(db); |
| return dbpd ? dbpd->dbpd_flags : 0; |
| } |
| |
| #endif |
| |
| #pragma mark - |
| #pragma mark dispatch_continuation_t |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_continuation_t |
| _dispatch_continuation_alloc_cacheonly(void) |
| { |
| dispatch_continuation_t dc = (dispatch_continuation_t) |
| _dispatch_thread_getspecific(dispatch_cache_key); |
| if (likely(dc)) { |
| _dispatch_thread_setspecific(dispatch_cache_key, dc->do_next); |
| } |
| return dc; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_continuation_t |
| _dispatch_continuation_alloc(void) |
| { |
| dispatch_continuation_t dc = |
| _dispatch_continuation_alloc_cacheonly(); |
| if (unlikely(!dc)) { |
| return _dispatch_continuation_alloc_from_heap(); |
| } |
| return dc; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_continuation_t |
| _dispatch_continuation_free_cacheonly(dispatch_continuation_t dc) |
| { |
| dispatch_continuation_t prev_dc = (dispatch_continuation_t) |
| _dispatch_thread_getspecific(dispatch_cache_key); |
| int cnt = prev_dc ? prev_dc->dc_cache_cnt + 1 : 1; |
| // Cap continuation cache |
| if (unlikely(cnt > _dispatch_continuation_cache_limit)) { |
| return dc; |
| } |
| dc->do_next = prev_dc; |
| dc->dc_cache_cnt = cnt; |
| _dispatch_thread_setspecific(dispatch_cache_key, dc); |
| return NULL; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_continuation_free(dispatch_continuation_t dc) |
| { |
| dc = _dispatch_continuation_free_cacheonly(dc); |
| if (unlikely(dc)) { |
| _dispatch_continuation_free_to_cache_limit(dc); |
| } |
| } |
| |
| #include "trace.h" |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_continuation_with_group_invoke(dispatch_continuation_t dc) |
| { |
| struct dispatch_object_s *dou = dc->dc_data; |
| unsigned long type = dx_type(dou); |
| if (type == DISPATCH_GROUP_TYPE) { |
| _dispatch_client_callout(dc->dc_ctxt, dc->dc_func); |
| _dispatch_introspection_queue_item_complete(dou); |
| dispatch_group_leave((dispatch_group_t)dou); |
| } else { |
| DISPATCH_INTERNAL_CRASH(dx_type(dou), "Unexpected object type"); |
| } |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_continuation_invoke_inline(dispatch_object_t dou, voucher_t ov, |
| dispatch_invoke_flags_t flags) |
| { |
| dispatch_continuation_t dc = dou._dc, dc1; |
| dispatch_invoke_with_autoreleasepool(flags, { |
| uintptr_t dc_flags = dc->dc_flags; |
| // Add the item back to the cache before calling the function. This |
| // allows the 'hot' continuation to be used for a quick callback. |
| // |
| // The ccache version is per-thread. |
| // Therefore, the object has not been reused yet. |
| // This generates better assembly. |
| _dispatch_continuation_voucher_adopt(dc, ov, dc_flags); |
| if (dc_flags & DISPATCH_OBJ_CONSUME_BIT) { |
| dc1 = _dispatch_continuation_free_cacheonly(dc); |
| } else { |
| dc1 = NULL; |
| } |
| if (unlikely(dc_flags & DISPATCH_OBJ_GROUP_BIT)) { |
| _dispatch_continuation_with_group_invoke(dc); |
| } else { |
| _dispatch_client_callout(dc->dc_ctxt, dc->dc_func); |
| _dispatch_introspection_queue_item_complete(dou); |
| } |
| if (unlikely(dc1)) { |
| _dispatch_continuation_free_to_cache_limit(dc1); |
| } |
| }); |
| _dispatch_perfmon_workitem_inc(); |
| } |
| |
| DISPATCH_ALWAYS_INLINE_NDEBUG |
| static inline void |
| _dispatch_continuation_pop_inline(dispatch_object_t dou, |
| dispatch_invoke_context_t dic, dispatch_invoke_flags_t flags, |
| dispatch_queue_t dq) |
| { |
| dispatch_pthread_root_queue_observer_hooks_t observer_hooks = |
| _dispatch_get_pthread_root_queue_observer_hooks(); |
| if (observer_hooks) observer_hooks->queue_will_execute(dq); |
| _dispatch_trace_continuation_pop(dq, dou); |
| flags &= _DISPATCH_INVOKE_PROPAGATE_MASK; |
| if (_dispatch_object_has_vtable(dou)) { |
| dx_invoke(dou._do, dic, flags); |
| } else { |
| _dispatch_continuation_invoke_inline(dou, DISPATCH_NO_VOUCHER, flags); |
| } |
| if (observer_hooks) observer_hooks->queue_did_execute(dq); |
| } |
| |
| // used to forward the do_invoke of a continuation with a vtable to its real |
| // implementation. |
| #define _dispatch_continuation_pop_forwarded(dc, ov, dc_flags, ...) \ |
| ({ \ |
| dispatch_continuation_t _dc = (dc), _dc1; \ |
| uintptr_t _dc_flags = (dc_flags); \ |
| _dispatch_continuation_voucher_adopt(_dc, ov, _dc_flags); \ |
| if (_dc_flags & DISPATCH_OBJ_CONSUME_BIT) { \ |
| _dc1 = _dispatch_continuation_free_cacheonly(_dc); \ |
| } else { \ |
| _dc1 = NULL; \ |
| } \ |
| __VA_ARGS__; \ |
| _dispatch_introspection_queue_item_complete(_dc); \ |
| if (unlikely(_dc1)) { \ |
| _dispatch_continuation_free_to_cache_limit(_dc1); \ |
| } \ |
| }) |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_continuation_priority_set(dispatch_continuation_t dc, |
| pthread_priority_t pp, dispatch_block_flags_t flags) |
| { |
| #if HAVE_PTHREAD_WORKQUEUE_QOS |
| if (likely(!(flags & DISPATCH_BLOCK_HAS_PRIORITY))) { |
| pp = _dispatch_priority_propagate(); |
| } |
| if (flags & DISPATCH_BLOCK_ENFORCE_QOS_CLASS) { |
| pp |= _PTHREAD_PRIORITY_ENFORCE_FLAG; |
| } |
| dc->dc_priority = pp; |
| #else |
| (void)dc; (void)pp; (void)flags; |
| #endif |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_qos_t |
| _dispatch_continuation_override_qos(dispatch_queue_t dq, |
| dispatch_continuation_t dc) |
| { |
| #if HAVE_PTHREAD_WORKQUEUE_QOS |
| dispatch_qos_t dc_qos = _dispatch_qos_from_pp(dc->dc_priority); |
| bool enforce = dc->dc_priority & _PTHREAD_PRIORITY_ENFORCE_FLAG; |
| dispatch_qos_t dq_qos = _dispatch_priority_qos(dq->dq_priority); |
| bool defaultqueue = dq->dq_priority & DISPATCH_PRIORITY_FLAG_DEFAULTQUEUE; |
| |
| dispatch_assert(dc->dc_priority != DISPATCH_NO_PRIORITY); |
| if (dc_qos && (enforce || !dq_qos || defaultqueue)) { |
| return dc_qos; |
| } |
| return dq_qos; |
| #else |
| (void)dq; (void)dc; |
| return 0; |
| #endif |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_continuation_init_f(dispatch_continuation_t dc, |
| dispatch_queue_class_t dqu, void *ctxt, dispatch_function_t func, |
| pthread_priority_t pp, dispatch_block_flags_t flags, uintptr_t dc_flags) |
| { |
| dc->dc_flags = dc_flags; |
| dc->dc_func = func; |
| dc->dc_ctxt = ctxt; |
| _dispatch_continuation_voucher_set(dc, dqu, flags); |
| _dispatch_continuation_priority_set(dc, pp, flags); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_continuation_init(dispatch_continuation_t dc, |
| dispatch_queue_class_t dqu, dispatch_block_t work, |
| pthread_priority_t pp, dispatch_block_flags_t flags, uintptr_t dc_flags) |
| { |
| dc->dc_flags = dc_flags | DISPATCH_OBJ_BLOCK_BIT; |
| dc->dc_ctxt = _dispatch_Block_copy(work); |
| _dispatch_continuation_priority_set(dc, pp, flags); |
| |
| if (unlikely(_dispatch_block_has_private_data(work))) { |
| // always sets dc_func & dc_voucher |
| // may update dc_priority & do_vtable |
| return _dispatch_continuation_init_slow(dc, dqu, flags); |
| } |
| |
| if (dc_flags & DISPATCH_OBJ_CONSUME_BIT) { |
| dc->dc_func = _dispatch_call_block_and_release; |
| } else { |
| dc->dc_func = _dispatch_Block_invoke(work); |
| } |
| _dispatch_continuation_voucher_set(dc, dqu, flags); |
| } |
| |
| #if HAVE_MACH |
| #pragma mark dispatch_mach_reply_refs_t |
| |
| // assumes low bit of mach port names is always set |
| #define DISPATCH_MACH_REPLY_PORT_UNOWNED 0x1u |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_mach_reply_mark_reply_port_owned(dispatch_mach_reply_refs_t dmr) |
| { |
| dmr->du_ident &= ~DISPATCH_MACH_REPLY_PORT_UNOWNED; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_mach_reply_is_reply_port_owned(dispatch_mach_reply_refs_t dmr) |
| { |
| mach_port_t reply_port = (mach_port_t)dmr->du_ident; |
| return reply_port ? !(reply_port & DISPATCH_MACH_REPLY_PORT_UNOWNED) :false; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline mach_port_t |
| _dispatch_mach_reply_get_reply_port(mach_port_t reply_port) |
| { |
| return reply_port ? (reply_port | DISPATCH_MACH_REPLY_PORT_UNOWNED) : 0; |
| } |
| |
| #endif // HAVE_MACH |
| |
| #endif // DISPATCH_PURE_C |
| |
| #endif /* __DISPATCH_INLINE_INTERNAL__ */ |