| /* |
| * Copyright (c) 2008-2016 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@ |
| */ |
| |
| #include "internal.h" |
| #if HAVE_MACH |
| |
| #define DISPATCH_MACH_RETURN_IMMEDIATE_SEND_RESULT 0x1 |
| #define DISPATCH_MACH_REGISTER_FOR_REPLY 0x2 |
| #define DISPATCH_MACH_WAIT_FOR_REPLY 0x4 |
| #define DISPATCH_MACH_OWNED_REPLY_PORT 0x8 |
| #define DISPATCH_MACH_ASYNC_REPLY 0x10 |
| #define DISPATCH_MACH_OPTIONS_MASK 0xffff |
| |
| #define DM_SEND_STATUS_SUCCESS 0x1 |
| #define DM_SEND_STATUS_RETURNING_IMMEDIATE_SEND_RESULT 0x2 |
| |
| DISPATCH_ENUM(dispatch_mach_send_invoke_flags, uint32_t, |
| DM_SEND_INVOKE_NONE = 0x0, |
| DM_SEND_INVOKE_MAKE_DIRTY = 0x1, |
| DM_SEND_INVOKE_NEEDS_BARRIER = 0x2, |
| DM_SEND_INVOKE_CANCEL = 0x4, |
| DM_SEND_INVOKE_CAN_RUN_BARRIER = 0x8, |
| DM_SEND_INVOKE_IMMEDIATE_SEND = 0x10, |
| ); |
| #define DM_SEND_INVOKE_IMMEDIATE_SEND_MASK \ |
| ((dispatch_mach_send_invoke_flags_t)DM_SEND_INVOKE_IMMEDIATE_SEND) |
| |
| static inline mach_msg_option_t _dispatch_mach_checkin_options(void); |
| static mach_port_t _dispatch_mach_msg_get_remote_port(dispatch_object_t dou); |
| static mach_port_t _dispatch_mach_msg_get_reply_port(dispatch_object_t dou); |
| static void _dispatch_mach_msg_disconnected(dispatch_mach_t dm, |
| mach_port_t local_port, mach_port_t remote_port); |
| static inline void _dispatch_mach_msg_reply_received(dispatch_mach_t dm, |
| dispatch_mach_reply_refs_t dmr, mach_port_t local_port); |
| static dispatch_mach_msg_t _dispatch_mach_msg_create_reply_disconnected( |
| dispatch_object_t dou, dispatch_mach_reply_refs_t dmr, |
| dispatch_mach_reason_t reason); |
| static bool _dispatch_mach_reconnect_invoke(dispatch_mach_t dm, |
| dispatch_object_t dou); |
| static inline mach_msg_header_t* _dispatch_mach_msg_get_msg( |
| dispatch_mach_msg_t dmsg); |
| static void _dispatch_mach_send_push(dispatch_mach_t dm, dispatch_object_t dou, |
| dispatch_qos_t qos); |
| static void _dispatch_mach_cancel(dispatch_mach_t dm); |
| static void _dispatch_mach_push_send_barrier_drain(dispatch_mach_t dm, |
| dispatch_qos_t qos); |
| static void _dispatch_mach_handle_or_push_received_msg(dispatch_mach_t dm, |
| dispatch_mach_msg_t dmsg); |
| static void _dispatch_mach_push_async_reply_msg(dispatch_mach_t dm, |
| dispatch_mach_msg_t dmsg, dispatch_queue_t drq); |
| static dispatch_queue_t _dispatch_mach_msg_context_async_reply_queue( |
| void *ctxt); |
| static dispatch_continuation_t _dispatch_mach_msg_async_reply_wrap( |
| dispatch_mach_msg_t dmsg, dispatch_mach_t dm); |
| static void _dispatch_mach_notification_kevent_unregister(dispatch_mach_t dm); |
| static void _dispatch_mach_notification_kevent_register(dispatch_mach_t dm, |
| mach_port_t send); |
| |
| // For tests only. |
| DISPATCH_EXPORT void _dispatch_mach_hooks_install_default(void); |
| |
| dispatch_source_t |
| _dispatch_source_create_mach_msg_direct_recv(mach_port_t recvp, |
| const struct dispatch_continuation_s *dc) |
| { |
| dispatch_source_t ds; |
| ds = dispatch_source_create(&_dispatch_source_type_mach_recv_direct, |
| recvp, 0, &_dispatch_mgr_q); |
| os_atomic_store(&ds->ds_refs->ds_handler[DS_EVENT_HANDLER], |
| (dispatch_continuation_t)dc, relaxed); |
| return ds; |
| } |
| |
| #pragma mark - |
| #pragma mark dispatch to XPC callbacks |
| |
| static dispatch_mach_xpc_hooks_t _dispatch_mach_xpc_hooks; |
| |
| // Default dmxh_direct_message_handler callback that does not handle |
| // messages inline. |
| static bool |
| _dispatch_mach_xpc_no_handle_message( |
| void *_Nullable context DISPATCH_UNUSED, |
| dispatch_mach_reason_t reason DISPATCH_UNUSED, |
| dispatch_mach_msg_t message DISPATCH_UNUSED, |
| mach_error_t error DISPATCH_UNUSED) |
| { |
| return false; |
| } |
| |
| // Default dmxh_msg_context_reply_queue callback that returns a NULL queue. |
| static dispatch_queue_t |
| _dispatch_mach_msg_context_no_async_reply_queue( |
| void *_Nonnull msg_context DISPATCH_UNUSED) |
| { |
| return NULL; |
| } |
| |
| // Default dmxh_async_reply_handler callback that crashes when called. |
| DISPATCH_NORETURN |
| static void |
| _dispatch_mach_default_async_reply_handler(void *context DISPATCH_UNUSED, |
| dispatch_mach_reason_t reason DISPATCH_UNUSED, |
| dispatch_mach_msg_t message DISPATCH_UNUSED) |
| { |
| DISPATCH_CLIENT_CRASH(_dispatch_mach_xpc_hooks, |
| "_dispatch_mach_default_async_reply_handler called"); |
| } |
| |
| // Default dmxh_enable_sigterm_notification callback that enables delivery of |
| // SIGTERM notifications (for backwards compatibility). |
| static bool |
| _dispatch_mach_enable_sigterm(void *_Nullable context DISPATCH_UNUSED) |
| { |
| return true; |
| } |
| |
| // Callbacks from dispatch to XPC. The default is to not support any callbacks. |
| static const struct dispatch_mach_xpc_hooks_s _dispatch_mach_xpc_hooks_default |
| = { |
| .version = DISPATCH_MACH_XPC_HOOKS_VERSION, |
| .dmxh_direct_message_handler = &_dispatch_mach_xpc_no_handle_message, |
| .dmxh_msg_context_reply_queue = |
| &_dispatch_mach_msg_context_no_async_reply_queue, |
| .dmxh_async_reply_handler = &_dispatch_mach_default_async_reply_handler, |
| .dmxh_enable_sigterm_notification = &_dispatch_mach_enable_sigterm, |
| }; |
| |
| static dispatch_mach_xpc_hooks_t _dispatch_mach_xpc_hooks |
| = &_dispatch_mach_xpc_hooks_default; |
| |
| void |
| dispatch_mach_hooks_install_4libxpc(dispatch_mach_xpc_hooks_t hooks) |
| { |
| if (!os_atomic_cmpxchg(&_dispatch_mach_xpc_hooks, |
| &_dispatch_mach_xpc_hooks_default, hooks, relaxed)) { |
| DISPATCH_CLIENT_CRASH(_dispatch_mach_xpc_hooks, |
| "dispatch_mach_hooks_install_4libxpc called twice"); |
| } |
| } |
| |
| void |
| _dispatch_mach_hooks_install_default(void) |
| { |
| os_atomic_store(&_dispatch_mach_xpc_hooks, |
| &_dispatch_mach_xpc_hooks_default, relaxed); |
| } |
| |
| #pragma mark - |
| #pragma mark dispatch_mach_t |
| |
| static dispatch_mach_t |
| _dispatch_mach_create(const char *label, dispatch_queue_t q, void *context, |
| dispatch_mach_handler_function_t handler, bool handler_is_block, |
| bool is_xpc) |
| { |
| dispatch_mach_recv_refs_t dmrr; |
| dispatch_mach_send_refs_t dmsr; |
| dispatch_mach_t dm; |
| dm = _dispatch_object_alloc(DISPATCH_VTABLE(mach), |
| sizeof(struct dispatch_mach_s)); |
| _dispatch_queue_init(dm->_as_dq, DQF_LEGACY, 1, |
| DISPATCH_QUEUE_INACTIVE | DISPATCH_QUEUE_ROLE_INNER); |
| |
| dm->dq_label = label; |
| dm->do_ref_cnt++; // the reference _dispatch_mach_cancel_invoke holds |
| dm->dm_is_xpc = is_xpc; |
| |
| dmrr = dux_create(&_dispatch_mach_type_recv, 0, 0)._dmrr; |
| dispatch_assert(dmrr->du_is_direct); |
| dmrr->du_owner_wref = _dispatch_ptr2wref(dm); |
| dmrr->dmrr_handler_func = handler; |
| dmrr->dmrr_handler_ctxt = context; |
| dmrr->dmrr_handler_is_block = handler_is_block; |
| dm->dm_recv_refs = dmrr; |
| |
| dmsr = dux_create(&_dispatch_mach_type_send, 0, |
| DISPATCH_MACH_SEND_POSSIBLE|DISPATCH_MACH_SEND_DEAD)._dmsr; |
| dmsr->du_owner_wref = _dispatch_ptr2wref(dm); |
| dm->dm_send_refs = dmsr; |
| |
| if (slowpath(!q)) { |
| q = _dispatch_get_root_queue(DISPATCH_QOS_DEFAULT, true); |
| } else { |
| _dispatch_retain(q); |
| } |
| dm->do_targetq = q; |
| _dispatch_object_debug(dm, "%s", __func__); |
| return dm; |
| } |
| |
| dispatch_mach_t |
| dispatch_mach_create(const char *label, dispatch_queue_t q, |
| dispatch_mach_handler_t handler) |
| { |
| dispatch_block_t bb = _dispatch_Block_copy((void*)handler); |
| return _dispatch_mach_create(label, q, bb, |
| (dispatch_mach_handler_function_t)_dispatch_Block_invoke(bb), true, |
| false); |
| } |
| |
| dispatch_mach_t |
| dispatch_mach_create_f(const char *label, dispatch_queue_t q, void *context, |
| dispatch_mach_handler_function_t handler) |
| { |
| return _dispatch_mach_create(label, q, context, handler, false, false); |
| } |
| |
| dispatch_mach_t |
| dispatch_mach_create_4libxpc(const char *label, dispatch_queue_t q, |
| void *context, dispatch_mach_handler_function_t handler) |
| { |
| return _dispatch_mach_create(label, q, context, handler, false, true); |
| } |
| |
| void |
| _dispatch_mach_dispose(dispatch_mach_t dm, bool *allow_free) |
| { |
| _dispatch_object_debug(dm, "%s", __func__); |
| _dispatch_unote_dispose(dm->dm_recv_refs); |
| dm->dm_recv_refs = NULL; |
| _dispatch_unote_dispose(dm->dm_send_refs); |
| dm->dm_send_refs = NULL; |
| if (dm->dm_xpc_term_refs) { |
| _dispatch_unote_dispose(dm->dm_xpc_term_refs); |
| dm->dm_xpc_term_refs = NULL; |
| } |
| _dispatch_queue_destroy(dm->_as_dq, allow_free); |
| } |
| |
| void |
| dispatch_mach_connect(dispatch_mach_t dm, mach_port_t receive, |
| mach_port_t send, dispatch_mach_msg_t checkin) |
| { |
| dispatch_mach_send_refs_t dmsr = dm->dm_send_refs; |
| uint32_t disconnect_cnt; |
| |
| if (MACH_PORT_VALID(receive)) { |
| dm->dm_recv_refs->du_ident = receive; |
| _dispatch_retain(dm); // the reference the manager queue holds |
| } |
| dmsr->dmsr_send = send; |
| if (MACH_PORT_VALID(send)) { |
| if (checkin) { |
| dispatch_mach_msg_t dmsg = checkin; |
| dispatch_retain(dmsg); |
| dmsg->dmsg_options = _dispatch_mach_checkin_options(); |
| dmsr->dmsr_checkin_port = _dispatch_mach_msg_get_remote_port(dmsg); |
| } |
| dmsr->dmsr_checkin = checkin; |
| } |
| dispatch_assert(DISPATCH_MACH_NEVER_CONNECTED - 1 == |
| DISPATCH_MACH_NEVER_INSTALLED); |
| disconnect_cnt = os_atomic_dec2o(dmsr, dmsr_disconnect_cnt, release); |
| if (unlikely(disconnect_cnt != DISPATCH_MACH_NEVER_INSTALLED)) { |
| DISPATCH_CLIENT_CRASH(disconnect_cnt, "Channel already connected"); |
| } |
| _dispatch_object_debug(dm, "%s", __func__); |
| return dispatch_activate(dm); |
| } |
| |
| static inline bool |
| _dispatch_mach_reply_tryremove(dispatch_mach_t dm, |
| dispatch_mach_reply_refs_t dmr) |
| { |
| bool removed; |
| _dispatch_unfair_lock_lock(&dm->dm_send_refs->dmsr_replies_lock); |
| if ((removed = _TAILQ_IS_ENQUEUED(dmr, dmr_list))) { |
| TAILQ_REMOVE(&dm->dm_send_refs->dmsr_replies, dmr, dmr_list); |
| _TAILQ_MARK_NOT_ENQUEUED(dmr, dmr_list); |
| } |
| _dispatch_unfair_lock_unlock(&dm->dm_send_refs->dmsr_replies_lock); |
| return removed; |
| } |
| |
| DISPATCH_NOINLINE |
| static void |
| _dispatch_mach_reply_waiter_unregister(dispatch_mach_t dm, |
| dispatch_mach_reply_refs_t dmr, uint32_t options) |
| { |
| dispatch_mach_msg_t dmsgr = NULL; |
| bool disconnected = (options & DU_UNREGISTER_DISCONNECTED); |
| if (options & DU_UNREGISTER_REPLY_REMOVE) { |
| _dispatch_unfair_lock_lock(&dm->dm_send_refs->dmsr_replies_lock); |
| if (unlikely(!_TAILQ_IS_ENQUEUED(dmr, dmr_list))) { |
| DISPATCH_INTERNAL_CRASH(0, "Could not find reply registration"); |
| } |
| TAILQ_REMOVE(&dm->dm_send_refs->dmsr_replies, dmr, dmr_list); |
| _TAILQ_MARK_NOT_ENQUEUED(dmr, dmr_list); |
| _dispatch_unfair_lock_unlock(&dm->dm_send_refs->dmsr_replies_lock); |
| } |
| if (disconnected) { |
| dmsgr = _dispatch_mach_msg_create_reply_disconnected(NULL, dmr, |
| DISPATCH_MACH_DISCONNECTED); |
| } else if (dmr->dmr_voucher) { |
| _voucher_release(dmr->dmr_voucher); |
| dmr->dmr_voucher = NULL; |
| } |
| _dispatch_debug("machport[0x%08x]: unregistering for sync reply%s, ctxt %p", |
| _dispatch_mach_reply_get_reply_port((mach_port_t)dmr->du_ident), |
| disconnected ? " (disconnected)" : "", dmr->dmr_ctxt); |
| if (dmsgr) { |
| return _dispatch_mach_handle_or_push_received_msg(dm, dmsgr); |
| } |
| } |
| |
| DISPATCH_NOINLINE |
| static bool |
| _dispatch_mach_reply_list_remove(dispatch_mach_t dm, |
| dispatch_mach_reply_refs_t dmr) { |
| // dmsr_replies_lock must be held by the caller. |
| bool removed = false; |
| if (likely(_TAILQ_IS_ENQUEUED(dmr, dmr_list))) { |
| TAILQ_REMOVE(&dm->dm_send_refs->dmsr_replies, dmr, dmr_list); |
| _TAILQ_MARK_NOT_ENQUEUED(dmr, dmr_list); |
| removed = true; |
| } |
| return removed; |
| } |
| |
| DISPATCH_NOINLINE |
| static bool |
| _dispatch_mach_reply_kevent_unregister(dispatch_mach_t dm, |
| dispatch_mach_reply_refs_t dmr, uint32_t options) |
| { |
| dispatch_assert(!_TAILQ_IS_ENQUEUED(dmr, dmr_list)); |
| |
| bool disconnected = (options & DU_UNREGISTER_DISCONNECTED); |
| _dispatch_debug("machport[0x%08x]: unregistering for reply%s, ctxt %p", |
| (mach_port_t)dmr->du_ident, disconnected ? " (disconnected)" : "", |
| dmr->dmr_ctxt); |
| if (!_dispatch_unote_unregister(dmr, options)) { |
| _dispatch_debug("machport[0x%08x]: deferred delete kevent[%p]", |
| (mach_port_t)dmr->du_ident, dmr); |
| dispatch_assert(options == DU_UNREGISTER_DISCONNECTED); |
| return false; |
| } |
| |
| dispatch_mach_msg_t dmsgr = NULL; |
| dispatch_queue_t drq = NULL; |
| if (disconnected) { |
| // The next call is guaranteed to always transfer or consume the voucher |
| // in the dmr, if there is one. |
| dmsgr = _dispatch_mach_msg_create_reply_disconnected(NULL, dmr, |
| dmr->dmr_async_reply ? DISPATCH_MACH_ASYNC_WAITER_DISCONNECTED |
| : DISPATCH_MACH_DISCONNECTED); |
| if (dmr->dmr_ctxt) { |
| drq = _dispatch_mach_msg_context_async_reply_queue(dmr->dmr_ctxt); |
| } |
| dispatch_assert(dmr->dmr_voucher == NULL); |
| } else if (dmr->dmr_voucher) { |
| _voucher_release(dmr->dmr_voucher); |
| dmr->dmr_voucher = NULL; |
| } |
| _dispatch_unote_dispose(dmr); |
| |
| if (dmsgr) { |
| if (drq) { |
| _dispatch_mach_push_async_reply_msg(dm, dmsgr, drq); |
| } else { |
| _dispatch_mach_handle_or_push_received_msg(dm, dmsgr); |
| } |
| } |
| return true; |
| } |
| |
| DISPATCH_NOINLINE |
| static void |
| _dispatch_mach_reply_waiter_register(dispatch_mach_t dm, |
| dispatch_mach_reply_refs_t dmr, mach_port_t reply_port, |
| dispatch_mach_msg_t dmsg, mach_msg_option_t msg_opts) |
| { |
| dmr->du_owner_wref = _dispatch_ptr2wref(dm); |
| dmr->du_wlh = NULL; |
| dmr->du_filter = EVFILT_MACHPORT; |
| dmr->du_ident = reply_port; |
| if (msg_opts & DISPATCH_MACH_OWNED_REPLY_PORT) { |
| _dispatch_mach_reply_mark_reply_port_owned(dmr); |
| } else { |
| if (dmsg->dmsg_voucher) { |
| dmr->dmr_voucher = _voucher_retain(dmsg->dmsg_voucher); |
| } |
| dmr->dmr_priority = _dispatch_priority_from_pp(dmsg->dmsg_priority); |
| // make reply context visible to leaks rdar://11777199 |
| dmr->dmr_ctxt = dmsg->do_ctxt; |
| } |
| |
| _dispatch_debug("machport[0x%08x]: registering for sync reply, ctxt %p", |
| reply_port, dmsg->do_ctxt); |
| _dispatch_unfair_lock_lock(&dm->dm_send_refs->dmsr_replies_lock); |
| if (unlikely(_TAILQ_IS_ENQUEUED(dmr, dmr_list))) { |
| DISPATCH_INTERNAL_CRASH(dmr->dmr_list.tqe_prev, |
| "Reply already registered"); |
| } |
| TAILQ_INSERT_TAIL(&dm->dm_send_refs->dmsr_replies, dmr, dmr_list); |
| _dispatch_unfair_lock_unlock(&dm->dm_send_refs->dmsr_replies_lock); |
| } |
| |
| DISPATCH_NOINLINE |
| static void |
| _dispatch_mach_reply_kevent_register(dispatch_mach_t dm, mach_port_t reply_port, |
| dispatch_mach_msg_t dmsg) |
| { |
| dispatch_mach_reply_refs_t dmr; |
| dispatch_priority_t mpri, pri, overcommit; |
| dispatch_wlh_t wlh; |
| |
| dmr = dux_create(&_dispatch_mach_type_reply, reply_port, 0)._dmr; |
| dispatch_assert(dmr->du_is_direct); |
| dmr->du_owner_wref = _dispatch_ptr2wref(dm); |
| if (dmsg->dmsg_voucher) { |
| dmr->dmr_voucher = _voucher_retain(dmsg->dmsg_voucher); |
| } |
| dmr->dmr_priority = _dispatch_priority_from_pp(dmsg->dmsg_priority); |
| // make reply context visible to leaks rdar://11777199 |
| dmr->dmr_ctxt = dmsg->do_ctxt; |
| |
| dispatch_queue_t drq = NULL; |
| if (dmsg->dmsg_options & DISPATCH_MACH_ASYNC_REPLY) { |
| dmr->dmr_async_reply = true; |
| drq = _dispatch_mach_msg_context_async_reply_queue(dmsg->do_ctxt); |
| } |
| |
| if (!drq) { |
| pri = dm->dq_priority; |
| wlh = dm->dm_recv_refs->du_wlh; |
| } else if (dx_type(drq) == DISPATCH_QUEUE_NETWORK_EVENT_TYPE) { |
| pri = DISPATCH_PRIORITY_FLAG_MANAGER; |
| wlh = (dispatch_wlh_t)drq; |
| } else if (dx_hastypeflag(drq, QUEUE_ROOT)) { |
| pri = drq->dq_priority; |
| wlh = DISPATCH_WLH_ANON; |
| } else if (drq == dm->do_targetq) { |
| pri = dm->dq_priority; |
| wlh = dm->dm_recv_refs->du_wlh; |
| } else if (!(pri = _dispatch_queue_compute_priority_and_wlh(drq, &wlh))) { |
| pri = drq->dq_priority; |
| wlh = DISPATCH_WLH_ANON; |
| } |
| if (pri & DISPATCH_PRIORITY_REQUESTED_MASK) { |
| overcommit = pri & DISPATCH_PRIORITY_FLAG_OVERCOMMIT; |
| pri &= DISPATCH_PRIORITY_REQUESTED_MASK; |
| mpri = _dispatch_priority_from_pp_strip_flags(dmsg->dmsg_priority); |
| if (pri < mpri) pri = mpri; |
| pri |= overcommit; |
| } else { |
| pri = DISPATCH_PRIORITY_FLAG_MANAGER; |
| } |
| |
| _dispatch_debug("machport[0x%08x]: registering for reply, ctxt %p", |
| reply_port, dmsg->do_ctxt); |
| _dispatch_unfair_lock_lock(&dm->dm_send_refs->dmsr_replies_lock); |
| if (unlikely(_TAILQ_IS_ENQUEUED(dmr, dmr_list))) { |
| DISPATCH_INTERNAL_CRASH(dmr->dmr_list.tqe_prev, |
| "Reply already registered"); |
| } |
| TAILQ_INSERT_TAIL(&dm->dm_send_refs->dmsr_replies, dmr, dmr_list); |
| _dispatch_unfair_lock_unlock(&dm->dm_send_refs->dmsr_replies_lock); |
| |
| if (!_dispatch_unote_register(dmr, wlh, pri)) { |
| _dispatch_unfair_lock_lock(&dm->dm_send_refs->dmsr_replies_lock); |
| _dispatch_mach_reply_list_remove(dm, dmr); |
| _dispatch_unfair_lock_unlock(&dm->dm_send_refs->dmsr_replies_lock); |
| _dispatch_mach_reply_kevent_unregister(dm, dmr, |
| DU_UNREGISTER_DISCONNECTED); |
| } |
| } |
| |
| #pragma mark - |
| #pragma mark dispatch_mach_msg |
| |
| DISPATCH_ALWAYS_INLINE DISPATCH_CONST |
| static inline bool |
| _dispatch_use_mach_special_reply_port(void) |
| { |
| #if DISPATCH_USE_MACH_SEND_SYNC_OVERRIDE |
| return true; |
| #else |
| #define thread_get_special_reply_port() ({__builtin_trap(); MACH_PORT_NULL;}) |
| return false; |
| #endif |
| } |
| |
| static mach_port_t |
| _dispatch_get_thread_reply_port(void) |
| { |
| mach_port_t reply_port, mrp; |
| if (_dispatch_use_mach_special_reply_port()) { |
| mrp = _dispatch_get_thread_special_reply_port(); |
| } else { |
| mrp = _dispatch_get_thread_mig_reply_port(); |
| } |
| if (mrp) { |
| reply_port = mrp; |
| _dispatch_debug("machport[0x%08x]: borrowed thread sync reply port", |
| reply_port); |
| } else { |
| if (_dispatch_use_mach_special_reply_port()) { |
| reply_port = thread_get_special_reply_port(); |
| _dispatch_set_thread_special_reply_port(reply_port); |
| } else { |
| reply_port = mach_reply_port(); |
| _dispatch_set_thread_mig_reply_port(reply_port); |
| } |
| if (unlikely(!MACH_PORT_VALID(reply_port))) { |
| DISPATCH_CLIENT_CRASH(_dispatch_use_mach_special_reply_port(), |
| "Unable to allocate reply port, possible port leak"); |
| } |
| _dispatch_debug("machport[0x%08x]: allocated thread sync reply port", |
| reply_port); |
| } |
| _dispatch_debug_machport(reply_port); |
| return reply_port; |
| } |
| |
| static void |
| _dispatch_clear_thread_reply_port(mach_port_t reply_port) |
| { |
| mach_port_t mrp; |
| if (_dispatch_use_mach_special_reply_port()) { |
| mrp = _dispatch_get_thread_special_reply_port(); |
| } else { |
| mrp = _dispatch_get_thread_mig_reply_port(); |
| } |
| if (reply_port != mrp) { |
| if (mrp) { |
| _dispatch_debug("machport[0x%08x]: did not clear thread sync reply " |
| "port (found 0x%08x)", reply_port, mrp); |
| } |
| return; |
| } |
| if (_dispatch_use_mach_special_reply_port()) { |
| _dispatch_set_thread_special_reply_port(MACH_PORT_NULL); |
| } else { |
| _dispatch_set_thread_mig_reply_port(MACH_PORT_NULL); |
| } |
| _dispatch_debug_machport(reply_port); |
| _dispatch_debug("machport[0x%08x]: cleared thread sync reply port", |
| reply_port); |
| } |
| |
| static void |
| _dispatch_set_thread_reply_port(mach_port_t reply_port) |
| { |
| _dispatch_debug_machport(reply_port); |
| mach_port_t mrp; |
| if (_dispatch_use_mach_special_reply_port()) { |
| mrp = _dispatch_get_thread_special_reply_port(); |
| } else { |
| mrp = _dispatch_get_thread_mig_reply_port(); |
| } |
| if (mrp) { |
| kern_return_t kr = mach_port_mod_refs(mach_task_self(), reply_port, |
| MACH_PORT_RIGHT_RECEIVE, -1); |
| DISPATCH_VERIFY_MIG(kr); |
| dispatch_assume_zero(kr); |
| _dispatch_debug("machport[0x%08x]: deallocated sync reply port " |
| "(found 0x%08x)", reply_port, mrp); |
| } else { |
| if (_dispatch_use_mach_special_reply_port()) { |
| _dispatch_set_thread_special_reply_port(reply_port); |
| } else { |
| _dispatch_set_thread_mig_reply_port(reply_port); |
| } |
| _dispatch_debug("machport[0x%08x]: restored thread sync reply port", |
| reply_port); |
| } |
| } |
| |
| static inline mach_port_t |
| _dispatch_mach_msg_get_remote_port(dispatch_object_t dou) |
| { |
| mach_msg_header_t *hdr = _dispatch_mach_msg_get_msg(dou._dmsg); |
| mach_port_t remote = hdr->msgh_remote_port; |
| return remote; |
| } |
| |
| static inline mach_port_t |
| _dispatch_mach_msg_get_reply_port(dispatch_object_t dou) |
| { |
| mach_msg_header_t *hdr = _dispatch_mach_msg_get_msg(dou._dmsg); |
| mach_port_t local = hdr->msgh_local_port; |
| if (!MACH_PORT_VALID(local) || MACH_MSGH_BITS_LOCAL(hdr->msgh_bits) != |
| MACH_MSG_TYPE_MAKE_SEND_ONCE) return MACH_PORT_NULL; |
| return local; |
| } |
| |
| static inline void |
| _dispatch_mach_msg_set_reason(dispatch_mach_msg_t dmsg, mach_error_t err, |
| unsigned long reason) |
| { |
| dispatch_assert_zero(reason & ~(unsigned long)code_emask); |
| dmsg->dmsg_error = ((err || !reason) ? err : |
| err_local|err_sub(0x3e0)|(mach_error_t)reason); |
| } |
| |
| static inline unsigned long |
| _dispatch_mach_msg_get_reason(dispatch_mach_msg_t dmsg, mach_error_t *err_ptr) |
| { |
| mach_error_t err = dmsg->dmsg_error; |
| |
| if ((err & system_emask) == err_local && err_get_sub(err) == 0x3e0) { |
| *err_ptr = 0; |
| return err_get_code(err); |
| } |
| *err_ptr = err; |
| return err ? DISPATCH_MACH_MESSAGE_SEND_FAILED : DISPATCH_MACH_MESSAGE_SENT; |
| } |
| |
| static inline dispatch_mach_msg_t |
| _dispatch_mach_msg_create_recv(mach_msg_header_t *hdr, mach_msg_size_t siz, |
| dispatch_mach_reply_refs_t dmr, uint32_t flags) |
| { |
| dispatch_mach_msg_destructor_t destructor; |
| dispatch_mach_msg_t dmsg; |
| voucher_t voucher; |
| pthread_priority_t pp; |
| |
| if (dmr) { |
| _voucher_mach_msg_clear(hdr, false); // deallocate reply message voucher |
| pp = _dispatch_priority_to_pp(dmr->dmr_priority); |
| voucher = dmr->dmr_voucher; |
| dmr->dmr_voucher = NULL; // transfer reference |
| } else { |
| voucher = voucher_create_with_mach_msg(hdr); |
| pp = _dispatch_priority_compute_propagated( |
| _voucher_get_priority(voucher), 0); |
| } |
| |
| destructor = (flags & DISPATCH_EV_MSG_NEEDS_FREE) ? |
| DISPATCH_MACH_MSG_DESTRUCTOR_FREE : |
| DISPATCH_MACH_MSG_DESTRUCTOR_DEFAULT; |
| dmsg = dispatch_mach_msg_create(hdr, siz, destructor, NULL); |
| if (!(flags & DISPATCH_EV_MSG_NEEDS_FREE)) { |
| _dispatch_ktrace2(DISPATCH_MACH_MSG_hdr_move, |
| (uint64_t)hdr, (uint64_t)dmsg->dmsg_buf); |
| } |
| dmsg->dmsg_voucher = voucher; |
| dmsg->dmsg_priority = pp; |
| dmsg->do_ctxt = dmr ? dmr->dmr_ctxt : NULL; |
| _dispatch_mach_msg_set_reason(dmsg, 0, DISPATCH_MACH_MESSAGE_RECEIVED); |
| _dispatch_voucher_debug("mach-msg[%p] create", voucher, dmsg); |
| _dispatch_voucher_ktrace_dmsg_push(dmsg); |
| return dmsg; |
| } |
| |
| void |
| _dispatch_mach_merge_msg(dispatch_unote_t du, uint32_t flags, |
| mach_msg_header_t *hdr, mach_msg_size_t siz) |
| { |
| // this function is very similar with what _dispatch_source_merge_evt does |
| // but can't reuse it as handling the message must be protected by the |
| // internal refcount between the first half and the trailer of what |
| // _dispatch_source_merge_evt does. |
| |
| dispatch_mach_recv_refs_t dmrr = du._dmrr; |
| dispatch_mach_t dm = _dispatch_wref2ptr(dmrr->du_owner_wref); |
| dispatch_queue_flags_t dqf; |
| dispatch_mach_msg_t dmsg; |
| |
| dispatch_assert(_dispatch_unote_needs_rearm(du)); |
| |
| if (flags & EV_VANISHED) { |
| DISPATCH_CLIENT_CRASH(du._du->du_ident, |
| "Unexpected EV_VANISHED (do not destroy random mach ports)"); |
| } |
| |
| // once we modify the queue atomic flags below, it will allow concurrent |
| // threads running _dispatch_mach_invoke2 to dispose of the source, |
| // so we can't safely borrow the reference we get from the muxnote udata |
| // anymore, and need our own |
| dispatch_wakeup_flags_t wflags = DISPATCH_WAKEUP_CONSUME_2; |
| _dispatch_retain_2(dm); // rdar://20382435 |
| |
| if (unlikely((flags & EV_ONESHOT) && !(flags & EV_DELETE))) { |
| dqf = _dispatch_queue_atomic_flags_set_and_clear(dm->_as_dq, |
| DSF_DEFERRED_DELETE, DSF_ARMED); |
| _dispatch_debug("kevent-source[%p]: deferred delete oneshot kevent[%p]", |
| dm, dmrr); |
| } else if (unlikely(flags & (EV_ONESHOT | EV_DELETE))) { |
| _dispatch_source_refs_unregister(dm->_as_ds, |
| DU_UNREGISTER_ALREADY_DELETED); |
| dqf = _dispatch_queue_atomic_flags(dm->_as_dq); |
| _dispatch_debug("kevent-source[%p]: deleted kevent[%p]", dm, dmrr); |
| } else { |
| dqf = _dispatch_queue_atomic_flags_clear(dm->_as_dq, DSF_ARMED); |
| _dispatch_debug("kevent-source[%p]: disarmed kevent[%p]", dm, dmrr); |
| } |
| |
| _dispatch_debug_machport(hdr->msgh_remote_port); |
| _dispatch_debug("machport[0x%08x]: received msg id 0x%x, reply on 0x%08x", |
| hdr->msgh_local_port, hdr->msgh_id, hdr->msgh_remote_port); |
| |
| if (dqf & DSF_CANCELED) { |
| _dispatch_debug("machport[0x%08x]: drop msg id 0x%x, reply on 0x%08x", |
| hdr->msgh_local_port, hdr->msgh_id, hdr->msgh_remote_port); |
| mach_msg_destroy(hdr); |
| if (flags & DISPATCH_EV_MSG_NEEDS_FREE) { |
| free(hdr); |
| } |
| return dx_wakeup(dm, 0, wflags | DISPATCH_WAKEUP_MAKE_DIRTY); |
| } |
| |
| // Once the mach channel disarming is visible, cancellation will switch to |
| // immediate deletion. If we're preempted here, then the whole cancellation |
| // sequence may be complete by the time we really enqueue the message. |
| // |
| // _dispatch_mach_msg_invoke_with_mach() is responsible for filtering it out |
| // to keep the promise that DISPATCH_MACH_DISCONNECTED is the last |
| // event sent. |
| |
| dmsg = _dispatch_mach_msg_create_recv(hdr, siz, NULL, flags); |
| _dispatch_mach_handle_or_push_received_msg(dm, dmsg); |
| return _dispatch_release_2_tailcall(dm); |
| } |
| |
| void |
| _dispatch_mach_reply_merge_msg(dispatch_unote_t du, uint32_t flags, |
| mach_msg_header_t *hdr, mach_msg_size_t siz) |
| { |
| dispatch_mach_reply_refs_t dmr = du._dmr; |
| dispatch_mach_t dm = _dispatch_wref2ptr(dmr->du_owner_wref); |
| bool canceled = (_dispatch_queue_atomic_flags(dm->_as_dq) & DSF_CANCELED); |
| dispatch_mach_msg_t dmsg = NULL; |
| |
| _dispatch_debug_machport(hdr->msgh_remote_port); |
| _dispatch_debug("machport[0x%08x]: received msg id 0x%x, reply on 0x%08x", |
| hdr->msgh_local_port, hdr->msgh_id, hdr->msgh_remote_port); |
| |
| if (!canceled) { |
| dmsg = _dispatch_mach_msg_create_recv(hdr, siz, dmr, flags); |
| } |
| |
| if (dmsg) { |
| dispatch_queue_t drq = NULL; |
| if (dmsg->do_ctxt) { |
| drq = _dispatch_mach_msg_context_async_reply_queue(dmsg->do_ctxt); |
| } |
| if (drq) { |
| _dispatch_mach_push_async_reply_msg(dm, dmsg, drq); |
| } else { |
| _dispatch_mach_handle_or_push_received_msg(dm, dmsg); |
| } |
| } else { |
| _dispatch_debug("machport[0x%08x]: drop msg id 0x%x, reply on 0x%08x", |
| hdr->msgh_local_port, hdr->msgh_id, hdr->msgh_remote_port); |
| mach_msg_destroy(hdr); |
| if (flags & DISPATCH_EV_MSG_NEEDS_FREE) { |
| free(hdr); |
| } |
| } |
| |
| dispatch_wakeup_flags_t wflags = 0; |
| uint32_t options = DU_UNREGISTER_IMMEDIATE_DELETE; |
| if (canceled) { |
| options |= DU_UNREGISTER_DISCONNECTED; |
| } |
| |
| _dispatch_unfair_lock_lock(&dm->dm_send_refs->dmsr_replies_lock); |
| bool removed = _dispatch_mach_reply_list_remove(dm, dmr); |
| dispatch_assert(removed); |
| if (TAILQ_EMPTY(&dm->dm_send_refs->dmsr_replies) && |
| (dm->dm_send_refs->dmsr_disconnect_cnt || |
| (dm->dq_atomic_flags & DSF_CANCELED))) { |
| // When the list is empty, _dispatch_mach_disconnect() may release the |
| // last reference count on the Mach channel. To avoid this, take our |
| // own reference before releasing the lock. |
| wflags = DISPATCH_WAKEUP_MAKE_DIRTY | DISPATCH_WAKEUP_CONSUME_2; |
| _dispatch_retain_2(dm); |
| } |
| _dispatch_unfair_lock_unlock(&dm->dm_send_refs->dmsr_replies_lock); |
| |
| bool result = _dispatch_mach_reply_kevent_unregister(dm, dmr, options); |
| dispatch_assert(result); |
| if (wflags) dx_wakeup(dm, 0, wflags); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_mach_msg_t |
| _dispatch_mach_msg_reply_recv(dispatch_mach_t dm, |
| dispatch_mach_reply_refs_t dmr, mach_port_t reply_port, |
| mach_port_t send) |
| { |
| if (slowpath(!MACH_PORT_VALID(reply_port))) { |
| DISPATCH_CLIENT_CRASH(reply_port, "Invalid reply port"); |
| } |
| void *ctxt = dmr->dmr_ctxt; |
| mach_msg_header_t *hdr, *hdr2 = NULL; |
| void *hdr_copyout_addr; |
| mach_msg_size_t siz, msgsiz = 0; |
| mach_msg_return_t kr; |
| mach_msg_option_t options; |
| mach_port_t notify = MACH_PORT_NULL; |
| siz = mach_vm_round_page(DISPATCH_MACH_RECEIVE_MAX_INLINE_MESSAGE_SIZE + |
| DISPATCH_MACH_TRAILER_SIZE); |
| hdr = alloca(siz); |
| for (mach_vm_address_t p = mach_vm_trunc_page(hdr + vm_page_size); |
| p < (mach_vm_address_t)hdr + siz; p += vm_page_size) { |
| *(char*)p = 0; // ensure alloca buffer doesn't overlap with stack guard |
| } |
| options = DISPATCH_MACH_RCV_OPTIONS & (~MACH_RCV_VOUCHER); |
| if (MACH_PORT_VALID(send)) { |
| notify = send; |
| options |= MACH_RCV_SYNC_WAIT; |
| } |
| |
| retry: |
| _dispatch_debug_machport(reply_port); |
| _dispatch_debug("machport[0x%08x]: MACH_RCV_MSG %s", reply_port, |
| (options & MACH_RCV_TIMEOUT) ? "poll" : "wait"); |
| kr = mach_msg(hdr, options, 0, siz, reply_port, MACH_MSG_TIMEOUT_NONE, |
| notify); |
| hdr_copyout_addr = hdr; |
| _dispatch_debug_machport(reply_port); |
| _dispatch_debug("machport[0x%08x]: MACH_RCV_MSG (size %u, opts 0x%x) " |
| "returned: %s - 0x%x", reply_port, siz, options, |
| mach_error_string(kr), kr); |
| switch (kr) { |
| case MACH_RCV_TOO_LARGE: |
| if (!fastpath(hdr->msgh_size <= UINT_MAX - |
| DISPATCH_MACH_TRAILER_SIZE)) { |
| DISPATCH_CLIENT_CRASH(hdr->msgh_size, "Overlarge message"); |
| } |
| if (options & MACH_RCV_LARGE) { |
| msgsiz = hdr->msgh_size + DISPATCH_MACH_TRAILER_SIZE; |
| hdr2 = malloc(msgsiz); |
| if (dispatch_assume(hdr2)) { |
| hdr = hdr2; |
| siz = msgsiz; |
| } |
| options |= MACH_RCV_TIMEOUT; |
| options &= ~MACH_RCV_LARGE; |
| goto retry; |
| } |
| _dispatch_log("BUG in libdispatch client: " |
| "dispatch_mach_send_and_wait_for_reply: dropped message too " |
| "large to fit in memory: id = 0x%x, size = %u", hdr->msgh_id, |
| hdr->msgh_size); |
| break; |
| case MACH_RCV_INVALID_NAME: // rdar://problem/21963848 |
| case MACH_RCV_PORT_CHANGED: // rdar://problem/21885327 |
| case MACH_RCV_PORT_DIED: |
| // channel was disconnected/canceled and reply port destroyed |
| _dispatch_debug("machport[0x%08x]: sync reply port destroyed, ctxt %p: " |
| "%s - 0x%x", reply_port, ctxt, mach_error_string(kr), kr); |
| goto out; |
| case MACH_MSG_SUCCESS: |
| if (hdr->msgh_remote_port) { |
| _dispatch_debug_machport(hdr->msgh_remote_port); |
| } |
| _dispatch_debug("machport[0x%08x]: received msg id 0x%x, size = %u, " |
| "reply on 0x%08x", hdr->msgh_local_port, hdr->msgh_id, |
| hdr->msgh_size, hdr->msgh_remote_port); |
| siz = hdr->msgh_size + DISPATCH_MACH_TRAILER_SIZE; |
| if (hdr2 && siz < msgsiz) { |
| void *shrink = realloc(hdr2, msgsiz); |
| if (shrink) hdr = hdr2 = shrink; |
| } |
| break; |
| case MACH_RCV_INVALID_NOTIFY: |
| default: |
| DISPATCH_INTERNAL_CRASH(kr, "Unexpected error from mach_msg_receive"); |
| break; |
| } |
| _dispatch_mach_msg_reply_received(dm, dmr, hdr->msgh_local_port); |
| hdr->msgh_local_port = MACH_PORT_NULL; |
| if (slowpath((dm->dq_atomic_flags & DSF_CANCELED) || kr)) { |
| if (!kr) mach_msg_destroy(hdr); |
| goto out; |
| } |
| dispatch_mach_msg_t dmsg; |
| dispatch_mach_msg_destructor_t destructor = (!hdr2) ? |
| DISPATCH_MACH_MSG_DESTRUCTOR_DEFAULT : |
| DISPATCH_MACH_MSG_DESTRUCTOR_FREE; |
| dmsg = dispatch_mach_msg_create(hdr, siz, destructor, NULL); |
| if (!hdr2 || hdr != hdr_copyout_addr) { |
| _dispatch_ktrace2(DISPATCH_MACH_MSG_hdr_move, |
| (uint64_t)hdr_copyout_addr, |
| (uint64_t)_dispatch_mach_msg_get_msg(dmsg)); |
| } |
| dmsg->do_ctxt = ctxt; |
| return dmsg; |
| out: |
| free(hdr2); |
| return NULL; |
| } |
| |
| static inline void |
| _dispatch_mach_msg_reply_received(dispatch_mach_t dm, |
| dispatch_mach_reply_refs_t dmr, mach_port_t local_port) |
| { |
| bool removed = _dispatch_mach_reply_tryremove(dm, dmr); |
| if (!MACH_PORT_VALID(local_port) || !removed) { |
| // port moved/destroyed during receive, or reply waiter was never |
| // registered or already removed (disconnected) |
| return; |
| } |
| mach_port_t reply_port = _dispatch_mach_reply_get_reply_port( |
| (mach_port_t)dmr->du_ident); |
| _dispatch_debug("machport[0x%08x]: unregistered for sync reply, ctxt %p", |
| reply_port, dmr->dmr_ctxt); |
| if (_dispatch_mach_reply_is_reply_port_owned(dmr)) { |
| _dispatch_set_thread_reply_port(reply_port); |
| if (local_port != reply_port) { |
| DISPATCH_CLIENT_CRASH(local_port, |
| "Reply received on unexpected port"); |
| } |
| return; |
| } |
| mach_msg_header_t *hdr; |
| dispatch_mach_msg_t dmsg; |
| dmsg = dispatch_mach_msg_create(NULL, sizeof(mach_msg_header_t), |
| DISPATCH_MACH_MSG_DESTRUCTOR_DEFAULT, &hdr); |
| hdr->msgh_local_port = local_port; |
| dmsg->dmsg_voucher = dmr->dmr_voucher; |
| dmr->dmr_voucher = NULL; // transfer reference |
| dmsg->dmsg_priority = _dispatch_priority_to_pp(dmr->dmr_priority); |
| dmsg->do_ctxt = dmr->dmr_ctxt; |
| _dispatch_mach_msg_set_reason(dmsg, 0, DISPATCH_MACH_REPLY_RECEIVED); |
| return _dispatch_mach_handle_or_push_received_msg(dm, dmsg); |
| } |
| |
| static inline void |
| _dispatch_mach_msg_disconnected(dispatch_mach_t dm, mach_port_t local_port, |
| mach_port_t remote_port) |
| { |
| mach_msg_header_t *hdr; |
| dispatch_mach_msg_t dmsg; |
| dmsg = dispatch_mach_msg_create(NULL, sizeof(mach_msg_header_t), |
| DISPATCH_MACH_MSG_DESTRUCTOR_DEFAULT, &hdr); |
| if (local_port) hdr->msgh_local_port = local_port; |
| if (remote_port) hdr->msgh_remote_port = remote_port; |
| _dispatch_mach_msg_set_reason(dmsg, 0, DISPATCH_MACH_DISCONNECTED); |
| _dispatch_debug("machport[0x%08x]: %s right disconnected", local_port ? |
| local_port : remote_port, local_port ? "receive" : "send"); |
| return _dispatch_mach_handle_or_push_received_msg(dm, dmsg); |
| } |
| |
| static inline dispatch_mach_msg_t |
| _dispatch_mach_msg_create_reply_disconnected(dispatch_object_t dou, |
| dispatch_mach_reply_refs_t dmr, dispatch_mach_reason_t reason) |
| { |
| dispatch_mach_msg_t dmsg = dou._dmsg, dmsgr; |
| mach_port_t reply_port = dmsg ? dmsg->dmsg_reply : |
| _dispatch_mach_reply_get_reply_port((mach_port_t)dmr->du_ident); |
| voucher_t v; |
| |
| if (!reply_port) { |
| if (!dmsg) { |
| v = dmr->dmr_voucher; |
| dmr->dmr_voucher = NULL; // transfer reference |
| if (v) _voucher_release(v); |
| } |
| return NULL; |
| } |
| |
| if (dmsg) { |
| v = dmsg->dmsg_voucher; |
| if (v) _voucher_retain(v); |
| } else { |
| v = dmr->dmr_voucher; |
| dmr->dmr_voucher = NULL; // transfer reference |
| } |
| |
| if ((dmsg && (dmsg->dmsg_options & DISPATCH_MACH_WAIT_FOR_REPLY) && |
| (dmsg->dmsg_options & DISPATCH_MACH_OWNED_REPLY_PORT)) || |
| (dmr && !_dispatch_unote_registered(dmr) && |
| _dispatch_mach_reply_is_reply_port_owned(dmr))) { |
| if (v) _voucher_release(v); |
| // deallocate owned reply port to break _dispatch_mach_msg_reply_recv |
| // out of waiting in mach_msg(MACH_RCV_MSG) |
| kern_return_t kr = mach_port_mod_refs(mach_task_self(), reply_port, |
| MACH_PORT_RIGHT_RECEIVE, -1); |
| DISPATCH_VERIFY_MIG(kr); |
| dispatch_assume_zero(kr); |
| return NULL; |
| } |
| |
| mach_msg_header_t *hdr; |
| dmsgr = dispatch_mach_msg_create(NULL, sizeof(mach_msg_header_t), |
| DISPATCH_MACH_MSG_DESTRUCTOR_DEFAULT, &hdr); |
| dmsgr->dmsg_voucher = v; |
| hdr->msgh_local_port = reply_port; |
| if (dmsg) { |
| dmsgr->dmsg_priority = dmsg->dmsg_priority; |
| dmsgr->do_ctxt = dmsg->do_ctxt; |
| } else { |
| dmsgr->dmsg_priority = _dispatch_priority_to_pp(dmr->dmr_priority); |
| dmsgr->do_ctxt = dmr->dmr_ctxt; |
| } |
| _dispatch_mach_msg_set_reason(dmsgr, 0, reason); |
| _dispatch_debug("machport[0x%08x]: reply disconnected, ctxt %p", |
| hdr->msgh_local_port, dmsgr->do_ctxt); |
| return dmsgr; |
| } |
| |
| DISPATCH_NOINLINE |
| static void |
| _dispatch_mach_msg_not_sent(dispatch_mach_t dm, dispatch_object_t dou) |
| { |
| dispatch_mach_msg_t dmsg = dou._dmsg, dmsgr; |
| dispatch_queue_t drq = NULL; |
| mach_msg_header_t *msg = _dispatch_mach_msg_get_msg(dmsg); |
| mach_msg_option_t msg_opts = dmsg->dmsg_options; |
| _dispatch_debug("machport[0x%08x]: not sent msg id 0x%x, ctxt %p, " |
| "msg_opts 0x%x, kvoucher 0x%08x, reply on 0x%08x", |
| msg->msgh_remote_port, msg->msgh_id, dmsg->do_ctxt, |
| msg_opts, msg->msgh_voucher_port, dmsg->dmsg_reply); |
| unsigned long reason = (msg_opts & DISPATCH_MACH_REGISTER_FOR_REPLY) ? |
| 0 : DISPATCH_MACH_MESSAGE_NOT_SENT; |
| dmsgr = _dispatch_mach_msg_create_reply_disconnected(dmsg, NULL, |
| msg_opts & DISPATCH_MACH_ASYNC_REPLY |
| ? DISPATCH_MACH_ASYNC_WAITER_DISCONNECTED |
| : DISPATCH_MACH_DISCONNECTED); |
| if (dmsg->do_ctxt) { |
| drq = _dispatch_mach_msg_context_async_reply_queue(dmsg->do_ctxt); |
| } |
| _dispatch_mach_msg_set_reason(dmsg, 0, reason); |
| _dispatch_mach_handle_or_push_received_msg(dm, dmsg); |
| if (dmsgr) { |
| if (drq) { |
| _dispatch_mach_push_async_reply_msg(dm, dmsgr, drq); |
| } else { |
| _dispatch_mach_handle_or_push_received_msg(dm, dmsgr); |
| } |
| } |
| } |
| |
| DISPATCH_NOINLINE |
| static uint32_t |
| _dispatch_mach_msg_send(dispatch_mach_t dm, dispatch_object_t dou, |
| dispatch_mach_reply_refs_t dmr, dispatch_qos_t qos, |
| dispatch_mach_send_invoke_flags_t send_flags) |
| { |
| dispatch_mach_send_refs_t dsrr = dm->dm_send_refs; |
| dispatch_mach_msg_t dmsg = dou._dmsg, dmsgr = NULL; |
| voucher_t voucher = dmsg->dmsg_voucher; |
| dispatch_queue_t drq = NULL; |
| mach_voucher_t ipc_kvoucher = MACH_VOUCHER_NULL; |
| uint32_t send_status = 0; |
| bool clear_voucher = false, kvoucher_move_send = false; |
| mach_msg_header_t *msg = _dispatch_mach_msg_get_msg(dmsg); |
| bool is_reply = (MACH_MSGH_BITS_REMOTE(msg->msgh_bits) == |
| MACH_MSG_TYPE_MOVE_SEND_ONCE); |
| mach_port_t reply_port = dmsg->dmsg_reply; |
| if (!is_reply) { |
| dm->dm_needs_mgr = 0; |
| if (unlikely(dsrr->dmsr_checkin && dmsg != dsrr->dmsr_checkin)) { |
| // send initial checkin message |
| if (unlikely(_dispatch_unote_registered(dsrr) && |
| _dispatch_queue_get_current() != &_dispatch_mgr_q)) { |
| // send kevent must be uninstalled on the manager queue |
| dm->dm_needs_mgr = 1; |
| goto out; |
| } |
| if (unlikely(!_dispatch_mach_msg_send(dm, |
| dsrr->dmsr_checkin, NULL, qos, DM_SEND_INVOKE_NONE))) { |
| goto out; |
| } |
| dsrr->dmsr_checkin = NULL; |
| } |
| } |
| mach_msg_return_t kr = 0; |
| mach_msg_option_t opts = 0, msg_opts = dmsg->dmsg_options; |
| if (!(msg_opts & DISPATCH_MACH_REGISTER_FOR_REPLY)) { |
| mach_msg_priority_t msg_priority = MACH_MSG_PRIORITY_UNSPECIFIED; |
| opts = MACH_SEND_MSG | (msg_opts & ~DISPATCH_MACH_OPTIONS_MASK); |
| if (!is_reply) { |
| if (dmsg != dsrr->dmsr_checkin) { |
| msg->msgh_remote_port = dsrr->dmsr_send; |
| } |
| if (_dispatch_queue_get_current() == &_dispatch_mgr_q) { |
| if (unlikely(!_dispatch_unote_registered(dsrr))) { |
| _dispatch_mach_notification_kevent_register(dm, |
| msg->msgh_remote_port); |
| } |
| if (likely(_dispatch_unote_registered(dsrr))) { |
| if (os_atomic_load2o(dsrr, dmsr_notification_armed, |
| relaxed)) { |
| goto out; |
| } |
| opts |= MACH_SEND_NOTIFY; |
| } |
| } |
| opts |= MACH_SEND_TIMEOUT; |
| if (dmsg->dmsg_priority != _voucher_get_priority(voucher)) { |
| ipc_kvoucher = _voucher_create_mach_voucher_with_priority( |
| voucher, dmsg->dmsg_priority); |
| } |
| _dispatch_voucher_debug("mach-msg[%p] msg_set", voucher, dmsg); |
| if (ipc_kvoucher) { |
| kvoucher_move_send = true; |
| clear_voucher = _voucher_mach_msg_set_mach_voucher(msg, |
| ipc_kvoucher, kvoucher_move_send); |
| } else { |
| clear_voucher = _voucher_mach_msg_set(msg, voucher); |
| } |
| if (qos) { |
| opts |= MACH_SEND_OVERRIDE; |
| msg_priority = (mach_msg_priority_t) |
| _dispatch_priority_compute_propagated( |
| _dispatch_qos_to_pp(qos), 0); |
| } |
| } |
| _dispatch_debug_machport(msg->msgh_remote_port); |
| if (reply_port) _dispatch_debug_machport(reply_port); |
| if (msg_opts & DISPATCH_MACH_WAIT_FOR_REPLY) { |
| if (msg_opts & DISPATCH_MACH_OWNED_REPLY_PORT) { |
| if (_dispatch_use_mach_special_reply_port()) { |
| opts |= MACH_SEND_SYNC_OVERRIDE; |
| } |
| _dispatch_clear_thread_reply_port(reply_port); |
| } |
| _dispatch_mach_reply_waiter_register(dm, dmr, reply_port, dmsg, |
| msg_opts); |
| } |
| kr = mach_msg(msg, opts, msg->msgh_size, 0, MACH_PORT_NULL, 0, |
| msg_priority); |
| _dispatch_debug("machport[0x%08x]: sent msg id 0x%x, ctxt %p, " |
| "opts 0x%x, msg_opts 0x%x, kvoucher 0x%08x, reply on 0x%08x: " |
| "%s - 0x%x", msg->msgh_remote_port, msg->msgh_id, dmsg->do_ctxt, |
| opts, msg_opts, msg->msgh_voucher_port, reply_port, |
| mach_error_string(kr), kr); |
| if (unlikely(kr && (msg_opts & DISPATCH_MACH_WAIT_FOR_REPLY))) { |
| _dispatch_mach_reply_waiter_unregister(dm, dmr, |
| DU_UNREGISTER_REPLY_REMOVE); |
| } |
| if (clear_voucher) { |
| if (kr == MACH_SEND_INVALID_VOUCHER && msg->msgh_voucher_port) { |
| DISPATCH_CLIENT_CRASH(kr, "Voucher port corruption"); |
| } |
| mach_voucher_t kv; |
| kv = _voucher_mach_msg_clear(msg, kvoucher_move_send); |
| if (kvoucher_move_send) ipc_kvoucher = kv; |
| } |
| } |
| if (kr == MACH_SEND_TIMED_OUT && (opts & MACH_SEND_TIMEOUT)) { |
| if (opts & MACH_SEND_NOTIFY) { |
| _dispatch_debug("machport[0x%08x]: send-possible notification " |
| "armed", (mach_port_t)dsrr->du_ident); |
| _dispatch_mach_notification_set_armed(dsrr); |
| } else { |
| // send kevent must be installed on the manager queue |
| dm->dm_needs_mgr = 1; |
| } |
| if (ipc_kvoucher) { |
| _dispatch_kvoucher_debug("reuse on re-send", ipc_kvoucher); |
| voucher_t ipc_voucher; |
| ipc_voucher = _voucher_create_with_priority_and_mach_voucher( |
| voucher, dmsg->dmsg_priority, ipc_kvoucher); |
| _dispatch_voucher_debug("mach-msg[%p] replace voucher[%p]", |
| ipc_voucher, dmsg, voucher); |
| if (dmsg->dmsg_voucher) _voucher_release(dmsg->dmsg_voucher); |
| dmsg->dmsg_voucher = ipc_voucher; |
| } |
| goto out; |
| } else if (ipc_kvoucher && (kr || !kvoucher_move_send)) { |
| _voucher_dealloc_mach_voucher(ipc_kvoucher); |
| } |
| dispatch_mach_recv_refs_t dmrr = dm->dm_recv_refs; |
| if (!(msg_opts & DISPATCH_MACH_WAIT_FOR_REPLY) && !kr && reply_port && |
| !(_dispatch_unote_registered(dmrr) && |
| dmrr->du_ident == reply_port)) { |
| _dispatch_mach_reply_kevent_register(dm, reply_port, dmsg); |
| } |
| if (unlikely(!is_reply && dmsg == dsrr->dmsr_checkin && |
| _dispatch_unote_registered(dsrr))) { |
| _dispatch_mach_notification_kevent_unregister(dm); |
| } |
| if (slowpath(kr)) { |
| // Send failed, so reply was never registered <rdar://problem/14309159> |
| dmsgr = _dispatch_mach_msg_create_reply_disconnected(dmsg, NULL, |
| msg_opts & DISPATCH_MACH_ASYNC_REPLY |
| ? DISPATCH_MACH_ASYNC_WAITER_DISCONNECTED |
| : DISPATCH_MACH_DISCONNECTED); |
| if (dmsg->do_ctxt) { |
| drq = _dispatch_mach_msg_context_async_reply_queue(dmsg->do_ctxt); |
| } |
| } |
| _dispatch_mach_msg_set_reason(dmsg, kr, 0); |
| if ((send_flags & DM_SEND_INVOKE_IMMEDIATE_SEND) && |
| (msg_opts & DISPATCH_MACH_RETURN_IMMEDIATE_SEND_RESULT)) { |
| // Return sent message synchronously <rdar://problem/25947334> |
| send_status |= DM_SEND_STATUS_RETURNING_IMMEDIATE_SEND_RESULT; |
| } else { |
| _dispatch_mach_handle_or_push_received_msg(dm, dmsg); |
| } |
| if (dmsgr) { |
| if (drq) { |
| _dispatch_mach_push_async_reply_msg(dm, dmsgr, drq); |
| } else { |
| _dispatch_mach_handle_or_push_received_msg(dm, dmsgr); |
| } |
| } |
| send_status |= DM_SEND_STATUS_SUCCESS; |
| out: |
| return send_status; |
| } |
| |
| #pragma mark - |
| #pragma mark dispatch_mach_send_refs_t |
| |
| #define _dmsr_state_needs_lock_override(dq_state, qos) \ |
| unlikely(qos < _dq_state_max_qos(dq_state)) |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_qos_t |
| _dmsr_state_max_qos(uint64_t dmsr_state) |
| { |
| return _dq_state_max_qos(dmsr_state); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dmsr_state_needs_override(uint64_t dmsr_state, dispatch_qos_t qos) |
| { |
| dmsr_state &= DISPATCH_MACH_STATE_MAX_QOS_MASK; |
| return dmsr_state < _dq_state_from_qos(qos); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline uint64_t |
| _dmsr_state_merge_override(uint64_t dmsr_state, dispatch_qos_t qos) |
| { |
| if (_dmsr_state_needs_override(dmsr_state, qos)) { |
| dmsr_state &= ~DISPATCH_MACH_STATE_MAX_QOS_MASK; |
| dmsr_state |= _dq_state_from_qos(qos); |
| dmsr_state |= DISPATCH_MACH_STATE_DIRTY; |
| dmsr_state |= DISPATCH_MACH_STATE_RECEIVED_OVERRIDE; |
| } |
| return dmsr_state; |
| } |
| |
| #define _dispatch_mach_send_push_update_tail(dmsr, tail) \ |
| os_mpsc_push_update_tail(dmsr, dmsr, tail, do_next) |
| #define _dispatch_mach_send_push_update_head(dmsr, head) \ |
| os_mpsc_push_update_head(dmsr, dmsr, head) |
| #define _dispatch_mach_send_get_head(dmsr) \ |
| os_mpsc_get_head(dmsr, dmsr) |
| #define _dispatch_mach_send_unpop_head(dmsr, dc, dc_next) \ |
| os_mpsc_undo_pop_head(dmsr, dmsr, dc, dc_next, do_next) |
| #define _dispatch_mach_send_pop_head(dmsr, head) \ |
| os_mpsc_pop_head(dmsr, dmsr, head, do_next) |
| |
| #define dm_push(dm, dc, qos) \ |
| _dispatch_queue_push((dm)->_as_dq, dc, qos) |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_mach_send_push_inline(dispatch_mach_send_refs_t dmsr, |
| dispatch_object_t dou) |
| { |
| if (_dispatch_mach_send_push_update_tail(dmsr, dou._do)) { |
| _dispatch_mach_send_push_update_head(dmsr, dou._do); |
| return true; |
| } |
| return false; |
| } |
| |
| DISPATCH_NOINLINE |
| static bool |
| _dispatch_mach_send_drain(dispatch_mach_t dm, dispatch_invoke_flags_t flags, |
| dispatch_mach_send_invoke_flags_t send_flags) |
| { |
| dispatch_mach_send_refs_t dmsr = dm->dm_send_refs; |
| dispatch_mach_reply_refs_t dmr; |
| dispatch_mach_msg_t dmsg; |
| struct dispatch_object_s *dc = NULL, *next_dc = NULL; |
| dispatch_qos_t qos = _dmsr_state_max_qos(dmsr->dmsr_state); |
| uint64_t old_state, new_state; |
| uint32_t send_status; |
| bool needs_mgr, disconnecting, returning_send_result = false; |
| |
| again: |
| needs_mgr = false; disconnecting = false; |
| while (dmsr->dmsr_tail) { |
| dc = _dispatch_mach_send_get_head(dmsr); |
| do { |
| dispatch_mach_send_invoke_flags_t sf = send_flags; |
| // Only request immediate send result for the first message |
| send_flags &= ~DM_SEND_INVOKE_IMMEDIATE_SEND_MASK; |
| next_dc = _dispatch_mach_send_pop_head(dmsr, dc); |
| if (_dispatch_object_has_type(dc, |
| DISPATCH_CONTINUATION_TYPE(MACH_SEND_BARRIER))) { |
| if (!(send_flags & DM_SEND_INVOKE_CAN_RUN_BARRIER)) { |
| goto partial_drain; |
| } |
| _dispatch_continuation_pop(dc, NULL, flags, dm->_as_dq); |
| continue; |
| } |
| if (_dispatch_object_is_sync_waiter(dc)) { |
| dmsg = ((dispatch_continuation_t)dc)->dc_data; |
| dmr = ((dispatch_continuation_t)dc)->dc_other; |
| } else if (_dispatch_object_has_vtable(dc)) { |
| dmsg = (dispatch_mach_msg_t)dc; |
| dmr = NULL; |
| } else { |
| if (_dispatch_unote_registered(dmsr) && |
| (_dispatch_queue_get_current() != &_dispatch_mgr_q)) { |
| // send kevent must be uninstalled on the manager queue |
| needs_mgr = true; |
| goto partial_drain; |
| } |
| if (unlikely(!_dispatch_mach_reconnect_invoke(dm, dc))) { |
| disconnecting = true; |
| goto partial_drain; |
| } |
| _dispatch_perfmon_workitem_inc(); |
| continue; |
| } |
| _dispatch_voucher_ktrace_dmsg_pop(dmsg); |
| if (unlikely(dmsr->dmsr_disconnect_cnt || |
| (dm->dq_atomic_flags & DSF_CANCELED))) { |
| _dispatch_mach_msg_not_sent(dm, dmsg); |
| _dispatch_perfmon_workitem_inc(); |
| continue; |
| } |
| send_status = _dispatch_mach_msg_send(dm, dmsg, dmr, qos, sf); |
| if (unlikely(!send_status)) { |
| goto partial_drain; |
| } |
| if (send_status & DM_SEND_STATUS_RETURNING_IMMEDIATE_SEND_RESULT) { |
| returning_send_result = true; |
| } |
| _dispatch_perfmon_workitem_inc(); |
| } while ((dc = next_dc)); |
| } |
| |
| os_atomic_rmw_loop2o(dmsr, dmsr_state, old_state, new_state, release, { |
| if (old_state & DISPATCH_MACH_STATE_DIRTY) { |
| new_state = old_state; |
| new_state &= ~DISPATCH_MACH_STATE_DIRTY; |
| new_state &= ~DISPATCH_MACH_STATE_RECEIVED_OVERRIDE; |
| new_state &= ~DISPATCH_MACH_STATE_PENDING_BARRIER; |
| } else { |
| // unlock |
| new_state = 0; |
| } |
| }); |
| goto out; |
| |
| partial_drain: |
| // if this is not a complete drain, we must undo some things |
| _dispatch_mach_send_unpop_head(dmsr, dc, next_dc); |
| |
| if (_dispatch_object_has_type(dc, |
| DISPATCH_CONTINUATION_TYPE(MACH_SEND_BARRIER))) { |
| os_atomic_rmw_loop2o(dmsr, dmsr_state, old_state, new_state, release, { |
| new_state = old_state; |
| new_state |= DISPATCH_MACH_STATE_DIRTY; |
| new_state |= DISPATCH_MACH_STATE_PENDING_BARRIER; |
| new_state &= ~DISPATCH_MACH_STATE_UNLOCK_MASK; |
| new_state &= ~DISPATCH_MACH_STATE_RECEIVED_OVERRIDE; |
| }); |
| } else { |
| os_atomic_rmw_loop2o(dmsr, dmsr_state, old_state, new_state, release, { |
| new_state = old_state; |
| if (old_state & (DISPATCH_MACH_STATE_DIRTY | |
| DISPATCH_MACH_STATE_RECEIVED_OVERRIDE)) { |
| new_state &= ~DISPATCH_MACH_STATE_DIRTY; |
| new_state &= ~DISPATCH_MACH_STATE_RECEIVED_OVERRIDE; |
| new_state &= ~DISPATCH_MACH_STATE_PENDING_BARRIER; |
| } else { |
| new_state |= DISPATCH_MACH_STATE_DIRTY; |
| new_state &= ~DISPATCH_MACH_STATE_UNLOCK_MASK; |
| } |
| }); |
| } |
| |
| out: |
| if (old_state & DISPATCH_MACH_STATE_RECEIVED_OVERRIDE) { |
| // Ensure that the root queue sees that this thread was overridden. |
| _dispatch_set_basepri_override_qos(_dmsr_state_max_qos(old_state)); |
| } |
| |
| if (unlikely(new_state & DISPATCH_MACH_STATE_UNLOCK_MASK)) { |
| qos = _dmsr_state_max_qos(new_state); |
| os_atomic_thread_fence(dependency); |
| dmsr = os_atomic_force_dependency_on(dmsr, new_state); |
| goto again; |
| } |
| |
| if (new_state & DISPATCH_MACH_STATE_PENDING_BARRIER) { |
| qos = _dmsr_state_max_qos(new_state); |
| _dispatch_mach_push_send_barrier_drain(dm, qos); |
| } else { |
| if (needs_mgr || dm->dm_needs_mgr) { |
| qos = _dmsr_state_max_qos(new_state); |
| } else { |
| qos = 0; |
| } |
| if (!disconnecting) dx_wakeup(dm, qos, DISPATCH_WAKEUP_MAKE_DIRTY); |
| } |
| return returning_send_result; |
| } |
| |
| DISPATCH_NOINLINE |
| static void |
| _dispatch_mach_send_invoke(dispatch_mach_t dm, dispatch_invoke_flags_t flags, |
| dispatch_mach_send_invoke_flags_t send_flags) |
| { |
| dispatch_mach_send_refs_t dmsr = dm->dm_send_refs; |
| dispatch_lock owner_self = _dispatch_lock_value_for_self(); |
| uint64_t old_state, new_state; |
| |
| uint64_t canlock_mask = DISPATCH_MACH_STATE_UNLOCK_MASK; |
| uint64_t canlock_state = 0; |
| |
| if (send_flags & DM_SEND_INVOKE_NEEDS_BARRIER) { |
| canlock_mask |= DISPATCH_MACH_STATE_PENDING_BARRIER; |
| canlock_state = DISPATCH_MACH_STATE_PENDING_BARRIER; |
| } else if (!(send_flags & DM_SEND_INVOKE_CAN_RUN_BARRIER)) { |
| canlock_mask |= DISPATCH_MACH_STATE_PENDING_BARRIER; |
| } |
| |
| dispatch_qos_t oq_floor = _dispatch_get_basepri_override_qos_floor(); |
| retry: |
| os_atomic_rmw_loop2o(dmsr, dmsr_state, old_state, new_state, acquire, { |
| new_state = old_state; |
| if (unlikely((old_state & canlock_mask) != canlock_state)) { |
| if (!(send_flags & DM_SEND_INVOKE_MAKE_DIRTY)) { |
| os_atomic_rmw_loop_give_up(break); |
| } |
| new_state |= DISPATCH_MACH_STATE_DIRTY; |
| } else { |
| if (_dmsr_state_needs_lock_override(old_state, oq_floor)) { |
| os_atomic_rmw_loop_give_up({ |
| oq_floor = _dispatch_queue_override_self(old_state); |
| goto retry; |
| }); |
| } |
| new_state |= owner_self; |
| new_state &= ~DISPATCH_MACH_STATE_DIRTY; |
| new_state &= ~DISPATCH_MACH_STATE_RECEIVED_OVERRIDE; |
| new_state &= ~DISPATCH_MACH_STATE_PENDING_BARRIER; |
| } |
| }); |
| |
| if (unlikely((old_state & canlock_mask) != canlock_state)) { |
| return; |
| } |
| if (send_flags & DM_SEND_INVOKE_CANCEL) { |
| _dispatch_mach_cancel(dm); |
| } |
| _dispatch_mach_send_drain(dm, flags, send_flags); |
| } |
| |
| DISPATCH_NOINLINE |
| void |
| _dispatch_mach_send_barrier_drain_invoke(dispatch_continuation_t dc, |
| DISPATCH_UNUSED dispatch_invoke_context_t dic, |
| dispatch_invoke_flags_t flags) |
| { |
| dispatch_mach_t dm = (dispatch_mach_t)_dispatch_queue_get_current(); |
| uintptr_t dc_flags = DISPATCH_OBJ_CONSUME_BIT; |
| dispatch_thread_frame_s dtf; |
| |
| DISPATCH_COMPILER_CAN_ASSUME(dc->dc_priority == DISPATCH_NO_PRIORITY); |
| DISPATCH_COMPILER_CAN_ASSUME(dc->dc_voucher == DISPATCH_NO_VOUCHER); |
| // hide the mach channel (see _dispatch_mach_barrier_invoke comment) |
| _dispatch_thread_frame_stash(&dtf); |
| _dispatch_continuation_pop_forwarded(dc, DISPATCH_NO_VOUCHER, dc_flags,{ |
| _dispatch_mach_send_invoke(dm, flags, |
| DM_SEND_INVOKE_NEEDS_BARRIER | DM_SEND_INVOKE_CAN_RUN_BARRIER); |
| }); |
| _dispatch_thread_frame_unstash(&dtf); |
| } |
| |
| DISPATCH_NOINLINE |
| static void |
| _dispatch_mach_push_send_barrier_drain(dispatch_mach_t dm, dispatch_qos_t qos) |
| { |
| dispatch_continuation_t dc = _dispatch_continuation_alloc(); |
| |
| dc->do_vtable = DC_VTABLE(MACH_SEND_BARRRIER_DRAIN); |
| dc->dc_func = NULL; |
| dc->dc_ctxt = NULL; |
| dc->dc_voucher = DISPATCH_NO_VOUCHER; |
| dc->dc_priority = DISPATCH_NO_PRIORITY; |
| dm_push(dm, dc, qos); |
| } |
| |
| DISPATCH_NOINLINE |
| static void |
| _dispatch_mach_send_push(dispatch_mach_t dm, dispatch_continuation_t dc, |
| dispatch_qos_t qos) |
| { |
| dispatch_mach_send_refs_t dmsr = dm->dm_send_refs; |
| uint64_t old_state, new_state, state_flags = 0; |
| dispatch_tid owner; |
| bool wakeup; |
| |
| // <rdar://problem/25896179> when pushing a send barrier that destroys |
| // the last reference to this channel, and the send queue is already |
| // draining on another thread, the send barrier may run as soon as |
| // _dispatch_mach_send_push_inline() returns. |
| _dispatch_retain_2(dm); |
| |
| wakeup = _dispatch_mach_send_push_inline(dmsr, dc); |
| if (wakeup) { |
| state_flags = DISPATCH_MACH_STATE_DIRTY; |
| if (dc->do_vtable == DC_VTABLE(MACH_SEND_BARRIER)) { |
| state_flags |= DISPATCH_MACH_STATE_PENDING_BARRIER; |
| } |
| } |
| |
| if (state_flags) { |
| os_atomic_rmw_loop2o(dmsr, dmsr_state, old_state, new_state, release, { |
| new_state = _dmsr_state_merge_override(old_state, qos); |
| new_state |= state_flags; |
| }); |
| } else { |
| os_atomic_rmw_loop2o(dmsr, dmsr_state, old_state, new_state, relaxed, { |
| new_state = _dmsr_state_merge_override(old_state, qos); |
| if (old_state == new_state) { |
| os_atomic_rmw_loop_give_up(break); |
| } |
| }); |
| } |
| |
| qos = _dmsr_state_max_qos(new_state); |
| owner = _dispatch_lock_owner((dispatch_lock)old_state); |
| if (owner) { |
| if (_dmsr_state_needs_override(old_state, qos)) { |
| _dispatch_wqthread_override_start_check_owner(owner, qos, |
| &dmsr->dmsr_state_lock.dul_lock); |
| } |
| return _dispatch_release_2_tailcall(dm); |
| } |
| |
| dispatch_wakeup_flags_t wflags = 0; |
| if (state_flags & DISPATCH_MACH_STATE_PENDING_BARRIER) { |
| _dispatch_mach_push_send_barrier_drain(dm, qos); |
| } else if (wakeup || dmsr->dmsr_disconnect_cnt || |
| (dm->dq_atomic_flags & DSF_CANCELED)) { |
| wflags = DISPATCH_WAKEUP_MAKE_DIRTY | DISPATCH_WAKEUP_CONSUME_2; |
| } else if (old_state & DISPATCH_MACH_STATE_PENDING_BARRIER) { |
| wflags = DISPATCH_WAKEUP_CONSUME_2; |
| } |
| if (wflags) { |
| return dx_wakeup(dm, qos, wflags); |
| } |
| return _dispatch_release_2_tailcall(dm); |
| } |
| |
| DISPATCH_NOINLINE |
| static bool |
| _dispatch_mach_send_push_and_trydrain(dispatch_mach_t dm, |
| dispatch_object_t dou, dispatch_qos_t qos, |
| dispatch_mach_send_invoke_flags_t send_flags) |
| { |
| dispatch_mach_send_refs_t dmsr = dm->dm_send_refs; |
| dispatch_lock owner_self = _dispatch_lock_value_for_self(); |
| uint64_t old_state, new_state, canlock_mask, state_flags = 0; |
| dispatch_tid owner; |
| |
| bool wakeup = _dispatch_mach_send_push_inline(dmsr, dou); |
| if (wakeup) { |
| state_flags = DISPATCH_MACH_STATE_DIRTY; |
| } |
| |
| if (unlikely(dmsr->dmsr_disconnect_cnt || |
| (dm->dq_atomic_flags & DSF_CANCELED))) { |
| os_atomic_rmw_loop2o(dmsr, dmsr_state, old_state, new_state, release, { |
| new_state = _dmsr_state_merge_override(old_state, qos); |
| new_state |= state_flags; |
| }); |
| dx_wakeup(dm, qos, DISPATCH_WAKEUP_MAKE_DIRTY); |
| return false; |
| } |
| |
| canlock_mask = DISPATCH_MACH_STATE_UNLOCK_MASK | |
| DISPATCH_MACH_STATE_PENDING_BARRIER; |
| if (state_flags) { |
| os_atomic_rmw_loop2o(dmsr, dmsr_state, old_state, new_state, seq_cst, { |
| new_state = _dmsr_state_merge_override(old_state, qos); |
| new_state |= state_flags; |
| if (likely((old_state & canlock_mask) == 0)) { |
| new_state |= owner_self; |
| new_state &= ~DISPATCH_MACH_STATE_DIRTY; |
| new_state &= ~DISPATCH_MACH_STATE_RECEIVED_OVERRIDE; |
| new_state &= ~DISPATCH_MACH_STATE_PENDING_BARRIER; |
| } |
| }); |
| } else { |
| os_atomic_rmw_loop2o(dmsr, dmsr_state, old_state, new_state, acquire, { |
| new_state = _dmsr_state_merge_override(old_state, qos); |
| if (new_state == old_state) { |
| os_atomic_rmw_loop_give_up(return false); |
| } |
| if (likely((old_state & canlock_mask) == 0)) { |
| new_state |= owner_self; |
| new_state &= ~DISPATCH_MACH_STATE_DIRTY; |
| new_state &= ~DISPATCH_MACH_STATE_RECEIVED_OVERRIDE; |
| new_state &= ~DISPATCH_MACH_STATE_PENDING_BARRIER; |
| } |
| }); |
| } |
| |
| owner = _dispatch_lock_owner((dispatch_lock)old_state); |
| if (owner) { |
| if (_dmsr_state_needs_override(old_state, qos)) { |
| _dispatch_wqthread_override_start_check_owner(owner, qos, |
| &dmsr->dmsr_state_lock.dul_lock); |
| } |
| return false; |
| } |
| |
| if (old_state & DISPATCH_MACH_STATE_PENDING_BARRIER) { |
| dx_wakeup(dm, qos, 0); |
| return false; |
| } |
| |
| // Ensure our message is still at the head of the queue and has not already |
| // been dequeued by another thread that raced us to the send queue lock. |
| // A plain load of the head and comparison against our object pointer is |
| // sufficient. |
| if (unlikely(!(wakeup && dou._do == dmsr->dmsr_head))) { |
| // Don't request immediate send result for messages we don't own |
| send_flags &= ~DM_SEND_INVOKE_IMMEDIATE_SEND_MASK; |
| } |
| return _dispatch_mach_send_drain(dm, DISPATCH_INVOKE_NONE, send_flags); |
| } |
| |
| #pragma mark - |
| #pragma mark dispatch_mach |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_mach_notification_kevent_unregister(dispatch_mach_t dm) |
| { |
| DISPATCH_ASSERT_ON_MANAGER_QUEUE(); |
| if (_dispatch_unote_registered(dm->dm_send_refs)) { |
| dispatch_assume(_dispatch_unote_unregister(dm->dm_send_refs, 0)); |
| } |
| dm->dm_send_refs->du_ident = 0; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_mach_notification_kevent_register(dispatch_mach_t dm,mach_port_t send) |
| { |
| DISPATCH_ASSERT_ON_MANAGER_QUEUE(); |
| dm->dm_send_refs->du_ident = send; |
| dispatch_assume(_dispatch_unote_register(dm->dm_send_refs, |
| DISPATCH_WLH_ANON, 0)); |
| } |
| |
| void |
| _dispatch_mach_merge_notification(dispatch_unote_t du, |
| uint32_t flags DISPATCH_UNUSED, uintptr_t data, |
| uintptr_t status DISPATCH_UNUSED, |
| pthread_priority_t pp DISPATCH_UNUSED) |
| { |
| dispatch_mach_send_refs_t dmsr = du._dmsr; |
| dispatch_mach_t dm = _dispatch_wref2ptr(dmsr->du_owner_wref); |
| |
| if (data & dmsr->du_fflags) { |
| _dispatch_mach_send_invoke(dm, DISPATCH_INVOKE_MANAGER_DRAIN, |
| DM_SEND_INVOKE_MAKE_DIRTY); |
| } |
| } |
| |
| DISPATCH_NOINLINE |
| static void |
| _dispatch_mach_handle_or_push_received_msg(dispatch_mach_t dm, |
| dispatch_mach_msg_t dmsg) |
| { |
| mach_error_t error; |
| dispatch_mach_reason_t reason = _dispatch_mach_msg_get_reason(dmsg, &error); |
| if (reason == DISPATCH_MACH_MESSAGE_RECEIVED || !dm->dm_is_xpc || |
| !_dispatch_mach_xpc_hooks->dmxh_direct_message_handler( |
| dm->dm_recv_refs->dmrr_handler_ctxt, reason, dmsg, error)) { |
| // Not XPC client or not a message that XPC can handle inline - push |
| // it onto the channel queue. |
| dm_push(dm, dmsg, _dispatch_qos_from_pp(dmsg->dmsg_priority)); |
| } else { |
| // XPC handled the message inline. Do the cleanup that would otherwise |
| // have happened in _dispatch_mach_msg_invoke(), leaving out steps that |
| // are not required in this context. |
| dmsg->do_next = DISPATCH_OBJECT_LISTLESS; |
| dispatch_release(dmsg); |
| } |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static void |
| _dispatch_mach_push_async_reply_msg(dispatch_mach_t dm, |
| dispatch_mach_msg_t dmsg, dispatch_queue_t drq) { |
| // Push the message onto the given queue. This function is only used for |
| // replies to messages sent by |
| // dispatch_mach_send_with_result_and_async_reply_4libxpc(). |
| dispatch_continuation_t dc = _dispatch_mach_msg_async_reply_wrap(dmsg, dm); |
| _dispatch_trace_continuation_push(drq, dc); |
| dx_push(drq, dc, _dispatch_qos_from_pp(dmsg->dmsg_priority)); |
| } |
| |
| #pragma mark - |
| #pragma mark dispatch_mach_t |
| |
| static inline mach_msg_option_t |
| _dispatch_mach_checkin_options(void) |
| { |
| mach_msg_option_t options = 0; |
| #if DISPATCH_USE_CHECKIN_NOIMPORTANCE |
| options = MACH_SEND_NOIMPORTANCE; // <rdar://problem/16996737> |
| #endif |
| return options; |
| } |
| |
| |
| static inline mach_msg_option_t |
| _dispatch_mach_send_options(void) |
| { |
| mach_msg_option_t options = 0; |
| return options; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_qos_t |
| _dispatch_mach_priority_propagate(mach_msg_option_t options, |
| pthread_priority_t *msg_pp) |
| { |
| #if DISPATCH_USE_NOIMPORTANCE_QOS |
| if (options & MACH_SEND_NOIMPORTANCE) { |
| *msg_pp = 0; |
| return 0; |
| } |
| #endif |
| unsigned int flags = DISPATCH_PRIORITY_PROPAGATE_CURRENT; |
| if ((options & DISPATCH_MACH_WAIT_FOR_REPLY) && |
| (options & DISPATCH_MACH_OWNED_REPLY_PORT) && |
| _dispatch_use_mach_special_reply_port()) { |
| flags |= DISPATCH_PRIORITY_PROPAGATE_FOR_SYNC_IPC; |
| } |
| *msg_pp = _dispatch_priority_compute_propagated(0, flags); |
| // TODO: remove QoS contribution of sync IPC messages to send queue |
| // rdar://31848737 |
| return _dispatch_qos_from_pp(*msg_pp); |
| } |
| |
| DISPATCH_NOINLINE |
| static bool |
| _dispatch_mach_send_msg(dispatch_mach_t dm, dispatch_mach_msg_t dmsg, |
| dispatch_continuation_t dc_wait, mach_msg_option_t options) |
| { |
| dispatch_mach_send_refs_t dmsr = dm->dm_send_refs; |
| if (slowpath(dmsg->do_next != DISPATCH_OBJECT_LISTLESS)) { |
| DISPATCH_CLIENT_CRASH(dmsg->do_next, "Message already enqueued"); |
| } |
| dispatch_retain(dmsg); |
| pthread_priority_t msg_pp; |
| dispatch_qos_t qos = _dispatch_mach_priority_propagate(options, &msg_pp); |
| options |= _dispatch_mach_send_options(); |
| dmsg->dmsg_options = options; |
| mach_msg_header_t *msg = _dispatch_mach_msg_get_msg(dmsg); |
| dmsg->dmsg_reply = _dispatch_mach_msg_get_reply_port(dmsg); |
| bool is_reply = (MACH_MSGH_BITS_REMOTE(msg->msgh_bits) == |
| MACH_MSG_TYPE_MOVE_SEND_ONCE); |
| dmsg->dmsg_priority = msg_pp; |
| dmsg->dmsg_voucher = _voucher_copy(); |
| _dispatch_voucher_debug("mach-msg[%p] set", dmsg->dmsg_voucher, dmsg); |
| |
| uint32_t send_status; |
| bool returning_send_result = false; |
| dispatch_mach_send_invoke_flags_t send_flags = DM_SEND_INVOKE_NONE; |
| if (options & DISPATCH_MACH_RETURN_IMMEDIATE_SEND_RESULT) { |
| send_flags = DM_SEND_INVOKE_IMMEDIATE_SEND; |
| } |
| if (is_reply && !dmsg->dmsg_reply && !dmsr->dmsr_disconnect_cnt && |
| !(dm->dq_atomic_flags & DSF_CANCELED)) { |
| // replies are sent to a send-once right and don't need the send queue |
| dispatch_assert(!dc_wait); |
| send_status = _dispatch_mach_msg_send(dm, dmsg, NULL, 0, send_flags); |
| dispatch_assert(send_status); |
| returning_send_result = !!(send_status & |
| DM_SEND_STATUS_RETURNING_IMMEDIATE_SEND_RESULT); |
| } else { |
| _dispatch_voucher_ktrace_dmsg_push(dmsg); |
| dispatch_object_t dou = { ._dmsg = dmsg }; |
| if (dc_wait) dou._dc = dc_wait; |
| returning_send_result = _dispatch_mach_send_push_and_trydrain(dm, dou, |
| qos, send_flags); |
| } |
| if (returning_send_result) { |
| _dispatch_voucher_debug("mach-msg[%p] clear", dmsg->dmsg_voucher, dmsg); |
| if (dmsg->dmsg_voucher) _voucher_release(dmsg->dmsg_voucher); |
| dmsg->dmsg_voucher = NULL; |
| dmsg->do_next = DISPATCH_OBJECT_LISTLESS; |
| dispatch_release(dmsg); |
| } |
| return returning_send_result; |
| } |
| |
| DISPATCH_NOINLINE |
| void |
| dispatch_mach_send(dispatch_mach_t dm, dispatch_mach_msg_t dmsg, |
| mach_msg_option_t options) |
| { |
| dispatch_assert_zero(options & DISPATCH_MACH_OPTIONS_MASK); |
| options &= ~DISPATCH_MACH_OPTIONS_MASK; |
| bool returned_send_result = _dispatch_mach_send_msg(dm, dmsg, NULL,options); |
| dispatch_assert(!returned_send_result); |
| } |
| |
| DISPATCH_NOINLINE |
| void |
| dispatch_mach_send_with_result(dispatch_mach_t dm, dispatch_mach_msg_t dmsg, |
| mach_msg_option_t options, dispatch_mach_send_flags_t send_flags, |
| dispatch_mach_reason_t *send_result, mach_error_t *send_error) |
| { |
| if (unlikely(send_flags != DISPATCH_MACH_SEND_DEFAULT)) { |
| DISPATCH_CLIENT_CRASH(send_flags, "Invalid send flags"); |
| } |
| dispatch_assert_zero(options & DISPATCH_MACH_OPTIONS_MASK); |
| options &= ~DISPATCH_MACH_OPTIONS_MASK; |
| options |= DISPATCH_MACH_RETURN_IMMEDIATE_SEND_RESULT; |
| bool returned_send_result = _dispatch_mach_send_msg(dm, dmsg, NULL,options); |
| unsigned long reason = DISPATCH_MACH_NEEDS_DEFERRED_SEND; |
| mach_error_t err = 0; |
| if (returned_send_result) { |
| reason = _dispatch_mach_msg_get_reason(dmsg, &err); |
| } |
| *send_result = reason; |
| *send_error = err; |
| } |
| |
| static inline |
| dispatch_mach_msg_t |
| _dispatch_mach_send_and_wait_for_reply(dispatch_mach_t dm, |
| dispatch_mach_msg_t dmsg, mach_msg_option_t options, |
| bool *returned_send_result) |
| { |
| mach_port_t send = MACH_PORT_NULL; |
| mach_port_t reply_port = _dispatch_mach_msg_get_reply_port(dmsg); |
| if (!reply_port) { |
| // use per-thread mach reply port <rdar://24597802> |
| reply_port = _dispatch_get_thread_reply_port(); |
| mach_msg_header_t *hdr = _dispatch_mach_msg_get_msg(dmsg); |
| dispatch_assert(MACH_MSGH_BITS_LOCAL(hdr->msgh_bits) == |
| MACH_MSG_TYPE_MAKE_SEND_ONCE); |
| hdr->msgh_local_port = reply_port; |
| options |= DISPATCH_MACH_OWNED_REPLY_PORT; |
| } |
| options |= DISPATCH_MACH_WAIT_FOR_REPLY; |
| |
| dispatch_mach_reply_refs_t dmr; |
| #if DISPATCH_DEBUG |
| dmr = _dispatch_calloc(1, sizeof(*dmr)); |
| #else |
| struct dispatch_mach_reply_refs_s dmr_buf = { }; |
| dmr = &dmr_buf; |
| #endif |
| struct dispatch_continuation_s dc_wait = { |
| .dc_flags = DISPATCH_OBJ_SYNC_WAITER_BIT, |
| .dc_data = dmsg, |
| .dc_other = dmr, |
| .dc_priority = DISPATCH_NO_PRIORITY, |
| .dc_voucher = DISPATCH_NO_VOUCHER, |
| }; |
| dmr->dmr_ctxt = dmsg->do_ctxt; |
| dmr->dmr_waiter_tid = _dispatch_tid_self(); |
| *returned_send_result = _dispatch_mach_send_msg(dm, dmsg, &dc_wait,options); |
| if (options & DISPATCH_MACH_OWNED_REPLY_PORT) { |
| _dispatch_clear_thread_reply_port(reply_port); |
| if (_dispatch_use_mach_special_reply_port()) { |
| // link special reply port to send right for remote receive right |
| // TODO: extend to pre-connect phase <rdar://problem/31823384> |
| send = dm->dm_send_refs->dmsr_send; |
| } |
| } |
| dmsg = _dispatch_mach_msg_reply_recv(dm, dmr, reply_port, send); |
| #if DISPATCH_DEBUG |
| free(dmr); |
| #endif |
| return dmsg; |
| } |
| |
| DISPATCH_NOINLINE |
| dispatch_mach_msg_t |
| dispatch_mach_send_and_wait_for_reply(dispatch_mach_t dm, |
| dispatch_mach_msg_t dmsg, mach_msg_option_t options) |
| { |
| bool returned_send_result; |
| dispatch_mach_msg_t reply; |
| dispatch_assert_zero(options & DISPATCH_MACH_OPTIONS_MASK); |
| options &= ~DISPATCH_MACH_OPTIONS_MASK; |
| reply = _dispatch_mach_send_and_wait_for_reply(dm, dmsg, options, |
| &returned_send_result); |
| dispatch_assert(!returned_send_result); |
| return reply; |
| } |
| |
| DISPATCH_NOINLINE |
| dispatch_mach_msg_t |
| dispatch_mach_send_with_result_and_wait_for_reply(dispatch_mach_t dm, |
| dispatch_mach_msg_t dmsg, mach_msg_option_t options, |
| dispatch_mach_send_flags_t send_flags, |
| dispatch_mach_reason_t *send_result, mach_error_t *send_error) |
| { |
| if (unlikely(send_flags != DISPATCH_MACH_SEND_DEFAULT)) { |
| DISPATCH_CLIENT_CRASH(send_flags, "Invalid send flags"); |
| } |
| bool returned_send_result; |
| dispatch_mach_msg_t reply; |
| dispatch_assert_zero(options & DISPATCH_MACH_OPTIONS_MASK); |
| options &= ~DISPATCH_MACH_OPTIONS_MASK; |
| options |= DISPATCH_MACH_RETURN_IMMEDIATE_SEND_RESULT; |
| reply = _dispatch_mach_send_and_wait_for_reply(dm, dmsg, options, |
| &returned_send_result); |
| unsigned long reason = DISPATCH_MACH_NEEDS_DEFERRED_SEND; |
| mach_error_t err = 0; |
| if (returned_send_result) { |
| reason = _dispatch_mach_msg_get_reason(dmsg, &err); |
| } |
| *send_result = reason; |
| *send_error = err; |
| return reply; |
| } |
| |
| DISPATCH_NOINLINE |
| void |
| dispatch_mach_send_with_result_and_async_reply_4libxpc(dispatch_mach_t dm, |
| dispatch_mach_msg_t dmsg, mach_msg_option_t options, |
| dispatch_mach_send_flags_t send_flags, |
| dispatch_mach_reason_t *send_result, mach_error_t *send_error) |
| { |
| if (unlikely(send_flags != DISPATCH_MACH_SEND_DEFAULT)) { |
| DISPATCH_CLIENT_CRASH(send_flags, "Invalid send flags"); |
| } |
| if (unlikely(!dm->dm_is_xpc)) { |
| DISPATCH_CLIENT_CRASH(0, |
| "dispatch_mach_send_with_result_and_wait_for_reply is XPC only"); |
| } |
| |
| dispatch_assert_zero(options & DISPATCH_MACH_OPTIONS_MASK); |
| options &= ~DISPATCH_MACH_OPTIONS_MASK; |
| options |= DISPATCH_MACH_RETURN_IMMEDIATE_SEND_RESULT; |
| mach_port_t reply_port = _dispatch_mach_msg_get_reply_port(dmsg); |
| if (!reply_port) { |
| DISPATCH_CLIENT_CRASH(0, "Reply port needed for async send with reply"); |
| } |
| options |= DISPATCH_MACH_ASYNC_REPLY; |
| bool returned_send_result = _dispatch_mach_send_msg(dm, dmsg, NULL,options); |
| unsigned long reason = DISPATCH_MACH_NEEDS_DEFERRED_SEND; |
| mach_error_t err = 0; |
| if (returned_send_result) { |
| reason = _dispatch_mach_msg_get_reason(dmsg, &err); |
| } |
| *send_result = reason; |
| *send_error = err; |
| } |
| |
| DISPATCH_NOINLINE |
| static bool |
| _dispatch_mach_disconnect(dispatch_mach_t dm) |
| { |
| dispatch_mach_send_refs_t dmsr = dm->dm_send_refs; |
| bool disconnected; |
| if (_dispatch_unote_registered(dmsr)) { |
| _dispatch_mach_notification_kevent_unregister(dm); |
| } |
| if (MACH_PORT_VALID(dmsr->dmsr_send)) { |
| _dispatch_mach_msg_disconnected(dm, MACH_PORT_NULL, dmsr->dmsr_send); |
| dmsr->dmsr_send = MACH_PORT_NULL; |
| } |
| if (dmsr->dmsr_checkin) { |
| _dispatch_mach_msg_not_sent(dm, dmsr->dmsr_checkin); |
| dmsr->dmsr_checkin = NULL; |
| } |
| _dispatch_unfair_lock_lock(&dm->dm_send_refs->dmsr_replies_lock); |
| dispatch_mach_reply_refs_t dmr, tmp; |
| TAILQ_FOREACH_SAFE(dmr, &dm->dm_send_refs->dmsr_replies, dmr_list, tmp) { |
| TAILQ_REMOVE(&dm->dm_send_refs->dmsr_replies, dmr, dmr_list); |
| _TAILQ_MARK_NOT_ENQUEUED(dmr, dmr_list); |
| if (_dispatch_unote_registered(dmr)) { |
| if (!_dispatch_mach_reply_kevent_unregister(dm, dmr, |
| DU_UNREGISTER_DISCONNECTED)) { |
| TAILQ_INSERT_HEAD(&dm->dm_send_refs->dmsr_replies, dmr, |
| dmr_list); |
| } |
| } else { |
| _dispatch_mach_reply_waiter_unregister(dm, dmr, |
| DU_UNREGISTER_DISCONNECTED); |
| } |
| } |
| disconnected = TAILQ_EMPTY(&dm->dm_send_refs->dmsr_replies); |
| _dispatch_unfair_lock_unlock(&dm->dm_send_refs->dmsr_replies_lock); |
| return disconnected; |
| } |
| |
| static void |
| _dispatch_mach_cancel(dispatch_mach_t dm) |
| { |
| _dispatch_object_debug(dm, "%s", __func__); |
| if (!_dispatch_mach_disconnect(dm)) return; |
| |
| bool uninstalled = true; |
| dispatch_assert(!dm->dm_uninstalled); |
| |
| if (dm->dm_xpc_term_refs) { |
| uninstalled = _dispatch_unote_unregister(dm->dm_xpc_term_refs, 0); |
| } |
| |
| dispatch_mach_recv_refs_t dmrr = dm->dm_recv_refs; |
| mach_port_t local_port = (mach_port_t)dmrr->du_ident; |
| if (local_port) { |
| // handle the deferred delete case properly, similar to what |
| // _dispatch_source_invoke2() does |
| dispatch_queue_flags_t dqf = _dispatch_queue_atomic_flags(dm->_as_dq); |
| if ((dqf & DSF_DEFERRED_DELETE) && !(dqf & DSF_ARMED)) { |
| _dispatch_source_refs_unregister(dm->_as_ds, |
| DU_UNREGISTER_IMMEDIATE_DELETE); |
| dqf = _dispatch_queue_atomic_flags(dm->_as_dq); |
| } else if (!(dqf & DSF_DEFERRED_DELETE) && !(dqf & DSF_DELETED)) { |
| _dispatch_source_refs_unregister(dm->_as_ds, 0); |
| dqf = _dispatch_queue_atomic_flags(dm->_as_dq); |
| } |
| if ((dqf & DSF_STATE_MASK) == DSF_DELETED) { |
| _dispatch_mach_msg_disconnected(dm, local_port, MACH_PORT_NULL); |
| dmrr->du_ident = 0; |
| } else { |
| uninstalled = false; |
| } |
| } else { |
| _dispatch_queue_atomic_flags_set_and_clear(dm->_as_dq, DSF_DELETED, |
| DSF_ARMED | DSF_DEFERRED_DELETE); |
| } |
| |
| if (dm->dm_send_refs->dmsr_disconnect_cnt) { |
| uninstalled = false; // <rdar://problem/31233110> |
| } |
| if (uninstalled) dm->dm_uninstalled = uninstalled; |
| } |
| |
| DISPATCH_NOINLINE |
| static bool |
| _dispatch_mach_reconnect_invoke(dispatch_mach_t dm, dispatch_object_t dou) |
| { |
| if (!_dispatch_mach_disconnect(dm)) return false; |
| dispatch_mach_send_refs_t dmsr = dm->dm_send_refs; |
| dmsr->dmsr_checkin = dou._dc->dc_data; |
| dmsr->dmsr_send = (mach_port_t)dou._dc->dc_other; |
| _dispatch_continuation_free(dou._dc); |
| (void)os_atomic_dec2o(dmsr, dmsr_disconnect_cnt, relaxed); |
| _dispatch_object_debug(dm, "%s", __func__); |
| _dispatch_release(dm); // <rdar://problem/26266265> |
| return true; |
| } |
| |
| DISPATCH_NOINLINE |
| void |
| dispatch_mach_reconnect(dispatch_mach_t dm, mach_port_t send, |
| dispatch_mach_msg_t checkin) |
| { |
| dispatch_mach_send_refs_t dmsr = dm->dm_send_refs; |
| (void)os_atomic_inc2o(dmsr, dmsr_disconnect_cnt, relaxed); |
| if (MACH_PORT_VALID(send) && checkin) { |
| dispatch_mach_msg_t dmsg = checkin; |
| dispatch_retain(dmsg); |
| dmsg->dmsg_options = _dispatch_mach_checkin_options(); |
| dmsr->dmsr_checkin_port = _dispatch_mach_msg_get_remote_port(dmsg); |
| } else { |
| checkin = NULL; |
| dmsr->dmsr_checkin_port = MACH_PORT_NULL; |
| } |
| dispatch_continuation_t dc = _dispatch_continuation_alloc(); |
| dc->dc_flags = DISPATCH_OBJ_CONSUME_BIT; |
| // actually called manually in _dispatch_mach_send_drain |
| dc->dc_func = (void*)_dispatch_mach_reconnect_invoke; |
| dc->dc_ctxt = dc; |
| dc->dc_data = checkin; |
| dc->dc_other = (void*)(uintptr_t)send; |
| dc->dc_voucher = DISPATCH_NO_VOUCHER; |
| dc->dc_priority = DISPATCH_NO_PRIORITY; |
| _dispatch_retain(dm); // <rdar://problem/26266265> |
| return _dispatch_mach_send_push(dm, dc, 0); |
| } |
| |
| DISPATCH_NOINLINE |
| mach_port_t |
| dispatch_mach_get_checkin_port(dispatch_mach_t dm) |
| { |
| dispatch_mach_send_refs_t dmsr = dm->dm_send_refs; |
| if (slowpath(dm->dq_atomic_flags & DSF_CANCELED)) { |
| return MACH_PORT_DEAD; |
| } |
| return dmsr->dmsr_checkin_port; |
| } |
| |
| DISPATCH_NOINLINE |
| static void |
| _dispatch_mach_connect_invoke(dispatch_mach_t dm) |
| { |
| dispatch_mach_recv_refs_t dmrr = dm->dm_recv_refs; |
| _dispatch_client_callout4(dmrr->dmrr_handler_ctxt, |
| DISPATCH_MACH_CONNECTED, NULL, 0, dmrr->dmrr_handler_func); |
| dm->dm_connect_handler_called = 1; |
| _dispatch_perfmon_workitem_inc(); |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static void |
| _dispatch_mach_msg_invoke_with_mach(dispatch_mach_msg_t dmsg, |
| dispatch_invoke_flags_t flags, dispatch_mach_t dm) |
| { |
| dispatch_mach_recv_refs_t dmrr; |
| mach_error_t err; |
| unsigned long reason = _dispatch_mach_msg_get_reason(dmsg, &err); |
| dispatch_thread_set_self_t adopt_flags = DISPATCH_PRIORITY_ENFORCE| |
| DISPATCH_VOUCHER_CONSUME|DISPATCH_VOUCHER_REPLACE; |
| |
| dmrr = dm->dm_recv_refs; |
| dmsg->do_next = DISPATCH_OBJECT_LISTLESS; |
| _dispatch_voucher_ktrace_dmsg_pop(dmsg); |
| _dispatch_voucher_debug("mach-msg[%p] adopt", dmsg->dmsg_voucher, dmsg); |
| (void)_dispatch_adopt_priority_and_set_voucher(dmsg->dmsg_priority, |
| dmsg->dmsg_voucher, adopt_flags); |
| dmsg->dmsg_voucher = NULL; |
| dispatch_invoke_with_autoreleasepool(flags, { |
| if (flags & DISPATCH_INVOKE_ASYNC_REPLY) { |
| _dispatch_client_callout3(dmrr->dmrr_handler_ctxt, reason, dmsg, |
| _dispatch_mach_xpc_hooks->dmxh_async_reply_handler); |
| } else { |
| if (slowpath(!dm->dm_connect_handler_called)) { |
| _dispatch_mach_connect_invoke(dm); |
| } |
| if (reason == DISPATCH_MACH_MESSAGE_RECEIVED && |
| (_dispatch_queue_atomic_flags(dm->_as_dq) & DSF_CANCELED)) { |
| // <rdar://problem/32184699> Do not deliver message received |
| // after cancellation: _dispatch_mach_merge_msg can be preempted |
| // for a long time between clearing DSF_ARMED but before |
| // enqueuing the message, allowing for cancellation to complete, |
| // and then the message event to be delivered. |
| // |
| // This makes XPC unhappy because some of these messages are |
| // port-destroyed notifications that can cause it to try to |
| // reconnect on a channel that is almost fully canceled |
| } else { |
| _dispatch_client_callout4(dmrr->dmrr_handler_ctxt, reason, dmsg, |
| err, dmrr->dmrr_handler_func); |
| } |
| } |
| _dispatch_perfmon_workitem_inc(); |
| }); |
| _dispatch_introspection_queue_item_complete(dmsg); |
| dispatch_release(dmsg); |
| } |
| |
| DISPATCH_NOINLINE |
| void |
| _dispatch_mach_msg_invoke(dispatch_mach_msg_t dmsg, |
| DISPATCH_UNUSED dispatch_invoke_context_t dic, |
| dispatch_invoke_flags_t flags) |
| { |
| dispatch_thread_frame_s dtf; |
| |
| // hide mach channel |
| dispatch_mach_t dm = (dispatch_mach_t)_dispatch_thread_frame_stash(&dtf); |
| _dispatch_mach_msg_invoke_with_mach(dmsg, flags, dm); |
| _dispatch_thread_frame_unstash(&dtf); |
| } |
| |
| DISPATCH_NOINLINE |
| void |
| _dispatch_mach_barrier_invoke(dispatch_continuation_t dc, |
| DISPATCH_UNUSED dispatch_invoke_context_t dic, |
| dispatch_invoke_flags_t flags) |
| { |
| dispatch_thread_frame_s dtf; |
| dispatch_mach_t dm = dc->dc_other; |
| dispatch_mach_recv_refs_t dmrr; |
| uintptr_t dc_flags = (uintptr_t)dc->dc_data; |
| unsigned long type = dc_type(dc); |
| |
| // hide mach channel from clients |
| if (type == DISPATCH_CONTINUATION_TYPE(MACH_RECV_BARRIER)) { |
| // on the send queue, the mach channel isn't the current queue |
| // its target queue is the current one already |
| _dispatch_thread_frame_stash(&dtf); |
| } |
| dmrr = dm->dm_recv_refs; |
| DISPATCH_COMPILER_CAN_ASSUME(dc_flags & DISPATCH_OBJ_CONSUME_BIT); |
| _dispatch_continuation_pop_forwarded(dc, DISPATCH_NO_VOUCHER, dc_flags, { |
| dispatch_invoke_with_autoreleasepool(flags, { |
| if (slowpath(!dm->dm_connect_handler_called)) { |
| _dispatch_mach_connect_invoke(dm); |
| } |
| _dispatch_client_callout(dc->dc_ctxt, dc->dc_func); |
| _dispatch_client_callout4(dmrr->dmrr_handler_ctxt, |
| DISPATCH_MACH_BARRIER_COMPLETED, NULL, 0, |
| dmrr->dmrr_handler_func); |
| }); |
| }); |
| if (type == DISPATCH_CONTINUATION_TYPE(MACH_RECV_BARRIER)) { |
| _dispatch_thread_frame_unstash(&dtf); |
| } |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline void |
| _dispatch_mach_barrier_set_vtable(dispatch_continuation_t dc, |
| dispatch_mach_t dm, dispatch_continuation_vtable_t vtable) |
| { |
| dc->dc_data = (void *)dc->dc_flags; |
| dc->dc_other = dm; |
| dc->do_vtable = vtable; // Must be after dc_flags load, dc_vtable aliases |
| } |
| |
| DISPATCH_NOINLINE |
| void |
| dispatch_mach_send_barrier_f(dispatch_mach_t dm, void *context, |
| dispatch_function_t func) |
| { |
| dispatch_continuation_t dc = _dispatch_continuation_alloc(); |
| uintptr_t dc_flags = DISPATCH_OBJ_CONSUME_BIT | DISPATCH_OBJ_MACH_BARRIER; |
| dispatch_qos_t qos; |
| |
| _dispatch_continuation_init_f(dc, dm, context, func, 0, 0, dc_flags); |
| _dispatch_mach_barrier_set_vtable(dc, dm, DC_VTABLE(MACH_SEND_BARRIER)); |
| _dispatch_trace_continuation_push(dm->_as_dq, dc); |
| qos = _dispatch_continuation_override_qos(dm->_as_dq, dc); |
| return _dispatch_mach_send_push(dm, dc, qos); |
| } |
| |
| DISPATCH_NOINLINE |
| void |
| dispatch_mach_send_barrier(dispatch_mach_t dm, dispatch_block_t barrier) |
| { |
| dispatch_continuation_t dc = _dispatch_continuation_alloc(); |
| uintptr_t dc_flags = DISPATCH_OBJ_CONSUME_BIT | DISPATCH_OBJ_MACH_BARRIER; |
| dispatch_qos_t qos; |
| |
| _dispatch_continuation_init(dc, dm, barrier, 0, 0, dc_flags); |
| _dispatch_mach_barrier_set_vtable(dc, dm, DC_VTABLE(MACH_SEND_BARRIER)); |
| _dispatch_trace_continuation_push(dm->_as_dq, dc); |
| qos = _dispatch_continuation_override_qos(dm->_as_dq, dc); |
| return _dispatch_mach_send_push(dm, dc, qos); |
| } |
| |
| DISPATCH_NOINLINE |
| void |
| dispatch_mach_receive_barrier_f(dispatch_mach_t dm, void *context, |
| dispatch_function_t func) |
| { |
| dispatch_continuation_t dc = _dispatch_continuation_alloc(); |
| uintptr_t dc_flags = DISPATCH_OBJ_CONSUME_BIT | DISPATCH_OBJ_MACH_BARRIER; |
| |
| _dispatch_continuation_init_f(dc, dm, context, func, 0, 0, dc_flags); |
| _dispatch_mach_barrier_set_vtable(dc, dm, DC_VTABLE(MACH_RECV_BARRIER)); |
| return _dispatch_continuation_async(dm->_as_dq, dc); |
| } |
| |
| DISPATCH_NOINLINE |
| void |
| dispatch_mach_receive_barrier(dispatch_mach_t dm, dispatch_block_t barrier) |
| { |
| dispatch_continuation_t dc = _dispatch_continuation_alloc(); |
| uintptr_t dc_flags = DISPATCH_OBJ_CONSUME_BIT | DISPATCH_OBJ_MACH_BARRIER; |
| |
| _dispatch_continuation_init(dc, dm, barrier, 0, 0, dc_flags); |
| _dispatch_mach_barrier_set_vtable(dc, dm, DC_VTABLE(MACH_RECV_BARRIER)); |
| return _dispatch_continuation_async(dm->_as_dq, dc); |
| } |
| |
| DISPATCH_NOINLINE |
| static void |
| _dispatch_mach_cancel_invoke(dispatch_mach_t dm, dispatch_invoke_flags_t flags) |
| { |
| dispatch_mach_recv_refs_t dmrr = dm->dm_recv_refs; |
| |
| dispatch_invoke_with_autoreleasepool(flags, { |
| if (slowpath(!dm->dm_connect_handler_called)) { |
| _dispatch_mach_connect_invoke(dm); |
| } |
| _dispatch_client_callout4(dmrr->dmrr_handler_ctxt, |
| DISPATCH_MACH_CANCELED, NULL, 0, dmrr->dmrr_handler_func); |
| _dispatch_perfmon_workitem_inc(); |
| }); |
| dm->dm_cancel_handler_called = 1; |
| _dispatch_release(dm); // the retain is done at creation time |
| } |
| |
| DISPATCH_NOINLINE |
| void |
| dispatch_mach_cancel(dispatch_mach_t dm) |
| { |
| dispatch_source_cancel(dm->_as_ds); |
| } |
| |
| static void |
| _dispatch_mach_install(dispatch_mach_t dm, dispatch_wlh_t wlh, |
| dispatch_priority_t pri) |
| { |
| dispatch_mach_recv_refs_t dmrr = dm->dm_recv_refs; |
| uint32_t disconnect_cnt; |
| |
| if (dmrr->du_ident) { |
| _dispatch_source_refs_register(dm->_as_ds, wlh, pri); |
| dispatch_assert(dmrr->du_is_direct); |
| } |
| |
| if (dm->dm_is_xpc) { |
| bool monitor_sigterm; |
| if (_dispatch_mach_xpc_hooks->version < 3) { |
| monitor_sigterm = true; |
| } else if (!_dispatch_mach_xpc_hooks->dmxh_enable_sigterm_notification){ |
| monitor_sigterm = true; |
| } else { |
| monitor_sigterm = |
| _dispatch_mach_xpc_hooks->dmxh_enable_sigterm_notification( |
| dm->dm_recv_refs->dmrr_handler_ctxt); |
| } |
| if (monitor_sigterm) { |
| dispatch_xpc_term_refs_t _dxtr = |
| dux_create(&_dispatch_xpc_type_sigterm, SIGTERM, 0)._dxtr; |
| _dxtr->du_owner_wref = _dispatch_ptr2wref(dm); |
| dm->dm_xpc_term_refs = _dxtr; |
| _dispatch_unote_register(dm->dm_xpc_term_refs, wlh, pri); |
| } |
| } |
| if (!dm->dq_priority) { |
| // _dispatch_mach_reply_kevent_register assumes this has been done |
| // which is unlike regular sources or queues, the DEFAULTQUEUE flag |
| // is used so that the priority of the channel doesn't act as |
| // a QoS floor for incoming messages (26761457) |
| dm->dq_priority = pri; |
| } |
| dm->ds_is_installed = true; |
| if (unlikely(!os_atomic_cmpxchgv2o(dm->dm_send_refs, dmsr_disconnect_cnt, |
| DISPATCH_MACH_NEVER_INSTALLED, 0, &disconnect_cnt, release))) { |
| DISPATCH_INTERNAL_CRASH(disconnect_cnt, "Channel already installed"); |
| } |
| } |
| |
| void |
| _dispatch_mach_finalize_activation(dispatch_mach_t dm, bool *allow_resume) |
| { |
| dispatch_priority_t pri; |
| dispatch_wlh_t wlh; |
| |
| // call "super" |
| _dispatch_queue_finalize_activation(dm->_as_dq, allow_resume); |
| |
| if (!dm->ds_is_installed) { |
| pri = _dispatch_queue_compute_priority_and_wlh(dm->_as_dq, &wlh); |
| if (pri) _dispatch_mach_install(dm, wlh, pri); |
| } |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline bool |
| _dispatch_mach_tryarm(dispatch_mach_t dm, dispatch_queue_flags_t *out_dqf) |
| { |
| dispatch_queue_flags_t oqf, nqf; |
| bool rc = os_atomic_rmw_loop2o(dm, dq_atomic_flags, oqf, nqf, relaxed, { |
| nqf = oqf; |
| if (nqf & (DSF_ARMED | DSF_CANCELED | DSF_DEFERRED_DELETE | |
| DSF_DELETED)) { |
| // the test is inside the loop because it's convenient but the |
| // result should not change for the duration of the rmw_loop |
| os_atomic_rmw_loop_give_up(break); |
| } |
| nqf |= DSF_ARMED; |
| }); |
| if (out_dqf) *out_dqf = nqf; |
| return rc; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static inline dispatch_queue_wakeup_target_t |
| _dispatch_mach_invoke2(dispatch_object_t dou, |
| dispatch_invoke_context_t dic, dispatch_invoke_flags_t flags, |
| uint64_t *owned) |
| { |
| dispatch_mach_t dm = dou._dm; |
| dispatch_queue_wakeup_target_t retq = NULL; |
| dispatch_queue_t dq = _dispatch_queue_get_current(); |
| dispatch_mach_send_refs_t dmsr = dm->dm_send_refs; |
| dispatch_mach_recv_refs_t dmrr = dm->dm_recv_refs; |
| dispatch_queue_flags_t dqf = 0; |
| |
| if (!(flags & DISPATCH_INVOKE_MANAGER_DRAIN) && dmrr && |
| _dispatch_unote_wlh_changed(dmrr, _dispatch_get_wlh())) { |
| dqf = _dispatch_queue_atomic_flags_set_orig(dm->_as_dq, |
| DSF_WLH_CHANGED); |
| if (!(dqf & DSF_WLH_CHANGED)) { |
| if (dm->dm_is_xpc) { |
| _dispatch_bug_deprecated("Changing target queue " |
| "hierarchy after xpc connection was activated"); |
| } else { |
| _dispatch_bug_deprecated("Changing target queue " |
| "hierarchy after mach channel was activated"); |
| } |
| } |
| } |
| |
| // This function performs all mach channel actions. Each action is |
| // responsible for verifying that it takes place on the appropriate queue. |
| // If the current queue is not the correct queue for this action, the |
| // correct queue will be returned and the invoke will be re-driven on that |
| // queue. |
| |
| // The order of tests here in invoke and in wakeup should be consistent. |
| |
| if (unlikely(!dm->ds_is_installed)) { |
| // The channel needs to be installed on the kevent queue. |
| if (unlikely(flags & DISPATCH_INVOKE_MANAGER_DRAIN)) { |
| return dm->do_targetq; |
| } |
| _dispatch_mach_install(dm, _dispatch_get_wlh(),_dispatch_get_basepri()); |
| _dispatch_perfmon_workitem_inc(); |
| } |
| |
| if (_dispatch_queue_class_probe(dm)) { |
| if (dq == dm->do_targetq) { |
| drain: |
| retq = _dispatch_queue_serial_drain(dm->_as_dq, dic, flags, owned); |
| } else { |
| retq = dm->do_targetq; |
| } |
| } |
| |
| if (!retq && _dispatch_unote_registered(dmrr)) { |
| if (_dispatch_mach_tryarm(dm, &dqf)) { |
| _dispatch_unote_resume(dmrr); |
| if (dq == dm->do_targetq && !dq->do_targetq && !dmsr->dmsr_tail && |
| (dq->dq_priority & DISPATCH_PRIORITY_FLAG_OVERCOMMIT) && |
| _dispatch_wlh_should_poll_unote(dmrr)) { |
| // try to redrive the drain from under the lock for channels |
| // targeting an overcommit root queue to avoid parking |
| // when the next message has already fired |
| _dispatch_event_loop_drain(KEVENT_FLAG_IMMEDIATE); |
| if (dm->dq_items_tail) goto drain; |
| } |
| } |
| } else { |
| dqf = _dispatch_queue_atomic_flags(dm->_as_dq); |
| } |
| |
| if (dmsr->dmsr_tail) { |
| bool requires_mgr = dm->dm_needs_mgr || (dmsr->dmsr_disconnect_cnt && |
| _dispatch_unote_registered(dmsr)); |
| if (!os_atomic_load2o(dmsr, dmsr_notification_armed, relaxed) || |
| (dqf & DSF_CANCELED) || dmsr->dmsr_disconnect_cnt) { |
| // The channel has pending messages to send. |
| if (unlikely(requires_mgr && dq != &_dispatch_mgr_q)) { |
| return retq ? retq : &_dispatch_mgr_q; |
| } |
| dispatch_mach_send_invoke_flags_t send_flags = DM_SEND_INVOKE_NONE; |
| if (dq != &_dispatch_mgr_q) { |
| send_flags |= DM_SEND_INVOKE_CAN_RUN_BARRIER; |
| } |
| _dispatch_mach_send_invoke(dm, flags, send_flags); |
| } |
| if (!retq) retq = DISPATCH_QUEUE_WAKEUP_WAIT_FOR_EVENT; |
| } else if (!retq && (dqf & DSF_CANCELED)) { |
| // The channel has been cancelled and needs to be uninstalled from the |
| // manager queue. After uninstallation, the cancellation handler needs |
| // to be delivered to the target queue. |
| if (!dm->dm_uninstalled) { |
| if ((dqf & DSF_STATE_MASK) == (DSF_ARMED | DSF_DEFERRED_DELETE)) { |
| // waiting for the delivery of a deferred delete event |
| return retq ? retq : DISPATCH_QUEUE_WAKEUP_WAIT_FOR_EVENT; |
| } |
| if (dq != &_dispatch_mgr_q) { |
| return retq ? retq : &_dispatch_mgr_q; |
| } |
| _dispatch_mach_send_invoke(dm, flags, DM_SEND_INVOKE_CANCEL); |
| if (unlikely(!dm->dm_uninstalled)) { |
| // waiting for the delivery of a deferred delete event |
| // or deletion didn't happen because send_invoke couldn't |
| // acquire the send lock |
| return retq ? retq : DISPATCH_QUEUE_WAKEUP_WAIT_FOR_EVENT; |
| } |
| } |
| if (!dm->dm_cancel_handler_called) { |
| if (dq != dm->do_targetq) { |
| return retq ? retq : dm->do_targetq; |
| } |
| _dispatch_mach_cancel_invoke(dm, flags); |
| } |
| } |
| |
| return retq; |
| } |
| |
| DISPATCH_NOINLINE |
| void |
| _dispatch_mach_invoke(dispatch_mach_t dm, |
| dispatch_invoke_context_t dic, dispatch_invoke_flags_t flags) |
| { |
| _dispatch_queue_class_invoke(dm, dic, flags, |
| DISPATCH_INVOKE_DISALLOW_SYNC_WAITERS, _dispatch_mach_invoke2); |
| } |
| |
| void |
| _dispatch_mach_wakeup(dispatch_mach_t dm, dispatch_qos_t qos, |
| dispatch_wakeup_flags_t flags) |
| { |
| // This function determines whether the mach channel needs to be invoked. |
| // The order of tests here in probe and in invoke should be consistent. |
| |
| dispatch_mach_send_refs_t dmsr = dm->dm_send_refs; |
| dispatch_queue_wakeup_target_t tq = DISPATCH_QUEUE_WAKEUP_NONE; |
| dispatch_queue_flags_t dqf = _dispatch_queue_atomic_flags(dm->_as_dq); |
| |
| if (!dm->ds_is_installed) { |
| // The channel needs to be installed on the kevent queue. |
| tq = DISPATCH_QUEUE_WAKEUP_TARGET; |
| goto done; |
| } |
| |
| if (_dispatch_queue_class_probe(dm)) { |
| tq = DISPATCH_QUEUE_WAKEUP_TARGET; |
| goto done; |
| } |
| |
| if (_dispatch_lock_is_locked(dmsr->dmsr_state_lock.dul_lock)) { |
| // Sending and uninstallation below require the send lock, the channel |
| // will be woken up when the lock is dropped <rdar://15132939&15203957> |
| goto done; |
| } |
| |
| if (dmsr->dmsr_tail) { |
| bool requires_mgr = dm->dm_needs_mgr || (dmsr->dmsr_disconnect_cnt && |
| _dispatch_unote_registered(dmsr)); |
| if (!os_atomic_load2o(dmsr, dmsr_notification_armed, relaxed) || |
| (dqf & DSF_CANCELED) || dmsr->dmsr_disconnect_cnt) { |
| if (unlikely(requires_mgr)) { |
| tq = DISPATCH_QUEUE_WAKEUP_MGR; |
| } else { |
| tq = DISPATCH_QUEUE_WAKEUP_TARGET; |
| } |
| } |
| } else if (dqf & DSF_CANCELED) { |
| if (!dm->dm_uninstalled) { |
| if ((dqf & DSF_STATE_MASK) == (DSF_ARMED | DSF_DEFERRED_DELETE)) { |
| // waiting for the delivery of a deferred delete event |
| } else { |
| // The channel needs to be uninstalled from the manager queue |
| tq = DISPATCH_QUEUE_WAKEUP_MGR; |
| } |
| } else if (!dm->dm_cancel_handler_called) { |
| // the cancellation handler needs to be delivered to the target |
| // queue. |
| tq = DISPATCH_QUEUE_WAKEUP_TARGET; |
| } |
| } |
| |
| done: |
| if ((tq == DISPATCH_QUEUE_WAKEUP_TARGET) && |
| dm->do_targetq == &_dispatch_mgr_q) { |
| tq = DISPATCH_QUEUE_WAKEUP_MGR; |
| } |
| |
| return _dispatch_queue_class_wakeup(dm->_as_dq, qos, flags, tq); |
| } |
| |
| static void |
| _dispatch_mach_sigterm_invoke(void *ctx) |
| { |
| dispatch_mach_t dm = ctx; |
| if (!(dm->dq_atomic_flags & DSF_CANCELED)) { |
| dispatch_mach_recv_refs_t dmrr = dm->dm_recv_refs; |
| _dispatch_client_callout4(dmrr->dmrr_handler_ctxt, |
| DISPATCH_MACH_SIGTERM_RECEIVED, NULL, 0, |
| dmrr->dmrr_handler_func); |
| } |
| } |
| |
| void |
| _dispatch_xpc_sigterm_merge(dispatch_unote_t du, |
| uint32_t flags DISPATCH_UNUSED, uintptr_t data DISPATCH_UNUSED, |
| uintptr_t status DISPATCH_UNUSED, pthread_priority_t pp) |
| { |
| dispatch_mach_t dm = _dispatch_wref2ptr(du._du->du_owner_wref); |
| uint32_t options = 0; |
| if ((flags & EV_UDATA_SPECIFIC) && (flags & EV_ONESHOT) && |
| !(flags & EV_DELETE)) { |
| options = DU_UNREGISTER_IMMEDIATE_DELETE; |
| } else { |
| dispatch_assert((flags & EV_ONESHOT) && (flags & EV_DELETE)); |
| options = DU_UNREGISTER_ALREADY_DELETED; |
| } |
| _dispatch_unote_unregister(du, options); |
| |
| if (!(dm->dq_atomic_flags & DSF_CANCELED)) { |
| _dispatch_barrier_async_detached_f(dm->_as_dq, dm, |
| _dispatch_mach_sigterm_invoke); |
| } else { |
| dx_wakeup(dm, _dispatch_qos_from_pp(pp), DISPATCH_WAKEUP_MAKE_DIRTY); |
| } |
| } |
| |
| #pragma mark - |
| #pragma mark dispatch_mach_msg_t |
| |
| dispatch_mach_msg_t |
| dispatch_mach_msg_create(mach_msg_header_t *msg, size_t size, |
| dispatch_mach_msg_destructor_t destructor, mach_msg_header_t **msg_ptr) |
| { |
| if (slowpath(size < sizeof(mach_msg_header_t)) || |
| slowpath(destructor && !msg)) { |
| DISPATCH_CLIENT_CRASH(size, "Empty message"); |
| } |
| |
| dispatch_mach_msg_t dmsg; |
| size_t msg_size = sizeof(struct dispatch_mach_msg_s); |
| if (!destructor && os_add_overflow(msg_size, |
| (size - sizeof(dmsg->dmsg_msg)), &msg_size)) { |
| DISPATCH_CLIENT_CRASH(size, "Message size too large"); |
| } |
| |
| dmsg = _dispatch_object_alloc(DISPATCH_VTABLE(mach_msg), msg_size); |
| if (destructor) { |
| dmsg->dmsg_msg = msg; |
| } else if (msg) { |
| memcpy(dmsg->dmsg_buf, msg, size); |
| } |
| dmsg->do_next = DISPATCH_OBJECT_LISTLESS; |
| dmsg->do_targetq = _dispatch_get_root_queue(DISPATCH_QOS_DEFAULT, false); |
| dmsg->dmsg_destructor = destructor; |
| dmsg->dmsg_size = size; |
| if (msg_ptr) { |
| *msg_ptr = _dispatch_mach_msg_get_msg(dmsg); |
| } |
| return dmsg; |
| } |
| |
| void |
| _dispatch_mach_msg_dispose(dispatch_mach_msg_t dmsg, |
| DISPATCH_UNUSED bool *allow_free) |
| { |
| if (dmsg->dmsg_voucher) { |
| _voucher_release(dmsg->dmsg_voucher); |
| dmsg->dmsg_voucher = NULL; |
| } |
| switch (dmsg->dmsg_destructor) { |
| case DISPATCH_MACH_MSG_DESTRUCTOR_DEFAULT: |
| break; |
| case DISPATCH_MACH_MSG_DESTRUCTOR_FREE: |
| free(dmsg->dmsg_msg); |
| break; |
| case DISPATCH_MACH_MSG_DESTRUCTOR_VM_DEALLOCATE: { |
| mach_vm_size_t vm_size = dmsg->dmsg_size; |
| mach_vm_address_t vm_addr = (uintptr_t)dmsg->dmsg_msg; |
| (void)dispatch_assume_zero(mach_vm_deallocate(mach_task_self(), |
| vm_addr, vm_size)); |
| break; |
| }} |
| } |
| |
| static inline mach_msg_header_t* |
| _dispatch_mach_msg_get_msg(dispatch_mach_msg_t dmsg) |
| { |
| return dmsg->dmsg_destructor ? dmsg->dmsg_msg : |
| (mach_msg_header_t*)dmsg->dmsg_buf; |
| } |
| |
| mach_msg_header_t* |
| dispatch_mach_msg_get_msg(dispatch_mach_msg_t dmsg, size_t *size_ptr) |
| { |
| if (size_ptr) { |
| *size_ptr = dmsg->dmsg_size; |
| } |
| return _dispatch_mach_msg_get_msg(dmsg); |
| } |
| |
| size_t |
| _dispatch_mach_msg_debug(dispatch_mach_msg_t dmsg, char* buf, size_t bufsiz) |
| { |
| size_t offset = 0; |
| offset += dsnprintf(&buf[offset], bufsiz - offset, "%s[%p] = { ", |
| dx_kind(dmsg), dmsg); |
| offset += _dispatch_object_debug_attr(dmsg, buf + offset, bufsiz - offset); |
| offset += dsnprintf(&buf[offset], bufsiz - offset, "opts/err = 0x%x, " |
| "msgh[%p] = { ", dmsg->dmsg_options, dmsg->dmsg_buf); |
| mach_msg_header_t *hdr = _dispatch_mach_msg_get_msg(dmsg); |
| if (hdr->msgh_id) { |
| offset += dsnprintf(&buf[offset], bufsiz - offset, "id 0x%x, ", |
| hdr->msgh_id); |
| } |
| if (hdr->msgh_size) { |
| offset += dsnprintf(&buf[offset], bufsiz - offset, "size %u, ", |
| hdr->msgh_size); |
| } |
| if (hdr->msgh_bits) { |
| offset += dsnprintf(&buf[offset], bufsiz - offset, "bits <l %u, r %u", |
| MACH_MSGH_BITS_LOCAL(hdr->msgh_bits), |
| MACH_MSGH_BITS_REMOTE(hdr->msgh_bits)); |
| if (MACH_MSGH_BITS_OTHER(hdr->msgh_bits)) { |
| offset += dsnprintf(&buf[offset], bufsiz - offset, ", o 0x%x", |
| MACH_MSGH_BITS_OTHER(hdr->msgh_bits)); |
| } |
| offset += dsnprintf(&buf[offset], bufsiz - offset, ">, "); |
| } |
| if (hdr->msgh_local_port && hdr->msgh_remote_port) { |
| offset += dsnprintf(&buf[offset], bufsiz - offset, "local 0x%x, " |
| "remote 0x%x", hdr->msgh_local_port, hdr->msgh_remote_port); |
| } else if (hdr->msgh_local_port) { |
| offset += dsnprintf(&buf[offset], bufsiz - offset, "local 0x%x", |
| hdr->msgh_local_port); |
| } else if (hdr->msgh_remote_port) { |
| offset += dsnprintf(&buf[offset], bufsiz - offset, "remote 0x%x", |
| hdr->msgh_remote_port); |
| } else { |
| offset += dsnprintf(&buf[offset], bufsiz - offset, "no ports"); |
| } |
| offset += dsnprintf(&buf[offset], bufsiz - offset, " } }"); |
| return offset; |
| } |
| |
| DISPATCH_ALWAYS_INLINE |
| static dispatch_queue_t |
| _dispatch_mach_msg_context_async_reply_queue(void *msg_context) |
| { |
| if (DISPATCH_MACH_XPC_SUPPORTS_ASYNC_REPLIES(_dispatch_mach_xpc_hooks)) { |
| return _dispatch_mach_xpc_hooks->dmxh_msg_context_reply_queue( |
| msg_context); |
| } |
| return NULL; |
| } |
| |
| static dispatch_continuation_t |
| _dispatch_mach_msg_async_reply_wrap(dispatch_mach_msg_t dmsg, |
| dispatch_mach_t dm) |
| { |
| _dispatch_retain(dm); // Released in _dispatch_mach_msg_async_reply_invoke() |
| dispatch_continuation_t dc = _dispatch_continuation_alloc(); |
| dc->do_vtable = DC_VTABLE(MACH_ASYNC_REPLY); |
| dc->dc_data = dmsg; |
| dc->dc_other = dm; |
| dc->dc_priority = DISPATCH_NO_PRIORITY; |
| dc->dc_voucher = DISPATCH_NO_VOUCHER; |
| return dc; |
| } |
| |
| DISPATCH_NOINLINE |
| void |
| _dispatch_mach_msg_async_reply_invoke(dispatch_continuation_t dc, |
| DISPATCH_UNUSED dispatch_invoke_context_t dic, |
| dispatch_invoke_flags_t flags) |
| { |
| // _dispatch_mach_msg_invoke_with_mach() releases the reference on dmsg |
| // taken by _dispatch_mach_msg_async_reply_wrap() after handling it. |
| dispatch_mach_msg_t dmsg = dc->dc_data; |
| dispatch_mach_t dm = dc->dc_other; |
| _dispatch_mach_msg_invoke_with_mach(dmsg, |
| flags | DISPATCH_INVOKE_ASYNC_REPLY, dm); |
| |
| // Balances _dispatch_mach_msg_async_reply_wrap |
| _dispatch_release(dc->dc_other); |
| |
| _dispatch_continuation_free(dc); |
| } |
| |
| #pragma mark - |
| #pragma mark dispatch_mig_server |
| |
| mach_msg_return_t |
| dispatch_mig_server(dispatch_source_t ds, size_t maxmsgsz, |
| dispatch_mig_callback_t callback) |
| { |
| mach_msg_options_t options = MACH_RCV_MSG | MACH_RCV_TIMEOUT |
| | MACH_RCV_TRAILER_ELEMENTS(MACH_RCV_TRAILER_CTX) |
| | MACH_RCV_TRAILER_TYPE(MACH_MSG_TRAILER_FORMAT_0) | MACH_RCV_VOUCHER; |
| mach_msg_options_t tmp_options; |
| mig_reply_error_t *bufTemp, *bufRequest, *bufReply; |
| mach_msg_return_t kr = 0; |
| uint64_t assertion_token = 0; |
| uint32_t cnt = 1000; // do not stall out serial queues |
| boolean_t demux_success; |
| bool received = false; |
| size_t rcv_size = maxmsgsz + MAX_TRAILER_SIZE; |
| dispatch_source_refs_t dr = ds->ds_refs; |
| |
| bufRequest = alloca(rcv_size); |
| bufRequest->RetCode = 0; |
| for (mach_vm_address_t p = mach_vm_trunc_page(bufRequest + vm_page_size); |
| p < (mach_vm_address_t)bufRequest + rcv_size; p += vm_page_size) { |
| *(char*)p = 0; // ensure alloca buffer doesn't overlap with stack guard |
| } |
| |
| bufReply = alloca(rcv_size); |
| bufReply->Head.msgh_size = 0; |
| for (mach_vm_address_t p = mach_vm_trunc_page(bufReply + vm_page_size); |
| p < (mach_vm_address_t)bufReply + rcv_size; p += vm_page_size) { |
| *(char*)p = 0; // ensure alloca buffer doesn't overlap with stack guard |
| } |
| |
| #if DISPATCH_DEBUG |
| options |= MACH_RCV_LARGE; // rdar://problem/8422992 |
| #endif |
| tmp_options = options; |
| // XXX FIXME -- change this to not starve out the target queue |
| for (;;) { |
| if (DISPATCH_QUEUE_IS_SUSPENDED(ds) || (--cnt == 0)) { |
| options &= ~MACH_RCV_MSG; |
| tmp_options &= ~MACH_RCV_MSG; |
| |
| if (!(tmp_options & MACH_SEND_MSG)) { |
| goto out; |
| } |
| } |
| kr = mach_msg(&bufReply->Head, tmp_options, bufReply->Head.msgh_size, |
| (mach_msg_size_t)rcv_size, (mach_port_t)dr->du_ident, 0, 0); |
| |
| tmp_options = options; |
| |
| if (slowpath(kr)) { |
| switch (kr) { |
| case MACH_SEND_INVALID_DEST: |
| case MACH_SEND_TIMED_OUT: |
| if (bufReply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX) { |
| mach_msg_destroy(&bufReply->Head); |
| } |
| break; |
| case MACH_RCV_TIMED_OUT: |
| // Don't return an error if a message was sent this time or |
| // a message was successfully received previously |
| // rdar://problems/7363620&7791738 |
| if(bufReply->Head.msgh_remote_port || received) { |
| kr = MACH_MSG_SUCCESS; |
| } |
| break; |
| case MACH_RCV_INVALID_NAME: |
| break; |
| #if DISPATCH_DEBUG |
| case MACH_RCV_TOO_LARGE: |
| // receive messages that are too large and log their id and size |
| // rdar://problem/8422992 |
| tmp_options &= ~MACH_RCV_LARGE; |
| size_t large_size = bufReply->Head.msgh_size + MAX_TRAILER_SIZE; |
| void *large_buf = malloc(large_size); |
| if (large_buf) { |
| rcv_size = large_size; |
| bufReply = large_buf; |
| } |
| if (!mach_msg(&bufReply->Head, tmp_options, 0, |
| (mach_msg_size_t)rcv_size, |
| (mach_port_t)dr->du_ident, 0, 0)) { |
| _dispatch_log("BUG in libdispatch client: " |
| "dispatch_mig_server received message larger than " |
| "requested size %zd: id = 0x%x, size = %d", |
| maxmsgsz, bufReply->Head.msgh_id, |
| bufReply->Head.msgh_size); |
| } |
| if (large_buf) { |
| free(large_buf); |
| } |
| // fall through |
| #endif |
| default: |
| _dispatch_bug_mach_client( |
| "dispatch_mig_server: mach_msg() failed", kr); |
| break; |
| } |
| goto out; |
| } |
| |
| if (!(tmp_options & MACH_RCV_MSG)) { |
| goto out; |
| } |
| |
| if (assertion_token) { |
| #if DISPATCH_USE_IMPORTANCE_ASSERTION |
| int r = proc_importance_assertion_complete(assertion_token); |
| (void)dispatch_assume_zero(r); |
| #endif |
| assertion_token = 0; |
| } |
| received = true; |
| |
| bufTemp = bufRequest; |
| bufRequest = bufReply; |
| bufReply = bufTemp; |
| |
| #if DISPATCH_USE_IMPORTANCE_ASSERTION |
| #pragma clang diagnostic push |
| #pragma clang diagnostic ignored "-Wdeprecated-declarations" |
| int r = proc_importance_assertion_begin_with_msg(&bufRequest->Head, |
| NULL, &assertion_token); |
| if (r && slowpath(r != EIO)) { |
| (void)dispatch_assume_zero(r); |
| } |
| #pragma clang diagnostic pop |
| #endif |
| _voucher_replace(voucher_create_with_mach_msg(&bufRequest->Head)); |
| demux_success = callback(&bufRequest->Head, &bufReply->Head); |
| |
| if (!demux_success) { |
| // destroy the request - but not the reply port |
| bufRequest->Head.msgh_remote_port = 0; |
| mach_msg_destroy(&bufRequest->Head); |
| } else if (!(bufReply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX)) { |
| // if MACH_MSGH_BITS_COMPLEX is _not_ set, then bufReply->RetCode |
| // is present |
| if (slowpath(bufReply->RetCode)) { |
| if (bufReply->RetCode == MIG_NO_REPLY) { |
| continue; |
| } |
| |
| // destroy the request - but not the reply port |
| bufRequest->Head.msgh_remote_port = 0; |
| mach_msg_destroy(&bufRequest->Head); |
| } |
| } |
| |
| if (bufReply->Head.msgh_remote_port) { |
| tmp_options |= MACH_SEND_MSG; |
| if (MACH_MSGH_BITS_REMOTE(bufReply->Head.msgh_bits) != |
| MACH_MSG_TYPE_MOVE_SEND_ONCE) { |
| tmp_options |= MACH_SEND_TIMEOUT; |
| } |
| } |
| } |
| |
| out: |
| if (assertion_token) { |
| #if DISPATCH_USE_IMPORTANCE_ASSERTION |
| int r = proc_importance_assertion_complete(assertion_token); |
| (void)dispatch_assume_zero(r); |
| #endif |
| } |
| |
| return kr; |
| } |
| |
| #pragma mark - |
| #pragma mark dispatch_mach_debug |
| |
| static size_t |
| _dispatch_mach_debug_attr(dispatch_mach_t dm, char *buf, size_t bufsiz) |
| { |
| dispatch_queue_t target = dm->do_targetq; |
| dispatch_mach_send_refs_t dmsr = dm->dm_send_refs; |
| dispatch_mach_recv_refs_t dmrr = dm->dm_recv_refs; |
| |
| return dsnprintf(buf, bufsiz, "target = %s[%p], receive = 0x%x, " |
| "send = 0x%x, send-possible = 0x%x%s, checkin = 0x%x%s, " |
| "send state = %016llx, disconnected = %d, canceled = %d ", |
| target && target->dq_label ? target->dq_label : "", target, |
| (mach_port_t)dmrr->du_ident, dmsr->dmsr_send, |
| (mach_port_t)dmsr->du_ident, |
| dmsr->dmsr_notification_armed ? " (armed)" : "", |
| dmsr->dmsr_checkin_port, dmsr->dmsr_checkin ? " (pending)" : "", |
| dmsr->dmsr_state, dmsr->dmsr_disconnect_cnt, |
| (bool)(dm->dq_atomic_flags & DSF_CANCELED)); |
| } |
| |
| size_t |
| _dispatch_mach_debug(dispatch_mach_t dm, char* buf, size_t bufsiz) |
| { |
| size_t offset = 0; |
| offset += dsnprintf(&buf[offset], bufsiz - offset, "%s[%p] = { ", |
| dm->dq_label && !dm->dm_cancel_handler_called ? dm->dq_label : |
| dx_kind(dm), dm); |
| offset += _dispatch_object_debug_attr(dm, &buf[offset], bufsiz - offset); |
| offset += _dispatch_mach_debug_attr(dm, &buf[offset], bufsiz - offset); |
| offset += dsnprintf(&buf[offset], bufsiz - offset, "}"); |
| return offset; |
| } |
| |
| #endif /* HAVE_MACH */ |