src/source_internal.h

   1 /*
   2  * Copyright (c) 2008-2011 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_APACHE_LICENSE_HEADER_START@
   5  *
   6  * Licensed under the Apache License, Version 2.0 (the "License");
   7  * you may not use this file except in compliance with the License.
   8  * You may obtain a copy of the License at
   9  *
  10  *     http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  * Unless required by applicable law or agreed to in writing, software
  13  * distributed under the License is distributed on an "AS IS" BASIS,
  14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  * See the License for the specific language governing permissions and
  16  * limitations under the License.
  17  *
  18  * @APPLE_APACHE_LICENSE_HEADER_END@
  19  */
  20
  21 /*
  22  * IMPORTANT: This header file describes INTERNAL interfaces to libdispatch
  23  * which are subject to change in future releases of Mac OS X. Any applications
  24  * relying on these interfaces WILL break.
  25  */
  26
  27 #ifndef __DISPATCH_SOURCE_INTERNAL__
  28 #define __DISPATCH_SOURCE_INTERNAL__
  29
  30 #ifndef __DISPATCH_INDIRECT__
  31 #error "Please #include <dispatch/dispatch.h> instead of this file directly."
  32 #include <dispatch/base.h> // for HeaderDoc
  33 #endif
  34
  35 // NOTE: dispatch_source_mach_send_flags_t and dispatch_source_mach_recv_flags_t
  36 //       bit values must not overlap as they share the same kevent fflags !
  37
  38 /*!
  39  * @enum dispatch_source_mach_send_flags_t
  40  *
  41  * @constant DISPATCH_MACH_SEND_DELETED
  42  * Port-deleted notification. Disabled for source registration.
  43  */
  44 enum {
  45         DISPATCH_MACH_SEND_DELETED = 0x4,
  46 };
  47 /*!
  48  * @enum dispatch_source_mach_recv_flags_t
  49  *
  50  * @constant DISPATCH_MACH_RECV_MESSAGE
  51  * Receive right has pending messages
  52  *
  53  * @constant DISPATCH_MACH_RECV_NO_SENDERS
  54  * Receive right has no more senders. TODO <rdar://problem/8132399>
  55  */
  56 enum {
  57         DISPATCH_MACH_RECV_MESSAGE = 0x2,
  58         DISPATCH_MACH_RECV_NO_SENDERS = 0x10,
  59 };
  60
  61 enum {
  62         DISPATCH_TIMER_WALL_CLOCK = 0x4,
  63 };
  64
  65 #define DISPATCH_EVFILT_TIMER           (-EVFILT_SYSCOUNT - 1)
  66 #define DISPATCH_EVFILT_CUSTOM_ADD      (-EVFILT_SYSCOUNT - 2)
  67 #define DISPATCH_EVFILT_CUSTOM_OR       (-EVFILT_SYSCOUNT - 3)
  68 #define DISPATCH_EVFILT_SYSCOUNT        ( EVFILT_SYSCOUNT + 3)
  69
  70 #define DISPATCH_TIMER_INDEX_WALL       0
  71 #define DISPATCH_TIMER_INDEX_MACH       1
  72 #define DISPATCH_TIMER_INDEX_DISARM     2
  73
  74 struct dispatch_kevent_s {
  75         TAILQ_ENTRY(dispatch_kevent_s) dk_list;
  76         TAILQ_HEAD(, dispatch_source_refs_s) dk_sources;
  77         struct kevent dk_kevent;
  78 };
  79
  80 typedef struct dispatch_kevent_s *dispatch_kevent_t;
  81
  82 struct dispatch_source_type_s {
  83         struct kevent ke;
  84         uint64_t mask;
  85         void (*init)(dispatch_source_t ds, dispatch_source_type_t type,
  86                         uintptr_t handle, unsigned long mask, dispatch_queue_t q);
  87 };
  88
  89 struct dispatch_timer_source_s {
  90         uint64_t target;
  91         uint64_t last_fire;
  92         uint64_t interval;
  93         uint64_t leeway;
  94         uint64_t flags; // dispatch_timer_flags_t
  95         unsigned long missed;
  96 };
  97
  98 // Source state which may contain references to the source object
  99 // Separately allocated so that 'leaks' can see sources <rdar://problem/9050566>
 100 struct dispatch_source_refs_s {
 101         TAILQ_ENTRY(dispatch_source_refs_s) dr_list;
 102         uintptr_t dr_source_wref; // "weak" backref to dispatch_source_t
 103         dispatch_function_t ds_handler_func;
 104         void *ds_handler_ctxt;
 105         void *ds_cancel_handler;
 106         void *ds_registration_handler;
 107 };
 108
 109 typedef struct dispatch_source_refs_s *dispatch_source_refs_t;
 110
 111 struct dispatch_timer_source_refs_s {
 112         struct dispatch_source_refs_s _ds_refs;
 113         struct dispatch_timer_source_s _ds_timer;
 114 };
 115
 116 #define _dispatch_ptr2wref(ptr) (~(uintptr_t)(ptr))
 117 #define _dispatch_wref2ptr(ref) ((void*)~(ref))
 118 #define _dispatch_source_from_refs(dr) \
 119                 ((dispatch_source_t)_dispatch_wref2ptr((dr)->dr_source_wref))
 120 #define ds_timer(dr) \
 121                 (((struct dispatch_timer_source_refs_s *)(dr))->_ds_timer)
 122
 123 // ds_atomic_flags bits
 124 #define DSF_CANCELED 1u // cancellation has been requested
 125 #define DSF_ARMED 2u // source is armed
 126
 127 DISPATCH_CLASS_DECL(source);
 128 struct dispatch_source_s {
 129         DISPATCH_STRUCT_HEADER(source);
 130         DISPATCH_QUEUE_HEADER;
 131         // Instruments always copies DISPATCH_QUEUE_MIN_LABEL_SIZE, which is 64,
 132         // so the remainder of the structure must be big enough
 133         union {
 134                 char _ds_pad[DISPATCH_QUEUE_MIN_LABEL_SIZE];
 135                 struct {
 136                         char dq_label[8];
 137                         dispatch_kevent_t ds_dkev;
 138                         dispatch_source_refs_t ds_refs;
 139                         unsigned int ds_atomic_flags;
 140                         unsigned int
 141                                 ds_is_level:1,
 142                                 ds_is_adder:1,
 143                                 ds_is_installed:1,
 144                                 ds_needs_rearm:1,
 145                                 ds_is_timer:1,
 146                                 ds_cancel_is_block:1,
 147                                 ds_handler_is_block:1,
 148                                 ds_registration_is_block:1;
 149                         unsigned long ds_data;
 150                         unsigned long ds_pending_data;
 151                         unsigned long ds_pending_data_mask;
 152                         unsigned long ds_ident_hack;
 153                 };
 154         };
 155 };
 156
 157 void _dispatch_source_xref_dispose(dispatch_source_t ds);
 158 void _dispatch_mach_notify_source_init(void *context);
 159 dispatch_queue_t _dispatch_source_invoke(dispatch_source_t ds);
 160 void _dispatch_source_dispose(dispatch_source_t ds);
 161 bool _dispatch_source_probe(dispatch_source_t ds);
 162 size_t _dispatch_source_debug(dispatch_source_t ds, char* buf, size_t bufsiz);
 163
 164 #endif /* __DISPATCH_SOURCE_INTERNAL__ */