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_source_vtable_s {
  75         DISPATCH_VTABLE_HEADER(dispatch_source_s);
  76 };
  77
  78 extern const struct dispatch_source_vtable_s _dispatch_source_kevent_vtable;
  79
  80 struct dispatch_kevent_s {
  81         TAILQ_ENTRY(dispatch_kevent_s) dk_list;
  82         TAILQ_HEAD(, dispatch_source_refs_s) dk_sources;
  83         struct kevent dk_kevent;
  84 };
  85
  86 typedef struct dispatch_kevent_s *dispatch_kevent_t;
  87
  88 struct dispatch_source_type_s {
  89         struct kevent ke;
  90         uint64_t mask;
  91         void (*init)(dispatch_source_t ds, dispatch_source_type_t type,
  92                         uintptr_t handle, unsigned long mask, dispatch_queue_t q);
  93 };
  94
  95 struct dispatch_timer_source_s {
  96         uint64_t target;
  97         uint64_t last_fire;
  98         uint64_t interval;
  99         uint64_t leeway;
 100         uint64_t flags; // dispatch_timer_flags_t
 101         unsigned long missed;
 102 };
 103
 104 // Source state which may contain references to the source object
 105 // Separately allocated so that 'leaks' can see sources <rdar://problem/9050566>
 106 struct dispatch_source_refs_s {
 107         TAILQ_ENTRY(dispatch_source_refs_s) dr_list;
 108         uintptr_t dr_source_wref; // "weak" backref to dispatch_source_t
 109         dispatch_function_t ds_handler_func;
 110         void *ds_handler_ctxt;
 111         void *ds_cancel_handler;
 112         void *ds_registration_handler;
 113 };
 114
 115 typedef struct dispatch_source_refs_s *dispatch_source_refs_t;
 116
 117 struct dispatch_timer_source_refs_s {
 118         struct dispatch_source_refs_s _ds_refs;
 119         struct dispatch_timer_source_s _ds_timer;
 120 };
 121
 122 #define _dispatch_ptr2wref(ptr) (~(uintptr_t)(ptr))
 123 #define _dispatch_wref2ptr(ref) ((void*)~(ref))
 124 #define _dispatch_source_from_refs(dr) \
 125                 ((dispatch_source_t)_dispatch_wref2ptr((dr)->dr_source_wref))
 126 #define ds_timer(dr) \
 127                 (((struct dispatch_timer_source_refs_s *)(dr))->_ds_timer)
 128
 129 // ds_atomic_flags bits
 130 #define DSF_CANCELED 1u // cancellation has been requested
 131 #define DSF_ARMED 2u // source is armed
 132
 133 struct dispatch_source_s {
 134         DISPATCH_STRUCT_HEADER(dispatch_source_s, dispatch_source_vtable_s);
 135         DISPATCH_QUEUE_HEADER;
 136         // Instruments always copies DISPATCH_QUEUE_MIN_LABEL_SIZE, which is 64,
 137         // so the remainder of the structure must be big enough
 138         union {
 139                 char _ds_pad[DISPATCH_QUEUE_MIN_LABEL_SIZE];
 140                 struct {
 141                         char dq_label[8];
 142                         dispatch_kevent_t ds_dkev;
 143                         dispatch_source_refs_t ds_refs;
 144                         unsigned int ds_atomic_flags;
 145                         unsigned int
 146                                 ds_is_level:1,
 147                                 ds_is_adder:1,
 148                                 ds_is_installed:1,
 149                                 ds_needs_rearm:1,
 150                                 ds_is_timer:1,
 151                                 ds_cancel_is_block:1,
 152                                 ds_handler_is_block:1,
 153                                 ds_registration_is_block:1;
 154                         unsigned long ds_data;
 155                         unsigned long ds_pending_data;
 156                         unsigned long ds_pending_data_mask;
 157                         unsigned long ds_ident_hack;
 158                 };
 159         };
 160 };
 161
 162 void _dispatch_source_xref_release(dispatch_source_t ds);
 163 void _dispatch_mach_notify_source_init(void *context);
 164
 165 #endif /* __DISPATCH_SOURCE_INTERNAL__ */