src/source_internal.h

   1 /*
   2  * Copyright (c) 2008-2013 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 #define DISPATCH_EVFILT_TIMER           (-EVFILT_SYSCOUNT - 1)
  36 #define DISPATCH_EVFILT_CUSTOM_ADD      (-EVFILT_SYSCOUNT - 2)
  37 #define DISPATCH_EVFILT_CUSTOM_OR       (-EVFILT_SYSCOUNT - 3)
  38 #define DISPATCH_EVFILT_MACH_NOTIFICATION       (-EVFILT_SYSCOUNT - 4)
  39 #define DISPATCH_EVFILT_SYSCOUNT        ( EVFILT_SYSCOUNT + 4)
  40
  41 // NOTE: dispatch_source_mach_send_flags_t and dispatch_source_mach_recv_flags_t
  42 //       bit values must not overlap as they share the same kevent fflags !
  43
  44 /*!
  45  * @enum dispatch_source_mach_send_flags_t
  46  *
  47  * @constant DISPATCH_MACH_SEND_DELETED
  48  * Port-deleted notification. Disabled for source registration.
  49  */
  50 enum {
  51         DISPATCH_MACH_SEND_DELETED = 0x4,
  52 };
  53 /*!
  54  * @enum dispatch_source_mach_recv_flags_t
  55  *
  56  * @constant DISPATCH_MACH_RECV_MESSAGE
  57  * Receive right has pending messages
  58  *
  59  * @constant DISPATCH_MACH_RECV_MESSAGE_DIRECT
  60  * Receive messages from receive right directly via kevent64()
  61  *
  62  * @constant DISPATCH_MACH_RECV_NO_SENDERS
  63  * Receive right has no more senders. TODO <rdar://problem/8132399>
  64  */
  65 enum {
  66         DISPATCH_MACH_RECV_MESSAGE = 0x2,
  67         DISPATCH_MACH_RECV_MESSAGE_DIRECT = 0x10,
  68         DISPATCH_MACH_RECV_MESSAGE_DIRECT_ONCE = 0x20,
  69         DISPATCH_MACH_RECV_NO_SENDERS = 0x40,
  70 };
  71
  72 enum {
  73         DISPATCH_TIMER_WALL_CLOCK = 0x4,
  74         DISPATCH_TIMER_INTERVAL = 0x8,
  75         DISPATCH_TIMER_WITH_AGGREGATE = 0x10,
  76 };
  77
  78 // low bits are timer QoS class
  79 #define DISPATCH_TIMER_QOS_NORMAL 0u
  80 #define DISPATCH_TIMER_QOS_CRITICAL 1u
  81 #define DISPATCH_TIMER_QOS_BACKGROUND 2u
  82 #define DISPATCH_TIMER_QOS_COUNT (DISPATCH_TIMER_QOS_BACKGROUND + 1)
  83 #define DISPATCH_TIMER_QOS(tidx) ((uintptr_t)(tidx) & 0x3ul)
  84
  85 #define DISPATCH_TIMER_KIND_WALL 0u
  86 #define DISPATCH_TIMER_KIND_MACH 1u
  87 #define DISPATCH_TIMER_KIND_COUNT (DISPATCH_TIMER_KIND_MACH + 1)
  88 #define DISPATCH_TIMER_KIND(tidx) (((uintptr_t)(tidx) >> 2) & 0x1ul)
  89
  90 #define DISPATCH_TIMER_INDEX(kind, qos) (((kind) << 2) | (qos))
  91 #define DISPATCH_TIMER_INDEX_DISARM \
  92                 DISPATCH_TIMER_INDEX(DISPATCH_TIMER_KIND_COUNT, 0)
  93 #define DISPATCH_TIMER_INDEX_COUNT (DISPATCH_TIMER_INDEX_DISARM + 1)
  94 #define DISPATCH_TIMER_IDENT(flags) ({ unsigned long f = (flags); \
  95                 DISPATCH_TIMER_INDEX(f & DISPATCH_TIMER_WALL_CLOCK ? \
  96                 DISPATCH_TIMER_KIND_WALL : DISPATCH_TIMER_KIND_MACH, \
  97                 f & DISPATCH_TIMER_STRICT ? DISPATCH_TIMER_QOS_CRITICAL : \
  98                 f & DISPATCH_TIMER_BACKGROUND ? DISPATCH_TIMER_QOS_BACKGROUND : \
  99                 DISPATCH_TIMER_QOS_NORMAL); })
 100
 101 struct dispatch_kevent_s {
 102         TAILQ_ENTRY(dispatch_kevent_s) dk_list;
 103         TAILQ_HEAD(, dispatch_source_refs_s) dk_sources;
 104         struct kevent64_s dk_kevent;
 105 };
 106
 107 typedef struct dispatch_kevent_s *dispatch_kevent_t;
 108
 109 struct dispatch_source_type_s {
 110         struct kevent64_s ke;
 111         uint64_t mask;
 112         void (*init)(dispatch_source_t ds, dispatch_source_type_t type,
 113                         uintptr_t handle, unsigned long mask, dispatch_queue_t q);
 114 };
 115
 116 struct dispatch_timer_source_s {
 117         uint64_t target;
 118         uint64_t deadline;
 119         uint64_t last_fire;
 120         uint64_t interval;
 121         uint64_t leeway;
 122         unsigned long flags; // dispatch_timer_flags_t
 123         unsigned long missed;
 124 };
 125
 126 enum {
 127         DS_EVENT_HANDLER = 0,
 128         DS_CANCEL_HANDLER,
 129         DS_REGISTN_HANDLER,
 130 };
 131
 132 // Source state which may contain references to the source object
 133 // Separately allocated so that 'leaks' can see sources <rdar://problem/9050566>
 134 typedef struct dispatch_source_refs_s {
 135         TAILQ_ENTRY(dispatch_source_refs_s) dr_list;
 136         uintptr_t dr_source_wref; // "weak" backref to dispatch_source_t
 137         dispatch_continuation_t ds_handler[3];
 138 } *dispatch_source_refs_t;
 139
 140 typedef struct dispatch_timer_source_refs_s {
 141         struct dispatch_source_refs_s _ds_refs;
 142         struct dispatch_timer_source_s _ds_timer;
 143         TAILQ_ENTRY(dispatch_timer_source_refs_s) dt_list;
 144 } *dispatch_timer_source_refs_t;
 145
 146 typedef struct dispatch_timer_source_aggregate_refs_s {
 147         struct dispatch_timer_source_refs_s _dsa_refs;
 148         TAILQ_ENTRY(dispatch_timer_source_aggregate_refs_s) dra_list;
 149         TAILQ_ENTRY(dispatch_timer_source_aggregate_refs_s) dta_list;
 150 } *dispatch_timer_source_aggregate_refs_t;
 151
 152 #define _dispatch_ptr2wref(ptr) (~(uintptr_t)(ptr))
 153 #define _dispatch_wref2ptr(ref) ((void*)~(ref))
 154 #define _dispatch_source_from_refs(dr) \
 155                 ((dispatch_source_t)_dispatch_wref2ptr((dr)->dr_source_wref))
 156 #define ds_timer(dr) \
 157                 (((dispatch_timer_source_refs_t)(dr))->_ds_timer)
 158 #define ds_timer_aggregate(ds) \
 159                 ((dispatch_timer_aggregate_t)((ds)->dq_specific_q))
 160
 161 DISPATCH_ALWAYS_INLINE
 162 static inline unsigned int
 163 _dispatch_source_timer_idx(dispatch_source_refs_t dr)
 164 {
 165         return DISPATCH_TIMER_IDENT(ds_timer(dr).flags);
 166 }
 167
 168 // ds_atomic_flags bits
 169 #define DSF_CANCELED 1u // cancellation has been requested
 170 #define DSF_ARMED 2u // source is armed
 171
 172 #define DISPATCH_SOURCE_HEADER(refs) \
 173         dispatch_kevent_t ds_dkev; \
 174         dispatch_##refs##_refs_t ds_refs; \
 175         unsigned int ds_atomic_flags; \
 176         unsigned int \
 177                 ds_is_level:1, \
 178                 ds_is_adder:1, \
 179                 ds_is_installed:1, \
 180                 ds_needs_rearm:1, \
 181                 ds_is_timer:1, \
 182                 ds_vmpressure_override:1, \
 183                 ds_memorystatus_override:1, \
 184                 dm_handler_is_block:1, \
 185                 dm_connect_handler_called:1, \
 186                 dm_cancel_handler_called:1; \
 187         unsigned long ds_pending_data_mask;
 188
 189 DISPATCH_CLASS_DECL(source);
 190 struct dispatch_source_s {
 191         DISPATCH_STRUCT_HEADER(source);
 192         DISPATCH_QUEUE_HEADER;
 193         DISPATCH_SOURCE_HEADER(source);
 194         unsigned long ds_ident_hack;
 195         unsigned long ds_data;
 196         unsigned long ds_pending_data;
 197 };
 198
 199 // Mach channel state which may contain references to the channel object
 200 // layout must match dispatch_source_refs_s
 201 struct dispatch_mach_refs_s {
 202         TAILQ_ENTRY(dispatch_mach_refs_s) dr_list;
 203         uintptr_t dr_source_wref; // "weak" backref to dispatch_mach_t
 204         dispatch_mach_handler_function_t dm_handler_func;
 205         void *dm_handler_ctxt;
 206 };
 207 typedef struct dispatch_mach_refs_s *dispatch_mach_refs_t;
 208
 209 struct dispatch_mach_reply_refs_s {
 210         TAILQ_ENTRY(dispatch_mach_reply_refs_s) dr_list;
 211         uintptr_t dr_source_wref; // "weak" backref to dispatch_mach_t
 212         dispatch_kevent_t dmr_dkev;
 213         void *dmr_ctxt;
 214         pthread_priority_t dmr_priority;
 215         voucher_t dmr_voucher;
 216         TAILQ_ENTRY(dispatch_mach_reply_refs_s) dmr_list;
 217 };
 218 typedef struct dispatch_mach_reply_refs_s *dispatch_mach_reply_refs_t;
 219
 220 struct dispatch_mach_send_refs_s {
 221         TAILQ_ENTRY(dispatch_mach_send_refs_s) dr_list;
 222         uintptr_t dr_source_wref; // "weak" backref to dispatch_mach_t
 223         dispatch_mach_msg_t dm_checkin;
 224         TAILQ_HEAD(, dispatch_mach_reply_refs_s) dm_replies;
 225         uint32_t volatile dm_disconnect_cnt;
 226         uint32_t volatile dm_sending;
 227         unsigned int dm_needs_mgr:1;
 228         struct dispatch_object_s *volatile dm_tail;
 229         struct dispatch_object_s *volatile dm_head;
 230         mach_port_t dm_send, dm_checkin_port;
 231 };
 232 typedef struct dispatch_mach_send_refs_s *dispatch_mach_send_refs_t;
 233
 234 DISPATCH_CLASS_DECL(mach);
 235 struct dispatch_mach_s {
 236         DISPATCH_STRUCT_HEADER(mach);
 237         DISPATCH_QUEUE_HEADER;
 238         DISPATCH_SOURCE_HEADER(mach);
 239         dispatch_kevent_t dm_dkev;
 240         dispatch_mach_send_refs_t dm_refs;
 241 };
 242
 243 DISPATCH_CLASS_DECL(mach_msg);
 244 struct dispatch_mach_msg_s {
 245         DISPATCH_STRUCT_HEADER(mach_msg);
 246         mach_port_t dmsg_reply;
 247         pthread_priority_t dmsg_priority;
 248         voucher_t dmsg_voucher;
 249         dispatch_mach_msg_destructor_t dmsg_destructor;
 250         size_t dmsg_size;
 251         union {
 252                 mach_msg_header_t *dmsg_msg;
 253                 char dmsg_buf[0];
 254         };
 255 };
 256
 257 #if TARGET_OS_EMBEDDED
 258 #define DSL_HASH_SIZE  64u // must be a power of two
 259 #else
 260 #define DSL_HASH_SIZE 256u // must be a power of two
 261 #endif
 262
 263 void _dispatch_source_xref_dispose(dispatch_source_t ds);
 264 void _dispatch_source_dispose(dispatch_source_t ds);
 265 void _dispatch_source_invoke(dispatch_source_t ds);
 266 unsigned long _dispatch_source_probe(dispatch_source_t ds);
 267 size_t _dispatch_source_debug(dispatch_source_t ds, char* buf, size_t bufsiz);
 268 void _dispatch_source_set_interval(dispatch_source_t ds, uint64_t interval);
 269 void _dispatch_source_set_event_handler_with_context_f(dispatch_source_t ds,
 270                 void *ctxt, dispatch_function_t handler);
 271
 272 void _dispatch_mach_dispose(dispatch_mach_t dm);
 273 void _dispatch_mach_invoke(dispatch_mach_t dm);
 274 unsigned long _dispatch_mach_probe(dispatch_mach_t dm);
 275 size_t _dispatch_mach_debug(dispatch_mach_t dm, char* buf, size_t bufsiz);
 276
 277 void _dispatch_mach_msg_dispose(dispatch_mach_msg_t dmsg);
 278 void _dispatch_mach_msg_invoke(dispatch_mach_msg_t dmsg);
 279 size_t _dispatch_mach_msg_debug(dispatch_mach_msg_t dmsg, char* buf, size_t bufsiz);
 280
 281 void _dispatch_mach_barrier_invoke(void *ctxt);
 282
 283 unsigned long _dispatch_mgr_wakeup(dispatch_queue_t dq);
 284 void _dispatch_mgr_thread(dispatch_queue_t dq);
 285
 286 #endif /* __DISPATCH_SOURCE_INTERNAL__ */