1/* 2 * Copyright (c) 2012-2013 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_INTROSPECTION_PRIVATE__ 28#define __DISPATCH_INTROSPECTION_PRIVATE__ 29 30/*! 31 * @header 32 * 33 * @abstract 34 * Introspection SPI for libdispatch. 35 * 36 * @discussion 37 * This SPI is only available in the introspection version of the library, 38 * loaded by running a process with the environment variable 39 * DYLD_LIBRARY_PATH=/usr/lib/system/introspection 40 * 41 * NOTE: most of these functions are _not_ exported from the shared library, 42 * the unexported functions are intended to only be called from a debugger 43 * context while the rest of the process is suspended. 44 */ 45 46#ifndef __BEGIN_DECLS 47#if defined(__cplusplus) 48#define __BEGIN_DECLS extern "C" { 49#define __END_DECLS } 50#else 51#define __BEGIN_DECLS 52#define __END_DECLS 53#endif 54#endif 55 56__BEGIN_DECLS 57 58#ifndef __DISPATCH_INDIRECT__ 59/* 60 * Typedefs of opaque types, for direct inclusion of header in lldb expressions 61 */ 62typedef __typeof__(sizeof(int)) size_t; 63typedef struct _opaque_pthread_t *pthread_t; 64typedef void (*dispatch_function_t)(void *); 65typedef struct Block_layout *dispatch_block_t; 66typedef struct dispatch_continuation_s *dispatch_continuation_t; 67typedef struct dispatch_queue_s *dispatch_queue_t; 68typedef struct dispatch_source_s *dispatch_source_t; 69typedef struct dispatch_group_s *dispatch_group_t; 70typedef struct dispatch_object_s *dispatch_object_t; 71#ifndef __OSX_AVAILABLE_STARTING 72#define __OSX_AVAILABLE_STARTING(x,y) 73#endif 74#ifndef DISPATCH_EXPORT 75#define DISPATCH_EXPORT extern 76#endif 77#endif // __DISPATCH_INDIRECT__ 78 79/*! 80 * @typedef dispatch_introspection_versions_s 81 * 82 * @abstract 83 * A structure of version and size information of introspection structures. 84 * 85 * @field introspection_version 86 * Version of overall dispatch_introspection SPI. 87 * 88 * @field hooks_version 89 * Version of dispatch_introspection_hooks_s structure. 90 * Version 2 adds the queue_item_complete member. 91 * 92 * @field hooks_size 93 * Size of dispatch_introspection_hooks_s structure. 94 * 95 * @field queue_item_version 96 * Version of dispatch_introspection_queue_item_s structure. 97 * 98 * @field queue_item_size 99 * Size of dispatch_introspection_queue_item_s structure. 100 * 101 * @field queue_block_version 102 * Version of dispatch_introspection_queue_block_s structure. 103 * 104 * @field queue_block_size 105 * Size of dispatch_introspection_queue_block_s structure. 106 * 107 * @field queue_function_version 108 * Version of dispatch_introspection_queue_function_s structure. 109 * 110 * @field queue_function_size 111 * Size of dispatch_introspection_queue_function_s structure. 112 * 113 * @field queue_thread_version 114 * Version of dispatch_introspection_queue_thread_s structure. 115 * 116 * @field queue_thread_size 117 * Size of dispatch_introspection_queue_thread_s structure. 118 * 119 * @field object_version 120 * Version of dispatch_introspection_object_s structure. 121 * 122 * @field object_size 123 * Size of dispatch_introspection_object_s structure. 124 * 125 * @field queue_version 126 * Version of dispatch_introspection_queue_s structure. 127 * 128 * @field queue_size 129 * Size of dispatch_introspection_queue_s structure. 130 * 131 * @field source_version 132 * Version of dispatch_introspection_source_s structure. 133 * 134 * @field source_size 135 * Size of dispatch_introspection_source_s structure. 136 */ 137 138__OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_7_0) 139DISPATCH_EXPORT const struct dispatch_introspection_versions_s { 140 unsigned long introspection_version; 141 unsigned long hooks_version; 142 size_t hooks_size; 143 unsigned long queue_item_version; 144 size_t queue_item_size; 145 unsigned long queue_block_version; 146 size_t queue_block_size; 147 unsigned long queue_function_version; 148 size_t queue_function_size; 149 unsigned long queue_thread_version; 150 size_t queue_thread_size; 151 unsigned long object_version; 152 size_t object_size; 153 unsigned long queue_version; 154 size_t queue_size; 155 unsigned long source_version; 156 size_t source_size; 157} dispatch_introspection_versions; 158 159/*! 160 * @typedef dispatch_introspection_queue_block_s 161 * 162 * @abstract 163 * A structure of introspection information for a block item enqueued on a 164 * dispatch queue. 165 * 166 * @field continuation 167 * Pointer to enqueued item. 168 * 169 * @field target_queue 170 * Target queue of item (may be different to the queue the item is currently 171 * enqueued on). 172 * 173 * @field block 174 * Block for enqueued item. 175 * 176 * @field block_invoke 177 * Function pointer of block for enqueued item. 178 * 179 * @field group 180 * Group containing enqueued item (may be NULL). 181 * 182 * @field waiter 183 * Thread waiting for completion of enqueued item (NULL if sync == 0). 184 * 185 * @field barrier 186 * Item is a barrier on the queue (all items on serial queues are barriers). 187 * 188 * @field sync 189 * Item was enqueued by a dispatch_sync/dispatch_barrier_sync. 190 * 191 * @field apply 192 * Item is part of a dispatch_apply. 193 */ 194typedef struct dispatch_introspection_queue_block_s { 195 dispatch_continuation_t continuation; 196 dispatch_queue_t target_queue; 197 dispatch_block_t block; 198 dispatch_function_t block_invoke; 199 dispatch_group_t group; 200 pthread_t waiter; 201 unsigned long barrier:1, 202 sync:1, 203 apply:1; 204} dispatch_introspection_queue_block_s; 205typedef dispatch_introspection_queue_block_s 206 *dispatch_introspection_queue_block_t; 207 208/*! 209 * @typedef dispatch_introspection_queue_function_s 210 * 211 * @abstract 212 * A structure of introspection information for a function & context pointer 213 * item enqueued on a dispatch queue. 214 * 215 * @field continuation 216 * Pointer to enqueued item. 217 * 218 * @field target_queue 219 * Target queue of item (may be different to the queue the item is currently 220 * enqueued on). 221 * 222 * @field context 223 * Context in enqueued item. 224 * 225 * @field block_invoke 226 * Function pointer in enqueued item. 227 * 228 * @field group 229 * Group containing enqueued item (may be NULL). 230 * 231 * @field waiter 232 * Thread waiting for completion of enqueued item (NULL if sync == 0). 233 * 234 * @field barrier 235 * Item is a barrier on the queue (all items on serial queues are barriers). 236 * 237 * @field sync 238 * Item was enqueued by a dispatch_sync_f/dispatch_barrier_sync_f. 239 * 240 * @field apply 241 * Item is part of a dispatch_apply_f. 242 */ 243typedef struct dispatch_introspection_queue_function_s { 244 dispatch_continuation_t continuation; 245 dispatch_queue_t target_queue; 246 void *context; 247 dispatch_function_t function; 248 dispatch_group_t group; 249 pthread_t waiter; 250 unsigned long barrier:1, 251 sync:1, 252 apply:1; 253} dispatch_introspection_queue_function_s; 254typedef dispatch_introspection_queue_function_s 255 *dispatch_introspection_queue_function_t; 256 257/*! 258 * @typedef dispatch_introspection_object_s 259 * 260 * @abstract 261 * A structure of introspection information for a generic dispatch object. 262 * 263 * @field object 264 * Pointer to object. 265 * 266 * @field target_queue 267 * Target queue of object (may be different to the queue the object is 268 * currently enqueued on). 269 * 270 * @field type 271 * Object class pointer. 272 * 273 * @field kind 274 * String describing the object type. 275 */ 276typedef struct dispatch_introspection_object_s { 277 dispatch_continuation_t object; 278 dispatch_queue_t target_queue; 279 void *type; 280 const char *kind; 281} dispatch_introspection_object_s; 282typedef dispatch_introspection_object_s *dispatch_introspection_object_t; 283 284/*! 285 * @typedef dispatch_introspection_queue_s 286 * 287 * @abstract 288 * A structure of introspection information for a dispatch queue. 289 * 290 * @field queue 291 * Pointer to queue object. 292 * 293 * @field target_queue 294 * Target queue of queue (may be different to the queue the queue is currently 295 * enqueued on). NULL indicates queue is a root queue. 296 * 297 * @field label 298 * Pointer to queue label. 299 * 300 * @field serialnum 301 * Queue serial number (unique per process). 302 * 303 * @field width 304 * Queue width (1: serial queue, UINT_MAX: concurrent queue). 305 * 306 * @field suspend_count 307 * Number of times the queue has been suspended. 308 * 309 * @field enqueued 310 * Queue is enqueued on another queue. 311 * 312 * @field barrier 313 * Queue is executing a barrier item. 314 * 315 * @field draining 316 * Queue is being drained (cannot get queue items). 317 * 318 * @field global 319 * Queue is a global queue. 320 * 321 * @field main 322 * Queue is the main queue. 323 */ 324typedef struct dispatch_introspection_queue_s { 325 dispatch_queue_t queue; 326 dispatch_queue_t target_queue; 327 const char *label; 328 unsigned long serialnum; 329 unsigned int width; 330 unsigned int suspend_count; 331 unsigned long enqueued:1, 332 barrier:1, 333 draining:1, 334 global:1, 335 main:1; 336} dispatch_introspection_queue_s; 337typedef dispatch_introspection_queue_s *dispatch_introspection_queue_t; 338 339/*! 340 * @typedef dispatch_introspection_source_s 341 * 342 * @abstract 343 * A structure of introspection information for a dispatch source. 344 * 345 * @field source 346 * Pointer to source object. 347 * 348 * @field target_queue 349 * Target queue of source (may be different to the queue the source is currently 350 * enqueued on). 351 * 352 * @field type 353 * Source type (kevent filter) 354 * 355 * @field handle 356 * Source handle (monitored entity). 357 * 358 * @field context 359 * Context pointer passed to source handler. Pointer to handler block if 360 * handler_is_block == 1. 361 * 362 * @field handler 363 * Source handler function. Function pointer of handler block if 364 * handler_is_block == 1. 365 * 366 * @field suspend_count 367 * Number of times the source has been suspended. 368 * 369 * @field enqueued 370 * Source is enqueued on a queue. 371 * 372 * @field handler_is_block 373 * Source handler is a block. 374 * 375 * @field timer 376 * Source is a timer. 377 * 378 * @field after 379 * Source is a dispatch_after timer. 380 */ 381typedef struct dispatch_introspection_source_s { 382 dispatch_source_t source; 383 dispatch_queue_t target_queue; 384 unsigned long type; 385 unsigned long handle; 386 void *context; 387 dispatch_function_t handler; 388 unsigned int suspend_count; 389 unsigned long enqueued:1, 390 handler_is_block:1, 391 timer:1, 392 after:1; 393} dispatch_introspection_source_s; 394typedef dispatch_introspection_source_s *dispatch_introspection_source_t; 395 396/*! 397 * @typedef dispatch_introspection_queue_thread_s 398 * 399 * @abstract 400 * A structure of introspection information about a thread executing items for 401 * a dispatch queue. 402 * 403 * @field object 404 * Pointer to thread object. 405 * 406 * @field thread 407 * Thread executing items for a queue. 408 * 409 * @field queue 410 * Queue introspection information. The queue.queue field is NULL if this thread 411 * is not currently executing items for a queue. 412 */ 413typedef struct dispatch_introspection_queue_thread_s { 414 dispatch_continuation_t object; 415 pthread_t thread; 416 dispatch_introspection_queue_s queue; 417} dispatch_introspection_queue_thread_s; 418typedef dispatch_introspection_queue_thread_s 419 *dispatch_introspection_queue_thread_t; 420 421/*! 422 * @enum dispatch_introspection_queue_item_type 423 * 424 * @abstract 425 * Types of items enqueued on a dispatch queue. 426 */ 427enum dispatch_introspection_queue_item_type { 428 dispatch_introspection_queue_item_type_none = 0x0, 429 dispatch_introspection_queue_item_type_block = 0x11, 430 dispatch_introspection_queue_item_type_function = 0x12, 431 dispatch_introspection_queue_item_type_object = 0x100, 432 dispatch_introspection_queue_item_type_queue = 0x101, 433 dispatch_introspection_queue_item_type_source = 0102, 434}; 435 436/*! 437 * @typedef dispatch_introspection_queue_item_s 438 * 439 * @abstract 440 * A structure of introspection information about an item enqueued on a 441 * dispatch queue. 442 * 443 * @field type 444 * Indicates which of the union members applies to this item. 445 */ 446typedef struct dispatch_introspection_queue_item_s { 447 unsigned long type; // dispatch_introspection_queue_item_type 448 union { 449 dispatch_introspection_queue_block_s block; 450 dispatch_introspection_queue_function_s function; 451 dispatch_introspection_object_s object; 452 dispatch_introspection_queue_s queue; 453 dispatch_introspection_source_s source; 454 }; 455} dispatch_introspection_queue_item_s; 456typedef dispatch_introspection_queue_item_s 457 *dispatch_introspection_queue_item_t; 458 459/*! 460 * @typedef dispatch_introspection_hook_queue_create_t 461 * 462 * @abstract 463 * A function pointer called when a dispatch queue is created. 464 * 465 * @param queue_info 466 * Pointer to queue introspection structure. 467 */ 468typedef void (*dispatch_introspection_hook_queue_create_t)( 469 dispatch_introspection_queue_t queue_info); 470 471/*! 472 * @typedef dispatch_introspection_hook_queue_dispose_t 473 * 474 * @abstract 475 * A function pointer called when a dispatch queue is destroyed. 476 * 477 * @param queue_info 478 * Pointer to queue introspection structure. 479 */ 480typedef void (*dispatch_introspection_hook_queue_dispose_t)( 481 dispatch_introspection_queue_t queue_info); 482 483/*! 484 * @typedef dispatch_introspection_hook_queue_item_enqueue_t 485 * 486 * @abstract 487 * A function pointer called when an item is enqueued onto a dispatch queue. 488 * 489 * @param queue 490 * Pointer to queue. 491 * 492 * @param item 493 * Pointer to item introspection structure. 494 */ 495typedef void (*dispatch_introspection_hook_queue_item_enqueue_t)( 496 dispatch_queue_t queue, dispatch_introspection_queue_item_t item); 497 498/*! 499 * @typedef dispatch_introspection_hook_queue_item_dequeue_t 500 * 501 * @abstract 502 * A function pointer called when an item is dequeued from a dispatch queue. 503 * 504 * @param queue 505 * Pointer to queue. 506 * 507 * @param item 508 * Pointer to item introspection structure. 509 */ 510typedef void (*dispatch_introspection_hook_queue_item_dequeue_t)( 511 dispatch_queue_t queue, dispatch_introspection_queue_item_t item); 512 513/*! 514 * @typedef dispatch_introspection_hook_queue_item_complete_t 515 * 516 * @abstract 517 * A function pointer called when an item previously dequeued from a dispatch 518 * queue has completed processing. 519 * 520 * @discussion 521 * The object pointer value passed to this function pointer must be treated as a 522 * value only. It is intended solely for matching up with an earlier call to a 523 * dequeue hook function pointer by comparing to the first member of the 524 * dispatch_introspection_queue_item_t structure. It must NOT be dereferenced 525 * or e.g. passed to dispatch_introspection_queue_item_get_info(), the memory 526 * that was backing it may have been reused at the time this hook is called. 527 * 528 * @param object 529 * Opaque dentifier for completed item. Must NOT be dereferenced. 530 */ 531typedef void (*dispatch_introspection_hook_queue_item_complete_t)( 532 dispatch_continuation_t object); 533 534/*! 535 * @typedef dispatch_introspection_hooks_s 536 * 537 * @abstract 538 * A structure of function pointer hoooks into libdispatch. 539 */ 540 541typedef struct dispatch_introspection_hooks_s { 542 dispatch_introspection_hook_queue_create_t queue_create; 543 dispatch_introspection_hook_queue_dispose_t queue_dispose; 544 dispatch_introspection_hook_queue_item_enqueue_t queue_item_enqueue; 545 dispatch_introspection_hook_queue_item_dequeue_t queue_item_dequeue; 546 dispatch_introspection_hook_queue_item_complete_t queue_item_complete; 547 void *_reserved[5]; 548} dispatch_introspection_hooks_s; 549typedef dispatch_introspection_hooks_s *dispatch_introspection_hooks_t; 550 551/*! 552 * @function dispatch_introspection_get_queues 553 * 554 * @abstract 555 * Retrieve introspection information about all dispatch queues in the process, 556 * in batches of specified size. 557 * 558 * @discussion 559 * Retrieving queue information and iterating through the list of all queues 560 * must take place from a debugger context (while the rest of the process is 561 * suspended). 562 * 563 * @param start 564 * Starting point for this batch of queue information, as returned by a previous 565 * call to _dispatch_introspection_get_queues(). 566 * Pass NULL to retrieve the initial batch. 567 * 568 * @param count 569 * Number of queues to introspect. 570 * 571 * @param queues 572 * Array to fill with queue information. If less than 'count' queues are left 573 * in this batch, the end of valid entries in the array will be indicated 574 * by an entry with NULL queue member. 575 * 576 * @result 577 * Queue to pass to another call to _dispatch_introspection_get_queues() to 578 * retrieve information about the next batch of queues. May be NULL if there 579 * are no more queues to iterate over. 580 */ 581extern dispatch_queue_t 582dispatch_introspection_get_queues(dispatch_queue_t start, size_t count, 583 dispatch_introspection_queue_t queues); 584 585/*! 586 * @function dispatch_introspection_get_queue_threads 587 * 588 * @abstract 589 * Retrieve introspection information about all threads in the process executing 590 * items for dispatch queues, in batches of specified size. 591 * 592 * @discussion 593 * Retrieving thread information and iterating through the list of all queue 594 * threads must take place from a debugger context (while the rest of the 595 * process is suspended). 596 * 597 * @param start 598 * Starting point for this batch of thread information, as returned by a 599 * previous call to _dispatch_introspection_get_queue_threads(). 600 * Pass NULL to retrieve the initial batch. 601 * 602 * @param count 603 * Number of queue threads to introspect. 604 * 605 * @param threads 606 * Array to fill with queue thread information. If less than 'count' threads are 607 * left in this batch, the end of valid entries in the array will be indicated 608 * by an entry with NULL object member. 609 * 610 * @result 611 * Object to pass to another call to _dispatch_introspection_get_queues() to 612 * retrieve information about the next batch of queues. May be NULL if there 613 * are no more queues to iterate over. 614 */ 615extern dispatch_continuation_t 616dispatch_introspection_get_queue_threads(dispatch_continuation_t start, 617 size_t count, dispatch_introspection_queue_thread_t threads); 618 619/*! 620 * @function dispatch_introspection_queue_get_items 621 * 622 * @abstract 623 * Retrieve introspection information about all items enqueued on a queue, in 624 * batches of specified size. 625 * 626 * @discussion 627 * Retrieving queue item information and iterating through a queue must take 628 * place from a debugger context (while the rest of the process is suspended). 629 * 630 * @param queue 631 * Queue to introspect. 632 * 633 * @param start 634 * Starting point for this batch of queue item information, as returned by a 635 * previous call to _dispatch_introspection_queue_get_items(). 636 * Pass NULL to retrieve the initial batch. 637 * 638 * @param count 639 * Number of items to introspect. 640 * 641 * @param items 642 * Array to fill with queue item information. If less than 'count' queues are 643 * left in this batch, the end of valid entries in the array will be indicated 644 * by an entry with type dispatch_introspection_queue_item_type_none. 645 * 646 * @result 647 * Item to pass to another call to _dispatch_introspection_queue_get_items() to 648 * retrieve information about the next batch of queue items. May be NULL if 649 * there are no more items to iterate over. 650 */ 651extern dispatch_continuation_t 652dispatch_introspection_queue_get_items(dispatch_queue_t queue, 653 dispatch_continuation_t start, size_t count, 654 dispatch_introspection_queue_item_t items); 655 656/*! 657 * @function dispatch_introspection_queue_get_info 658 * 659 * @abstract 660 * Retrieve introspection information about a specified dispatch queue. 661 * 662 * @discussion 663 * Retrieving queue information must take place from a debugger context (while 664 * the rest of the process is suspended). 665 * 666 * @param queue 667 * Queue to introspect. 668 * 669 * @result 670 * Queue information struct. 671 */ 672extern dispatch_introspection_queue_s 673dispatch_introspection_queue_get_info(dispatch_queue_t queue); 674 675/*! 676 * @function dispatch_introspection_queue_item_get_info 677 * 678 * @abstract 679 * Retrieve introspection information about a specified dispatch queue item. 680 * 681 * @discussion 682 * Retrieving queue item information must take place from a debugger context 683 * (while the rest of the process is suspended). 684 * 685 * @param queue 686 * Queue to introspect. 687 * 688 * @param item 689 * Item to introspect. 690 * 691 * @result 692 * Queue item information struct. 693 */ 694extern dispatch_introspection_queue_item_s 695dispatch_introspection_queue_item_get_info(dispatch_queue_t queue, 696 dispatch_continuation_t item); 697 698/*! 699 * @function dispatch_introspection_hooks_install 700 * 701 * @abstract 702 * Install hook functions into libdispatch. 703 * 704 * @discussion 705 * Installing hook functions must take place from a debugger context (while the 706 * rest of the process is suspended) or early enough in the process lifecycle 707 * that the process is still single-threaded. 708 * 709 * The caller is responsible for implementing chaining to the hooks that were 710 * previously installed (if any). 711 * 712 * @param hooks 713 * Pointer to structure of hook function pointers. Any of the structure members 714 * may be NULL to indicate that the hook in question should not be installed. 715 * The structure is copied on input and filled with the previously installed 716 * hooks on output. 717 */ 718 719__OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_7_0) 720DISPATCH_EXPORT void 721dispatch_introspection_hooks_install(dispatch_introspection_hooks_t hooks); 722 723/*! 724 * @function dispatch_introspection_hook_callouts_enable 725 * 726 * @abstract 727 * Enable hook callout functions in libdispatch that a debugger can break on 728 * and get introspection arguments even if there are no hook functions 729 * installed via dispatch_introspection_hooks_install(). 730 * 731 * @discussion 732 * Enabling hook callout functions must take place from a debugger context 733 * (while the rest of the process is suspended). 734 * 735 * @param enable 736 * Pointer to dispatch_introspection_hooks_s structure. For every structure 737 * member with (any) non-NULL value, the corresponding hook callout will be 738 * enabled; for every NULL member the hook callout will be disabled (if there 739 * is no hook function installed). 740 * As a convenience, the 'enable' pointer may itself be NULL to indicate that 741 * all hook callouts should be enabled. 742 */ 743 744extern void 745dispatch_introspection_hook_callouts_enable( 746 dispatch_introspection_hooks_t enable); 747 748/*! 749 * @function dispatch_introspection_hook_callout_queue_create 750 * 751 * @abstract 752 * Callout to queue creation hook that a debugger can break on. 753 */ 754 755extern void 756dispatch_introspection_hook_callout_queue_create( 757 dispatch_introspection_queue_t queue_info); 758 759/*! 760 * @function dispatch_introspection_hook_callout_queue_dispose 761 * 762 * @abstract 763 * Callout to queue destruction hook that a debugger can break on. 764 */ 765 766extern void 767dispatch_introspection_hook_callout_queue_dispose( 768 dispatch_introspection_queue_t queue_info); 769 770/*! 771 * @function dispatch_introspection_hook_callout_queue_item_enqueue 772 * 773 * @abstract 774 * Callout to queue enqueue hook that a debugger can break on. 775 */ 776 777extern void 778dispatch_introspection_hook_callout_queue_item_enqueue( 779 dispatch_queue_t queue, dispatch_introspection_queue_item_t item); 780 781/*! 782 * @function dispatch_introspection_hook_callout_queue_item_dequeue 783 * 784 * @abstract 785 * Callout to queue dequeue hook that a debugger can break on. 786 */ 787 788extern void 789dispatch_introspection_hook_callout_queue_item_dequeue( 790 dispatch_queue_t queue, dispatch_introspection_queue_item_t item); 791 792/*! 793 * @function dispatch_introspection_hook_callout_queue_item_complete 794 * 795 * @abstract 796 * Callout to queue item complete hook that a debugger can break on. 797 */ 798 799extern void 800dispatch_introspection_hook_callout_queue_item_complete( 801 dispatch_continuation_t object); 802 803__END_DECLS 804 805#endif 806