1------------------------------------------------------------------------------ 2-- -- 3-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS -- 4-- -- 5-- S Y S T E M . T A S K I N G . I N I T I A L I Z A T I O N -- 6-- -- 7-- B o d y -- 8-- -- 9-- Copyright (C) 1992-2015, Free Software Foundation, Inc. -- 10-- -- 11-- GNARL is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. -- 17-- -- 18-- As a special exception under Section 7 of GPL version 3, you are granted -- 19-- additional permissions described in the GCC Runtime Library Exception, -- 20-- version 3.1, as published by the Free Software Foundation. -- 21-- -- 22-- You should have received a copy of the GNU General Public License and -- 23-- a copy of the GCC Runtime Library Exception along with this program; -- 24-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 25-- <http://www.gnu.org/licenses/>. -- 26-- -- 27-- GNARL was developed by the GNARL team at Florida State University. -- 28-- Extensive contributions were provided by Ada Core Technologies, Inc. -- 29-- -- 30------------------------------------------------------------------------------ 31 32pragma Style_Checks (All_Checks); 33-- Turn off subprogram alpha ordering check, since we group soft link bodies 34-- and dummy soft link bodies together separately in this unit. 35 36pragma Polling (Off); 37-- Turn polling off for this package. We don't need polling during any of the 38-- routines in this package, and more to the point, if we try to poll it can 39-- cause infinite loops. 40 41with Ada.Exceptions; 42 43with System.Task_Primitives; 44with System.Task_Primitives.Operations; 45with System.Soft_Links; 46with System.Soft_Links.Tasking; 47with System.Tasking.Debug; 48with System.Tasking.Task_Attributes; 49with System.Parameters; 50 51with System.Secondary_Stack; 52pragma Elaborate_All (System.Secondary_Stack); 53pragma Unreferenced (System.Secondary_Stack); 54-- Make sure the body of Secondary_Stack is elaborated before calling 55-- Init_Tasking_Soft_Links. See comments for this routine for explanation. 56 57package body System.Tasking.Initialization is 58 59 package STPO renames System.Task_Primitives.Operations; 60 package SSL renames System.Soft_Links; 61 62 use Parameters; 63 use Task_Primitives.Operations; 64 65 Global_Task_Lock : aliased System.Task_Primitives.RTS_Lock; 66 -- This is a global lock; it is used to execute in mutual exclusion from 67 -- all other tasks. It is only used by Task_Lock, Task_Unlock, and 68 -- Final_Task_Unlock. 69 70 ---------------------------------------------------------------------- 71 -- Tasking versions of some services needed by non-tasking programs -- 72 ---------------------------------------------------------------------- 73 74 procedure Abort_Defer; 75 -- NON-INLINE versions without Self_ID for soft links 76 77 procedure Abort_Undefer; 78 -- NON-INLINE versions without Self_ID for soft links 79 80 procedure Task_Lock; 81 -- Locks out other tasks. Preceding a section of code by Task_Lock and 82 -- following it by Task_Unlock creates a critical region. This is used 83 -- for ensuring that a region of non-tasking code (such as code used to 84 -- allocate memory) is tasking safe. Note that it is valid for calls to 85 -- Task_Lock/Task_Unlock to be nested, and this must work properly, i.e. 86 -- only the corresponding outer level Task_Unlock will actually unlock. 87 88 procedure Task_Unlock; 89 -- Releases lock previously set by call to Task_Lock. In the nested case, 90 -- all nested locks must be released before other tasks competing for the 91 -- tasking lock are released. 92 93 function Get_Current_Excep return SSL.EOA; 94 -- Task-safe version of SSL.Get_Current_Excep 95 96 function Task_Name return String; 97 -- Returns current task's name 98 99 ------------------------ 100 -- Local Subprograms -- 101 ------------------------ 102 103 ---------------------------- 104 -- Tasking Initialization -- 105 ---------------------------- 106 107 procedure Init_RTS; 108 -- This procedure completes the initialization of the GNARL. The first part 109 -- of the initialization is done in the body of System.Tasking. It consists 110 -- of initializing global locks, and installing tasking versions of certain 111 -- operations used by the compiler. Init_RTS is called during elaboration. 112 113 -------------------------- 114 -- Change_Base_Priority -- 115 -------------------------- 116 117 -- Call only with abort deferred and holding Self_ID locked 118 119 procedure Change_Base_Priority (T : Task_Id) is 120 begin 121 if T.Common.Base_Priority /= T.New_Base_Priority then 122 T.Common.Base_Priority := T.New_Base_Priority; 123 Set_Priority (T, T.Common.Base_Priority); 124 end if; 125 end Change_Base_Priority; 126 127 ------------------------ 128 -- Check_Abort_Status -- 129 ------------------------ 130 131 function Check_Abort_Status return Integer is 132 Self_ID : constant Task_Id := Self; 133 begin 134 if Self_ID /= null 135 and then Self_ID.Deferral_Level = 0 136 and then Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level 137 then 138 return 1; 139 else 140 return 0; 141 end if; 142 end Check_Abort_Status; 143 144 ----------------- 145 -- Defer_Abort -- 146 ----------------- 147 148 procedure Defer_Abort (Self_ID : Task_Id) is 149 begin 150 if No_Abort then 151 return; 152 end if; 153 154 pragma Assert (Self_ID.Deferral_Level = 0); 155 156 -- pragma Assert 157 -- (Self_ID.Pending_ATC_Level >= Self_ID.ATC_Nesting_Level); 158 159 -- The above check has been useful in detecting mismatched defer/undefer 160 -- pairs. You may uncomment it when testing on systems that support 161 -- preemptive abort. 162 163 -- If the OS supports preemptive abort (e.g. pthread_kill), it should 164 -- have happened already. A problem is with systems that do not support 165 -- preemptive abort, and so rely on polling. On such systems we may get 166 -- false failures of the assertion, since polling for pending abort does 167 -- no occur until the abort undefer operation. 168 169 -- Even on systems that only poll for abort, the assertion may be useful 170 -- for catching missed abort completion polling points. The operations 171 -- that undefer abort poll for pending aborts. This covers most of the 172 -- places where the core Ada semantics require abort to be caught, 173 -- without any special attention. However, this generally happens on 174 -- exit from runtime system call, which means a pending abort will not 175 -- be noticed on the way into the runtime system. We considered adding a 176 -- check for pending aborts at this point, but chose not to, because of 177 -- the overhead. Instead, we searched for RTS calls where abort 178 -- completion is required and a task could go farther than Ada allows 179 -- before undeferring abort; we then modified the code to ensure the 180 -- abort would be detected. 181 182 Self_ID.Deferral_Level := Self_ID.Deferral_Level + 1; 183 end Defer_Abort; 184 185 -------------------------- 186 -- Defer_Abort_Nestable -- 187 -------------------------- 188 189 procedure Defer_Abort_Nestable (Self_ID : Task_Id) is 190 begin 191 if No_Abort then 192 return; 193 end if; 194 195 -- The following assertion is by default disabled. See the comment in 196 -- Defer_Abort on the situations in which it may be useful to uncomment 197 -- this assertion and enable the test. 198 199 -- pragma Assert 200 -- (Self_ID.Pending_ATC_Level >= Self_ID.ATC_Nesting_Level or else 201 -- Self_ID.Deferral_Level > 0); 202 203 Self_ID.Deferral_Level := Self_ID.Deferral_Level + 1; 204 end Defer_Abort_Nestable; 205 206 ----------------- 207 -- Abort_Defer -- 208 ----------------- 209 210 procedure Abort_Defer is 211 Self_ID : Task_Id; 212 begin 213 if No_Abort then 214 return; 215 end if; 216 217 Self_ID := STPO.Self; 218 Self_ID.Deferral_Level := Self_ID.Deferral_Level + 1; 219 end Abort_Defer; 220 221 ----------------------- 222 -- Get_Current_Excep -- 223 ----------------------- 224 225 function Get_Current_Excep return SSL.EOA is 226 begin 227 return STPO.Self.Common.Compiler_Data.Current_Excep'Access; 228 end Get_Current_Excep; 229 230 ----------------------- 231 -- Do_Pending_Action -- 232 ----------------------- 233 234 -- Call only when holding no locks 235 236 procedure Do_Pending_Action (Self_ID : Task_Id) is 237 use type Ada.Exceptions.Exception_Id; 238 239 begin 240 pragma Assert (Self_ID = Self and then Self_ID.Deferral_Level = 0); 241 242 -- Needs loop to recheck for pending action in case a new one occurred 243 -- while we had abort deferred below. 244 245 loop 246 -- Temporarily defer abort so that we can lock Self_ID 247 248 Self_ID.Deferral_Level := Self_ID.Deferral_Level + 1; 249 250 if Single_Lock then 251 Lock_RTS; 252 end if; 253 254 Write_Lock (Self_ID); 255 Self_ID.Pending_Action := False; 256 Unlock (Self_ID); 257 258 if Single_Lock then 259 Unlock_RTS; 260 end if; 261 262 -- Restore the original Deferral value 263 264 Self_ID.Deferral_Level := Self_ID.Deferral_Level - 1; 265 266 if not Self_ID.Pending_Action then 267 if Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level then 268 if not Self_ID.Aborting then 269 Self_ID.Aborting := True; 270 pragma Debug 271 (Debug.Trace (Self_ID, "raise Abort_Signal", 'B')); 272 raise Standard'Abort_Signal; 273 274 pragma Assert (not Self_ID.ATC_Hack); 275 276 elsif Self_ID.ATC_Hack then 277 278 -- The solution really belongs in the Abort_Signal handler 279 -- for async. entry calls. The present hack is very 280 -- fragile. It relies that the very next point after 281 -- Exit_One_ATC_Level at which the task becomes abortable 282 -- will be the call to Undefer_Abort in the 283 -- Abort_Signal handler. 284 285 Self_ID.ATC_Hack := False; 286 287 pragma Debug 288 (Debug.Trace 289 (Self_ID, "raise Abort_Signal (ATC hack)", 'B')); 290 raise Standard'Abort_Signal; 291 end if; 292 end if; 293 294 return; 295 end if; 296 end loop; 297 end Do_Pending_Action; 298 299 ----------------------- 300 -- Final_Task_Unlock -- 301 ----------------------- 302 303 -- This version is only for use in Terminate_Task, when the task is 304 -- relinquishing further rights to its own ATCB. 305 306 -- There is a very interesting potential race condition there, where the 307 -- old task may run concurrently with a new task that is allocated the old 308 -- tasks (now reused) ATCB. The critical thing here is to not make any 309 -- reference to the ATCB after the lock is released. See also comments on 310 -- Terminate_Task and Unlock. 311 312 procedure Final_Task_Unlock (Self_ID : Task_Id) is 313 begin 314 pragma Assert (Self_ID.Common.Global_Task_Lock_Nesting = 1); 315 Unlock (Global_Task_Lock'Access, Global_Lock => True); 316 end Final_Task_Unlock; 317 318 -------------- 319 -- Init_RTS -- 320 -------------- 321 322 procedure Init_RTS is 323 Self_Id : Task_Id; 324 begin 325 Tasking.Initialize; 326 327 -- Terminate run time (regular vs restricted) specific initialization 328 -- of the environment task. 329 330 Self_Id := Environment_Task; 331 Self_Id.Master_of_Task := Environment_Task_Level; 332 Self_Id.Master_Within := Self_Id.Master_of_Task + 1; 333 334 for L in Self_Id.Entry_Calls'Range loop 335 Self_Id.Entry_Calls (L).Self := Self_Id; 336 Self_Id.Entry_Calls (L).Level := L; 337 end loop; 338 339 Self_Id.Awake_Count := 1; 340 Self_Id.Alive_Count := 1; 341 342 -- Normally, a task starts out with internal master nesting level one 343 -- larger than external master nesting level. It is incremented to one 344 -- by Enter_Master, which is called in the task body only if the 345 -- compiler thinks the task may have dependent tasks. There is no 346 -- corresponding call to Enter_Master for the environment task, so we 347 -- would need to increment it to 2 here. Instead, we set it to 3. By 348 -- doing this we reserve the level 2 for server tasks of the runtime 349 -- system. The environment task does not need to wait for these server 350 351 Self_Id.Master_Within := Library_Task_Level; 352 353 -- Initialize lock used to implement mutual exclusion between all tasks 354 355 Initialize_Lock (Global_Task_Lock'Access, STPO.Global_Task_Level); 356 357 -- Notify that the tasking run time has been elaborated so that 358 -- the tasking version of the soft links can be used. 359 360 if not No_Abort then 361 SSL.Abort_Defer := Abort_Defer'Access; 362 SSL.Abort_Undefer := Abort_Undefer'Access; 363 end if; 364 365 SSL.Lock_Task := Task_Lock'Access; 366 SSL.Unlock_Task := Task_Unlock'Access; 367 SSL.Check_Abort_Status := Check_Abort_Status'Access; 368 SSL.Task_Name := Task_Name'Access; 369 SSL.Get_Current_Excep := Get_Current_Excep'Access; 370 371 -- Initialize the tasking soft links (if not done yet) that are common 372 -- to the full and the restricted run times. 373 374 SSL.Tasking.Init_Tasking_Soft_Links; 375 376 -- Abort is deferred in a new ATCB, so we need to undefer abort at this 377 -- stage to make the environment task abortable. 378 379 Undefer_Abort (Environment_Task); 380 end Init_RTS; 381 382 --------------------------- 383 -- Locked_Abort_To_Level-- 384 --------------------------- 385 386 -- Abort a task to the specified ATC nesting level. 387 -- Call this only with T locked. 388 389 -- An earlier version of this code contained a call to Wakeup. That should 390 -- not be necessary here, if Abort_Task is implemented correctly, since 391 -- Abort_Task should include the effect of Wakeup. However, the above call 392 -- was in earlier versions of this file, and at least for some targets 393 -- Abort_Task has not been doing Wakeup. It should not hurt to uncomment 394 -- the above call, until the error is corrected for all targets. 395 396 -- See extended comments in package body System.Tasking.Abort for the 397 -- overall design of the implementation of task abort. 398 -- ??? there is no such package ??? 399 400 -- If the task is sleeping it will be in an abort-deferred region, and will 401 -- not have Abort_Signal raised by Abort_Task. Such an "abort deferral" is 402 -- just to protect the RTS internals, and not necessarily required to 403 -- enforce Ada semantics. Abort_Task should wake the task up and let it 404 -- decide if it wants to complete the aborted construct immediately. 405 406 -- Note that the effect of the low-level Abort_Task is not persistent. 407 -- If the target task is not blocked, this wakeup will be missed. 408 409 -- We don't bother calling Abort_Task if this task is aborting itself, 410 -- since we are inside the RTS and have abort deferred. Similarly, We don't 411 -- bother to call Abort_Task if T is terminated, since there is no need to 412 -- abort a terminated task, and it could be dangerous to try if the task 413 -- has stopped executing. 414 415 -- Note that an earlier version of this code had some false reasoning about 416 -- being able to reliably wake up a task that had suspended on a blocking 417 -- system call that does not atomically release the task's lock (e.g., UNIX 418 -- nanosleep, which we once thought could be used to implement delays). 419 -- That still left the possibility of missed wakeups. 420 421 -- We cannot safely call Vulnerable_Complete_Activation here, since that 422 -- requires locking Self_ID.Parent. The anti-deadlock lock ordering rules 423 -- would then require us to release the lock on Self_ID first, which would 424 -- create a timing window for other tasks to lock Self_ID. This is 425 -- significant for tasks that may be aborted before their execution can 426 -- enter the task body, and so they do not get a chance to call 427 -- Complete_Task. The actual work for this case is done in Terminate_Task. 428 429 procedure Locked_Abort_To_Level 430 (Self_ID : Task_Id; 431 T : Task_Id; 432 L : ATC_Level) 433 is 434 begin 435 if not T.Aborting and then T /= Self_ID then 436 case T.Common.State is 437 when Unactivated | Terminated => 438 pragma Assert (False); 439 null; 440 441 when Activating | Runnable => 442 443 -- This is needed to cancel an asynchronous protected entry 444 -- call during a requeue with abort. 445 446 T.Entry_Calls 447 (T.ATC_Nesting_Level).Cancellation_Attempted := True; 448 449 when Interrupt_Server_Blocked_On_Event_Flag => 450 null; 451 452 when Delay_Sleep | 453 Async_Select_Sleep | 454 Interrupt_Server_Idle_Sleep | 455 Interrupt_Server_Blocked_Interrupt_Sleep | 456 Timer_Server_Sleep | 457 AST_Server_Sleep => 458 Wakeup (T, T.Common.State); 459 460 when Acceptor_Sleep | Acceptor_Delay_Sleep => 461 T.Open_Accepts := null; 462 Wakeup (T, T.Common.State); 463 464 when Entry_Caller_Sleep => 465 T.Entry_Calls 466 (T.ATC_Nesting_Level).Cancellation_Attempted := True; 467 Wakeup (T, T.Common.State); 468 469 when Activator_Sleep | 470 Master_Completion_Sleep | 471 Master_Phase_2_Sleep | 472 Asynchronous_Hold => 473 null; 474 end case; 475 end if; 476 477 if T.Pending_ATC_Level > L then 478 T.Pending_ATC_Level := L; 479 T.Pending_Action := True; 480 481 if L = 0 then 482 T.Callable := False; 483 end if; 484 485 -- This prevents aborted task from accepting calls 486 487 if T.Aborting then 488 489 -- The test above is just a heuristic, to reduce wasteful 490 -- calls to Abort_Task. We are holding T locked, and this 491 -- value will not be set to False except with T also locked, 492 -- inside Exit_One_ATC_Level, so we should not miss wakeups. 493 494 if T.Common.State = Acceptor_Sleep 495 or else 496 T.Common.State = Acceptor_Delay_Sleep 497 then 498 T.Open_Accepts := null; 499 end if; 500 501 elsif T /= Self_ID and then 502 (T.Common.State = Runnable 503 or else T.Common.State = Interrupt_Server_Blocked_On_Event_Flag) 504 505 -- The task is blocked on a system call waiting for the 506 -- completion event. In this case Abort_Task may need to take 507 -- special action in order to succeed. 508 509 then 510 Abort_Task (T); 511 end if; 512 end if; 513 end Locked_Abort_To_Level; 514 515 -------------------------------- 516 -- Remove_From_All_Tasks_List -- 517 -------------------------------- 518 519 procedure Remove_From_All_Tasks_List (T : Task_Id) is 520 C : Task_Id; 521 Previous : Task_Id; 522 523 begin 524 pragma Debug 525 (Debug.Trace (Self, "Remove_From_All_Tasks_List", 'C')); 526 527 Previous := Null_Task; 528 C := All_Tasks_List; 529 while C /= Null_Task loop 530 if C = T then 531 if Previous = Null_Task then 532 All_Tasks_List := All_Tasks_List.Common.All_Tasks_Link; 533 else 534 Previous.Common.All_Tasks_Link := C.Common.All_Tasks_Link; 535 end if; 536 537 return; 538 end if; 539 540 Previous := C; 541 C := C.Common.All_Tasks_Link; 542 end loop; 543 544 pragma Assert (False); 545 end Remove_From_All_Tasks_List; 546 547 --------------- 548 -- Task_Lock -- 549 --------------- 550 551 procedure Task_Lock (Self_ID : Task_Id) is 552 begin 553 Self_ID.Common.Global_Task_Lock_Nesting := 554 Self_ID.Common.Global_Task_Lock_Nesting + 1; 555 556 if Self_ID.Common.Global_Task_Lock_Nesting = 1 then 557 Defer_Abort_Nestable (Self_ID); 558 Write_Lock (Global_Task_Lock'Access, Global_Lock => True); 559 end if; 560 end Task_Lock; 561 562 procedure Task_Lock is 563 begin 564 Task_Lock (STPO.Self); 565 end Task_Lock; 566 567 --------------- 568 -- Task_Name -- 569 --------------- 570 571 function Task_Name return String is 572 Self_Id : constant Task_Id := STPO.Self; 573 begin 574 return Self_Id.Common.Task_Image (1 .. Self_Id.Common.Task_Image_Len); 575 end Task_Name; 576 577 ----------------- 578 -- Task_Unlock -- 579 ----------------- 580 581 procedure Task_Unlock (Self_ID : Task_Id) is 582 begin 583 pragma Assert (Self_ID.Common.Global_Task_Lock_Nesting > 0); 584 Self_ID.Common.Global_Task_Lock_Nesting := 585 Self_ID.Common.Global_Task_Lock_Nesting - 1; 586 587 if Self_ID.Common.Global_Task_Lock_Nesting = 0 then 588 Unlock (Global_Task_Lock'Access, Global_Lock => True); 589 Undefer_Abort_Nestable (Self_ID); 590 end if; 591 end Task_Unlock; 592 593 procedure Task_Unlock is 594 begin 595 Task_Unlock (STPO.Self); 596 end Task_Unlock; 597 598 ------------------- 599 -- Undefer_Abort -- 600 ------------------- 601 602 -- Precondition : Self does not hold any locks 603 604 -- Undefer_Abort is called on any abort completion point (aka. 605 -- synchronization point). It performs the following actions if they 606 -- are pending: (1) change the base priority, (2) abort the task. 607 608 -- The priority change has to occur before abort. Otherwise, it would 609 -- take effect no earlier than the next abort completion point. 610 611 procedure Undefer_Abort (Self_ID : Task_Id) is 612 begin 613 if No_Abort then 614 return; 615 end if; 616 617 pragma Assert (Self_ID.Deferral_Level = 1); 618 619 Self_ID.Deferral_Level := Self_ID.Deferral_Level - 1; 620 621 if Self_ID.Deferral_Level = 0 then 622 pragma Assert (Check_No_Locks (Self_ID)); 623 624 if Self_ID.Pending_Action then 625 Do_Pending_Action (Self_ID); 626 end if; 627 end if; 628 end Undefer_Abort; 629 630 ---------------------------- 631 -- Undefer_Abort_Nestable -- 632 ---------------------------- 633 634 -- An earlier version would re-defer abort if an abort is in progress. 635 -- Then, we modified the effect of the raise statement so that it defers 636 -- abort until control reaches a handler. That was done to prevent 637 -- "skipping over" a handler if another asynchronous abort occurs during 638 -- the propagation of the abort to the handler. 639 640 -- There has been talk of reversing that decision, based on a newer 641 -- implementation of exception propagation. Care must be taken to evaluate 642 -- how such a change would interact with the above code and all the places 643 -- where abort-deferral is used to bridge over critical transitions, such 644 -- as entry to the scope of a region with a finalizer and entry into the 645 -- body of an accept-procedure. 646 647 procedure Undefer_Abort_Nestable (Self_ID : Task_Id) is 648 begin 649 if No_Abort then 650 return; 651 end if; 652 653 pragma Assert (Self_ID.Deferral_Level > 0); 654 655 Self_ID.Deferral_Level := Self_ID.Deferral_Level - 1; 656 657 if Self_ID.Deferral_Level = 0 then 658 659 pragma Assert (Check_No_Locks (Self_ID)); 660 661 if Self_ID.Pending_Action then 662 Do_Pending_Action (Self_ID); 663 end if; 664 end if; 665 end Undefer_Abort_Nestable; 666 667 ------------------- 668 -- Abort_Undefer -- 669 ------------------- 670 671 procedure Abort_Undefer is 672 Self_ID : Task_Id; 673 begin 674 if No_Abort then 675 return; 676 end if; 677 678 Self_ID := STPO.Self; 679 680 if Self_ID.Deferral_Level = 0 then 681 682 -- In case there are different views on whether Abort is supported 683 -- between the expander and the run time, we may end up with 684 -- Self_ID.Deferral_Level being equal to zero, when called from 685 -- the procedure created by the expander that corresponds to a 686 -- task body. In this case, there's nothing to be done. 687 688 -- See related code in System.Tasking.Stages.Create_Task resetting 689 -- Deferral_Level when System.Restrictions.Abort_Allowed is False. 690 691 return; 692 end if; 693 694 pragma Assert (Self_ID.Deferral_Level > 0); 695 Self_ID.Deferral_Level := Self_ID.Deferral_Level - 1; 696 697 if Self_ID.Deferral_Level = 0 then 698 pragma Assert (Check_No_Locks (Self_ID)); 699 700 if Self_ID.Pending_Action then 701 Do_Pending_Action (Self_ID); 702 end if; 703 end if; 704 end Abort_Undefer; 705 706 -------------------------- 707 -- Wakeup_Entry_Caller -- 708 -------------------------- 709 710 -- This is called at the end of service of an entry call, to abort the 711 -- caller if he is in an abortable part, and to wake up the caller if it 712 -- is on Entry_Caller_Sleep. It assumes that the call is already off-queue. 713 714 -- (This enforces the rule that a task must be off-queue if its state is 715 -- Done or Cancelled.) Call it holding the lock of Entry_Call.Self. 716 717 -- Timed_Call or Simple_Call: 718 -- The caller is waiting on Entry_Caller_Sleep, in 719 -- Wait_For_Completion, or Wait_For_Completion_With_Timeout. 720 721 -- Conditional_Call: 722 -- The caller might be in Wait_For_Completion, 723 -- waiting for a rendezvous (possibly requeued without abort) 724 -- to complete. 725 726 -- Asynchronous_Call: 727 -- The caller may be executing in the abortable part o 728 -- an async. select, or on a time delay, 729 -- if Entry_Call.State >= Was_Abortable. 730 731 procedure Wakeup_Entry_Caller 732 (Self_ID : Task_Id; 733 Entry_Call : Entry_Call_Link; 734 New_State : Entry_Call_State) 735 is 736 Caller : constant Task_Id := Entry_Call.Self; 737 738 begin 739 pragma Debug (Debug.Trace 740 (Self_ID, "Wakeup_Entry_Caller", 'E', Caller)); 741 pragma Assert (New_State = Done or else New_State = Cancelled); 742 743 pragma Assert (Caller.Common.State /= Unactivated); 744 745 Entry_Call.State := New_State; 746 747 if Entry_Call.Mode = Asynchronous_Call then 748 749 -- Abort the caller in his abortable part, but do so only if call has 750 -- been queued abortably. 751 752 if Entry_Call.State >= Was_Abortable or else New_State = Done then 753 Locked_Abort_To_Level (Self_ID, Caller, Entry_Call.Level - 1); 754 end if; 755 756 elsif Caller.Common.State = Entry_Caller_Sleep then 757 Wakeup (Caller, Entry_Caller_Sleep); 758 end if; 759 end Wakeup_Entry_Caller; 760 761 ------------------------- 762 -- Finalize_Attributes -- 763 ------------------------- 764 765 procedure Finalize_Attributes (T : Task_Id) is 766 Attr : Atomic_Address; 767 768 begin 769 for J in T.Attributes'Range loop 770 Attr := T.Attributes (J); 771 772 if Attr /= 0 and then Task_Attributes.Require_Finalization (J) then 773 Task_Attributes.To_Attribute (Attr).Free (Attr); 774 T.Attributes (J) := 0; 775 end if; 776 end loop; 777 end Finalize_Attributes; 778 779begin 780 Init_RTS; 781end System.Tasking.Initialization; 782