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) 1992-2020, 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 36with System.Task_Primitives; 37with System.Task_Primitives.Operations; 38with System.Soft_Links; 39with System.Soft_Links.Tasking; 40with System.Tasking.Debug; 41with System.Tasking.Task_Attributes; 42 43with System.Secondary_Stack; 44pragma Elaborate_All (System.Secondary_Stack); 45pragma Unreferenced (System.Secondary_Stack); 46-- Make sure the body of Secondary_Stack is elaborated before calling 47-- Init_Tasking_Soft_Links. See comments for this routine for explanation. 48 49package body System.Tasking.Initialization is 50 51 package STPO renames System.Task_Primitives.Operations; 52 package SSL renames System.Soft_Links; 53 54 use Parameters; 55 use Task_Primitives.Operations; 56 57 Global_Task_Lock : aliased System.Task_Primitives.RTS_Lock; 58 -- This is a global lock; it is used to execute in mutual exclusion from 59 -- all other tasks. It is only used by Task_Lock, Task_Unlock, and 60 -- Final_Task_Unlock. 61 62 ---------------------------------------------------------------------- 63 -- Tasking versions of some services needed by non-tasking programs -- 64 ---------------------------------------------------------------------- 65 66 procedure Abort_Defer; 67 -- NON-INLINE versions without Self_ID for soft links 68 69 procedure Abort_Undefer; 70 -- NON-INLINE versions without Self_ID for soft links 71 72 procedure Task_Lock; 73 -- Locks out other tasks. Preceding a section of code by Task_Lock and 74 -- following it by Task_Unlock creates a critical region. This is used 75 -- for ensuring that a region of non-tasking code (such as code used to 76 -- allocate memory) is tasking safe. Note that it is valid for calls to 77 -- Task_Lock/Task_Unlock to be nested, and this must work properly, i.e. 78 -- only the corresponding outer level Task_Unlock will actually unlock. 79 80 procedure Task_Unlock; 81 -- Releases lock previously set by call to Task_Lock. In the nested case, 82 -- all nested locks must be released before other tasks competing for the 83 -- tasking lock are released. 84 85 function Get_Current_Excep return SSL.EOA; 86 -- Task-safe version of SSL.Get_Current_Excep 87 88 function Task_Name return String; 89 -- Returns current task's name 90 91 ------------------------ 92 -- Local Subprograms -- 93 ------------------------ 94 95 ---------------------------- 96 -- Tasking Initialization -- 97 ---------------------------- 98 99 procedure Init_RTS; 100 -- This procedure completes the initialization of the GNARL. The first part 101 -- of the initialization is done in the body of System.Tasking. It consists 102 -- of initializing global locks, and installing tasking versions of certain 103 -- operations used by the compiler. Init_RTS is called during elaboration. 104 105 -------------------------- 106 -- Change_Base_Priority -- 107 -------------------------- 108 109 -- Call only with abort deferred and holding Self_ID locked 110 111 procedure Change_Base_Priority (T : Task_Id) is 112 begin 113 if T.Common.Base_Priority /= T.New_Base_Priority then 114 T.Common.Base_Priority := T.New_Base_Priority; 115 Set_Priority (T, T.Common.Base_Priority); 116 end if; 117 end Change_Base_Priority; 118 119 ------------------------ 120 -- Check_Abort_Status -- 121 ------------------------ 122 123 function Check_Abort_Status return Integer is 124 Self_ID : constant Task_Id := Self; 125 begin 126 if Self_ID /= null 127 and then Self_ID.Deferral_Level = 0 128 and then Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level 129 then 130 return 1; 131 else 132 return 0; 133 end if; 134 end Check_Abort_Status; 135 136 ----------------- 137 -- Defer_Abort -- 138 ----------------- 139 140 procedure Defer_Abort (Self_ID : Task_Id) is 141 begin 142 if No_Abort then 143 return; 144 end if; 145 146 pragma Assert (Self_ID.Deferral_Level = 0); 147 148 -- pragma Assert 149 -- (Self_ID.Pending_ATC_Level >= Self_ID.ATC_Nesting_Level); 150 151 -- The above check has been useful in detecting mismatched defer/undefer 152 -- pairs. You may uncomment it when testing on systems that support 153 -- preemptive abort. 154 155 -- If the OS supports preemptive abort (e.g. pthread_kill), it should 156 -- have happened already. A problem is with systems that do not support 157 -- preemptive abort, and so rely on polling. On such systems we may get 158 -- false failures of the assertion, since polling for pending abort does 159 -- no occur until the abort undefer operation. 160 161 -- Even on systems that only poll for abort, the assertion may be useful 162 -- for catching missed abort completion polling points. The operations 163 -- that undefer abort poll for pending aborts. This covers most of the 164 -- places where the core Ada semantics require abort to be caught, 165 -- without any special attention. However, this generally happens on 166 -- exit from runtime system call, which means a pending abort will not 167 -- be noticed on the way into the runtime system. We considered adding a 168 -- check for pending aborts at this point, but chose not to, because of 169 -- the overhead. Instead, we searched for RTS calls where abort 170 -- completion is required and a task could go farther than Ada allows 171 -- before undeferring abort; we then modified the code to ensure the 172 -- abort would be detected. 173 174 Self_ID.Deferral_Level := Self_ID.Deferral_Level + 1; 175 end Defer_Abort; 176 177 -------------------------- 178 -- Defer_Abort_Nestable -- 179 -------------------------- 180 181 procedure Defer_Abort_Nestable (Self_ID : Task_Id) is 182 begin 183 if No_Abort then 184 return; 185 end if; 186 187 -- The following assertion is by default disabled. See the comment in 188 -- Defer_Abort on the situations in which it may be useful to uncomment 189 -- this assertion and enable the test. 190 191 -- pragma Assert 192 -- (Self_ID.Pending_ATC_Level >= Self_ID.ATC_Nesting_Level or else 193 -- Self_ID.Deferral_Level > 0); 194 195 Self_ID.Deferral_Level := Self_ID.Deferral_Level + 1; 196 end Defer_Abort_Nestable; 197 198 ----------------- 199 -- Abort_Defer -- 200 ----------------- 201 202 procedure Abort_Defer is 203 Self_ID : Task_Id; 204 begin 205 if No_Abort then 206 return; 207 end if; 208 209 Self_ID := STPO.Self; 210 Self_ID.Deferral_Level := Self_ID.Deferral_Level + 1; 211 end Abort_Defer; 212 213 ----------------------- 214 -- Get_Current_Excep -- 215 ----------------------- 216 217 function Get_Current_Excep return SSL.EOA is 218 begin 219 return STPO.Self.Common.Compiler_Data.Current_Excep'Access; 220 end Get_Current_Excep; 221 222 ----------------------- 223 -- Do_Pending_Action -- 224 ----------------------- 225 226 -- Call only when holding no locks 227 228 procedure Do_Pending_Action (Self_ID : Task_Id) is 229 230 begin 231 pragma Assert (Self_ID = Self and then Self_ID.Deferral_Level = 0); 232 233 -- Needs loop to recheck for pending action in case a new one occurred 234 -- while we had abort deferred below. 235 236 loop 237 -- Temporarily defer abort so that we can lock Self_ID 238 239 Self_ID.Deferral_Level := Self_ID.Deferral_Level + 1; 240 241 Write_Lock (Self_ID); 242 Self_ID.Pending_Action := False; 243 Unlock (Self_ID); 244 245 -- Restore the original Deferral value 246 247 Self_ID.Deferral_Level := Self_ID.Deferral_Level - 1; 248 249 if not Self_ID.Pending_Action then 250 if Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level then 251 if not Self_ID.Aborting then 252 Self_ID.Aborting := True; 253 pragma Debug 254 (Debug.Trace (Self_ID, "raise Abort_Signal", 'B')); 255 raise Standard'Abort_Signal; 256 257 pragma Assert (not Self_ID.ATC_Hack); 258 259 elsif Self_ID.ATC_Hack then 260 261 -- The solution really belongs in the Abort_Signal handler 262 -- for async. entry calls. The present hack is very 263 -- fragile. It relies that the very next point after 264 -- Exit_One_ATC_Level at which the task becomes abortable 265 -- will be the call to Undefer_Abort in the 266 -- Abort_Signal handler. 267 268 Self_ID.ATC_Hack := False; 269 270 pragma Debug 271 (Debug.Trace 272 (Self_ID, "raise Abort_Signal (ATC hack)", 'B')); 273 raise Standard'Abort_Signal; 274 end if; 275 end if; 276 277 return; 278 end if; 279 end loop; 280 end Do_Pending_Action; 281 282 ----------------------- 283 -- Final_Task_Unlock -- 284 ----------------------- 285 286 -- This version is only for use in Terminate_Task, when the task is 287 -- relinquishing further rights to its own ATCB. 288 289 -- There is a very interesting potential race condition there, where the 290 -- old task may run concurrently with a new task that is allocated the old 291 -- tasks (now reused) ATCB. The critical thing here is to not make any 292 -- reference to the ATCB after the lock is released. See also comments on 293 -- Terminate_Task and Unlock. 294 295 procedure Final_Task_Unlock (Self_ID : Task_Id) is 296 begin 297 pragma Assert (Self_ID.Common.Global_Task_Lock_Nesting = 1); 298 Unlock (Global_Task_Lock'Access); 299 end Final_Task_Unlock; 300 301 -------------- 302 -- Init_RTS -- 303 -------------- 304 305 procedure Init_RTS is 306 Self_Id : Task_Id; 307 begin 308 Tasking.Initialize; 309 310 -- Terminate run time (regular vs restricted) specific initialization 311 -- of the environment task. 312 313 Self_Id := Environment_Task; 314 Self_Id.Master_Of_Task := Environment_Task_Level; 315 Self_Id.Master_Within := Self_Id.Master_Of_Task + 1; 316 317 for L in Self_Id.Entry_Calls'Range loop 318 Self_Id.Entry_Calls (L).Self := Self_Id; 319 Self_Id.Entry_Calls (L).Level := L; 320 end loop; 321 322 Self_Id.Awake_Count := 1; 323 Self_Id.Alive_Count := 1; 324 325 -- Normally, a task starts out with internal master nesting level one 326 -- larger than external master nesting level. It is incremented to one 327 -- by Enter_Master, which is called in the task body only if the 328 -- compiler thinks the task may have dependent tasks. There is no 329 -- corresponding call to Enter_Master for the environment task, so we 330 -- would need to increment it to 2 here. Instead, we set it to 3. By 331 -- doing this we reserve the level 2 for server tasks of the runtime 332 -- system. The environment task does not need to wait for these server 333 334 Self_Id.Master_Within := Library_Task_Level; 335 336 -- Initialize lock used to implement mutual exclusion between all tasks 337 338 Initialize_Lock (Global_Task_Lock'Access, STPO.Global_Task_Level); 339 340 -- Notify that the tasking run time has been elaborated so that 341 -- the tasking version of the soft links can be used. 342 343 if not No_Abort then 344 SSL.Abort_Defer := Abort_Defer'Access; 345 SSL.Abort_Undefer := Abort_Undefer'Access; 346 end if; 347 348 SSL.Lock_Task := Task_Lock'Access; 349 SSL.Unlock_Task := Task_Unlock'Access; 350 SSL.Check_Abort_Status := Check_Abort_Status'Access; 351 SSL.Task_Name := Task_Name'Access; 352 SSL.Get_Current_Excep := Get_Current_Excep'Access; 353 354 -- Initialize the tasking soft links (if not done yet) that are common 355 -- to the full and the restricted run times. 356 357 SSL.Tasking.Init_Tasking_Soft_Links; 358 359 -- Abort is deferred in a new ATCB, so we need to undefer abort at this 360 -- stage to make the environment task abortable. 361 362 Undefer_Abort (Environment_Task); 363 end Init_RTS; 364 365 --------------------------- 366 -- Locked_Abort_To_Level-- 367 --------------------------- 368 369 -- Abort a task to the specified ATC nesting level. 370 -- Call this only with T locked. 371 372 -- An earlier version of this code contained a call to Wakeup. That should 373 -- not be necessary here, if Abort_Task is implemented correctly, since 374 -- Abort_Task should include the effect of Wakeup. However, the above call 375 -- was in earlier versions of this file, and at least for some targets 376 -- Abort_Task has not been doing Wakeup. It should not hurt to uncomment 377 -- the above call, until the error is corrected for all targets. 378 379 -- See extended comments in package body System.Tasking.Abort for the 380 -- overall design of the implementation of task abort. 381 -- ??? there is no such package ??? 382 383 -- If the task is sleeping it will be in an abort-deferred region, and will 384 -- not have Abort_Signal raised by Abort_Task. Such an "abort deferral" is 385 -- just to protect the RTS internals, and not necessarily required to 386 -- enforce Ada semantics. Abort_Task should wake the task up and let it 387 -- decide if it wants to complete the aborted construct immediately. 388 389 -- Note that the effect of the low-level Abort_Task is not persistent. 390 -- If the target task is not blocked, this wakeup will be missed. 391 392 -- We don't bother calling Abort_Task if this task is aborting itself, 393 -- since we are inside the RTS and have abort deferred. Similarly, We don't 394 -- bother to call Abort_Task if T is terminated, since there is no need to 395 -- abort a terminated task, and it could be dangerous to try if the task 396 -- has stopped executing. 397 398 -- Note that an earlier version of this code had some false reasoning about 399 -- being able to reliably wake up a task that had suspended on a blocking 400 -- system call that does not atomically release the task's lock (e.g., UNIX 401 -- nanosleep, which we once thought could be used to implement delays). 402 -- That still left the possibility of missed wakeups. 403 404 -- We cannot safely call Vulnerable_Complete_Activation here, since that 405 -- requires locking Self_ID.Parent. The anti-deadlock lock ordering rules 406 -- would then require us to release the lock on Self_ID first, which would 407 -- create a timing window for other tasks to lock Self_ID. This is 408 -- significant for tasks that may be aborted before their execution can 409 -- enter the task body, and so they do not get a chance to call 410 -- Complete_Task. The actual work for this case is done in Terminate_Task. 411 412 procedure Locked_Abort_To_Level 413 (Self_ID : Task_Id; 414 T : Task_Id; 415 L : ATC_Level_Base) 416 is 417 begin 418 if not T.Aborting and then T /= Self_ID then 419 case T.Common.State is 420 when Terminated 421 | Unactivated 422 => 423 pragma Assert (False); 424 null; 425 426 when Activating 427 | Runnable 428 => 429 if T.ATC_Nesting_Level > Level_No_ATC_Occurring then 430 -- This scenario occurs when an asynchronous protected entry 431 -- call is canceled during a requeue with abort. 432 433 T.Entry_Calls 434 (T.ATC_Nesting_Level).Cancellation_Attempted := True; 435 end if; 436 437 when Interrupt_Server_Blocked_On_Event_Flag => 438 null; 439 440 when AST_Server_Sleep 441 | Async_Select_Sleep 442 | Delay_Sleep 443 | Interrupt_Server_Blocked_Interrupt_Sleep 444 | Interrupt_Server_Idle_Sleep 445 | Timer_Server_Sleep 446 => 447 Wakeup (T, T.Common.State); 448 449 when Acceptor_Delay_Sleep 450 | Acceptor_Sleep 451 => 452 T.Open_Accepts := null; 453 Wakeup (T, T.Common.State); 454 455 when Entry_Caller_Sleep => 456 pragma Assert (T.ATC_Nesting_Level > Level_No_ATC_Occurring); 457 458 T.Entry_Calls 459 (T.ATC_Nesting_Level).Cancellation_Attempted := True; 460 Wakeup (T, T.Common.State); 461 462 when Activator_Sleep 463 | Asynchronous_Hold 464 | Master_Completion_Sleep 465 | Master_Phase_2_Sleep 466 => 467 null; 468 end case; 469 end if; 470 471 if T.Pending_ATC_Level > L then 472 T.Pending_ATC_Level := L; 473 T.Pending_Action := True; 474 475 if L = Level_Completed_Task then 476 T.Callable := False; 477 end if; 478 479 -- This prevents aborted task from accepting calls 480 481 if T.Aborting then 482 483 -- The test above is just a heuristic, to reduce wasteful 484 -- calls to Abort_Task. We are holding T locked, and this 485 -- value will not be set to False except with T also locked, 486 -- inside Exit_One_ATC_Level, so we should not miss wakeups. 487 488 if T.Common.State = Acceptor_Sleep 489 or else 490 T.Common.State = Acceptor_Delay_Sleep 491 then 492 T.Open_Accepts := null; 493 end if; 494 495 elsif T /= Self_ID and then 496 (T.Common.State = Runnable 497 or else T.Common.State = Interrupt_Server_Blocked_On_Event_Flag) 498 499 -- The task is blocked on a system call waiting for the 500 -- completion event. In this case Abort_Task may need to take 501 -- special action in order to succeed. 502 503 then 504 Abort_Task (T); 505 end if; 506 end if; 507 end Locked_Abort_To_Level; 508 509 -------------------------------- 510 -- Remove_From_All_Tasks_List -- 511 -------------------------------- 512 513 procedure Remove_From_All_Tasks_List (T : Task_Id) is 514 C : Task_Id; 515 Previous : Task_Id; 516 517 begin 518 pragma Debug 519 (Debug.Trace (Self, "Remove_From_All_Tasks_List", 'C')); 520 521 Previous := Null_Task; 522 C := All_Tasks_List; 523 while C /= Null_Task loop 524 if C = T then 525 if Previous = Null_Task then 526 All_Tasks_List := All_Tasks_List.Common.All_Tasks_Link; 527 else 528 Previous.Common.All_Tasks_Link := C.Common.All_Tasks_Link; 529 end if; 530 531 return; 532 end if; 533 534 Previous := C; 535 C := C.Common.All_Tasks_Link; 536 end loop; 537 538 pragma Assert (False); 539 end Remove_From_All_Tasks_List; 540 541 --------------- 542 -- Task_Lock -- 543 --------------- 544 545 procedure Task_Lock (Self_ID : Task_Id) is 546 begin 547 Self_ID.Common.Global_Task_Lock_Nesting := 548 Self_ID.Common.Global_Task_Lock_Nesting + 1; 549 550 if Self_ID.Common.Global_Task_Lock_Nesting = 1 then 551 Defer_Abort_Nestable (Self_ID); 552 Write_Lock (Global_Task_Lock'Access); 553 end if; 554 end Task_Lock; 555 556 procedure Task_Lock is 557 begin 558 Task_Lock (STPO.Self); 559 end Task_Lock; 560 561 --------------- 562 -- Task_Name -- 563 --------------- 564 565 function Task_Name return String is 566 Self_Id : constant Task_Id := STPO.Self; 567 begin 568 return Self_Id.Common.Task_Image (1 .. Self_Id.Common.Task_Image_Len); 569 end Task_Name; 570 571 ----------------- 572 -- Task_Unlock -- 573 ----------------- 574 575 procedure Task_Unlock (Self_ID : Task_Id) is 576 begin 577 pragma Assert (Self_ID.Common.Global_Task_Lock_Nesting > 0); 578 Self_ID.Common.Global_Task_Lock_Nesting := 579 Self_ID.Common.Global_Task_Lock_Nesting - 1; 580 581 if Self_ID.Common.Global_Task_Lock_Nesting = 0 then 582 Unlock (Global_Task_Lock'Access); 583 Undefer_Abort_Nestable (Self_ID); 584 end if; 585 end Task_Unlock; 586 587 procedure Task_Unlock is 588 begin 589 Task_Unlock (STPO.Self); 590 end Task_Unlock; 591 592 ------------------- 593 -- Undefer_Abort -- 594 ------------------- 595 596 -- Precondition : Self does not hold any locks 597 598 -- Undefer_Abort is called on any abort completion point (aka. 599 -- synchronization point). It performs the following actions if they 600 -- are pending: (1) change the base priority, (2) abort the task. 601 602 -- The priority change has to occur before abort. Otherwise, it would 603 -- take effect no earlier than the next abort completion point. 604 605 procedure Undefer_Abort (Self_ID : Task_Id) is 606 begin 607 if No_Abort then 608 return; 609 end if; 610 611 pragma Assert (Self_ID.Deferral_Level = 1); 612 613 Self_ID.Deferral_Level := Self_ID.Deferral_Level - 1; 614 615 if Self_ID.Deferral_Level = 0 then 616 pragma Assert (Check_No_Locks (Self_ID)); 617 618 if Self_ID.Pending_Action then 619 Do_Pending_Action (Self_ID); 620 end if; 621 end if; 622 end Undefer_Abort; 623 624 ---------------------------- 625 -- Undefer_Abort_Nestable -- 626 ---------------------------- 627 628 -- An earlier version would re-defer abort if an abort is in progress. 629 -- Then, we modified the effect of the raise statement so that it defers 630 -- abort until control reaches a handler. That was done to prevent 631 -- "skipping over" a handler if another asynchronous abort occurs during 632 -- the propagation of the abort to the handler. 633 634 -- There has been talk of reversing that decision, based on a newer 635 -- implementation of exception propagation. Care must be taken to evaluate 636 -- how such a change would interact with the above code and all the places 637 -- where abort-deferral is used to bridge over critical transitions, such 638 -- as entry to the scope of a region with a finalizer and entry into the 639 -- body of an accept-procedure. 640 641 procedure Undefer_Abort_Nestable (Self_ID : Task_Id) is 642 begin 643 if No_Abort then 644 return; 645 end if; 646 647 pragma Assert (Self_ID.Deferral_Level > 0); 648 649 Self_ID.Deferral_Level := Self_ID.Deferral_Level - 1; 650 651 if Self_ID.Deferral_Level = 0 then 652 653 pragma Assert (Check_No_Locks (Self_ID)); 654 655 if Self_ID.Pending_Action then 656 Do_Pending_Action (Self_ID); 657 end if; 658 end if; 659 end Undefer_Abort_Nestable; 660 661 ------------------- 662 -- Abort_Undefer -- 663 ------------------- 664 665 procedure Abort_Undefer is 666 Self_ID : Task_Id; 667 begin 668 if No_Abort then 669 return; 670 end if; 671 672 Self_ID := STPO.Self; 673 674 if Self_ID.Deferral_Level = 0 then 675 676 -- In case there are different views on whether Abort is supported 677 -- between the expander and the run time, we may end up with 678 -- Self_ID.Deferral_Level being equal to zero, when called from 679 -- the procedure created by the expander that corresponds to a 680 -- task body. In this case, there's nothing to be done. 681 682 -- See related code in System.Tasking.Stages.Create_Task resetting 683 -- Deferral_Level when System.Restrictions.Abort_Allowed is False. 684 685 return; 686 end if; 687 688 pragma Assert (Self_ID.Deferral_Level > 0); 689 Self_ID.Deferral_Level := Self_ID.Deferral_Level - 1; 690 691 if Self_ID.Deferral_Level = 0 then 692 pragma Assert (Check_No_Locks (Self_ID)); 693 694 if Self_ID.Pending_Action then 695 Do_Pending_Action (Self_ID); 696 end if; 697 end if; 698 end Abort_Undefer; 699 700 -------------------------- 701 -- Wakeup_Entry_Caller -- 702 -------------------------- 703 704 -- This is called at the end of service of an entry call, to abort the 705 -- caller if he is in an abortable part, and to wake up the caller if it 706 -- is on Entry_Caller_Sleep. It assumes that the call is already off-queue. 707 708 -- (This enforces the rule that a task must be off-queue if its state is 709 -- Done or Cancelled.) Call it holding the lock of Entry_Call.Self. 710 711 -- Timed_Call or Simple_Call: 712 -- The caller is waiting on Entry_Caller_Sleep, in 713 -- Wait_For_Completion, or Wait_For_Completion_With_Timeout. 714 715 -- Conditional_Call: 716 -- The caller might be in Wait_For_Completion, 717 -- waiting for a rendezvous (possibly requeued without abort) 718 -- to complete. 719 720 -- Asynchronous_Call: 721 -- The caller may be executing in the abortable part o 722 -- an async. select, or on a time delay, 723 -- if Entry_Call.State >= Was_Abortable. 724 725 procedure Wakeup_Entry_Caller 726 (Self_ID : Task_Id; 727 Entry_Call : Entry_Call_Link; 728 New_State : Entry_Call_State) 729 is 730 Caller : constant Task_Id := Entry_Call.Self; 731 732 begin 733 pragma Debug (Debug.Trace 734 (Self_ID, "Wakeup_Entry_Caller", 'E', Caller)); 735 pragma Assert (New_State = Done or else New_State = Cancelled); 736 737 pragma Assert (Caller.Common.State /= Unactivated); 738 739 Entry_Call.State := New_State; 740 741 if Entry_Call.Mode = Asynchronous_Call then 742 743 -- Abort the caller in his abortable part, but do so only if call has 744 -- been queued abortably. 745 746 if Entry_Call.State >= Was_Abortable or else New_State = Done then 747 Locked_Abort_To_Level (Self_ID, Caller, Entry_Call.Level - 1); 748 end if; 749 750 elsif Caller.Common.State = Entry_Caller_Sleep then 751 Wakeup (Caller, Entry_Caller_Sleep); 752 end if; 753 end Wakeup_Entry_Caller; 754 755 ------------------------- 756 -- Finalize_Attributes -- 757 ------------------------- 758 759 procedure Finalize_Attributes (T : Task_Id) is 760 Attr : Atomic_Address; 761 762 begin 763 for J in T.Attributes'Range loop 764 Attr := T.Attributes (J); 765 766 if Attr /= 0 and then Task_Attributes.Require_Finalization (J) then 767 Task_Attributes.To_Attribute (Attr).Free (Attr); 768 T.Attributes (J) := 0; 769 end if; 770 end loop; 771 end Finalize_Attributes; 772 773begin 774 Init_RTS; 775end System.Tasking.Initialization; 776