gcc/ada/5htaprop.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS               --
   4 --                                                                          --
   5 --     S Y S T E M . T A S K _ P R I M I T I V E S . O P E R A T I O N S    --
   6 --                                                                          --
   7 --                                  B o d y                                 --
   8 --                                                                          --
   9 --                             $Revision: 1.42 $
  10 --                                                                          --
  11 --             Copyright (C) 1991-2001, Florida State University            --
  12 --                                                                          --
  13 -- GNARL is free software; you can  redistribute it  and/or modify it under --
  14 -- terms of the  GNU General Public License as published  by the Free Soft- --
  15 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  16 -- sion. GNARL is distributed in the hope that it will be useful, but WITH- --
  17 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  18 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  19 -- for  more details.  You should have  received  a copy of the GNU General --
  20 -- Public License  distributed with GNARL; see file COPYING.  If not, write --
  21 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  22 -- MA 02111-1307, USA.                                                      --
  23 --                                                                          --
  24 -- As a special exception,  if other files  instantiate  generics from this --
  25 -- unit, or you link  this unit with other files  to produce an executable, --
  26 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  27 -- covered  by the  GNU  General  Public  License.  This exception does not --
  28 -- however invalidate  any other reasons why  the executable file  might be --
  29 -- covered by the  GNU Public License.                                      --
  30 --                                                                          --
  31 -- GNARL was developed by the GNARL team at Florida State University. It is --
  32 -- now maintained by Ada Core Technologies Inc. in cooperation with Florida --
  33 -- State University (http://www.gnat.com).                                  --
  34 --                                                                          --
  35 ------------------------------------------------------------------------------
  36
  37 --  This is a HP-UX version of this package
  38
  39 --  This package contains all the GNULL primitives that interface directly
  40 --  with the underlying OS.
  41
  42 pragma Polling (Off);
  43 --  Turn off polling, we do not want ATC polling to take place during
  44 --  tasking operations. It causes infinite loops and other problems.
  45
  46 with System.Tasking.Debug;
  47 --  used for Known_Tasks
  48
  49 with Interfaces.C;
  50 --  used for int
  51 --           size_t
  52
  53 with System.Interrupt_Management;
  54 --  used for Keep_Unmasked
  55 --           Abort_Task_Interrupt
  56 --           Interrupt_ID
  57
  58 with System.Interrupt_Management.Operations;
  59 --  used for Set_Interrupt_Mask
  60 --           All_Tasks_Mask
  61 pragma Elaborate_All (System.Interrupt_Management.Operations);
  62
  63 with System.Parameters;
  64 --  used for Size_Type
  65
  66 with System.Task_Primitives.Interrupt_Operations;
  67 --  used for Get_Interrupt_ID
  68
  69 with System.Tasking;
  70 --  used for Ada_Task_Control_Block
  71 --           Task_ID
  72
  73 with System.Soft_Links;
  74 --  used for Defer/Undefer_Abort
  75
  76 --  Note that we do not use System.Tasking.Initialization directly since
  77 --  this is a higher level package that we shouldn't depend on. For example
  78 --  when using the restricted run time, it is replaced by
  79 --  System.Tasking.Restricted.Initialization
  80
  81 with System.OS_Primitives;
  82 --  used for Delay_Modes
  83
  84 with Unchecked_Conversion;
  85 with Unchecked_Deallocation;
  86
  87 package body System.Task_Primitives.Operations is
  88
  89    use System.Tasking.Debug;
  90    use System.Tasking;
  91    use Interfaces.C;
  92    use System.OS_Interface;
  93    use System.Parameters;
  94    use System.OS_Primitives;
  95
  96    package PIO renames System.Task_Primitives.Interrupt_Operations;
  97    package SSL renames System.Soft_Links;
  98
  99    ------------------
 100    --  Local Data  --
 101    ------------------
 102
 103    --  The followings are logically constants, but need to be initialized
 104    --  at run time.
 105
 106    ATCB_Key : aliased pthread_key_t;
 107    --  Key used to find the Ada Task_ID associated with a thread
 108
 109    All_Tasks_L : aliased System.Task_Primitives.RTS_Lock;
 110    --  See comments on locking rules in System.Tasking (spec).
 111
 112    Environment_Task_ID : Task_ID;
 113    --  A variable to hold Task_ID for the environment task.
 114
 115    Unblocked_Signal_Mask : aliased sigset_t;
 116    --  The set of signals that should unblocked in all tasks
 117
 118    Time_Slice_Val : Integer;
 119    pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
 120
 121    Locking_Policy : Character;
 122    pragma Import (C, Locking_Policy, "__gl_locking_policy");
 123
 124    Dispatching_Policy : Character;
 125    pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy");
 126
 127    FIFO_Within_Priorities : constant Boolean := Dispatching_Policy = 'F';
 128    --  Indicates whether FIFO_Within_Priorities is set.
 129
 130    --  The followings are internal configuration constants needed.
 131
 132    -----------------------
 133    -- Local Subprograms --
 134    -----------------------
 135
 136    procedure Abort_Handler (Sig : Signal);
 137
 138    function To_Task_ID is new Unchecked_Conversion (System.Address, Task_ID);
 139
 140    function To_Address is new Unchecked_Conversion (Task_ID, System.Address);
 141
 142    -------------------
 143    -- Abort_Handler --
 144    -------------------
 145
 146    --  Target-dependent binding of inter-thread Abort signal to
 147    --  the raising of the Abort_Signal exception.
 148
 149    --  The technical issues and alternatives here are essentially
 150    --  the same as for raising exceptions in response to other
 151    --  signals (e.g. Storage_Error).  See code and comments in
 152    --  the package body System.Interrupt_Management.
 153
 154    --  Some implementations may not allow an exception to be propagated
 155    --  out of a handler, and others might leave the signal or
 156    --  interrupt that invoked this handler masked after the exceptional
 157    --  return to the application code.
 158
 159    --  GNAT exceptions are originally implemented using setjmp()/longjmp().
 160    --  On most UNIX systems, this will allow transfer out of a signal handler,
 161    --  which is usually the only mechanism available for implementing
 162    --  asynchronous handlers of this kind.  However, some
 163    --  systems do not restore the signal mask on longjmp(), leaving the
 164    --  abort signal masked.
 165
 166    --  Alternative solutions include:
 167
 168    --       1. Change the PC saved in the system-dependent Context
 169    --          parameter to point to code that raises the exception.
 170    --          Normal return from this handler will then raise
 171    --          the exception after the mask and other system state has
 172    --          been restored (see example below).
 173    --       2. Use siglongjmp()/sigsetjmp() to implement exceptions.
 174    --       3. Unmask the signal in the Abortion_Signal exception handler
 175    --          (in the RTS).
 176
 177    --  The following procedure would be needed if we can't lonjmp out of
 178    --  a signal handler.  (See below.)
 179    --  procedure Raise_Abort_Signal is
 180    --  begin
 181    --     raise Standard'Abort_Signal;
 182    --  end if;
 183
 184    procedure Abort_Handler (Sig : Signal) is
 185       Self_Id : constant Task_ID := Self;
 186       Result  : Interfaces.C.int;
 187       Old_Set : aliased sigset_t;
 188
 189    begin
 190       --  Assuming it is safe to longjmp out of a signal handler, the
 191       --  following code can be used:
 192
 193       if Self_Id.Deferral_Level = 0
 194         and then Self_Id.Pending_ATC_Level < Self_Id.ATC_Nesting_Level and then
 195         not Self_Id.Aborting
 196       then
 197          Self_Id.Aborting := True;
 198
 199          --  Make sure signals used for RTS internal purpose are unmasked
 200
 201          Result := pthread_sigmask (SIG_UNBLOCK,
 202            Unblocked_Signal_Mask'Unchecked_Access, Old_Set'Unchecked_Access);
 203          pragma Assert (Result = 0);
 204
 205          raise Standard'Abort_Signal;
 206       end if;
 207
 208       --  Otherwise, something like this is required:
 209       --  if not Abort_Is_Deferred.all then
 210       --    --  Overwrite the return PC address with the address of the
 211       --    --  special raise routine, and "return" to that routine's
 212       --    --  starting address.
 213       --    Context.PC := Raise_Abort_Signal'Address;
 214       --    return;
 215       --  end if;
 216    end Abort_Handler;
 217
 218    -----------------
 219    -- Stack_Guard --
 220    -----------------
 221
 222    --  The underlying thread system sets a guard page at the
 223    --  bottom of a thread stack, so nothing is needed.
 224    --  ??? Check the comment above
 225
 226    procedure Stack_Guard (T : ST.Task_ID; On : Boolean) is
 227    begin
 228       null;
 229    end Stack_Guard;
 230
 231    -------------------
 232    -- Get_Thread_Id --
 233    -------------------
 234
 235    function Get_Thread_Id (T : ST.Task_ID) return OSI.Thread_Id is
 236    begin
 237       return T.Common.LL.Thread;
 238    end Get_Thread_Id;
 239
 240    ----------
 241    -- Self --
 242    ----------
 243
 244    function Self return Task_ID is
 245       Result : System.Address;
 246
 247    begin
 248       Result := pthread_getspecific (ATCB_Key);
 249       pragma Assert (Result /= System.Null_Address);
 250       return To_Task_ID (Result);
 251    end Self;
 252
 253    ---------------------
 254    -- Initialize_Lock --
 255    ---------------------
 256
 257    --  Note: mutexes and cond_variables needed per-task basis are
 258    --        initialized in Intialize_TCB and the Storage_Error is
 259    --        handled. Other mutexes (such as All_Tasks_Lock, Memory_Lock...)
 260    --        used in RTS is initialized before any status change of RTS.
 261    --        Therefore rasing Storage_Error in the following routines
 262    --        should be able to be handled safely.
 263
 264    procedure Initialize_Lock
 265      (Prio : System.Any_Priority;
 266       L    : access Lock)
 267    is
 268       Attributes : aliased pthread_mutexattr_t;
 269       Result : Interfaces.C.int;
 270    begin
 271       Result := pthread_mutexattr_init (Attributes'Access);
 272       pragma Assert (Result = 0 or else Result = ENOMEM);
 273
 274       if Result = ENOMEM then
 275          raise Storage_Error;
 276       end if;
 277
 278       L.Priority := Prio;
 279
 280       Result := pthread_mutex_init (L.L'Access, Attributes'Access);
 281       pragma Assert (Result = 0 or else Result = ENOMEM);
 282
 283       if Result = ENOMEM then
 284          raise Storage_Error;
 285       end if;
 286
 287       Result := pthread_mutexattr_destroy (Attributes'Access);
 288       pragma Assert (Result = 0);
 289    end Initialize_Lock;
 290
 291    procedure Initialize_Lock (L : access RTS_Lock; Level : Lock_Level) is
 292       Attributes : aliased pthread_mutexattr_t;
 293       Result : Interfaces.C.int;
 294
 295    begin
 296       Result := pthread_mutexattr_init (Attributes'Access);
 297       pragma Assert (Result = 0 or else Result = ENOMEM);
 298
 299       if Result = ENOMEM then
 300          raise Storage_Error;
 301       end if;
 302
 303       Result := pthread_mutex_init (L, Attributes'Access);
 304
 305       pragma Assert (Result = 0 or else Result = ENOMEM);
 306
 307       if Result = ENOMEM then
 308          raise Storage_Error;
 309       end if;
 310
 311       Result := pthread_mutexattr_destroy (Attributes'Access);
 312       pragma Assert (Result = 0);
 313    end Initialize_Lock;
 314
 315    -------------------
 316    -- Finalize_Lock --
 317    -------------------
 318
 319    procedure Finalize_Lock (L : access Lock) is
 320       Result : Interfaces.C.int;
 321
 322    begin
 323       Result := pthread_mutex_destroy (L.L'Access);
 324       pragma Assert (Result = 0);
 325    end Finalize_Lock;
 326
 327    procedure Finalize_Lock (L : access RTS_Lock) is
 328       Result : Interfaces.C.int;
 329
 330    begin
 331       Result := pthread_mutex_destroy (L);
 332       pragma Assert (Result = 0);
 333    end Finalize_Lock;
 334
 335    ----------------
 336    -- Write_Lock --
 337    ----------------
 338
 339    procedure Write_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
 340       Result    : Interfaces.C.int;
 341
 342    begin
 343       L.Owner_Priority := Get_Priority (Self);
 344
 345       if L.Priority < L.Owner_Priority then
 346          Ceiling_Violation := True;
 347          return;
 348       end if;
 349
 350       Result := pthread_mutex_lock (L.L'Access);
 351       pragma Assert (Result = 0);
 352       Ceiling_Violation := False;
 353    end Write_Lock;
 354
 355    procedure Write_Lock (L : access RTS_Lock) is
 356       Result : Interfaces.C.int;
 357
 358    begin
 359       Result := pthread_mutex_lock (L);
 360       pragma Assert (Result = 0);
 361    end Write_Lock;
 362
 363    procedure Write_Lock (T : Task_ID) is
 364       Result : Interfaces.C.int;
 365
 366    begin
 367       Result := pthread_mutex_lock (T.Common.LL.L'Access);
 368       pragma Assert (Result = 0);
 369    end Write_Lock;
 370
 371    ---------------
 372    -- Read_Lock --
 373    ---------------
 374
 375    procedure Read_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
 376    begin
 377       Write_Lock (L, Ceiling_Violation);
 378    end Read_Lock;
 379
 380    ------------
 381    -- Unlock --
 382    ------------
 383
 384    procedure Unlock (L : access Lock) is
 385       Result    : Interfaces.C.int;
 386
 387    begin
 388       Result := pthread_mutex_unlock (L.L'Access);
 389       pragma Assert (Result = 0);
 390    end Unlock;
 391
 392    procedure Unlock (L : access RTS_Lock) is
 393       Result : Interfaces.C.int;
 394
 395    begin
 396       Result := pthread_mutex_unlock (L);
 397       pragma Assert (Result = 0);
 398    end Unlock;
 399
 400    procedure Unlock (T : Task_ID) is
 401       Result : Interfaces.C.int;
 402
 403    begin
 404       Result := pthread_mutex_unlock (T.Common.LL.L'Access);
 405       pragma Assert (Result = 0);
 406    end Unlock;
 407
 408    -------------
 409    --  Sleep  --
 410    -------------
 411
 412    procedure Sleep (Self_ID : Task_ID;
 413                     Reason   : System.Tasking.Task_States) is
 414       Result : Interfaces.C.int;
 415
 416    begin
 417       pragma Assert (Self_ID = Self);
 418       Result := pthread_cond_wait (Self_ID.Common.LL.CV'Access,
 419         Self_ID.Common.LL.L'Access);
 420       --  EINTR is not considered a failure.
 421       pragma Assert (Result = 0 or else Result = EINTR);
 422    end Sleep;
 423
 424    -----------------
 425    -- Timed_Sleep --
 426    -----------------
 427
 428    --  This is for use within the run-time system, so abort is
 429    --  assumed to be already deferred, and the caller should be
 430    --  holding its own ATCB lock.
 431
 432    procedure Timed_Sleep
 433      (Self_ID  : Task_ID;
 434       Time     : Duration;
 435       Mode     : ST.Delay_Modes;
 436       Reason   : System.Tasking.Task_States;
 437       Timedout : out Boolean;
 438       Yielded  : out Boolean)
 439    is
 440       Check_Time : constant Duration := Monotonic_Clock;
 441       Abs_Time   : Duration;
 442       Request    : aliased timespec;
 443       Result     : Interfaces.C.int;
 444    begin
 445       Timedout := True;
 446       Yielded := False;
 447
 448       if Mode = Relative then
 449          Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
 450       else
 451          Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
 452       end if;
 453
 454       if Abs_Time > Check_Time then
 455          Request := To_Timespec (Abs_Time);
 456
 457          loop
 458             exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level
 459               or else Self_ID.Pending_Priority_Change;
 460
 461             Result := pthread_cond_timedwait
 462               (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access,
 463                Request'Access);
 464
 465             exit when Abs_Time <= Monotonic_Clock;
 466
 467             if Result = 0 or Result = EINTR then
 468                --  somebody may have called Wakeup for us
 469                Timedout := False;
 470                exit;
 471             end if;
 472
 473             pragma Assert (Result = ETIMEDOUT);
 474          end loop;
 475       end if;
 476    end Timed_Sleep;
 477
 478    -----------------
 479    -- Timed_Delay --
 480    -----------------
 481
 482    --  This is for use in implementing delay statements, so
 483    --  we assume the caller is abort-deferred but is holding
 484    --  no locks.
 485
 486    procedure Timed_Delay
 487      (Self_ID  : Task_ID;
 488       Time     : Duration;
 489       Mode     : ST.Delay_Modes)
 490    is
 491       Check_Time : constant Duration := Monotonic_Clock;
 492       Abs_Time   : Duration;
 493       Request    : aliased timespec;
 494       Result     : Interfaces.C.int;
 495    begin
 496
 497       --  Only the little window between deferring abort and
 498       --  locking Self_ID is the reason we need to
 499       --  check for pending abort and priority change below! :(
 500
 501       SSL.Abort_Defer.all;
 502       Write_Lock (Self_ID);
 503
 504       if Mode = Relative then
 505          Abs_Time := Time + Check_Time;
 506       else
 507          Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
 508       end if;
 509
 510       if Abs_Time > Check_Time then
 511          Request := To_Timespec (Abs_Time);
 512          Self_ID.Common.State := Delay_Sleep;
 513
 514          loop
 515             if Self_ID.Pending_Priority_Change then
 516                Self_ID.Pending_Priority_Change := False;
 517                Self_ID.Common.Base_Priority := Self_ID.New_Base_Priority;
 518                Set_Priority (Self_ID, Self_ID.Common.Base_Priority);
 519             end if;
 520
 521             exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
 522
 523             Result := pthread_cond_timedwait (Self_ID.Common.LL.CV'Access,
 524               Self_ID.Common.LL.L'Access, Request'Access);
 525
 526             exit when Abs_Time <= Monotonic_Clock;
 527
 528             pragma Assert (Result = 0 or else
 529               Result = ETIMEDOUT or else
 530               Result = EINTR);
 531          end loop;
 532
 533          Self_ID.Common.State := Runnable;
 534       end if;
 535
 536       Unlock (Self_ID);
 537       Result := sched_yield;
 538       SSL.Abort_Undefer.all;
 539    end Timed_Delay;
 540
 541    ---------------------
 542    -- Monotonic_Clock --
 543    ---------------------
 544
 545    function Monotonic_Clock return Duration is
 546       TS     : aliased timespec;
 547       Result : Interfaces.C.int;
 548
 549    begin
 550       Result := Clock_Gettime (CLOCK_REALTIME, TS'Unchecked_Access);
 551       pragma Assert (Result = 0);
 552       return To_Duration (TS);
 553    end Monotonic_Clock;
 554
 555    -------------------
 556    -- RT_Resolution --
 557    -------------------
 558
 559    function RT_Resolution return Duration is
 560    begin
 561       return 10#1.0#E-6;
 562    end RT_Resolution;
 563
 564    ------------
 565    -- Wakeup --
 566    ------------
 567
 568    procedure Wakeup (T : Task_ID; Reason : System.Tasking.Task_States) is
 569       Result : Interfaces.C.int;
 570
 571    begin
 572       Result := pthread_cond_signal (T.Common.LL.CV'Access);
 573       pragma Assert (Result = 0);
 574    end Wakeup;
 575
 576    -----------
 577    -- Yield --
 578    -----------
 579
 580    procedure Yield (Do_Yield : Boolean := True) is
 581       Result : Interfaces.C.int;
 582
 583    begin
 584       if Do_Yield then
 585          Result := sched_yield;
 586       end if;
 587    end Yield;
 588
 589    ------------------
 590    -- Set_Priority --
 591    ------------------
 592
 593    type Prio_Array_Type is array (System.Any_Priority) of Integer;
 594    pragma Atomic_Components (Prio_Array_Type);
 595
 596    Prio_Array : Prio_Array_Type;
 597    --  Global array containing the id of the currently running task for
 598    --  each priority.
 599    --
 600    --  Note: we assume that we are on a single processor with run-til-blocked
 601    --  scheduling.
 602
 603    procedure Set_Priority
 604      (T : Task_ID;
 605       Prio : System.Any_Priority;
 606       Loss_Of_Inheritance : Boolean := False)
 607    is
 608       Result     : Interfaces.C.int;
 609       Array_Item : Integer;
 610       Param      : aliased struct_sched_param;
 611
 612    begin
 613       Param.sched_priority  := Interfaces.C.int (Underlying_Priorities (Prio));
 614
 615       if Time_Slice_Val > 0 then
 616          Result := pthread_setschedparam
 617            (T.Common.LL.Thread, SCHED_RR, Param'Access);
 618
 619       elsif FIFO_Within_Priorities or else Time_Slice_Val = 0 then
 620          Result := pthread_setschedparam
 621            (T.Common.LL.Thread, SCHED_FIFO, Param'Access);
 622
 623       else
 624          Result := pthread_setschedparam
 625            (T.Common.LL.Thread, SCHED_OTHER, Param'Access);
 626       end if;
 627
 628       pragma Assert (Result = 0);
 629
 630       if FIFO_Within_Priorities then
 631
 632          --  Annex D requirement [RM D.2.2 par. 9]:
 633          --    If the task drops its priority due to the loss of inherited
 634          --    priority, it is added at the head of the ready queue for its
 635          --    new active priority.
 636
 637          if Loss_Of_Inheritance
 638            and then Prio < T.Common.Current_Priority
 639          then
 640             Array_Item := Prio_Array (T.Common.Base_Priority) + 1;
 641             Prio_Array (T.Common.Base_Priority) := Array_Item;
 642
 643             loop
 644                --  Let some processes a chance to arrive
 645
 646                Yield;
 647
 648                --  Then wait for our turn to proceed
 649
 650                exit when Array_Item = Prio_Array (T.Common.Base_Priority)
 651                  or else Prio_Array (T.Common.Base_Priority) = 1;
 652             end loop;
 653
 654             Prio_Array (T.Common.Base_Priority) :=
 655               Prio_Array (T.Common.Base_Priority) - 1;
 656          end if;
 657       end if;
 658
 659       T.Common.Current_Priority := Prio;
 660    end Set_Priority;
 661
 662    ------------------
 663    -- Get_Priority --
 664    ------------------
 665
 666    function Get_Priority (T : Task_ID) return System.Any_Priority is
 667    begin
 668       return T.Common.Current_Priority;
 669    end Get_Priority;
 670
 671    ----------------
 672    -- Enter_Task --
 673    ----------------
 674
 675    procedure Enter_Task (Self_ID : Task_ID) is
 676       Result  : Interfaces.C.int;
 677
 678    begin
 679       Self_ID.Common.LL.Thread := pthread_self;
 680
 681       Result := pthread_setspecific (ATCB_Key, To_Address (Self_ID));
 682       pragma Assert (Result = 0);
 683
 684       Lock_All_Tasks_List;
 685       for I in Known_Tasks'Range loop
 686          if Known_Tasks (I) = null then
 687             Known_Tasks (I) := Self_ID;
 688             Self_ID.Known_Tasks_Index := I;
 689             exit;
 690          end if;
 691       end loop;
 692       Unlock_All_Tasks_List;
 693    end Enter_Task;
 694
 695    --------------
 696    -- New_ATCB --
 697    --------------
 698
 699    function New_ATCB (Entry_Num : Task_Entry_Index) return Task_ID is
 700    begin
 701       return new Ada_Task_Control_Block (Entry_Num);
 702    end New_ATCB;
 703
 704    ----------------------
 705    --  Initialize_TCB  --
 706    ----------------------
 707
 708    procedure Initialize_TCB (Self_ID : Task_ID; Succeeded : out Boolean) is
 709       Mutex_Attr : aliased pthread_mutexattr_t;
 710       Result : Interfaces.C.int;
 711       Cond_Attr : aliased pthread_condattr_t;
 712
 713    begin
 714       Result := pthread_mutexattr_init (Mutex_Attr'Access);
 715       pragma Assert (Result = 0 or else Result = ENOMEM);
 716
 717       if Result /= 0 then
 718          Succeeded := False;
 719          return;
 720       end if;
 721
 722       Result := pthread_mutex_init (Self_ID.Common.LL.L'Access,
 723         Mutex_Attr'Access);
 724       pragma Assert (Result = 0 or else Result = ENOMEM);
 725
 726       if Result /= 0 then
 727          Succeeded := False;
 728          return;
 729       end if;
 730
 731       Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
 732       pragma Assert (Result = 0);
 733
 734       Result := pthread_condattr_init (Cond_Attr'Access);
 735       pragma Assert (Result = 0 or else Result = ENOMEM);
 736
 737       if Result /= 0 then
 738          Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access);
 739          pragma Assert (Result = 0);
 740          Succeeded := False;
 741          return;
 742       end if;
 743
 744       Result := pthread_cond_init (Self_ID.Common.LL.CV'Access,
 745         Cond_Attr'Access);
 746       pragma Assert (Result = 0 or else Result = ENOMEM);
 747
 748       if Result = 0 then
 749          Succeeded := True;
 750       else
 751          Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access);
 752          pragma Assert (Result = 0);
 753          Succeeded := False;
 754       end if;
 755
 756       Result := pthread_condattr_destroy (Cond_Attr'Access);
 757       pragma Assert (Result = 0);
 758    end Initialize_TCB;
 759
 760    -----------------
 761    -- Create_Task --
 762    -----------------
 763
 764    procedure Create_Task
 765      (T          : Task_ID;
 766       Wrapper    : System.Address;
 767       Stack_Size : System.Parameters.Size_Type;
 768       Priority   : System.Any_Priority;
 769       Succeeded  : out Boolean)
 770    is
 771       Attributes          : aliased pthread_attr_t;
 772       Adjusted_Stack_Size : Interfaces.C.size_t;
 773       Result              : Interfaces.C.int;
 774
 775       function Thread_Body_Access is new
 776         Unchecked_Conversion (System.Address, Thread_Body);
 777
 778    begin
 779       if Stack_Size = Unspecified_Size then
 780          Adjusted_Stack_Size := Interfaces.C.size_t (Default_Stack_Size);
 781
 782       elsif Stack_Size < Minimum_Stack_Size then
 783          Adjusted_Stack_Size := Interfaces.C.size_t (Minimum_Stack_Size);
 784
 785       else
 786          Adjusted_Stack_Size := Interfaces.C.size_t (Stack_Size);
 787       end if;
 788
 789       Result := pthread_attr_init (Attributes'Access);
 790       pragma Assert (Result = 0 or else Result = ENOMEM);
 791
 792       if Result /= 0 then
 793          Succeeded := False;
 794          return;
 795       end if;
 796
 797       Result := pthread_attr_setstacksize
 798         (Attributes'Access, Adjusted_Stack_Size);
 799       pragma Assert (Result = 0);
 800
 801       --  Since the initial signal mask of a thread is inherited from the
 802       --  creator, and the Environment task has all its signals masked, we
 803       --  do not need to manipulate caller's signal mask at this point.
 804       --  All tasks in RTS will have All_Tasks_Mask initially.
 805
 806       Result := pthread_create
 807         (T.Common.LL.Thread'Access,
 808          Attributes'Access,
 809          Thread_Body_Access (Wrapper),
 810          To_Address (T));
 811       pragma Assert (Result = 0 or else Result = EAGAIN);
 812
 813       Succeeded := Result = 0;
 814
 815       pthread_detach (T.Common.LL.Thread'Access);
 816       --  Detach the thread using pthread_detach, sinc DCE threads do not have
 817       --  pthread_attr_set_detachstate.
 818
 819       Result := pthread_attr_destroy (Attributes'Access);
 820       pragma Assert (Result = 0);
 821
 822       Set_Priority (T, Priority);
 823    end Create_Task;
 824
 825    ------------------
 826    -- Finalize_TCB --
 827    ------------------
 828
 829    procedure Finalize_TCB (T : Task_ID) is
 830       Result : Interfaces.C.int;
 831       Tmp    : Task_ID := T;
 832
 833       procedure Free is new
 834         Unchecked_Deallocation (Ada_Task_Control_Block, Task_ID);
 835
 836    begin
 837       Result := pthread_mutex_destroy (T.Common.LL.L'Access);
 838       pragma Assert (Result = 0);
 839       Result := pthread_cond_destroy (T.Common.LL.CV'Access);
 840       pragma Assert (Result = 0);
 841
 842       if T.Known_Tasks_Index /= -1 then
 843          Known_Tasks (T.Known_Tasks_Index) := null;
 844       end if;
 845
 846       Free (Tmp);
 847    end Finalize_TCB;
 848
 849    ---------------
 850    -- Exit_Task --
 851    ---------------
 852
 853    procedure Exit_Task is
 854    begin
 855       pthread_exit (System.Null_Address);
 856    end Exit_Task;
 857
 858    ----------------
 859    -- Abort_Task --
 860    ----------------
 861
 862    procedure Abort_Task (T : Task_ID) is
 863    begin
 864       --
 865       --  Interrupt Server_Tasks may be waiting on an "event" flag (signal)
 866       --
 867       if T.Common.State = Interrupt_Server_Blocked_On_Event_Flag then
 868          System.Interrupt_Management.Operations.Interrupt_Self_Process
 869            (System.Interrupt_Management.Interrupt_ID
 870              (PIO.Get_Interrupt_ID (T)));
 871       end if;
 872    end Abort_Task;
 873
 874    ----------------
 875    -- Check_Exit --
 876    ----------------
 877
 878    --  Dummy versions.  The only currently working versions is for solaris
 879    --  (native).
 880
 881    function Check_Exit (Self_ID : ST.Task_ID) return Boolean is
 882    begin
 883       return True;
 884    end Check_Exit;
 885
 886    --------------------
 887    -- Check_No_Locks --
 888    --------------------
 889
 890    function Check_No_Locks (Self_ID : ST.Task_ID) return Boolean is
 891    begin
 892       return True;
 893    end Check_No_Locks;
 894
 895    ----------------------
 896    -- Environment_Task --
 897    ----------------------
 898
 899    function Environment_Task return Task_ID is
 900    begin
 901       return Environment_Task_ID;
 902    end Environment_Task;
 903
 904    -------------------------
 905    -- Lock_All_Tasks_List --
 906    -------------------------
 907
 908    procedure Lock_All_Tasks_List is
 909    begin
 910       Write_Lock (All_Tasks_L'Access);
 911    end Lock_All_Tasks_List;
 912
 913    ---------------------------
 914    -- Unlock_All_Tasks_List --
 915    ---------------------------
 916
 917    procedure Unlock_All_Tasks_List is
 918    begin
 919       Unlock (All_Tasks_L'Access);
 920    end Unlock_All_Tasks_List;
 921
 922    ------------------
 923    -- Suspend_Task --
 924    ------------------
 925
 926    function Suspend_Task
 927      (T           : ST.Task_ID;
 928       Thread_Self : Thread_Id) return Boolean is
 929    begin
 930       return False;
 931    end Suspend_Task;
 932
 933    -----------------
 934    -- Resume_Task --
 935    -----------------
 936
 937    function Resume_Task
 938      (T           : ST.Task_ID;
 939       Thread_Self : Thread_Id) return Boolean is
 940    begin
 941       return False;
 942    end Resume_Task;
 943
 944    ----------------
 945    -- Initialize --
 946    ----------------
 947
 948    procedure Initialize (Environment_Task : Task_ID) is
 949       act       : aliased struct_sigaction;
 950       old_act   : aliased struct_sigaction;
 951       Tmp_Set   : aliased sigset_t;
 952       Result    : Interfaces.C.int;
 953
 954    begin
 955
 956       Environment_Task_ID := Environment_Task;
 957
 958       Initialize_Lock (All_Tasks_L'Access, All_Tasks_Level);
 959       --  Initialize the lock used to synchronize chain of all ATCBs.
 960
 961       Enter_Task (Environment_Task);
 962
 963       --  Install the abort-signal handler
 964
 965       act.sa_flags := 0;
 966       act.sa_handler := Abort_Handler'Address;
 967
 968       Result := sigemptyset (Tmp_Set'Access);
 969       pragma Assert (Result = 0);
 970       act.sa_mask := Tmp_Set;
 971
 972       Result :=
 973         sigaction (
 974           Signal (System.Interrupt_Management.Abort_Task_Interrupt),
 975           act'Unchecked_Access,
 976           old_act'Unchecked_Access);
 977       pragma Assert (Result = 0);
 978    end Initialize;
 979
 980    procedure do_nothing (arg : System.Address);
 981
 982    procedure do_nothing (arg : System.Address) is
 983    begin
 984       null;
 985    end do_nothing;
 986
 987 begin
 988
 989    declare
 990       Result : Interfaces.C.int;
 991    begin
 992       --  NOTE: Unlike other pthread implementations, we do *not* mask all
 993       --  signals here since we handle signals using the process-wide primitive
 994       --  signal, rather than using sigthreadmask and sigwait. The reason of
 995       --  this difference is that sigwait doesn't work when some critical
 996       --  signals (SIGABRT, SIGPIPE) are masked.
 997
 998       Result := pthread_key_create (ATCB_Key'Access, do_nothing'Access);
 999       pragma Assert (Result = 0);
1000    end;
1001
1002 end System.Task_Primitives.Operations;