gcc/ada/s-taprop-irix.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                 GNAT 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 --         Copyright (C) 1992-2007, 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 2,  or (at your option) any later ver- --
  14 -- sion. GNARL 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.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNARL; see file COPYING.  If not, write --
  19 -- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, USA.                                              --
  21 --                                                                          --
  22 -- As a special exception,  if other files  instantiate  generics from this --
  23 -- unit, or you link  this unit with other files  to produce an executable, --
  24 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  25 -- covered  by the  GNU  General  Public  License.  This exception does not --
  26 -- however invalidate  any other reasons why  the executable file  might be --
  27 -- covered by the  GNU Public License.                                      --
  28 --                                                                          --
  29 -- GNARL was developed by the GNARL team at Florida State University.       --
  30 -- Extensive contributions were provided by Ada Core Technologies, Inc.     --
  31 --                                                                          --
  32 ------------------------------------------------------------------------------
  33
  34 --  This is a IRIX (pthread library) version of this package
  35
  36 --  This package contains all the GNULL primitives that interface directly
  37 --  with the underlying OS.
  38
  39 pragma Polling (Off);
  40 --  Turn off polling, we do not want ATC polling to take place during
  41 --  tasking operations. It causes infinite loops and other problems.
  42
  43 with Interfaces.C;
  44 --  used for int
  45 --           size_t
  46
  47 with System.Task_Info;
  48
  49 with System.Tasking.Debug;
  50 --  used for Known_Tasks
  51
  52 with System.Interrupt_Management;
  53 --  used for Keep_Unmasked
  54 --           Abort_Task_Interrupt
  55 --           Interrupt_ID
  56
  57 with System.OS_Primitives;
  58 --  used for Delay_Modes
  59
  60 with System.IO;
  61 --  used for Put_Line
  62
  63 with System.Soft_Links;
  64 --  used for Abort_Defer/Undefer
  65
  66 --  We use System.Soft_Links instead of System.Tasking.Initialization
  67 --  because the later is a higher level package that we shouldn't depend on.
  68 --  For example when using the restricted run time, it is replaced by
  69 --  System.Tasking.Restricted.Stages.
  70
  71 with Ada.Unchecked_Conversion;
  72 with Ada.Unchecked_Deallocation;
  73
  74 package body System.Task_Primitives.Operations is
  75
  76    package SSL renames System.Soft_Links;
  77
  78    use System.Tasking;
  79    use System.Tasking.Debug;
  80    use Interfaces.C;
  81    use System.OS_Interface;
  82    use System.OS_Primitives;
  83    use System.Parameters;
  84
  85    ----------------
  86    -- Local Data --
  87    ----------------
  88
  89    --  The followings are logically constants, but need to be initialized
  90    --  at run time.
  91
  92    Single_RTS_Lock : aliased RTS_Lock;
  93    --  This is a lock to allow only one thread of control in the RTS at
  94    --  a time; it is used to execute in mutual exclusion from all other tasks.
  95    --  Used mainly in Single_Lock mode, but also to protect All_Tasks_List
  96
  97    ATCB_Key : aliased pthread_key_t;
  98    --  Key used to find the Ada Task_Id associated with a thread
  99
 100    Environment_Task_Id : Task_Id;
 101    --  A variable to hold Task_Id for the environment task
 102
 103    Locking_Policy : Character;
 104    pragma Import (C, Locking_Policy, "__gl_locking_policy");
 105
 106    Time_Slice_Val : Integer;
 107    pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
 108
 109    Dispatching_Policy : Character;
 110    pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy");
 111
 112    Real_Time_Clock_Id : constant clockid_t := CLOCK_REALTIME;
 113
 114    Unblocked_Signal_Mask : aliased sigset_t;
 115
 116    Foreign_Task_Elaborated : aliased Boolean := True;
 117    --  Used to identified fake tasks (i.e., non-Ada Threads)
 118
 119    --------------------
 120    -- Local Packages --
 121    --------------------
 122
 123    package Specific is
 124
 125       procedure Initialize (Environment_Task : Task_Id);
 126       pragma Inline (Initialize);
 127       --  Initialize various data needed by this package
 128
 129       function Is_Valid_Task return Boolean;
 130       pragma Inline (Is_Valid_Task);
 131       --  Does executing thread have a TCB?
 132
 133       procedure Set (Self_Id : Task_Id);
 134       pragma Inline (Set);
 135       --  Set the self id for the current task
 136
 137       function Self return Task_Id;
 138       pragma Inline (Self);
 139       --  Return a pointer to the Ada Task Control Block of the calling task
 140
 141    end Specific;
 142
 143    package body Specific is separate;
 144    --  The body of this package is target specific
 145
 146    ---------------------------------
 147    -- Support for foreign threads --
 148    ---------------------------------
 149
 150    function Register_Foreign_Thread (Thread : Thread_Id) return Task_Id;
 151    --  Allocate and Initialize a new ATCB for the current Thread
 152
 153    function Register_Foreign_Thread
 154      (Thread : Thread_Id) return Task_Id is separate;
 155
 156    -----------------------
 157    -- Local Subprograms --
 158    -----------------------
 159
 160    function To_Address is
 161      new Ada.Unchecked_Conversion (Task_Id, System.Address);
 162
 163    procedure Abort_Handler (Sig : Signal);
 164    --  Signal handler used to implement asynchronous abort
 165
 166    -------------------
 167    -- Abort_Handler --
 168    -------------------
 169
 170    procedure Abort_Handler (Sig : Signal) is
 171       pragma Unreferenced (Sig);
 172
 173       T       : constant Task_Id := Self;
 174       Result  : Interfaces.C.int;
 175       Old_Set : aliased sigset_t;
 176
 177    begin
 178       --  It is not safe to raise an exception when using ZCX and the GCC
 179       --  exception handling mechanism.
 180
 181       if ZCX_By_Default and then GCC_ZCX_Support then
 182          return;
 183       end if;
 184
 185       if T.Deferral_Level = 0
 186         and then T.Pending_ATC_Level < T.ATC_Nesting_Level
 187       then
 188          --  Make sure signals used for RTS internal purpose are unmasked
 189
 190          Result := pthread_sigmask
 191            (SIG_UNBLOCK,
 192             Unblocked_Signal_Mask'Access,
 193             Old_Set'Access);
 194          pragma Assert (Result = 0);
 195
 196          raise Standard'Abort_Signal;
 197       end if;
 198    end Abort_Handler;
 199
 200    -----------------
 201    -- Stack_Guard --
 202    -----------------
 203
 204    --  The underlying thread system sets a guard page at the
 205    --  bottom of a thread stack, so nothing is needed.
 206
 207    procedure Stack_Guard (T : ST.Task_Id; On : Boolean) is
 208       pragma Unreferenced (On);
 209       pragma Unreferenced (T);
 210    begin
 211       null;
 212    end Stack_Guard;
 213
 214    -------------------
 215    -- Get_Thread_Id --
 216    -------------------
 217
 218    function Get_Thread_Id (T : ST.Task_Id) return OSI.Thread_Id is
 219    begin
 220       return T.Common.LL.Thread;
 221    end Get_Thread_Id;
 222
 223    ----------
 224    -- Self --
 225    ----------
 226
 227    function Self return Task_Id renames Specific.Self;
 228
 229    ---------------------
 230    -- Initialize_Lock --
 231    ---------------------
 232
 233    --  Note: mutexes and cond_variables needed per-task basis are initialized
 234    --  in Initialize_TCB and the Storage_Error is handled. Other mutexes (such
 235    --  as RTS_Lock, Memory_Lock...) used in RTS is initialized before any
 236    --  status change of RTS. Therefore rasing Storage_Error in the following
 237    --  routines should be able to be handled safely.
 238
 239    procedure Initialize_Lock
 240      (Prio : System.Any_Priority;
 241       L    : not null access Lock)
 242    is
 243       Attributes : aliased pthread_mutexattr_t;
 244       Result     : Interfaces.C.int;
 245
 246    begin
 247       Result := pthread_mutexattr_init (Attributes'Access);
 248       pragma Assert (Result = 0 or else Result = ENOMEM);
 249
 250       if Result = ENOMEM then
 251          raise Storage_Error;
 252       end if;
 253
 254       if Locking_Policy = 'C' then
 255          Result :=
 256            pthread_mutexattr_setprotocol
 257              (Attributes'Access, PTHREAD_PRIO_PROTECT);
 258          pragma Assert (Result = 0);
 259
 260          Result :=
 261            pthread_mutexattr_setprioceiling
 262              (Attributes'Access, Interfaces.C.int (Prio));
 263          pragma Assert (Result = 0);
 264       end if;
 265
 266       Result := pthread_mutex_init (L, Attributes'Access);
 267       pragma Assert (Result = 0 or else Result = ENOMEM);
 268
 269       if Result = ENOMEM then
 270          Result := pthread_mutexattr_destroy (Attributes'Access);
 271          raise Storage_Error;
 272       end if;
 273
 274       Result := pthread_mutexattr_destroy (Attributes'Access);
 275       pragma Assert (Result = 0);
 276    end Initialize_Lock;
 277
 278    procedure Initialize_Lock
 279      (L     : not null access RTS_Lock;
 280       Level : Lock_Level)
 281    is
 282       pragma Unreferenced (Level);
 283
 284       Attributes : aliased pthread_mutexattr_t;
 285       Result : Interfaces.C.int;
 286
 287    begin
 288       Result := pthread_mutexattr_init (Attributes'Access);
 289       pragma Assert (Result = 0 or else Result = ENOMEM);
 290
 291       if Result = ENOMEM then
 292          raise Storage_Error;
 293       end if;
 294
 295       if Locking_Policy = 'C' then
 296          Result := pthread_mutexattr_setprotocol
 297            (Attributes'Access, PTHREAD_PRIO_PROTECT);
 298          pragma Assert (Result = 0);
 299
 300          Result := pthread_mutexattr_setprioceiling
 301             (Attributes'Access, Interfaces.C.int (System.Any_Priority'Last));
 302          pragma Assert (Result = 0);
 303       end if;
 304
 305       Result := pthread_mutex_init (L, Attributes'Access);
 306
 307       pragma Assert (Result = 0 or else Result = ENOMEM);
 308
 309       if Result = ENOMEM then
 310          Result := pthread_mutexattr_destroy (Attributes'Access);
 311          raise Storage_Error;
 312       end if;
 313
 314       Result := pthread_mutexattr_destroy (Attributes'Access);
 315       pragma Assert (Result = 0);
 316    end Initialize_Lock;
 317
 318    -------------------
 319    -- Finalize_Lock --
 320    -------------------
 321
 322    procedure Finalize_Lock (L : not null access Lock) is
 323       Result : Interfaces.C.int;
 324    begin
 325       Result := pthread_mutex_destroy (L);
 326       pragma Assert (Result = 0);
 327    end Finalize_Lock;
 328
 329    procedure Finalize_Lock (L : not null access RTS_Lock) is
 330       Result : Interfaces.C.int;
 331    begin
 332       Result := pthread_mutex_destroy (L);
 333       pragma Assert (Result = 0);
 334    end Finalize_Lock;
 335
 336    ----------------
 337    -- Write_Lock --
 338    ----------------
 339
 340    procedure Write_Lock
 341      (L : not null access Lock; Ceiling_Violation : out Boolean)
 342    is
 343       Result : Interfaces.C.int;
 344
 345    begin
 346       Result := pthread_mutex_lock (L);
 347       Ceiling_Violation := Result = EINVAL;
 348
 349       --  Assumes the cause of EINVAL is a priority ceiling violation
 350
 351       pragma Assert (Result = 0 or else Result = EINVAL);
 352    end Write_Lock;
 353
 354    procedure Write_Lock
 355      (L           : not null access RTS_Lock;
 356       Global_Lock : Boolean := False)
 357    is
 358       Result : Interfaces.C.int;
 359    begin
 360       if not Single_Lock or else Global_Lock then
 361          Result := pthread_mutex_lock (L);
 362          pragma Assert (Result = 0);
 363       end if;
 364    end Write_Lock;
 365
 366    procedure Write_Lock (T : Task_Id) is
 367       Result : Interfaces.C.int;
 368    begin
 369       if not Single_Lock then
 370          Result := pthread_mutex_lock (T.Common.LL.L'Access);
 371          pragma Assert (Result = 0);
 372       end if;
 373    end Write_Lock;
 374
 375    ---------------
 376    -- Read_Lock --
 377    ---------------
 378
 379    procedure Read_Lock
 380      (L : not null access Lock; Ceiling_Violation : out Boolean) is
 381    begin
 382       Write_Lock (L, Ceiling_Violation);
 383    end Read_Lock;
 384
 385    ------------
 386    -- Unlock --
 387    ------------
 388
 389    procedure Unlock (L : not null access Lock) is
 390       Result : Interfaces.C.int;
 391    begin
 392       Result := pthread_mutex_unlock (L);
 393       pragma Assert (Result = 0);
 394    end Unlock;
 395
 396    procedure Unlock
 397      (L           : not null access RTS_Lock;
 398       Global_Lock : Boolean := False)
 399    is
 400       Result : Interfaces.C.int;
 401    begin
 402       if not Single_Lock or else Global_Lock then
 403          Result := pthread_mutex_unlock (L);
 404          pragma Assert (Result = 0);
 405       end if;
 406    end Unlock;
 407
 408    procedure Unlock (T : Task_Id) is
 409       Result : Interfaces.C.int;
 410    begin
 411       if not Single_Lock then
 412          Result := pthread_mutex_unlock (T.Common.LL.L'Access);
 413          pragma Assert (Result = 0);
 414       end if;
 415    end Unlock;
 416
 417    -----------------
 418    -- Set_Ceiling --
 419    -----------------
 420
 421    --  Dynamic priority ceilings are not supported by the underlying system
 422
 423    procedure Set_Ceiling
 424      (L    : not null access Lock;
 425       Prio : System.Any_Priority)
 426    is
 427       pragma Unreferenced (L, Prio);
 428    begin
 429       null;
 430    end Set_Ceiling;
 431
 432    -----------
 433    -- Sleep --
 434    -----------
 435
 436    procedure Sleep
 437      (Self_ID : ST.Task_Id;
 438       Reason  : System.Tasking.Task_States)
 439    is
 440       pragma Unreferenced (Reason);
 441       Result : Interfaces.C.int;
 442
 443    begin
 444       if Single_Lock then
 445          Result :=
 446            pthread_cond_wait
 447              (Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access);
 448       else
 449          Result :=
 450            pthread_cond_wait
 451              (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access);
 452       end if;
 453
 454       --  EINTR is not considered a failure
 455
 456       pragma Assert (Result = 0 or else Result = EINTR);
 457    end Sleep;
 458
 459    -----------------
 460    -- Timed_Sleep --
 461    -----------------
 462
 463    procedure Timed_Sleep
 464      (Self_ID  : Task_Id;
 465       Time     : Duration;
 466       Mode     : ST.Delay_Modes;
 467       Reason   : Task_States;
 468       Timedout : out Boolean;
 469       Yielded  : out Boolean)
 470    is
 471       pragma Unreferenced (Reason);
 472
 473       Base_Time  : constant Duration := Monotonic_Clock;
 474       Check_Time : Duration := Base_Time;
 475       Abs_Time   : Duration;
 476       Request    : aliased timespec;
 477       Result     : Interfaces.C.int;
 478
 479    begin
 480       Timedout := True;
 481       Yielded  := False;
 482
 483       if Mode = Relative then
 484          Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
 485       else
 486          Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
 487       end if;
 488
 489       if Abs_Time > Check_Time then
 490          Request := To_Timespec (Abs_Time);
 491
 492          loop
 493             exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
 494
 495             if Single_Lock then
 496                Result :=
 497                  pthread_cond_timedwait
 498                    (Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access,
 499                     Request'Access);
 500
 501             else
 502                Result :=
 503                  pthread_cond_timedwait
 504                    (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access,
 505                     Request'Access);
 506             end if;
 507
 508             Check_Time := Monotonic_Clock;
 509             exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
 510
 511             if Result = 0 or else errno = EINTR then
 512                Timedout := False;
 513                exit;
 514             end if;
 515          end loop;
 516       end if;
 517    end Timed_Sleep;
 518
 519    -----------------
 520    -- Timed_Delay --
 521    -----------------
 522
 523    --  This is for use in implementing delay statements, so we assume
 524    --  the caller is abort-deferred but is holding no locks.
 525
 526    procedure Timed_Delay
 527      (Self_ID : Task_Id;
 528       Time    : Duration;
 529       Mode    : ST.Delay_Modes)
 530    is
 531       Base_Time  : constant Duration := Monotonic_Clock;
 532       Check_Time : Duration := Base_Time;
 533       Abs_Time   : Duration;
 534       Request    : aliased timespec;
 535       Result     : Interfaces.C.int;
 536
 537    begin
 538       if Single_Lock then
 539          Lock_RTS;
 540       end if;
 541
 542       Write_Lock (Self_ID);
 543
 544       if Mode = Relative then
 545          Abs_Time := Time + Check_Time;
 546       else
 547          Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
 548       end if;
 549
 550       if Abs_Time > Check_Time then
 551          Request := To_Timespec (Abs_Time);
 552          Self_ID.Common.State := Delay_Sleep;
 553
 554          loop
 555             exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
 556
 557             if Single_Lock then
 558                Result := pthread_cond_timedwait
 559                            (Self_ID.Common.LL.CV'Access,
 560                             Single_RTS_Lock'Access,
 561                             Request'Access);
 562             else
 563                Result := pthread_cond_timedwait
 564                            (Self_ID.Common.LL.CV'Access,
 565                             Self_ID.Common.LL.L'Access,
 566                             Request'Access);
 567             end if;
 568
 569             Check_Time := Monotonic_Clock;
 570             exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
 571
 572             pragma Assert (Result = 0
 573               or else Result = ETIMEDOUT
 574               or else Result = EINTR);
 575          end loop;
 576
 577          Self_ID.Common.State := Runnable;
 578       end if;
 579
 580       Unlock (Self_ID);
 581
 582       if Single_Lock then
 583          Unlock_RTS;
 584       end if;
 585
 586       Yield;
 587    end Timed_Delay;
 588
 589    ---------------------
 590    -- Monotonic_Clock --
 591    ---------------------
 592
 593    function Monotonic_Clock return Duration is
 594       TS     : aliased timespec;
 595       Result : Interfaces.C.int;
 596    begin
 597       Result := clock_gettime (Real_Time_Clock_Id, TS'Unchecked_Access);
 598       pragma Assert (Result = 0);
 599       return To_Duration (TS);
 600    end Monotonic_Clock;
 601
 602    -------------------
 603    -- RT_Resolution --
 604    -------------------
 605
 606    function RT_Resolution return Duration is
 607    begin
 608       --  The clock_getres (Real_Time_Clock_Id) function appears to return
 609       --  the interrupt resolution of the realtime clock and not the actual
 610       --  resolution of reading the clock. Even though this last value is
 611       --  only guaranteed to be 100 Hz, at least the Origin 200 appears to
 612       --  have a microsecond resolution or better.
 613
 614       --  ??? We should figure out a method to return the right value on
 615       --  all SGI hardware.
 616
 617       return 0.000_001;
 618    end RT_Resolution;
 619
 620    ------------
 621    -- Wakeup --
 622    ------------
 623
 624    procedure Wakeup (T : ST.Task_Id; Reason : System.Tasking.Task_States) is
 625       pragma Unreferenced (Reason);
 626       Result : Interfaces.C.int;
 627    begin
 628       Result := pthread_cond_signal (T.Common.LL.CV'Access);
 629       pragma Assert (Result = 0);
 630    end Wakeup;
 631
 632    -----------
 633    -- Yield --
 634    -----------
 635
 636    procedure Yield (Do_Yield : Boolean := True) is
 637       Result : Interfaces.C.int;
 638       pragma Unreferenced (Result);
 639    begin
 640       if Do_Yield then
 641          Result := sched_yield;
 642       end if;
 643    end Yield;
 644
 645    ------------------
 646    -- Set_Priority --
 647    ------------------
 648
 649    procedure Set_Priority
 650      (T                   : Task_Id;
 651       Prio                : System.Any_Priority;
 652       Loss_Of_Inheritance : Boolean := False)
 653    is
 654       pragma Unreferenced (Loss_Of_Inheritance);
 655
 656       Result       : Interfaces.C.int;
 657       Param        : aliased struct_sched_param;
 658       Sched_Policy : Interfaces.C.int;
 659
 660       use type System.Task_Info.Task_Info_Type;
 661
 662       function To_Int is new Ada.Unchecked_Conversion
 663         (System.Task_Info.Thread_Scheduling_Policy, Interfaces.C.int);
 664
 665       function Get_Policy (Prio : System.Any_Priority) return Character;
 666       pragma Import (C, Get_Policy, "__gnat_get_specific_dispatching");
 667       --  Get priority specific dispatching policy
 668
 669       Priority_Specific_Policy : constant Character := Get_Policy (Prio);
 670       --  Upper case first character of the policy name corresponding to the
 671       --  task as set by a Priority_Specific_Dispatching pragma.
 672
 673    begin
 674       T.Common.Current_Priority := Prio;
 675       Param.sched_priority := Interfaces.C.int (Prio);
 676
 677       if T.Common.Task_Info /= null then
 678          Sched_Policy := To_Int (T.Common.Task_Info.Policy);
 679
 680       elsif Dispatching_Policy = 'R'
 681         or else Priority_Specific_Policy = 'R'
 682         or else Time_Slice_Val > 0
 683       then
 684          Sched_Policy := SCHED_RR;
 685
 686       else
 687          Sched_Policy := SCHED_FIFO;
 688       end if;
 689
 690       Result := pthread_setschedparam (T.Common.LL.Thread, Sched_Policy,
 691         Param'Access);
 692       pragma Assert (Result = 0);
 693    end Set_Priority;
 694
 695    ------------------
 696    -- Get_Priority --
 697    ------------------
 698
 699    function Get_Priority (T : Task_Id) return System.Any_Priority is
 700    begin
 701       return T.Common.Current_Priority;
 702    end Get_Priority;
 703
 704    ----------------
 705    -- Enter_Task --
 706    ----------------
 707
 708    procedure Enter_Task (Self_ID : Task_Id) is
 709       Result : Interfaces.C.int;
 710
 711       function To_Int is new Ada.Unchecked_Conversion
 712         (System.Task_Info.CPU_Number, Interfaces.C.int);
 713
 714       use System.Task_Info;
 715
 716    begin
 717       Self_ID.Common.LL.Thread := pthread_self;
 718       Specific.Set (Self_ID);
 719
 720       if Self_ID.Common.Task_Info /= null
 721         and then Self_ID.Common.Task_Info.Scope = PTHREAD_SCOPE_SYSTEM
 722         and then Self_ID.Common.Task_Info.Runon_CPU /= ANY_CPU
 723       then
 724          Result := pthread_setrunon_np
 725            (To_Int (Self_ID.Common.Task_Info.Runon_CPU));
 726          pragma Assert (Result = 0);
 727       end if;
 728
 729       Lock_RTS;
 730
 731       for J in Known_Tasks'Range loop
 732          if Known_Tasks (J) = null then
 733             Known_Tasks (J) := Self_ID;
 734             Self_ID.Known_Tasks_Index := J;
 735             exit;
 736          end if;
 737       end loop;
 738
 739       Unlock_RTS;
 740    end Enter_Task;
 741
 742    --------------
 743    -- New_ATCB --
 744    --------------
 745
 746    function New_ATCB (Entry_Num : Task_Entry_Index) return Task_Id is
 747    begin
 748       return new Ada_Task_Control_Block (Entry_Num);
 749    end New_ATCB;
 750
 751    -------------------
 752    -- Is_Valid_Task --
 753    -------------------
 754
 755    function Is_Valid_Task return Boolean renames Specific.Is_Valid_Task;
 756
 757    -----------------------------
 758    -- Register_Foreign_Thread --
 759    -----------------------------
 760
 761    function Register_Foreign_Thread return Task_Id is
 762    begin
 763       if Is_Valid_Task then
 764          return Self;
 765       else
 766          return Register_Foreign_Thread (pthread_self);
 767       end if;
 768    end Register_Foreign_Thread;
 769
 770    --------------------
 771    -- Initialize_TCB --
 772    --------------------
 773
 774    procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is
 775       Result    : Interfaces.C.int;
 776       Cond_Attr : aliased pthread_condattr_t;
 777
 778    begin
 779       if not Single_Lock then
 780          Initialize_Lock (Self_ID.Common.LL.L'Access, ATCB_Level);
 781       end if;
 782
 783       Result := pthread_condattr_init (Cond_Attr'Access);
 784       pragma Assert (Result = 0 or else Result = ENOMEM);
 785
 786       if Result = 0 then
 787          Result :=
 788            pthread_cond_init (Self_ID.Common.LL.CV'Access, Cond_Attr'Access);
 789          pragma Assert (Result = 0 or else Result = ENOMEM);
 790       end if;
 791
 792       if Result = 0 then
 793          Succeeded := True;
 794       else
 795          if not Single_Lock then
 796             Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access);
 797             pragma Assert (Result = 0);
 798          end if;
 799
 800          Succeeded := False;
 801       end if;
 802
 803       Result := pthread_condattr_destroy (Cond_Attr'Access);
 804       pragma Assert (Result = 0);
 805    end Initialize_TCB;
 806
 807    -----------------
 808    -- Create_Task --
 809    -----------------
 810
 811    procedure Create_Task
 812      (T          : Task_Id;
 813       Wrapper    : System.Address;
 814       Stack_Size : System.Parameters.Size_Type;
 815       Priority   : System.Any_Priority;
 816       Succeeded  : out Boolean)
 817    is
 818       use System.Task_Info;
 819
 820       Attributes  : aliased pthread_attr_t;
 821       Sched_Param : aliased struct_sched_param;
 822       Result      : Interfaces.C.int;
 823
 824       function Thread_Body_Access is new
 825         Ada.Unchecked_Conversion (System.Address, Thread_Body);
 826       function To_Int is new Ada.Unchecked_Conversion
 827         (System.Task_Info.Thread_Scheduling_Scope, Interfaces.C.int);
 828       function To_Int is new Ada.Unchecked_Conversion
 829         (System.Task_Info.Thread_Scheduling_Inheritance, Interfaces.C.int);
 830       function To_Int is new Ada.Unchecked_Conversion
 831         (System.Task_Info.Thread_Scheduling_Policy, Interfaces.C.int);
 832
 833    begin
 834       Result := pthread_attr_init (Attributes'Access);
 835       pragma Assert (Result = 0 or else Result = ENOMEM);
 836
 837       if Result /= 0 then
 838          Succeeded := False;
 839          return;
 840       end if;
 841
 842       Result :=
 843         pthread_attr_setdetachstate
 844           (Attributes'Access, PTHREAD_CREATE_DETACHED);
 845       pragma Assert (Result = 0);
 846
 847       Result :=
 848         pthread_attr_setstacksize
 849           (Attributes'Access, Interfaces.C.size_t (Stack_Size));
 850       pragma Assert (Result = 0);
 851
 852       if T.Common.Task_Info /= null then
 853          Result :=
 854            pthread_attr_setscope
 855              (Attributes'Access, To_Int (T.Common.Task_Info.Scope));
 856          pragma Assert (Result = 0);
 857
 858          Result :=
 859            pthread_attr_setinheritsched
 860              (Attributes'Access, To_Int (T.Common.Task_Info.Inheritance));
 861          pragma Assert (Result = 0);
 862
 863          Result :=
 864            pthread_attr_setschedpolicy
 865              (Attributes'Access, To_Int (T.Common.Task_Info.Policy));
 866          pragma Assert (Result = 0);
 867
 868          Sched_Param.sched_priority :=
 869            Interfaces.C.int (T.Common.Task_Info.Priority);
 870
 871          Result :=
 872            pthread_attr_setschedparam
 873              (Attributes'Access, Sched_Param'Access);
 874          pragma Assert (Result = 0);
 875       end if;
 876
 877       --  Since the initial signal mask of a thread is inherited from the
 878       --  creator, and the Environment task has all its signals masked, we
 879       --  do not need to manipulate caller's signal mask at this point.
 880       --  All tasks in RTS will have All_Tasks_Mask initially.
 881
 882       Result :=
 883         pthread_create
 884           (T.Common.LL.Thread'Access,
 885            Attributes'Access,
 886            Thread_Body_Access (Wrapper),
 887            To_Address (T));
 888
 889       if Result /= 0
 890         and then T.Common.Task_Info /= null
 891         and then T.Common.Task_Info.Scope = PTHREAD_SCOPE_SYSTEM
 892       then
 893          --  The pthread_create call may have failed because we asked for a
 894          --  system scope pthread and none were available (probably because
 895          --  the program was not executed by the superuser). Let's try for
 896          --  a process scope pthread instead of raising Tasking_Error.
 897
 898          System.IO.Put_Line
 899            ("Request for PTHREAD_SCOPE_SYSTEM in Task_Info pragma for task");
 900          System.IO.Put ("""");
 901          System.IO.Put (T.Common.Task_Image (1 .. T.Common.Task_Image_Len));
 902          System.IO.Put_Line (""" could not be honored. ");
 903          System.IO.Put_Line ("Scope changed to PTHREAD_SCOPE_PROCESS");
 904
 905          T.Common.Task_Info.Scope := PTHREAD_SCOPE_PROCESS;
 906          Result :=
 907            pthread_attr_setscope
 908              (Attributes'Access, To_Int (T.Common.Task_Info.Scope));
 909          pragma Assert (Result = 0);
 910
 911          Result :=
 912            pthread_create
 913              (T.Common.LL.Thread'Access,
 914               Attributes'Access,
 915               Thread_Body_Access (Wrapper),
 916               To_Address (T));
 917       end if;
 918
 919       pragma Assert (Result = 0 or else Result = EAGAIN);
 920
 921       Succeeded := Result = 0;
 922
 923       --  The following needs significant commenting ???
 924
 925       if T.Common.Task_Info /= null then
 926          T.Common.Base_Priority := T.Common.Task_Info.Priority;
 927          Set_Priority (T, T.Common.Task_Info.Priority);
 928       else
 929          Set_Priority (T, Priority);
 930       end if;
 931
 932       Result := pthread_attr_destroy (Attributes'Access);
 933       pragma Assert (Result = 0);
 934    end Create_Task;
 935
 936    ------------------
 937    -- Finalize_TCB --
 938    ------------------
 939
 940    procedure Finalize_TCB (T : Task_Id) is
 941       Result  : Interfaces.C.int;
 942       Tmp     : Task_Id := T;
 943       Is_Self : constant Boolean := T = Self;
 944
 945       procedure Free is new
 946         Ada.Unchecked_Deallocation (Ada_Task_Control_Block, Task_Id);
 947
 948    begin
 949       if not Single_Lock then
 950          Result := pthread_mutex_destroy (T.Common.LL.L'Access);
 951          pragma Assert (Result = 0);
 952       end if;
 953
 954       Result := pthread_cond_destroy (T.Common.LL.CV'Access);
 955       pragma Assert (Result = 0);
 956
 957       if T.Known_Tasks_Index /= -1 then
 958          Known_Tasks (T.Known_Tasks_Index) := null;
 959       end if;
 960
 961       Free (Tmp);
 962
 963       if Is_Self then
 964          Specific.Set (null);
 965       end if;
 966    end Finalize_TCB;
 967
 968    ---------------
 969    -- Exit_Task --
 970    ---------------
 971
 972    procedure Exit_Task is
 973    begin
 974       Specific.Set (null);
 975    end Exit_Task;
 976
 977    ----------------
 978    -- Abort_Task --
 979    ----------------
 980
 981    procedure Abort_Task (T : Task_Id) is
 982       Result : Interfaces.C.int;
 983    begin
 984       Result :=
 985         pthread_kill
 986           (T.Common.LL.Thread,
 987            Signal (System.Interrupt_Management.Abort_Task_Interrupt));
 988       pragma Assert (Result = 0);
 989    end Abort_Task;
 990
 991    ----------------
 992    -- Initialize --
 993    ----------------
 994
 995    procedure Initialize (S : in out Suspension_Object) is
 996       Mutex_Attr : aliased pthread_mutexattr_t;
 997       Cond_Attr  : aliased pthread_condattr_t;
 998       Result     : Interfaces.C.int;
 999
1000    begin
1001       --  Initialize internal state (always to False (RM D.10(6))
1002
1003       S.State := False;
1004       S.Waiting := False;
1005
1006       --  Initialize internal mutex
1007
1008       Result := pthread_mutexattr_init (Mutex_Attr'Access);
1009       pragma Assert (Result = 0 or else Result = ENOMEM);
1010
1011       if Result = ENOMEM then
1012          raise Storage_Error;
1013       end if;
1014
1015       Result := pthread_mutex_init (S.L'Access, Mutex_Attr'Access);
1016       pragma Assert (Result = 0 or else Result = ENOMEM);
1017
1018       if Result = ENOMEM then
1019          Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
1020          pragma Assert (Result = 0);
1021
1022          raise Storage_Error;
1023       end if;
1024
1025       Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
1026       pragma Assert (Result = 0);
1027
1028       --  Initialize internal condition variable
1029
1030       Result := pthread_condattr_init (Cond_Attr'Access);
1031       pragma Assert (Result = 0 or else Result = ENOMEM);
1032
1033       if Result /= 0 then
1034          Result := pthread_mutex_destroy (S.L'Access);
1035          pragma Assert (Result = 0);
1036
1037          if Result = ENOMEM then
1038             raise Storage_Error;
1039          end if;
1040       end if;
1041
1042       Result := pthread_cond_init (S.CV'Access, Cond_Attr'Access);
1043       pragma Assert (Result = 0 or else Result = ENOMEM);
1044
1045       if Result /= 0 then
1046          Result := pthread_mutex_destroy (S.L'Access);
1047          pragma Assert (Result = 0);
1048
1049          if Result = ENOMEM then
1050             Result := pthread_condattr_destroy (Cond_Attr'Access);
1051             pragma Assert (Result = 0);
1052             raise Storage_Error;
1053          end if;
1054       end if;
1055
1056       Result := pthread_condattr_destroy (Cond_Attr'Access);
1057       pragma Assert (Result = 0);
1058    end Initialize;
1059
1060    --------------
1061    -- Finalize --
1062    --------------
1063
1064    procedure Finalize (S : in out Suspension_Object) is
1065       Result : Interfaces.C.int;
1066
1067    begin
1068       --  Destroy internal mutex
1069
1070       Result := pthread_mutex_destroy (S.L'Access);
1071       pragma Assert (Result = 0);
1072
1073       --  Destroy internal condition variable
1074
1075       Result := pthread_cond_destroy (S.CV'Access);
1076       pragma Assert (Result = 0);
1077    end Finalize;
1078
1079    -------------------
1080    -- Current_State --
1081    -------------------
1082
1083    function Current_State (S : Suspension_Object) return Boolean is
1084    begin
1085       --  We do not want to use lock on this read operation. State is marked
1086       --  as Atomic so that we ensure that the value retrieved is correct.
1087
1088       return S.State;
1089    end Current_State;
1090
1091    ---------------
1092    -- Set_False --
1093    ---------------
1094
1095    procedure Set_False (S : in out Suspension_Object) is
1096       Result : Interfaces.C.int;
1097
1098    begin
1099       SSL.Abort_Defer.all;
1100
1101       Result := pthread_mutex_lock (S.L'Access);
1102       pragma Assert (Result = 0);
1103
1104       S.State := False;
1105
1106       Result := pthread_mutex_unlock (S.L'Access);
1107       pragma Assert (Result = 0);
1108
1109       SSL.Abort_Undefer.all;
1110    end Set_False;
1111
1112    --------------
1113    -- Set_True --
1114    --------------
1115
1116    procedure Set_True (S : in out Suspension_Object) is
1117       Result : Interfaces.C.int;
1118
1119    begin
1120       SSL.Abort_Defer.all;
1121
1122       Result := pthread_mutex_lock (S.L'Access);
1123       pragma Assert (Result = 0);
1124
1125       --  If there is already a task waiting on this suspension object then
1126       --  we resume it, leaving the state of the suspension object to False,
1127       --  as it is specified in ARM D.10 par. 9. Otherwise, it just leaves
1128       --  the state to True.
1129
1130       if S.Waiting then
1131          S.Waiting := False;
1132          S.State := False;
1133
1134          Result := pthread_cond_signal (S.CV'Access);
1135          pragma Assert (Result = 0);
1136
1137       else
1138          S.State := True;
1139       end if;
1140
1141       Result := pthread_mutex_unlock (S.L'Access);
1142       pragma Assert (Result = 0);
1143
1144       SSL.Abort_Undefer.all;
1145    end Set_True;
1146
1147    ------------------------
1148    -- Suspend_Until_True --
1149    ------------------------
1150
1151    procedure Suspend_Until_True (S : in out Suspension_Object) is
1152       Result : Interfaces.C.int;
1153
1154    begin
1155       SSL.Abort_Defer.all;
1156
1157       Result := pthread_mutex_lock (S.L'Access);
1158       pragma Assert (Result = 0);
1159
1160       if S.Waiting then
1161
1162          --  Program_Error must be raised upon calling Suspend_Until_True
1163          --  if another task is already waiting on that suspension object
1164          --  (RM D.10(10)).
1165
1166          Result := pthread_mutex_unlock (S.L'Access);
1167          pragma Assert (Result = 0);
1168
1169          SSL.Abort_Undefer.all;
1170
1171          raise Program_Error;
1172       else
1173          --  Suspend the task if the state is False. Otherwise, the task
1174          --  continues its execution, and the state of the suspension object
1175          --  is set to False (ARM D.10 par. 9).
1176
1177          if S.State then
1178             S.State := False;
1179          else
1180             S.Waiting := True;
1181             Result := pthread_cond_wait (S.CV'Access, S.L'Access);
1182          end if;
1183
1184          Result := pthread_mutex_unlock (S.L'Access);
1185          pragma Assert (Result = 0);
1186
1187          SSL.Abort_Undefer.all;
1188       end if;
1189    end Suspend_Until_True;
1190
1191    ----------------
1192    -- Check_Exit --
1193    ----------------
1194
1195    --  Dummy version
1196
1197    function Check_Exit (Self_ID : ST.Task_Id) return Boolean is
1198       pragma Unreferenced (Self_ID);
1199    begin
1200       return True;
1201    end Check_Exit;
1202
1203    --------------------
1204    -- Check_No_Locks --
1205    --------------------
1206
1207    function Check_No_Locks (Self_ID : ST.Task_Id) return Boolean is
1208       pragma Unreferenced (Self_ID);
1209    begin
1210       return True;
1211    end Check_No_Locks;
1212
1213    ----------------------
1214    -- Environment_Task --
1215    ----------------------
1216
1217    function Environment_Task return Task_Id is
1218    begin
1219       return Environment_Task_Id;
1220    end Environment_Task;
1221
1222    --------------
1223    -- Lock_RTS --
1224    --------------
1225
1226    procedure Lock_RTS is
1227    begin
1228       Write_Lock (Single_RTS_Lock'Access, Global_Lock => True);
1229    end Lock_RTS;
1230
1231    ----------------
1232    -- Unlock_RTS --
1233    ----------------
1234
1235    procedure Unlock_RTS is
1236    begin
1237       Unlock (Single_RTS_Lock'Access, Global_Lock => True);
1238    end Unlock_RTS;
1239
1240    ------------------
1241    -- Suspend_Task --
1242    ------------------
1243
1244    function Suspend_Task
1245      (T           : ST.Task_Id;
1246       Thread_Self : Thread_Id) return Boolean
1247    is
1248       pragma Unreferenced (T);
1249       pragma Unreferenced (Thread_Self);
1250    begin
1251       return False;
1252    end Suspend_Task;
1253
1254    -----------------
1255    -- Resume_Task --
1256    -----------------
1257
1258    function Resume_Task
1259      (T           : ST.Task_Id;
1260       Thread_Self : Thread_Id) return Boolean
1261    is
1262       pragma Unreferenced (T);
1263       pragma Unreferenced (Thread_Self);
1264    begin
1265       return False;
1266    end Resume_Task;
1267
1268    --------------------
1269    -- Stop_All_Tasks --
1270    --------------------
1271
1272    procedure Stop_All_Tasks is
1273    begin
1274       null;
1275    end Stop_All_Tasks;
1276
1277    ---------------
1278    -- Stop_Task --
1279    ---------------
1280
1281    function Stop_Task (T : ST.Task_Id) return Boolean is
1282       pragma Unreferenced (T);
1283    begin
1284       return False;
1285    end Stop_Task;
1286
1287    -------------------
1288    -- Continue_Task --
1289    -------------------
1290
1291    function Continue_Task (T : ST.Task_Id) return Boolean is
1292       pragma Unreferenced (T);
1293    begin
1294       return False;
1295    end Continue_Task;
1296
1297    ----------------
1298    -- Initialize --
1299    ----------------
1300
1301    procedure Initialize (Environment_Task : Task_Id) is
1302       act     : aliased struct_sigaction;
1303       old_act : aliased struct_sigaction;
1304       Tmp_Set : aliased sigset_t;
1305       Result  : Interfaces.C.int;
1306
1307       function State
1308         (Int : System.Interrupt_Management.Interrupt_ID) return Character;
1309       pragma Import (C, State, "__gnat_get_interrupt_state");
1310       --  Get interrupt state. Defined in a-init.c. The input argument is
1311       --  the interrupt number, and the result is one of the following:
1312
1313       Default : constant Character := 's';
1314       --    'n'   this interrupt not set by any Interrupt_State pragma
1315       --    'u'   Interrupt_State pragma set state to User
1316       --    'r'   Interrupt_State pragma set state to Runtime
1317       --    's'   Interrupt_State pragma set state to System (use "default"
1318       --           system handler)
1319
1320    begin
1321       Environment_Task_Id := Environment_Task;
1322
1323       Interrupt_Management.Initialize;
1324
1325       --  Initialize the lock used to synchronize chain of all ATCBs
1326
1327       Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
1328
1329       Specific.Initialize (Environment_Task);
1330
1331       Enter_Task (Environment_Task);
1332
1333       --  Prepare the set of signals that should unblocked in all tasks
1334
1335       Result := sigemptyset (Unblocked_Signal_Mask'Access);
1336       pragma Assert (Result = 0);
1337
1338       for J in Interrupt_Management.Interrupt_ID loop
1339          if System.Interrupt_Management.Keep_Unmasked (J) then
1340             Result := sigaddset (Unblocked_Signal_Mask'Access, Signal (J));
1341             pragma Assert (Result = 0);
1342          end if;
1343       end loop;
1344
1345       --  Install the abort-signal handler
1346
1347       if State
1348           (System.Interrupt_Management.Abort_Task_Interrupt) /= Default
1349       then
1350          act.sa_flags := 0;
1351          act.sa_handler := Abort_Handler'Address;
1352
1353          Result := sigemptyset (Tmp_Set'Access);
1354          pragma Assert (Result = 0);
1355          act.sa_mask := Tmp_Set;
1356
1357          Result :=
1358            sigaction
1359              (Signal (System.Interrupt_Management.Abort_Task_Interrupt),
1360               act'Unchecked_Access,
1361               old_act'Unchecked_Access);
1362          pragma Assert (Result = 0);
1363       end if;
1364    end Initialize;
1365
1366 end System.Task_Primitives.Operations;