gcc/ada/s-interr-sigaction.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS               --
   4 --                                                                          --
   5 --                     S Y S T E M . I N T E R R U P T S                    --
   6 --                                                                          --
   7 --                                  B o d y                                 --
   8 --                                                                          --
   9 --              Copyright (C) 1998-2004 Free Software Fundation             --
  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,  59 Temple Place - Suite 330,  Boston, --
  20 -- MA 02111-1307, 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 the IRIX & NT version of this package.
  35
  36 with Ada.Task_Identification;
  37 --  used for Task_Id
  38
  39 with Ada.Exceptions;
  40 --  used for Raise_Exception
  41
  42 with System.OS_Interface;
  43 --  used for intr_attach
  44
  45 with System.Storage_Elements;
  46 --  used for To_Address
  47 --           To_Integer
  48
  49 with System.Task_Primitives.Operations;
  50 --  used for Self
  51 --           Sleep
  52 --           Wakeup
  53 --           Write_Lock
  54 --           Unlock
  55
  56 with System.Tasking.Utilities;
  57 --  used for Make_Independent
  58
  59 with System.Tasking.Rendezvous;
  60 --  used for Call_Simple
  61
  62 with System.Tasking.Initialization;
  63 --  used for Defer_Abort
  64 --           Undefer_Abort
  65
  66 with System.Interrupt_Management;
  67
  68 with System.Parameters;
  69 --  used for Single_Lock
  70
  71 with Interfaces.C;
  72 --  used for int
  73
  74 with Unchecked_Conversion;
  75
  76 package body System.Interrupts is
  77
  78    use Parameters;
  79    use Tasking;
  80    use Ada.Exceptions;
  81    use System.OS_Interface;
  82    use Interfaces.C;
  83
  84    package STPO renames System.Task_Primitives.Operations;
  85    package IMNG renames System.Interrupt_Management;
  86
  87    subtype int is Interfaces.C.int;
  88
  89    function To_System is new Unchecked_Conversion
  90      (Ada.Task_Identification.Task_Id, Task_ID);
  91
  92    type Handler_Kind is (Unknown, Task_Entry, Protected_Procedure);
  93
  94    type Handler_Desc is record
  95       Kind   : Handler_Kind := Unknown;
  96       T      : Task_ID;
  97       E      : Task_Entry_Index;
  98       H      : Parameterless_Handler;
  99       Static : Boolean := False;
 100    end record;
 101
 102    task type Server_Task (Interrupt : Interrupt_ID) is
 103       pragma Interrupt_Priority (System.Interrupt_Priority'Last);
 104    end Server_Task;
 105
 106    type Server_Task_Access is access Server_Task;
 107
 108    Attached_Interrupts : array (Interrupt_ID) of Boolean;
 109    Handlers            : array (Interrupt_ID) of Task_ID;
 110    Descriptors         : array (Interrupt_ID) of Handler_Desc;
 111    Interrupt_Count     : array (Interrupt_ID) of Integer := (others => 0);
 112
 113    pragma Volatile_Components (Interrupt_Count);
 114
 115    procedure Attach_Handler
 116      (New_Handler : Parameterless_Handler;
 117       Interrupt   : Interrupt_ID;
 118       Static      : Boolean;
 119       Restoration : Boolean);
 120    --  This internal procedure is needed to finalize protected objects
 121    --  that contain interrupt handlers.
 122
 123    procedure Signal_Handler (Sig : Interrupt_ID);
 124    --  This procedure is used to handle all the signals.
 125
 126    --  Type and Head, Tail of the list containing Registered Interrupt
 127    --  Handlers. These definitions are used to register the handlers
 128    --  specified by the pragma Interrupt_Handler.
 129
 130    --
 131    --  Handler Registration:
 132    --
 133
 134    type Registered_Handler;
 135    type R_Link is access all Registered_Handler;
 136
 137    type Registered_Handler is record
 138       H    : System.Address := System.Null_Address;
 139       Next : R_Link := null;
 140    end record;
 141
 142    Registered_Handlers : R_Link := null;
 143
 144    function Is_Registered (Handler : Parameterless_Handler) return Boolean;
 145    --  See if the Handler has been "pragma"ed using Interrupt_Handler.
 146    --  Always consider a null handler as registered.
 147
 148    type Handler_Ptr is access procedure (Sig : Interrupt_ID);
 149
 150    function TISR is new Unchecked_Conversion (Handler_Ptr, isr_address);
 151
 152    procedure Signal_Handler (Sig : Interrupt_ID) is
 153       Handler : Task_ID renames Handlers (Sig);
 154    begin
 155       if Intr_Attach_Reset and then
 156         intr_attach (int (Sig), TISR (Signal_Handler'Access)) = FUNC_ERR
 157       then
 158          raise Program_Error;
 159       end if;
 160
 161       if Handler /= null then
 162          Interrupt_Count (Sig) := Interrupt_Count (Sig) + 1;
 163          STPO.Wakeup (Handler, Interrupt_Server_Idle_Sleep);
 164       end if;
 165    end Signal_Handler;
 166
 167    -----------------
 168    -- Is_Reserved --
 169    -----------------
 170
 171    function Is_Reserved (Interrupt : Interrupt_ID) return Boolean is
 172    begin
 173       return IMNG.Reserve (IMNG.Interrupt_ID (Interrupt));
 174    end Is_Reserved;
 175
 176    -----------------------
 177    -- Is_Entry_Attached --
 178    -----------------------
 179
 180    function Is_Entry_Attached (Interrupt : Interrupt_ID) return Boolean is
 181    begin
 182       if Is_Reserved (Interrupt) then
 183          Raise_Exception (Program_Error'Identity, "Interrupt" &
 184            Interrupt_ID'Image (Interrupt) & " is reserved");
 185       end if;
 186
 187       return Descriptors (Interrupt).T /= Null_Task;
 188    end Is_Entry_Attached;
 189
 190    -------------------------
 191    -- Is_Handler_Attached --
 192    -------------------------
 193
 194    function Is_Handler_Attached (Interrupt : Interrupt_ID) return Boolean is
 195    begin
 196       if Is_Reserved (Interrupt) then
 197          Raise_Exception (Program_Error'Identity, "Interrupt" &
 198            Interrupt_ID'Image (Interrupt) & " is reserved");
 199       end if;
 200
 201       return Descriptors (Interrupt).Kind /= Unknown;
 202    end Is_Handler_Attached;
 203
 204    ----------------
 205    -- Is_Ignored --
 206    ----------------
 207
 208    function Is_Ignored (Interrupt : Interrupt_ID) return Boolean is
 209    begin
 210       raise Program_Error;
 211       return False;
 212    end Is_Ignored;
 213
 214    ------------------
 215    -- Unblocked_By --
 216    ------------------
 217
 218    function Unblocked_By (Interrupt : Interrupt_ID) return Task_ID is
 219    begin
 220       raise Program_Error;
 221       return Null_Task;
 222    end Unblocked_By;
 223
 224    ----------------------
 225    -- Ignore_Interrupt --
 226    ----------------------
 227
 228    procedure Ignore_Interrupt (Interrupt : Interrupt_ID) is
 229    begin
 230       raise Program_Error;
 231    end Ignore_Interrupt;
 232
 233    ------------------------
 234    -- Unignore_Interrupt --
 235    ------------------------
 236
 237    procedure Unignore_Interrupt (Interrupt : Interrupt_ID) is
 238    begin
 239       raise Program_Error;
 240    end Unignore_Interrupt;
 241
 242    -------------------------------------
 243    -- Has_Interrupt_Or_Attach_Handler --
 244    -------------------------------------
 245
 246    function Has_Interrupt_Or_Attach_Handler
 247      (Object : access Dynamic_Interrupt_Protection) return Boolean
 248    is
 249       pragma Unreferenced (Object);
 250    begin
 251       return True;
 252    end Has_Interrupt_Or_Attach_Handler;
 253
 254    ----------------
 255    --  Finalize  --
 256    ----------------
 257
 258    procedure Finalize (Object : in out Static_Interrupt_Protection) is
 259    begin
 260       --  ??? loop to be executed only when we're not doing library level
 261       --  finalization, since in this case all interrupt tasks are gone.
 262
 263       for N in reverse Object.Previous_Handlers'Range loop
 264          Attach_Handler
 265            (New_Handler => Object.Previous_Handlers (N).Handler,
 266             Interrupt   => Object.Previous_Handlers (N).Interrupt,
 267             Static      => Object.Previous_Handlers (N).Static,
 268             Restoration => True);
 269       end loop;
 270
 271       Tasking.Protected_Objects.Entries.Finalize
 272         (Tasking.Protected_Objects.Entries.Protection_Entries (Object));
 273    end Finalize;
 274
 275    -------------------------------------
 276    -- Has_Interrupt_Or_Attach_Handler --
 277    -------------------------------------
 278
 279    function Has_Interrupt_Or_Attach_Handler
 280      (Object : access Static_Interrupt_Protection) return Boolean
 281    is
 282       pragma Unreferenced (Object);
 283    begin
 284       return True;
 285    end Has_Interrupt_Or_Attach_Handler;
 286
 287    ----------------------
 288    -- Install_Handlers --
 289    ----------------------
 290
 291    procedure Install_Handlers
 292      (Object       : access Static_Interrupt_Protection;
 293       New_Handlers : New_Handler_Array)
 294    is
 295    begin
 296       for N in New_Handlers'Range loop
 297
 298          --  We need a lock around this ???
 299
 300          Object.Previous_Handlers (N).Interrupt := New_Handlers (N).Interrupt;
 301          Object.Previous_Handlers (N).Static    := Descriptors
 302            (New_Handlers (N).Interrupt).Static;
 303
 304          --  We call Exchange_Handler and not directly Interrupt_Manager.
 305          --  Exchange_Handler so we get the Is_Reserved check.
 306
 307          Exchange_Handler
 308            (Old_Handler => Object.Previous_Handlers (N).Handler,
 309             New_Handler => New_Handlers (N).Handler,
 310             Interrupt   => New_Handlers (N).Interrupt,
 311             Static      => True);
 312       end loop;
 313    end Install_Handlers;
 314
 315    ---------------------
 316    -- Current_Handler --
 317    ---------------------
 318
 319    function Current_Handler
 320      (Interrupt : Interrupt_ID) return Parameterless_Handler
 321    is
 322    begin
 323       if Is_Reserved (Interrupt) then
 324          raise Program_Error;
 325       end if;
 326
 327       if Descriptors (Interrupt).Kind = Protected_Procedure then
 328          return Descriptors (Interrupt).H;
 329       else
 330          return null;
 331       end if;
 332    end Current_Handler;
 333
 334    --------------------
 335    -- Attach_Handler --
 336    --------------------
 337
 338    procedure Attach_Handler
 339      (New_Handler : Parameterless_Handler;
 340       Interrupt   : Interrupt_ID;
 341       Static      : Boolean := False) is
 342    begin
 343       Attach_Handler (New_Handler, Interrupt, Static, False);
 344    end Attach_Handler;
 345
 346    procedure Attach_Handler
 347      (New_Handler : Parameterless_Handler;
 348       Interrupt   : Interrupt_ID;
 349       Static      : Boolean;
 350       Restoration : Boolean)
 351    is
 352       New_Task : Server_Task_Access;
 353
 354    begin
 355       if Is_Reserved (Interrupt) then
 356          raise Program_Error;
 357       end if;
 358
 359       if not Restoration and then not Static
 360
 361          --  Tries to overwrite a static Interrupt Handler with a
 362          --  dynamic Handler
 363
 364         and then (Descriptors (Interrupt).Static
 365
 366                      --  The new handler is not specified as an
 367                      --  Interrupt Handler by a pragma.
 368
 369                      or else not Is_Registered (New_Handler))
 370       then
 371          Raise_Exception (Program_Error'Identity,
 372            "Trying to overwrite a static Interrupt Handler with a " &
 373            "dynamic Handler");
 374       end if;
 375
 376       if Handlers (Interrupt) = null then
 377          New_Task := new Server_Task (Interrupt);
 378          Handlers (Interrupt) := To_System (New_Task.all'Identity);
 379       end if;
 380
 381       if intr_attach (int (Interrupt),
 382         TISR (Signal_Handler'Access)) = FUNC_ERR
 383       then
 384          raise Program_Error;
 385       end if;
 386
 387       if New_Handler = null then
 388
 389          --  The null handler means we are detaching the handler.
 390
 391          Attached_Interrupts (Interrupt) := False;
 392          Descriptors (Interrupt) :=
 393            (Kind => Unknown, T => null, E => 0, H => null, Static => False);
 394
 395       else
 396          Descriptors (Interrupt).Kind := Protected_Procedure;
 397          Descriptors (Interrupt).H := New_Handler;
 398          Descriptors (Interrupt).Static := Static;
 399          Attached_Interrupts (Interrupt) := True;
 400       end if;
 401    end Attach_Handler;
 402
 403    ----------------------
 404    -- Exchange_Handler --
 405    ----------------------
 406
 407    procedure Exchange_Handler
 408      (Old_Handler : out Parameterless_Handler;
 409       New_Handler : Parameterless_Handler;
 410       Interrupt   : Interrupt_ID;
 411       Static      : Boolean := False) is
 412    begin
 413       if Is_Reserved (Interrupt) then
 414          raise Program_Error;
 415       end if;
 416
 417       if Descriptors (Interrupt).Kind = Task_Entry then
 418
 419          --  In case we have an Interrupt Entry already installed.
 420          --  raise a program error. (propagate it to the caller).
 421
 422          Raise_Exception (Program_Error'Identity,
 423            "An interrupt is already installed");
 424       end if;
 425
 426       Old_Handler := Current_Handler (Interrupt);
 427       Attach_Handler (New_Handler, Interrupt, Static);
 428    end Exchange_Handler;
 429
 430    --------------------
 431    -- Detach_Handler --
 432    --------------------
 433
 434    procedure Detach_Handler
 435      (Interrupt : Interrupt_ID;
 436       Static    : Boolean := False) is
 437    begin
 438       if Is_Reserved (Interrupt) then
 439          raise Program_Error;
 440       end if;
 441
 442       if Descriptors (Interrupt).Kind = Task_Entry then
 443          Raise_Exception (Program_Error'Identity,
 444            "Trying to detach an Interrupt Entry");
 445       end if;
 446
 447       if not Static and then Descriptors (Interrupt).Static then
 448          Raise_Exception (Program_Error'Identity,
 449            "Trying to detach a static Interrupt Handler");
 450       end if;
 451
 452       Attached_Interrupts (Interrupt) := False;
 453       Descriptors (Interrupt) :=
 454         (Kind => Unknown, T => null, E => 0, H => null, Static => False);
 455
 456       if intr_attach (int (Interrupt), null) = FUNC_ERR then
 457          raise Program_Error;
 458       end if;
 459    end Detach_Handler;
 460
 461    ---------------
 462    -- Reference --
 463    ---------------
 464
 465    function Reference (Interrupt : Interrupt_ID) return System.Address is
 466       Signal : constant System.Address :=
 467                  System.Storage_Elements.To_Address
 468                    (System.Storage_Elements.Integer_Address (Interrupt));
 469
 470    begin
 471       if Is_Reserved (Interrupt) then
 472
 473          --  Only usable Interrupts can be used for binding it to an Entry
 474
 475          raise Program_Error;
 476       end if;
 477
 478       return Signal;
 479    end Reference;
 480
 481    --------------------------------
 482    -- Register_Interrupt_Handler --
 483    --------------------------------
 484
 485    procedure Register_Interrupt_Handler (Handler_Addr : System.Address) is
 486    begin
 487       Registered_Handlers :=
 488        new Registered_Handler'(H => Handler_Addr, Next => Registered_Handlers);
 489    end Register_Interrupt_Handler;
 490
 491    -------------------
 492    -- Is_Registered --
 493    -------------------
 494
 495    --  See if the Handler has been "pragma"ed using Interrupt_Handler.
 496    --  Always consider a null handler as registered.
 497
 498    function Is_Registered (Handler : Parameterless_Handler) return Boolean is
 499       Ptr : R_Link := Registered_Handlers;
 500
 501       type Fat_Ptr is record
 502          Object_Addr  : System.Address;
 503          Handler_Addr : System.Address;
 504       end record;
 505
 506       function To_Fat_Ptr is new Unchecked_Conversion
 507         (Parameterless_Handler, Fat_Ptr);
 508
 509       Fat : Fat_Ptr;
 510
 511    begin
 512       if Handler = null then
 513          return True;
 514       end if;
 515
 516       Fat := To_Fat_Ptr (Handler);
 517
 518       while Ptr /= null loop
 519
 520          if Ptr.H = Fat.Handler_Addr then
 521             return True;
 522          end if;
 523
 524          Ptr := Ptr.Next;
 525       end loop;
 526
 527       return False;
 528    end Is_Registered;
 529
 530    -----------------------------
 531    -- Bind_Interrupt_To_Entry --
 532    -----------------------------
 533
 534    procedure Bind_Interrupt_To_Entry
 535      (T       : Task_ID;
 536       E       : Task_Entry_Index;
 537       Int_Ref : System.Address)
 538    is
 539       Interrupt   : constant Interrupt_ID :=
 540         Interrupt_ID (Storage_Elements.To_Integer (Int_Ref));
 541
 542       New_Task : Server_Task_Access;
 543
 544    begin
 545       if Is_Reserved (Interrupt) then
 546          raise Program_Error;
 547       end if;
 548
 549       if Descriptors (Interrupt).Kind /= Unknown then
 550          Raise_Exception (Program_Error'Identity,
 551            "A binding for this interrupt is already present");
 552       end if;
 553
 554       if Handlers (Interrupt) = null then
 555          New_Task := new Server_Task (Interrupt);
 556          Handlers (Interrupt) := To_System (New_Task.all'Identity);
 557       end if;
 558
 559       if intr_attach (int (Interrupt),
 560         TISR (Signal_Handler'Access)) = FUNC_ERR
 561       then
 562          raise Program_Error;
 563       end if;
 564
 565       Descriptors (Interrupt).Kind := Task_Entry;
 566       Descriptors (Interrupt).T := T;
 567       Descriptors (Interrupt).E := E;
 568
 569       --  Indicate the attachment of Interrupt Entry in ATCB.
 570       --  This is need so that when an Interrupt Entry task terminates
 571       --  the binding can be cleaned. The call to unbinding must be
 572       --  make by the task before it terminates.
 573
 574       T.Interrupt_Entry := True;
 575
 576       Attached_Interrupts (Interrupt) := True;
 577    end Bind_Interrupt_To_Entry;
 578
 579    ------------------------------
 580    -- Detach_Interrupt_Entries --
 581    ------------------------------
 582
 583    procedure Detach_Interrupt_Entries (T : Task_ID) is
 584    begin
 585       for I in Interrupt_ID loop
 586          if not Is_Reserved (I) then
 587             if Descriptors (I).Kind = Task_Entry and then
 588               Descriptors (I).T = T then
 589                Attached_Interrupts (I) := False;
 590                Descriptors (I).Kind := Unknown;
 591
 592                if intr_attach (int (I), null) = FUNC_ERR then
 593                   raise Program_Error;
 594                end if;
 595             end if;
 596          end if;
 597       end loop;
 598
 599       --  Indicate in ATCB that no Interrupt Entries are attached.
 600
 601       T.Interrupt_Entry := True;
 602    end Detach_Interrupt_Entries;
 603
 604    ---------------------
 605    -- Block_Interrupt --
 606    ---------------------
 607
 608    procedure Block_Interrupt (Interrupt : Interrupt_ID) is
 609    begin
 610       raise Program_Error;
 611    end Block_Interrupt;
 612
 613    -----------------------
 614    -- Unblock_Interrupt --
 615    -----------------------
 616
 617    procedure Unblock_Interrupt (Interrupt : Interrupt_ID) is
 618    begin
 619       raise Program_Error;
 620    end Unblock_Interrupt;
 621
 622    ----------------
 623    -- Is_Blocked --
 624    ----------------
 625
 626    function Is_Blocked (Interrupt : Interrupt_ID) return Boolean is
 627    begin
 628       raise Program_Error;
 629       return False;
 630    end Is_Blocked;
 631
 632    task body Server_Task is
 633       Desc    : Handler_Desc renames Descriptors (Interrupt);
 634       Self_Id : constant Task_ID := STPO.Self;
 635       Temp    : Parameterless_Handler;
 636
 637    begin
 638       Utilities.Make_Independent;
 639
 640       loop
 641          while Interrupt_Count (Interrupt) > 0 loop
 642             Interrupt_Count (Interrupt) := Interrupt_Count (Interrupt) - 1;
 643             begin
 644                case Desc.Kind is
 645                   when Unknown =>
 646                      null;
 647                   when Task_Entry =>
 648                      Rendezvous.Call_Simple (Desc.T, Desc.E, Null_Address);
 649                   when Protected_Procedure =>
 650                      Temp := Desc.H;
 651                      Temp.all;
 652                end case;
 653             exception
 654                when others => null;
 655             end;
 656          end loop;
 657
 658          Initialization.Defer_Abort (Self_Id);
 659
 660          if Single_Lock then
 661             STPO.Lock_RTS;
 662          end if;
 663
 664          STPO.Write_Lock (Self_Id);
 665          Self_Id.Common.State := Interrupt_Server_Idle_Sleep;
 666          STPO.Sleep (Self_Id, Interrupt_Server_Idle_Sleep);
 667          Self_Id.Common.State := Runnable;
 668          STPO.Unlock (Self_Id);
 669
 670          if Single_Lock then
 671             STPO.Unlock_RTS;
 672          end if;
 673
 674          Initialization.Undefer_Abort (Self_Id);
 675
 676          --  Undefer abort here to allow a window for this task
 677          --  to be aborted  at the time of system shutdown.
 678
 679       end loop;
 680    end Server_Task;
 681
 682 end System.Interrupts;