gcc/ada/s-osinte-freebsd.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                  GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS                --
   4 --                                                                          --
   5 --                   S Y S T E M . O S _ I N T E R F A C E                  --
   6 --                                                                          --
   7 --                                   S p e c                                --
   8 --                                                                          --
   9 --             Copyright (C) 1991-1994, Florida State University            --
  10 --             Copyright (C) 1995-2006, Free Software Foundation, Inc.      --
  11 --                                                                          --
  12 -- GNARL is free software; you can  redistribute it  and/or modify it under --
  13 -- terms of the  GNU General Public License as published  by the Free Soft- --
  14 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  15 -- sion. GNARL is distributed in the hope that it will be useful, but WITH- --
  16 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  17 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  18 -- for  more details.  You should have  received  a copy of the GNU General --
  19 -- Public License  distributed with GNARL; see file COPYING.  If not, write --
  20 -- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
  21 -- Boston, MA 02110-1301, USA.                                              --
  22 --                                                                          --
  23 -- As a special exception,  if other files  instantiate  generics from this --
  24 -- unit, or you link  this unit with other files  to produce an executable, --
  25 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  26 -- covered  by the  GNU  General  Public  License.  This exception does not --
  27 -- however invalidate  any other reasons why  the executable file  might be --
  28 -- covered by the  GNU Public License.                                      --
  29 --                                                                          --
  30 -- GNARL was developed by the GNARL team at Florida State University. It is --
  31 -- now maintained by Ada Core Technologies Inc. in cooperation with Florida --
  32 -- State University (http://www.gnat.com).                                  --
  33 --                                                                          --
  34 ------------------------------------------------------------------------------
  35
  36 --  This is the FreeBSD PTHREADS version of this package
  37
  38 --  This package encapsulates all direct interfaces to OS services
  39 --  that are needed by children of System.
  40
  41 --  PLEASE DO NOT add any with-clauses to this package or remove the pragma
  42 --  Preelaborate. This package is designed to be a bottom-level (leaf) package.
  43
  44 with Interfaces.C;
  45 with Unchecked_Conversion;
  46
  47 package System.OS_Interface is
  48    pragma Preelaborate;
  49
  50    pragma Linker_Options ("-pthread");
  51
  52    subtype int            is Interfaces.C.int;
  53    subtype short          is Interfaces.C.short;
  54    subtype long           is Interfaces.C.long;
  55    subtype unsigned       is Interfaces.C.unsigned;
  56    subtype unsigned_short is Interfaces.C.unsigned_short;
  57    subtype unsigned_long  is Interfaces.C.unsigned_long;
  58    subtype unsigned_char  is Interfaces.C.unsigned_char;
  59    subtype plain_char     is Interfaces.C.plain_char;
  60    subtype size_t         is Interfaces.C.size_t;
  61
  62    -----------
  63    -- Errno --
  64    -----------
  65
  66    function Errno return int;
  67    pragma Inline (Errno);
  68
  69    EAGAIN   : constant := 35;
  70    EINTR    : constant := 4;
  71    EINVAL   : constant := 22;
  72    ENOMEM   : constant := 12;
  73    ETIMEDOUT    : constant := 60;
  74
  75    -------------
  76    -- Signals --
  77    -------------
  78
  79    Max_Interrupt : constant := 31;
  80    type Signal is new int range 0 .. Max_Interrupt;
  81    for Signal'Size use int'Size;
  82
  83    SIGHUP     : constant := 1; --  hangup
  84    SIGINT     : constant := 2; --  interrupt (rubout)
  85    SIGQUIT    : constant := 3; --  quit (ASCD FS)
  86    SIGILL     : constant := 4; --  illegal instruction (not reset)
  87    SIGTRAP    : constant := 5; --  trace trap (not reset)
  88    SIGIOT     : constant := 6; --  IOT instruction
  89    SIGABRT    : constant := 6; --  used by abort, replace SIGIOT in the  future
  90    SIGEMT     : constant := 7; --  EMT instruction
  91    SIGFPE     : constant := 8; --  floating point exception
  92    SIGKILL    : constant := 9; --  kill (cannot be caught or ignored)
  93    SIGBUS     : constant := 10; --  bus error
  94    SIGSEGV    : constant := 11; --  segmentation violation
  95    SIGSYS     : constant := 12; --  bad argument to system call
  96    SIGPIPE    : constant := 13; --  write on a pipe with no one to read it
  97    SIGALRM    : constant := 14; --  alarm clock
  98    SIGTERM    : constant := 15; --  software termination signal from kill
  99    SIGURG     : constant := 16; --  urgent condition on IO channel
 100    SIGSTOP    : constant := 17; --  stop (cannot be caught or ignored)
 101    SIGTSTP    : constant := 18; --  user stop requested from tty
 102    SIGCONT    : constant := 19; --  stopped process has been continued
 103    SIGCLD     : constant := 20; --  alias for SIGCHLD
 104    SIGCHLD    : constant := 20; --  child status change
 105    SIGTTIN    : constant := 21; --  background tty read attempted
 106    SIGTTOU    : constant := 22; --  background tty write attempted
 107    SIGIO      : constant := 23; --  I/O possible (Solaris SIGPOLL alias)
 108    SIGXCPU    : constant := 24; --  CPU time limit exceeded
 109    SIGXFSZ    : constant := 25; --  filesize limit exceeded
 110    SIGVTALRM  : constant := 26; --  virtual timer expired
 111    SIGPROF    : constant := 27; --  profiling timer expired
 112    SIGWINCH   : constant := 28; --  window size change
 113    SIGINFO    : constant := 29; --  information request (NetBSD/FreeBSD)
 114    SIGUSR1    : constant := 30; --  user defined signal 1
 115    SIGUSR2    : constant := 31; --  user defined signal 2
 116
 117    SIGADAABORT : constant := SIGABRT;
 118    --  Change this if you want to use another signal for task abort.
 119    --  SIGTERM might be a good one.
 120
 121    type Signal_Set is array (Natural range <>) of Signal;
 122
 123    --  Interrupts that must be unmasked at all times.  FreeBSD
 124    --  pthreads will not allow an application to mask out any
 125    --  interrupt needed by the threads library.
 126    Unmasked : constant Signal_Set :=
 127      (SIGTRAP, SIGBUS, SIGTTIN, SIGTTOU, SIGTSTP);
 128
 129    --  FreeBSD will uses SIGPROF for timing.  Do not allow a
 130    --  handler to attach to this signal.
 131    Reserved : constant Signal_Set := (0 .. 0 => SIGPROF);
 132
 133    type sigset_t is private;
 134
 135    function sigaddset
 136      (set : access sigset_t;
 137       sig : Signal) return int;
 138    pragma Import (C, sigaddset, "sigaddset");
 139
 140    function sigdelset
 141      (set : access sigset_t;
 142       sig : Signal) return int;
 143    pragma Import (C, sigdelset, "sigdelset");
 144
 145    function sigfillset (set : access sigset_t) return int;
 146    pragma Import (C, sigfillset, "sigfillset");
 147
 148    function sigismember
 149      (set : access sigset_t;
 150       sig : Signal) return int;
 151    pragma Import (C, sigismember, "sigismember");
 152
 153    function sigemptyset (set : access sigset_t) return int;
 154    pragma Import (C, sigemptyset, "sigemptyset");
 155
 156    --  sigcontext is architecture dependent, so define it private
 157    type struct_sigcontext is private;
 158
 159    type old_struct_sigaction is record
 160       sa_handler : System.Address;
 161       sa_mask    : sigset_t;
 162       sa_flags   : int;
 163    end record;
 164    pragma Convention (C, old_struct_sigaction);
 165
 166    type new_struct_sigaction is record
 167       sa_handler : System.Address;
 168       sa_flags   : int;
 169       sa_mask    : sigset_t;
 170    end record;
 171    pragma Convention (C, new_struct_sigaction);
 172
 173    subtype struct_sigaction is new_struct_sigaction;
 174    type struct_sigaction_ptr is access all struct_sigaction;
 175
 176    SIG_BLOCK   : constant := 1;
 177    SIG_UNBLOCK : constant := 2;
 178    SIG_SETMASK : constant := 3;
 179
 180    SIG_DFL : constant := 0;
 181    SIG_IGN : constant := 1;
 182
 183    SA_SIGINFO : constant := 16#0040#;
 184
 185    function sigaction
 186      (sig  : Signal;
 187       act  : struct_sigaction_ptr;
 188       oact : struct_sigaction_ptr) return int;
 189    pragma Import (C, sigaction, "sigaction");
 190
 191    ----------
 192    -- Time --
 193    ----------
 194
 195    Time_Slice_Supported : constant Boolean := True;
 196    --  Indicates wether time slicing is supported (i.e SCHED_RR is supported)
 197
 198    type timespec is private;
 199
 200    function nanosleep (rqtp, rmtp : access timespec)  return int;
 201    pragma Import (C, nanosleep, "nanosleep");
 202
 203    type clockid_t is private;
 204
 205    CLOCK_REALTIME : constant clockid_t;
 206
 207    function clock_gettime
 208      (clock_id : clockid_t;
 209       tp       : access timespec)
 210       return int;
 211    pragma Import (C, clock_gettime, "clock_gettime");
 212
 213    function To_Duration (TS : timespec) return Duration;
 214    pragma Inline (To_Duration);
 215
 216    function To_Timespec (D : Duration) return timespec;
 217    pragma Inline (To_Timespec);
 218
 219    type struct_timezone is record
 220       tz_minuteswest : int;
 221       tz_dsttime     : int;
 222    end record;
 223    pragma Convention (C, struct_timezone);
 224    type struct_timeval is private;
 225    --  This is needed on systems that do not have clock_gettime()
 226    --  but do have gettimeofday().
 227
 228    function To_Duration (TV : struct_timeval) return Duration;
 229    pragma Inline (To_Duration);
 230
 231    function To_Timeval (D : Duration) return struct_timeval;
 232    pragma Inline (To_Timeval);
 233
 234    function gettimeofday
 235      (tv : access struct_timeval;
 236       tz : System.Address) return int;
 237    pragma Import (C, gettimeofday, "gettimeofday");
 238
 239    procedure usleep (useconds : unsigned_long);
 240    pragma Import (C, usleep, "usleep");
 241
 242    -------------------------
 243    -- Priority Scheduling --
 244    -------------------------
 245
 246    SCHED_FIFO  : constant := 1;
 247    SCHED_OTHER : constant := 2;
 248    SCHED_RR    : constant := 3;
 249
 250    function To_Target_Priority
 251      (Prio : System.Any_Priority) return Interfaces.C.int;
 252    --  Maps System.Any_Priority to a POSIX priority.
 253
 254    -------------
 255    -- Process --
 256    -------------
 257
 258    type pid_t is private;
 259
 260    Self_PID : constant pid_t;
 261
 262    function kill (pid : pid_t; sig : Signal) return int;
 263    pragma Import (C, kill, "kill");
 264
 265    function getpid return pid_t;
 266    pragma Import (C, getpid, "getpid");
 267
 268    ---------
 269    -- LWP --
 270    ---------
 271
 272    function lwp_self return System.Address;
 273    --  lwp_self does not exist on this thread library, revert to pthread_self
 274    --  which is the closest approximation (with getpid). This function is
 275    --  needed to share 7staprop.adb across POSIX-like targets.
 276    pragma Import (C, lwp_self, "pthread_self");
 277
 278    -------------
 279    -- Threads --
 280    -------------
 281
 282    type Thread_Body is access
 283      function (arg : System.Address) return System.Address;
 284
 285    function Thread_Body_Access is new
 286      Unchecked_Conversion (System.Address, Thread_Body);
 287
 288    type pthread_t           is private;
 289    subtype Thread_Id        is pthread_t;
 290
 291    type pthread_mutex_t     is limited private;
 292    type pthread_cond_t      is limited private;
 293    type pthread_attr_t      is limited private;
 294    type pthread_mutexattr_t is limited private;
 295    type pthread_condattr_t  is limited private;
 296    type pthread_key_t       is private;
 297
 298    PTHREAD_CREATE_DETACHED : constant := 1;
 299    PTHREAD_CREATE_JOINABLE : constant := 0;
 300
 301    -----------
 302    -- Stack --
 303    -----------
 304
 305    Stack_Base_Available : constant Boolean := False;
 306    --  Indicates wether the stack base is available on this target.
 307    --  This allows us to share s-osinte.adb between all the FSU run time.
 308    --  Note that this value can only be true if pthread_t has a complete
 309    --  definition that corresponds exactly to the C header files.
 310
 311    function Get_Stack_Base (thread : pthread_t) return Address;
 312    pragma Inline (Get_Stack_Base);
 313    --  returns the stack base of the specified thread.
 314    --  Only call this function when Stack_Base_Available is True.
 315
 316    function Get_Page_Size return size_t;
 317    function Get_Page_Size return Address;
 318    pragma Import (C, Get_Page_Size, "getpagesize");
 319    --  returns the size of a page, or 0 if this is not relevant on this
 320    --  target
 321
 322    PROT_NONE  : constant := 0;
 323    PROT_READ  : constant := 1;
 324    PROT_WRITE : constant := 2;
 325    PROT_EXEC  : constant := 4;
 326    PROT_ALL   : constant := PROT_READ + PROT_WRITE + PROT_EXEC;
 327
 328    PROT_ON    : constant := PROT_NONE;
 329    PROT_OFF   : constant := PROT_ALL;
 330
 331    function mprotect
 332      (addr : Address; len : size_t; prot : int) return int;
 333    pragma Import (C, mprotect);
 334
 335    ---------------------------------------
 336    -- Nonstandard Thread Initialization --
 337    ---------------------------------------
 338
 339    --  FSU_THREADS requires pthread_init, which is nonstandard and
 340    --  this should be invoked during the elaboration of s-taprop.adb
 341
 342    --  FreeBSD does not require this so we provide an empty Ada body
 343
 344    procedure pthread_init;
 345
 346    -------------------------
 347    -- POSIX.1c  Section 3 --
 348    -------------------------
 349
 350    function sigwait
 351      (set : access sigset_t;
 352       sig : access Signal) return int;
 353    pragma Import (C, sigwait, "sigwait");
 354
 355    function pthread_kill
 356      (thread : pthread_t;
 357       sig    : Signal) return int;
 358    pragma Import (C, pthread_kill, "pthread_kill");
 359
 360    function pthread_sigmask
 361      (how  : int;
 362       set  : access sigset_t;
 363       oset : access sigset_t) return int;
 364    pragma Import (C, pthread_sigmask, "pthread_sigmask");
 365
 366    --------------------------
 367    -- POSIX.1c  Section 11 --
 368    --------------------------
 369
 370    function pthread_mutexattr_init
 371      (attr : access pthread_mutexattr_t) return int;
 372    pragma Import (C, pthread_mutexattr_init, "pthread_mutexattr_init");
 373
 374    function pthread_mutexattr_destroy
 375      (attr : access pthread_mutexattr_t) return int;
 376    pragma Import (C, pthread_mutexattr_destroy, "pthread_mutexattr_destroy");
 377
 378    function pthread_mutex_init
 379      (mutex : access pthread_mutex_t;
 380       attr  : access pthread_mutexattr_t) return int;
 381    pragma Import (C, pthread_mutex_init, "pthread_mutex_init");
 382
 383    function pthread_mutex_destroy (mutex : access pthread_mutex_t) return int;
 384    pragma Import (C, pthread_mutex_destroy, "pthread_mutex_destroy");
 385
 386    function pthread_mutex_lock (mutex : access pthread_mutex_t) return int;
 387    pragma Import (C, pthread_mutex_lock, "pthread_mutex_lock");
 388
 389    function pthread_mutex_unlock (mutex : access pthread_mutex_t) return int;
 390    pragma Import (C, pthread_mutex_unlock, "pthread_mutex_unlock");
 391
 392    function pthread_condattr_init
 393      (attr : access pthread_condattr_t) return int;
 394    pragma Import (C, pthread_condattr_init, "pthread_condattr_init");
 395
 396    function pthread_condattr_destroy
 397      (attr : access pthread_condattr_t) return int;
 398    pragma Import (C, pthread_condattr_destroy, "pthread_condattr_destroy");
 399
 400    function pthread_cond_init
 401      (cond : access pthread_cond_t;
 402       attr : access pthread_condattr_t) return int;
 403    pragma Import (C, pthread_cond_init, "pthread_cond_init");
 404
 405    function pthread_cond_destroy (cond : access pthread_cond_t) return int;
 406    pragma Import (C, pthread_cond_destroy, "pthread_cond_destroy");
 407
 408    function pthread_cond_signal (cond : access pthread_cond_t) return int;
 409    pragma Import (C, pthread_cond_signal, "pthread_cond_signal");
 410
 411    function pthread_cond_wait
 412      (cond  : access pthread_cond_t;
 413       mutex : access pthread_mutex_t) return int;
 414    pragma Import (C, pthread_cond_wait, "pthread_cond_wait");
 415
 416    function pthread_cond_timedwait
 417      (cond    : access pthread_cond_t;
 418       mutex   : access pthread_mutex_t;
 419       abstime : access timespec) return int;
 420    pragma Import (C, pthread_cond_timedwait, "pthread_cond_timedwait");
 421
 422    Relative_Timed_Wait : constant Boolean := False;
 423    --  pthread_cond_timedwait requires an absolute delay time
 424
 425    --------------------------
 426    -- POSIX.1c  Section 13 --
 427    --------------------------
 428
 429    PTHREAD_PRIO_NONE    : constant := 0;
 430    PTHREAD_PRIO_PROTECT : constant := 2;
 431    PTHREAD_PRIO_INHERIT : constant := 1;
 432
 433    function pthread_mutexattr_setprotocol
 434      (attr     : access pthread_mutexattr_t;
 435       protocol : int) return int;
 436    pragma Import
 437       (C, pthread_mutexattr_setprotocol, "pthread_mutexattr_setprotocol");
 438
 439    function pthread_mutexattr_getprotocol
 440      (attr     : access pthread_mutexattr_t;
 441       protocol : access int) return int;
 442    pragma Import
 443      (C, pthread_mutexattr_getprotocol, "pthread_mutexattr_getprotocol");
 444
 445    function pthread_mutexattr_setprioceiling
 446      (attr     : access pthread_mutexattr_t;
 447       prioceiling : int) return int;
 448    pragma Import
 449      (C, pthread_mutexattr_setprioceiling,
 450       "pthread_mutexattr_setprioceiling");
 451
 452    function pthread_mutexattr_getprioceiling
 453      (attr     : access pthread_mutexattr_t;
 454       prioceiling : access int) return int;
 455    pragma Import
 456      (C, pthread_mutexattr_getprioceiling,
 457       "pthread_mutexattr_getprioceiling");
 458
 459    type struct_sched_param is record
 460       sched_priority : int;
 461    end record;
 462    pragma Convention (C, struct_sched_param);
 463
 464    function pthread_getschedparam
 465      (thread : pthread_t;
 466       policy : access int;
 467       param  : access struct_sched_param) return int;
 468    pragma Import (C, pthread_getschedparam, "pthread_getschedparam");
 469
 470    function pthread_setschedparam
 471      (thread : pthread_t;
 472       policy : int;
 473       param  : access struct_sched_param) return int;
 474    pragma Import (C, pthread_setschedparam, "pthread_setschedparam");
 475
 476    function pthread_attr_setscope
 477      (attr            : access pthread_attr_t;
 478       contentionscope : int) return int;
 479    pragma Import (C, pthread_attr_setscope, "pthread_attr_setscope");
 480
 481    function pthread_attr_getscope
 482      (attr            : access pthread_attr_t;
 483       contentionscope : access int) return int;
 484    pragma Import (C, pthread_attr_getscope, "pthread_attr_getscope");
 485
 486    function pthread_attr_setinheritsched
 487      (attr            : access pthread_attr_t;
 488       inheritsched : int) return int;
 489    pragma Import
 490      (C, pthread_attr_setinheritsched, "pthread_attr_setinheritsched");
 491
 492    function pthread_attr_getinheritsched
 493      (attr         : access pthread_attr_t;
 494       inheritsched : access int) return int;
 495    pragma Import
 496      (C, pthread_attr_getinheritsched, "pthread_attr_getinheritsched");
 497
 498    function pthread_attr_setschedpolicy
 499      (attr   : access pthread_attr_t;
 500       policy : int) return int;
 501    pragma Import (C, pthread_attr_setschedpolicy,
 502      "pthread_attr_setschedpolicy");
 503
 504    function pthread_attr_getschedpolicy
 505      (attr   : access pthread_attr_t;
 506       policy : access int) return int;
 507    pragma Import (C, pthread_attr_getschedpolicy,
 508      "pthread_attr_getschedpolicy");
 509
 510    function pthread_attr_setschedparam
 511      (attr        : access pthread_attr_t;
 512       sched_param : int) return int;
 513    pragma Import (C, pthread_attr_setschedparam, "pthread_attr_setschedparam");
 514
 515    function pthread_attr_getschedparam
 516      (attr        : access pthread_attr_t;
 517       sched_param : access int) return int;
 518    pragma Import (C, pthread_attr_getschedparam, "pthread_attr_getschedparam");
 519
 520    function sched_yield return int;
 521    pragma Import (C, sched_yield, "pthread_yield");
 522
 523    --------------------------
 524    -- P1003.1c  Section 16 --
 525    --------------------------
 526
 527    function pthread_attr_init (attributes : access pthread_attr_t) return int;
 528    pragma Import (C, pthread_attr_init, "pthread_attr_init");
 529
 530    function pthread_attr_destroy
 531      (attributes : access pthread_attr_t) return int;
 532    pragma Import (C, pthread_attr_destroy, "pthread_attr_destroy");
 533
 534    function pthread_attr_setdetachstate
 535      (attr        : access pthread_attr_t;
 536       detachstate : int) return int;
 537    pragma Import
 538      (C, pthread_attr_setdetachstate, "pthread_attr_setdetachstate");
 539
 540    function pthread_attr_getdetachstate
 541      (attr        : access pthread_attr_t;
 542       detachstate : access int) return int;
 543    pragma Import
 544      (C, pthread_attr_getdetachstate, "pthread_attr_getdetachstate");
 545
 546    function pthread_attr_getstacksize
 547      (attr      : access pthread_attr_t;
 548       stacksize : access size_t) return int;
 549    pragma Import
 550      (C, pthread_attr_getstacksize, "pthread_attr_getstacksize");
 551
 552    function pthread_attr_setstacksize
 553      (attr      : access pthread_attr_t;
 554       stacksize : size_t) return int;
 555    pragma Import
 556      (C, pthread_attr_setstacksize, "pthread_attr_setstacksize");
 557
 558    function pthread_create
 559      (thread        : access pthread_t;
 560       attributes    : access pthread_attr_t;
 561       start_routine : Thread_Body;
 562       arg           : System.Address) return int;
 563    pragma Import (C, pthread_create, "pthread_create");
 564
 565    function pthread_detach (thread : pthread_t) return int;
 566    pragma Import (C, pthread_detach, "pthread_detach");
 567
 568    procedure pthread_exit (status : System.Address);
 569    pragma Import (C, pthread_exit, "pthread_exit");
 570
 571    function pthread_self return pthread_t;
 572    pragma Import (C, pthread_self, "pthread_self");
 573
 574    --------------------------
 575    -- POSIX.1c  Section 17 --
 576    --------------------------
 577
 578    function pthread_setspecific
 579      (key   : pthread_key_t;
 580       value : System.Address) return  int;
 581    pragma Import (C, pthread_setspecific, "pthread_setspecific");
 582
 583    function pthread_getspecific (key : pthread_key_t) return System.Address;
 584    pragma Import (C, pthread_getspecific, "pthread_getspecific");
 585
 586    type destructor_pointer is access
 587       procedure (arg : System.Address);
 588
 589    function pthread_key_create
 590      (key        : access pthread_key_t;
 591       destructor : destructor_pointer) return int;
 592    pragma Import (C, pthread_key_create, "pthread_key_create");
 593
 594    ------------------------------------
 595    -- Non-portable Pthread Functions --
 596    ------------------------------------
 597
 598    function pthread_set_name_np
 599      (thread : pthread_t;
 600       name   : System.Address) return int;
 601    pragma Import (C, pthread_set_name_np, "pthread_set_name_np");
 602
 603 private
 604
 605    type sigset_t is array (1 .. 4) of unsigned;
 606
 607    --  In FreeBSD the component sa_handler turns out to
 608    --  be one a union type, and the selector is a macro:
 609    --  #define sa_handler __sigaction_u._handler
 610    --  #define sa_sigaction __sigaction_u._sigaction
 611
 612    --  Should we add a signal_context type here ???
 613    --  How could it be done independent of the CPU architecture ???
 614    --  sigcontext type is opaque, so it is architecturally neutral.
 615    --  It is always passed as an access type, so define it as an empty record
 616    --  since the contents are not used anywhere.
 617
 618    type struct_sigcontext is null record;
 619    pragma Convention (C, struct_sigcontext);
 620
 621    type pid_t is new int;
 622    Self_PID : constant pid_t := 0;
 623
 624    type time_t is new long;
 625
 626    type timespec is record
 627       ts_sec  : time_t;
 628       ts_nsec : long;
 629    end record;
 630    pragma Convention (C, timespec);
 631
 632    type clockid_t is new int;
 633    CLOCK_REALTIME : constant clockid_t := 0;
 634
 635    type struct_timeval is record
 636       tv_sec  : long;
 637       tv_usec : long;
 638    end record;
 639    pragma Convention (C, struct_timeval);
 640
 641    type pthread_t           is new System.Address;
 642    type pthread_attr_t      is new System.Address;
 643    type pthread_mutex_t     is new System.Address;
 644    type pthread_mutexattr_t is new System.Address;
 645    type pthread_cond_t      is new System.Address;
 646    type pthread_condattr_t  is new System.Address;
 647    type pthread_key_t       is new int;
 648
 649 end System.OS_Interface;