1------------------------------------------------------------------------------ 2-- -- 3-- GNU ADA 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) 1995-2019, Free Software Foundation, Inc. -- 11-- -- 12-- GNAT 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 3, or (at your option) any later ver- -- 15-- sion. GNAT 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. -- 18-- -- 19-- As a special exception under Section 7 of GPL version 3, you are granted -- 20-- additional permissions described in the GCC Runtime Library Exception, -- 21-- version 3.1, as published by the Free Software Foundation. -- 22-- -- 23-- You should have received a copy of the GNU General Public License and -- 24-- a copy of the GCC Runtime Library Exception along with this program; -- 25-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 26-- <http://www.gnu.org/licenses/>. -- 27-- -- 28-- GNARL was developed by the GNARL team at Florida State University. -- 29-- Extensive contributions were provided by Ada Core Technologies, Inc. -- 30-- -- 31------------------------------------------------------------------------------ 32 33-- This is the GNU/kFreeBSD (POSIX Threads) version of this package 34 35-- This package encapsulates all direct interfaces to OS services 36-- that are needed by children of System. 37 38-- PLEASE DO NOT add any with-clauses to this package or remove the pragma 39-- Preelaborate. This package is designed to be a bottom-level (leaf) package 40 41with Interfaces.C; 42with Unchecked_Conversion; 43 44package System.OS_Interface is 45 pragma Preelaborate; 46 47 pragma Linker_Options ("-lpthread"); 48 49 subtype int is Interfaces.C.int; 50 subtype char is Interfaces.C.char; 51 subtype short is Interfaces.C.short; 52 subtype long is Interfaces.C.long; 53 subtype unsigned is Interfaces.C.unsigned; 54 subtype unsigned_short is Interfaces.C.unsigned_short; 55 subtype unsigned_long is Interfaces.C.unsigned_long; 56 subtype unsigned_char is Interfaces.C.unsigned_char; 57 subtype plain_char is Interfaces.C.plain_char; 58 subtype size_t is Interfaces.C.size_t; 59 60 ----------- 61 -- Errno -- 62 ----------- 63 64 function errno return int; 65 pragma Import (C, errno, "__get_errno"); 66 67 EAGAIN : constant := 35; 68 EINTR : constant := 4; 69 EINVAL : constant := 22; 70 ENOMEM : constant := 12; 71 EPERM : constant := 1; 72 ETIMEDOUT : constant := 60; 73 74 ------------- 75 -- Signals -- 76 ------------- 77 78 Max_Interrupt : constant := 128; 79 type Signal is new int range 0 .. Max_Interrupt; 80 for Signal'Size use int'Size; 81 82 SIGHUP : constant := 1; -- hangup 83 SIGINT : constant := 2; -- interrupt (rubout) 84 SIGQUIT : constant := 3; -- quit (ASCD FS) 85 SIGILL : constant := 4; -- illegal instruction (not reset) 86 SIGTRAP : constant := 5; -- trace trap (not reset) 87 SIGIOT : constant := 6; -- IOT instruction 88 SIGABRT : constant := 6; -- used by abort, replace SIGIOT in the future 89 SIGEMT : constant := 7; -- EMT instruction 90 SIGFPE : constant := 8; -- floating point exception 91 SIGKILL : constant := 9; -- kill (cannot be caught or ignored) 92 SIGBUS : constant := 10; -- bus error 93 SIGSEGV : constant := 11; -- segmentation violation 94 SIGSYS : constant := 12; -- bad argument to system call 95 SIGPIPE : constant := 13; -- write on a pipe with no one to read it 96 SIGALRM : constant := 14; -- alarm clock 97 SIGTERM : constant := 15; -- software termination signal from kill 98 SIGURG : constant := 16; -- urgent condition on IO channel 99 SIGSTOP : constant := 17; -- stop (cannot be caught or ignored) 100 SIGTSTP : constant := 18; -- user stop requested from tty 101 SIGCONT : constant := 19; -- stopped process has been continued 102 SIGCLD : constant := 20; -- alias for SIGCHLD 103 SIGCHLD : constant := 20; -- child status change 104 SIGTTIN : constant := 21; -- background tty read attempted 105 SIGTTOU : constant := 22; -- background tty write attempted 106 SIGIO : constant := 23; -- I/O possible (Solaris SIGPOLL alias) 107 SIGXCPU : constant := 24; -- CPU time limit exceeded 108 SIGXFSZ : constant := 25; -- filesize limit exceeded 109 SIGVTALRM : constant := 26; -- virtual timer expired 110 SIGPROF : constant := 27; -- profiling timer expired 111 SIGWINCH : constant := 28; -- window size change 112 SIGINFO : constant := 29; -- information request (NetBSD/FreeBSD) 113 SIGUSR1 : constant := 30; -- user defined signal 1 114 SIGUSR2 : constant := 31; -- user defined signal 2 115 SIGLTHRRES : constant := 32; -- GNU/LinuxThreads restart signal 116 SIGLTHRCAN : constant := 33; -- GNU/LinuxThreads cancel signal 117 SIGLTHRDBG : constant := 34; -- GNU/LinuxThreads debugger signal 118 119 SIGADAABORT : constant := SIGABRT; 120 -- Change this if you want to use another signal for task abort. 121 -- SIGTERM might be a good one. 122 123 type Signal_Set is array (Natural range <>) of Signal; 124 125 Unmasked : constant Signal_Set := ( 126 SIGTRAP, 127 -- To enable debugging on multithreaded applications, mark SIGTRAP to 128 -- be kept unmasked. 129 130 SIGBUS, 131 132 SIGTTIN, SIGTTOU, SIGTSTP, 133 -- Keep these three signals unmasked so that background processes 134 -- and IO behaves as normal "C" applications 135 136 SIGPROF, 137 -- To avoid confusing the profiler 138 139 SIGKILL, SIGSTOP, 140 -- These two signals actually cannot be masked; 141 -- POSIX simply won't allow it. 142 143 SIGLTHRRES, SIGLTHRCAN, SIGLTHRDBG); 144 -- These three signals are used by GNU/LinuxThreads starting from 145 -- glibc 2.1 (future 2.2). 146 147 Reserved : constant Signal_Set := 148 -- I am not sure why the following signal is reserved. 149 -- I guess they are not supported by this version of GNU/kFreeBSD. 150 (0 .. 0 => SIGVTALRM); 151 152 type sigset_t is private; 153 154 function sigaddset (set : access sigset_t; sig : Signal) return int; 155 pragma Import (C, sigaddset, "sigaddset"); 156 157 function sigdelset (set : access sigset_t; sig : Signal) return int; 158 pragma Import (C, sigdelset, "sigdelset"); 159 160 function sigfillset (set : access sigset_t) return int; 161 pragma Import (C, sigfillset, "sigfillset"); 162 163 function sigismember (set : access sigset_t; sig : Signal) return int; 164 pragma Import (C, sigismember, "sigismember"); 165 166 function sigemptyset (set : access sigset_t) return int; 167 pragma Import (C, sigemptyset, "sigemptyset"); 168 169 -- sigcontext is architecture dependent, so define it private 170 type struct_sigcontext is private; 171 172 type struct_sigaction is record 173 sa_handler : System.Address; 174 sa_flags : int; 175 sa_mask : sigset_t; 176 end record; 177 pragma Convention (C, struct_sigaction); 178 179 type struct_sigaction_ptr is access all struct_sigaction; 180 181 SIG_BLOCK : constant := 1; 182 SIG_UNBLOCK : constant := 2; 183 SIG_SETMASK : constant := 3; 184 185 SIG_DFL : constant := 0; 186 SIG_IGN : constant := 1; 187 188 SA_SIGINFO : constant := 16#0040#; 189 SA_ONSTACK : constant := 16#0001#; 190 191 function sigaction 192 (sig : Signal; 193 act : struct_sigaction_ptr; 194 oact : struct_sigaction_ptr) return int; 195 pragma Import (C, sigaction, "sigaction"); 196 197 ---------- 198 -- Time -- 199 ---------- 200 201 Time_Slice_Supported : constant Boolean := True; 202 -- Indicates whether time slicing is supported (i.e SCHED_RR is supported) 203 204 type timespec is private; 205 206 function nanosleep (rqtp, rmtp : access timespec) return int; 207 pragma Import (C, nanosleep, "nanosleep"); 208 209 type clockid_t is private; 210 211 CLOCK_REALTIME : constant clockid_t; 212 213 function clock_gettime 214 (clock_id : clockid_t; 215 tp : access timespec) 216 return int; 217 pragma Import (C, clock_gettime, "clock_gettime"); 218 219 function clock_getres 220 (clock_id : clockid_t; 221 res : access timespec) return int; 222 pragma Import (C, clock_getres, "clock_getres"); 223 224 function To_Duration (TS : timespec) return Duration; 225 pragma Inline (To_Duration); 226 227 function To_Timespec (D : Duration) return timespec; 228 pragma Inline (To_Timespec); 229 230 function sysconf (name : int) return long; 231 pragma Import (C, sysconf); 232 233 SC_CLK_TCK : constant := 2; 234 SC_NPROCESSORS_ONLN : constant := 84; 235 236 ------------------------- 237 -- Priority Scheduling -- 238 ------------------------- 239 240 SCHED_FIFO : constant := 1; 241 SCHED_OTHER : constant := 2; 242 SCHED_RR : constant := 3; 243 244 function To_Target_Priority 245 (Prio : System.Any_Priority) return Interfaces.C.int; 246 -- Maps System.Any_Priority to a POSIX priority. 247 248 ------------- 249 -- Process -- 250 ------------- 251 252 type pid_t is private; 253 254 function kill (pid : pid_t; sig : Signal) return int; 255 pragma Import (C, kill, "kill"); 256 257 function getpid return pid_t; 258 pragma Import (C, getpid, "getpid"); 259 260 --------- 261 -- LWP -- 262 --------- 263 264 function lwp_self return System.Address; 265 -- lwp_self does not exist on this thread library, revert to pthread_self 266 -- which is the closest approximation (with getpid). This function is 267 -- needed to share 7staprop.adb across POSIX-like targets. 268 pragma Import (C, lwp_self, "pthread_self"); 269 270 ------------- 271 -- Threads -- 272 ------------- 273 274 type Thread_Body is access 275 function (arg : System.Address) return System.Address; 276 pragma Convention (C, Thread_Body); 277 278 function Thread_Body_Access is new 279 Unchecked_Conversion (System.Address, Thread_Body); 280 281 type pthread_t is new unsigned_long; 282 subtype Thread_Id is pthread_t; 283 284 function To_pthread_t is new Unchecked_Conversion 285 (unsigned_long, pthread_t); 286 287 type pthread_mutex_t is limited private; 288 type pthread_cond_t is limited private; 289 type pthread_attr_t is limited private; 290 type pthread_mutexattr_t is limited private; 291 type pthread_condattr_t is limited private; 292 type pthread_key_t is private; 293 294 PTHREAD_CREATE_DETACHED : constant := 1; 295 PTHREAD_CREATE_JOINABLE : constant := 0; 296 297 PTHREAD_SCOPE_PROCESS : constant := 0; 298 PTHREAD_SCOPE_SYSTEM : constant := 2; 299 300 -- Read/Write lock not supported on kfreebsd. To add support both types 301 -- pthread_rwlock_t and pthread_rwlockattr_t must properly be defined 302 -- with the associated routines pthread_rwlock_[init/destroy] and 303 -- pthread_rwlock_[rdlock/wrlock/unlock]. 304 305 subtype pthread_rwlock_t is pthread_mutex_t; 306 subtype pthread_rwlockattr_t is pthread_mutexattr_t; 307 308 ----------- 309 -- Stack -- 310 ----------- 311 312 type stack_t is record 313 ss_sp : System.Address; 314 ss_size : size_t; 315 ss_flags : int; 316 end record; 317 pragma Convention (C, stack_t); 318 319 function sigaltstack 320 (ss : not null access stack_t; 321 oss : access stack_t) return int; 322 pragma Import (C, sigaltstack, "sigaltstack"); 323 324 Alternate_Stack : aliased System.Address; 325 -- This is a dummy definition, never used (Alternate_Stack_Size is null) 326 327 Alternate_Stack_Size : constant := 0; 328 -- No alternate signal stack is used on this platform 329 330 Stack_Base_Available : constant Boolean := False; 331 -- Indicates whether the stack base is available on this target 332 333 function Get_Stack_Base (thread : pthread_t) return Address; 334 pragma Inline (Get_Stack_Base); 335 -- returns the stack base of the specified thread. Only call this function 336 -- when Stack_Base_Available is True. 337 338 function Get_Page_Size return int; 339 pragma Import (C, Get_Page_Size, "getpagesize"); 340 -- Returns the size of a page 341 342 PROT_NONE : constant := 0; 343 PROT_READ : constant := 1; 344 PROT_WRITE : constant := 2; 345 PROT_EXEC : constant := 4; 346 PROT_ALL : constant := PROT_READ + PROT_WRITE + PROT_EXEC; 347 PROT_ON : constant := PROT_NONE; 348 PROT_OFF : constant := PROT_ALL; 349 350 function mprotect (addr : Address; len : size_t; prot : int) return int; 351 pragma Import (C, mprotect); 352 353 --------------------------------------- 354 -- Nonstandard Thread Initialization -- 355 --------------------------------------- 356 357 procedure pthread_init; 358 pragma Inline (pthread_init); 359 -- This is a dummy procedure to share some GNULLI files 360 361 ------------------------- 362 -- POSIX.1c Section 3 -- 363 ------------------------- 364 365 function sigwait (set : access sigset_t; sig : access Signal) return int; 366 pragma Import (C, sigwait, "sigwait"); 367 368 function pthread_kill (thread : pthread_t; sig : Signal) return int; 369 pragma Import (C, pthread_kill, "pthread_kill"); 370 371 function pthread_sigmask 372 (how : int; 373 set : access sigset_t; 374 oset : access sigset_t) return int; 375 pragma Import (C, pthread_sigmask, "pthread_sigmask"); 376 377 -------------------------- 378 -- POSIX.1c Section 11 -- 379 -------------------------- 380 381 function pthread_mutexattr_init 382 (attr : access pthread_mutexattr_t) return int; 383 pragma Import (C, pthread_mutexattr_init, "pthread_mutexattr_init"); 384 385 function pthread_mutexattr_destroy 386 (attr : access pthread_mutexattr_t) return int; 387 pragma Import (C, pthread_mutexattr_destroy, "pthread_mutexattr_destroy"); 388 389 function pthread_mutex_init 390 (mutex : access pthread_mutex_t; 391 attr : access pthread_mutexattr_t) return int; 392 pragma Import (C, pthread_mutex_init, "pthread_mutex_init"); 393 394 function pthread_mutex_destroy (mutex : access pthread_mutex_t) return int; 395 pragma Import (C, pthread_mutex_destroy, "pthread_mutex_destroy"); 396 397 function pthread_mutex_lock (mutex : access pthread_mutex_t) return int; 398 pragma Import (C, pthread_mutex_lock, "pthread_mutex_lock"); 399 400 function pthread_mutex_unlock (mutex : access pthread_mutex_t) return int; 401 pragma Import (C, pthread_mutex_unlock, "pthread_mutex_unlock"); 402 403 function pthread_condattr_init 404 (attr : access pthread_condattr_t) return int; 405 pragma Import (C, pthread_condattr_init, "pthread_condattr_init"); 406 407 function pthread_condattr_destroy 408 (attr : access pthread_condattr_t) return int; 409 pragma Import (C, pthread_condattr_destroy, "pthread_condattr_destroy"); 410 411 function pthread_cond_init 412 (cond : access pthread_cond_t; 413 attr : access pthread_condattr_t) return int; 414 pragma Import (C, pthread_cond_init, "pthread_cond_init"); 415 416 function pthread_cond_destroy (cond : access pthread_cond_t) return int; 417 pragma Import (C, pthread_cond_destroy, "pthread_cond_destroy"); 418 419 function pthread_cond_signal (cond : access pthread_cond_t) return int; 420 pragma Import (C, pthread_cond_signal, "pthread_cond_signal"); 421 422 function pthread_cond_wait 423 (cond : access pthread_cond_t; 424 mutex : access pthread_mutex_t) return int; 425 pragma Import (C, pthread_cond_wait, "pthread_cond_wait"); 426 427 function pthread_cond_timedwait 428 (cond : access pthread_cond_t; 429 mutex : access pthread_mutex_t; 430 abstime : access timespec) return int; 431 pragma Import (C, pthread_cond_timedwait, "pthread_cond_timedwait"); 432 433 -------------------------- 434 -- POSIX.1c Section 13 -- 435 -------------------------- 436 437 PTHREAD_PRIO_NONE : constant := 0; 438 PTHREAD_PRIO_PROTECT : constant := 2; 439 PTHREAD_PRIO_INHERIT : constant := 1; 440 441 function pthread_mutexattr_setprotocol 442 (attr : access pthread_mutexattr_t; 443 protocol : int) return int; 444 pragma Import 445 (C, pthread_mutexattr_setprotocol, "pthread_mutexattr_setprotocol"); 446 447 function pthread_mutexattr_getprotocol 448 (attr : access pthread_mutexattr_t; 449 protocol : access int) return int; 450 pragma Import 451 (C, pthread_mutexattr_getprotocol, "pthread_mutexattr_getprotocol"); 452 453 function pthread_mutexattr_setprioceiling 454 (attr : access pthread_mutexattr_t; 455 prioceiling : int) return int; 456 pragma Import 457 (C, pthread_mutexattr_setprioceiling, 458 "pthread_mutexattr_setprioceiling"); 459 460 function pthread_mutexattr_getprioceiling 461 (attr : access pthread_mutexattr_t; 462 prioceiling : access int) return int; 463 pragma Import 464 (C, pthread_mutexattr_getprioceiling, 465 "pthread_mutexattr_getprioceiling"); 466 467 type struct_sched_param is record 468 sched_priority : int; -- scheduling priority 469 end record; 470 pragma Convention (C, struct_sched_param); 471 472 function pthread_setschedparam 473 (thread : pthread_t; 474 policy : int; 475 param : access struct_sched_param) return int; 476 pragma Import (C, pthread_setschedparam, "pthread_setschedparam"); 477 478 function pthread_attr_setscope 479 (attr : access pthread_attr_t; 480 contentionscope : int) return int; 481 pragma Import (C, pthread_attr_setscope, "pthread_attr_setscope"); 482 483 function pthread_attr_getscope 484 (attr : access pthread_attr_t; 485 contentionscope : access int) return int; 486 pragma Import (C, pthread_attr_getscope, "pthread_attr_getscope"); 487 488 function pthread_attr_setinheritsched 489 (attr : access pthread_attr_t; 490 inheritsched : int) return int; 491 pragma Import 492 (C, pthread_attr_setinheritsched, "pthread_attr_setinheritsched"); 493 494 function pthread_attr_getinheritsched 495 (attr : access pthread_attr_t; 496 inheritsched : access int) return int; 497 pragma Import 498 (C, pthread_attr_getinheritsched, "pthread_attr_getinheritsched"); 499 500 function pthread_attr_setschedpolicy 501 (attr : access pthread_attr_t; 502 policy : int) return int; 503 pragma Import 504 (C, pthread_attr_setschedpolicy, "pthread_attr_setschedpolicy"); 505 506 function sched_yield return int; 507 pragma Import (C, sched_yield, "sched_yield"); 508 509 --------------------------- 510 -- P1003.1c - Section 16 -- 511 --------------------------- 512 513 function pthread_attr_init 514 (attributes : access pthread_attr_t) return int; 515 pragma Import (C, pthread_attr_init, "pthread_attr_init"); 516 517 function pthread_attr_destroy 518 (attributes : access pthread_attr_t) return int; 519 pragma Import (C, pthread_attr_destroy, "pthread_attr_destroy"); 520 521 function pthread_attr_setdetachstate 522 (attr : access pthread_attr_t; 523 detachstate : int) return int; 524 pragma Import 525 (C, pthread_attr_setdetachstate, "pthread_attr_setdetachstate"); 526 527 function pthread_attr_setstacksize 528 (attr : access pthread_attr_t; 529 stacksize : size_t) return int; 530 pragma Import (C, pthread_attr_setstacksize, "pthread_attr_setstacksize"); 531 532 function pthread_create 533 (thread : access pthread_t; 534 attributes : access pthread_attr_t; 535 start_routine : Thread_Body; 536 arg : System.Address) return int; 537 pragma Import (C, pthread_create, "pthread_create"); 538 539 procedure pthread_exit (status : System.Address); 540 pragma Import (C, pthread_exit, "pthread_exit"); 541 542 function pthread_self return pthread_t; 543 pragma Import (C, pthread_self, "pthread_self"); 544 545 -------------------------- 546 -- POSIX.1c Section 17 -- 547 -------------------------- 548 549 function pthread_setspecific 550 (key : pthread_key_t; 551 value : System.Address) return int; 552 pragma Import (C, pthread_setspecific, "pthread_setspecific"); 553 554 function pthread_getspecific (key : pthread_key_t) return System.Address; 555 pragma Import (C, pthread_getspecific, "pthread_getspecific"); 556 557 type destructor_pointer is access procedure (arg : System.Address); 558 pragma Convention (C, destructor_pointer); 559 560 function pthread_key_create 561 (key : access pthread_key_t; 562 destructor : destructor_pointer) return int; 563 pragma Import (C, pthread_key_create, "pthread_key_create"); 564 565 CPU_SETSIZE : constant := 1_024; 566 567 type bit_field is array (1 .. CPU_SETSIZE) of Boolean; 568 for bit_field'Size use CPU_SETSIZE; 569 pragma Pack (bit_field); 570 pragma Convention (C, bit_field); 571 572 type cpu_set_t is record 573 bits : bit_field; 574 end record; 575 pragma Convention (C, cpu_set_t); 576 577 function pthread_setaffinity_np 578 (thread : pthread_t; 579 cpusetsize : size_t; 580 cpuset : access cpu_set_t) return int; 581 pragma Import (C, pthread_setaffinity_np, "__gnat_pthread_setaffinity_np"); 582 583private 584 585 type sigset_t is array (1 .. 4) of unsigned; 586 587 -- In FreeBSD the component sa_handler turns out to 588 -- be one a union type, and the selector is a macro: 589 -- #define sa_handler __sigaction_u._handler 590 -- #define sa_sigaction __sigaction_u._sigaction 591 592 -- Should we add a signal_context type here ? 593 -- How could it be done independent of the CPU architecture ? 594 -- sigcontext type is opaque, so it is architecturally neutral. 595 -- It is always passed as an access type, so define it as an empty record 596 -- since the contents are not used anywhere. 597 type struct_sigcontext is null record; 598 pragma Convention (C, struct_sigcontext); 599 600 type pid_t is new int; 601 602 type time_t is new long; 603 604 type timespec is record 605 tv_sec : time_t; 606 tv_nsec : long; 607 end record; 608 pragma Convention (C, timespec); 609 610 type clockid_t is new int; 611 CLOCK_REALTIME : constant clockid_t := 0; 612 613 type pthread_attr_t is record 614 detachstate : int; 615 schedpolicy : int; 616 schedparam : struct_sched_param; 617 inheritsched : int; 618 scope : int; 619 guardsize : size_t; 620 stackaddr_set : int; 621 stackaddr : System.Address; 622 stacksize : size_t; 623 end record; 624 pragma Convention (C, pthread_attr_t); 625 626 type pthread_condattr_t is record 627 dummy : int; 628 end record; 629 pragma Convention (C, pthread_condattr_t); 630 631 type pthread_mutexattr_t is record 632 mutexkind : int; 633 end record; 634 pragma Convention (C, pthread_mutexattr_t); 635 636 type struct_pthread_fast_lock is record 637 status : long; 638 spinlock : int; 639 end record; 640 pragma Convention (C, struct_pthread_fast_lock); 641 642 type pthread_mutex_t is record 643 m_reserved : int; 644 m_count : int; 645 m_owner : System.Address; 646 m_kind : int; 647 m_lock : struct_pthread_fast_lock; 648 end record; 649 pragma Convention (C, pthread_mutex_t); 650 651 type pthread_cond_t is array (0 .. 47) of unsigned_char; 652 pragma Convention (C, pthread_cond_t); 653 654 type pthread_key_t is new unsigned; 655 656end System.OS_Interface; 657