aboutsummaryrefslogtreecommitdiffstats
path: root/gcc-4.9/gcc/ada/s-osinte-aix.ads
blob: 6fce65ffd23aa10f194ce263ebf1ad6f06499ac5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
------------------------------------------------------------------------------
--                                                                          --
--                 GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS                 --
--                                                                          --
--                   S Y S T E M . O S _ I N T E R F A C E                  --
--                                                                          --
--                                  S p e c                                 --
--                                                                          --
--             Copyright (C) 1991-1994, Florida State University            --
--          Copyright (C) 1995-2013, Free Software Foundation, Inc.         --
--                                                                          --
-- GNAT is free software;  you can  redistribute it  and/or modify it under --
-- terms of the  GNU General Public License as published  by the Free Soft- --
-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
--                                                                          --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception,   --
-- version 3.1, as published by the Free Software Foundation.               --
--                                                                          --
-- You should have received a copy of the GNU General Public License and    --
-- a copy of the GCC Runtime Library Exception along with this program;     --
-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
-- <http://www.gnu.org/licenses/>.                                          --
--                                                                          --
-- GNARL was developed by the GNARL team at Florida State University.       --
-- Extensive contributions were provided by Ada Core Technologies, Inc.     --
--                                                                          --
------------------------------------------------------------------------------

--  This is a AIX (Native THREADS) version of this package

--  This package encapsulates all direct interfaces to OS services that are
--  needed by the tasking run-time (libgnarl).

--  PLEASE DO NOT add any with-clauses to this package or remove the pragma
--  Preelaborate. This package is designed to be a bottom-level (leaf) package.

with Ada.Unchecked_Conversion;

with Interfaces.C;
with Interfaces.C.Extensions;

package System.OS_Interface is
   pragma Preelaborate;

   pragma Linker_Options ("-pthread");
   --  This implies -lpthreads + other things depending on the GCC
   --  configuration, such as the selection of a proper libgcc variant
   --  for table-based exception handling when it is available.

   pragma Linker_Options ("-lc_r");

   subtype int            is Interfaces.C.int;
   subtype short          is Interfaces.C.short;
   subtype long           is Interfaces.C.long;
   subtype long_long      is Interfaces.C.Extensions.long_long;
   subtype unsigned       is Interfaces.C.unsigned;
   subtype unsigned_short is Interfaces.C.unsigned_short;
   subtype unsigned_long  is Interfaces.C.unsigned_long;
   subtype unsigned_char  is Interfaces.C.unsigned_char;
   subtype plain_char     is Interfaces.C.plain_char;
   subtype size_t         is Interfaces.C.size_t;

   -----------
   -- Errno --
   -----------

   function errno return int;
   pragma Import (C, errno, "__get_errno");

   EAGAIN    : constant := 11;
   EINTR     : constant := 4;
   EINVAL    : constant := 22;
   ENOMEM    : constant := 12;
   ETIMEDOUT : constant := 78;

   -------------
   -- Signals --
   -------------

   Max_Interrupt : constant := 63;
   type Signal is new int range 0 .. Max_Interrupt;
   for Signal'Size use int'Size;

   SIGHUP      : constant := 1; --  hangup
   SIGINT      : constant := 2; --  interrupt (rubout)
   SIGQUIT     : constant := 3; --  quit (ASCD FS)
   SIGILL      : constant := 4; --  illegal instruction (not reset)
   SIGTRAP     : constant := 5; --  trace trap (not reset)
   SIGIOT      : constant := 6; --  IOT instruction
   SIGABRT     : constant := 6; --  used by abort, replace SIGIOT in the future
   SIGEMT      : constant := 7; --  EMT instruction
   SIGFPE      : constant := 8; --  floating point exception
   SIGKILL     : constant := 9; --  kill (cannot be caught or ignored)
   SIGBUS      : constant := 10; --  bus error
   SIGSEGV     : constant := 11; --  segmentation violation
   SIGSYS      : constant := 12; --  bad argument to system call
   SIGPIPE     : constant := 13; --  write on a pipe with no one to read it
   SIGALRM     : constant := 14; --  alarm clock
   SIGTERM     : constant := 15; --  software termination signal from kill
   SIGUSR1     : constant := 30; --  user defined signal 1
   SIGUSR2     : constant := 31; --  user defined signal 2
   SIGCLD      : constant := 20; --  alias for SIGCHLD
   SIGCHLD     : constant := 20; --  child status change
   SIGPWR      : constant := 29; --  power-fail restart
   SIGWINCH    : constant := 28; --  window size change
   SIGURG      : constant := 16; --  urgent condition on IO channel
   SIGPOLL     : constant := 23; --  pollable event occurred
   SIGIO       : constant := 23; --  I/O possible (Solaris SIGPOLL alias)
   SIGSTOP     : constant := 17; --  stop (cannot be caught or ignored)
   SIGTSTP     : constant := 18; --  user stop requested from tty
   SIGCONT     : constant := 19; --  stopped process has been continued
   SIGTTIN     : constant := 21; --  background tty read attempted
   SIGTTOU     : constant := 22; --  background tty write attempted
   SIGVTALRM   : constant := 34; --  virtual timer expired
   SIGPROF     : constant := 32; --  profiling timer expired
   SIGXCPU     : constant := 24; --  CPU time limit exceeded
   SIGXFSZ     : constant := 25; --  filesize limit exceeded
   SIGWAITING  : constant := 39; --  m:n scheduling

   --  The following signals are AIX specific

   SIGMSG      : constant := 27; -- input data is in the ring buffer
   SIGDANGER   : constant := 33; -- system crash imminent
   SIGMIGRATE  : constant := 35; -- migrate process
   SIGPRE      : constant := 36; -- programming exception
   SIGVIRT     : constant := 37; -- AIX virtual time alarm
   SIGALRM1    : constant := 38; -- m:n condition variables
   SIGCPUFAIL  : constant := 59; -- Predictive De-configuration of Processors
   SIGKAP      : constant := 60; -- keep alive poll from native keyboard
   SIGGRANT    : constant := SIGKAP; -- monitor mode granted
   SIGRETRACT  : constant := 61; -- monitor mode should be relinquished
   SIGSOUND    : constant := 62; -- sound control has completed
   SIGSAK      : constant := 63; -- secure attention key

   SIGADAABORT : constant := SIGEMT;
   --  Note: on other targets, we usually use SIGABRT, but on AIX, it appears
   --  that SIGABRT can't be used in sigwait(), so we use SIGEMT.
   --  SIGEMT is "Emulator Trap Instruction" from the PDP-11, and does not
   --  have a standardized usage.

   type Signal_Set is array (Natural range <>) of Signal;

   Unmasked : constant Signal_Set :=
                (SIGTRAP, SIGTTIN, SIGTTOU, SIGTSTP, SIGPROF);
   Reserved : constant Signal_Set :=
                (SIGABRT, SIGKILL, SIGSTOP, SIGALRM1, SIGWAITING, SIGCPUFAIL);

   type sigset_t is private;

   function sigaddset (set : access sigset_t; sig : Signal) return int;
   pragma Import (C, sigaddset, "sigaddset");

   function sigdelset (set : access sigset_t; sig : Signal) return int;
   pragma Import (C, sigdelset, "sigdelset");

   function sigfillset (set : access sigset_t) return int;
   pragma Import (C, sigfillset, "sigfillset");

   function sigismember (set : access sigset_t; sig : Signal) return int;
   pragma Import (C, sigismember, "sigismember");

   function sigemptyset (set : access sigset_t) return int;
   pragma Import (C, sigemptyset, "sigemptyset");

   type struct_sigaction is record
      sa_handler : System.Address;
      sa_mask    : sigset_t;
      sa_flags   : int;
   end record;
   pragma Convention (C, struct_sigaction);
   type struct_sigaction_ptr is access all struct_sigaction;

   SA_SIGINFO : constant := 16#0100#;
   SA_ONSTACK : constant := 16#0001#;

   SIG_BLOCK   : constant := 0;
   SIG_UNBLOCK : constant := 1;
   SIG_SETMASK : constant := 2;

   SIG_DFL : constant := 0;
   SIG_IGN : constant := 1;

   function sigaction
     (sig  : Signal;
      act  : struct_sigaction_ptr;
      oact : struct_sigaction_ptr) return int;
   pragma Import (C, sigaction, "sigaction");

   ----------
   -- Time --
   ----------

   Time_Slice_Supported : constant Boolean := True;
   --  Indicates whether time slicing is supported

   type timespec is private;

   type clockid_t is new long_long;

   function clock_gettime
     (clock_id : clockid_t;
      tp       : access timespec) return int;
   pragma Import (C, clock_gettime, "clock_gettime");

   function To_Duration (TS : timespec) return Duration;
   pragma Inline (To_Duration);

   function To_Timespec (D : Duration) return timespec;
   pragma Inline (To_Timespec);

   type struct_timezone is record
      tz_minuteswest : int;
      tz_dsttime     : int;
   end record;
   pragma Convention (C, struct_timezone);
   type struct_timezone_ptr is access all struct_timezone;

   -------------------------
   -- Priority Scheduling --
   -------------------------

   SCHED_FIFO  : constant := 1;
   SCHED_RR    : constant := 2;
   SCHED_OTHER : constant := 0;

   function To_Target_Priority
     (Prio : System.Any_Priority) return Interfaces.C.int;
   --  Maps System.Any_Priority to a POSIX priority

   -------------
   -- Process --
   -------------

   type pid_t is private;

   function kill (pid : pid_t; sig : Signal) return int;
   pragma Import (C, kill, "kill");

   function getpid return pid_t;
   pragma Import (C, getpid, "getpid");

   ---------
   -- LWP --
   ---------

   function lwp_self return System.Address;
   pragma Import (C, lwp_self, "thread_self");

   -------------
   -- Threads --
   -------------

   type Thread_Body is access
     function (arg : System.Address) return System.Address;
   pragma Convention (C, Thread_Body);

   function Thread_Body_Access is new
     Ada.Unchecked_Conversion (System.Address, Thread_Body);

   type pthread_t           is private;
   subtype Thread_Id        is pthread_t;

   type pthread_mutex_t     is limited private;
   type pthread_cond_t      is limited private;
   type pthread_attr_t      is limited private;
   type pthread_mutexattr_t is limited private;
   type pthread_condattr_t  is limited private;
   type pthread_key_t       is private;

   PTHREAD_CREATE_DETACHED : constant := 1;

   PTHREAD_SCOPE_PROCESS : constant := 1;
   PTHREAD_SCOPE_SYSTEM  : constant := 0;

   --  Read/Write lock not supported on AIX. To add support both types
   --  pthread_rwlock_t and pthread_rwlockattr_t must properly be defined
   --  with the associated routines pthread_rwlock_[init/destroy] and
   --  pthread_rwlock_[rdlock/wrlock/unlock].

   subtype pthread_rwlock_t     is pthread_mutex_t;
   subtype pthread_rwlockattr_t is pthread_mutexattr_t;

   -----------
   -- Stack --
   -----------

   type stack_t is record
      ss_sp    : System.Address;
      ss_size  : size_t;
      ss_flags : int;
   end record;
   pragma Convention (C, stack_t);

   function sigaltstack
     (ss  : not null access stack_t;
      oss : access stack_t) return int;
   pragma Import (C, sigaltstack, "sigaltstack");

   Alternate_Stack : aliased System.Address;
   --  This is a dummy definition, never used (Alternate_Stack_Size is null)

   Alternate_Stack_Size : constant := 0;
   --  No alternate signal stack is used on this platform

   Stack_Base_Available : constant Boolean := False;
   --  Indicates whether the stack base is available on this target

   function Get_Stack_Base (thread : pthread_t) return Address;
   pragma Inline (Get_Stack_Base);
   --  Returns the stack base of the specified thread. Only call this function
   --  when Stack_Base_Available is True.

   function Get_Page_Size return size_t;
   function Get_Page_Size return Address;
   pragma Import (C, Get_Page_Size, "getpagesize");
   --  Returns the size of a page

   PROT_NONE  : constant := 0;
   PROT_READ  : constant := 1;
   PROT_WRITE : constant := 2;
   PROT_EXEC  : constant := 4;
   PROT_ALL   : constant := PROT_READ + PROT_WRITE + PROT_EXEC;
   PROT_ON    : constant := PROT_READ;
   PROT_OFF   : constant := PROT_ALL;

   function mprotect (addr : Address; len : size_t; prot : int) return int;
   pragma Import (C, mprotect);

   ---------------------------------------
   -- Nonstandard Thread Initialization --
   ---------------------------------------

   --  Though not documented, pthread_init *must* be called before any other
   --  pthread call.

   procedure pthread_init;
   pragma Import (C, pthread_init, "pthread_init");

   -------------------------
   -- POSIX.1c  Section 3 --
   -------------------------

   function sigwait
     (set : access sigset_t;
      sig : access Signal) return int;
   pragma Import (C, sigwait, "sigwait");

   function pthread_kill
     (thread : pthread_t;
      sig    : Signal) return int;
   pragma Import (C, pthread_kill, "pthread_kill");

   function pthread_sigmask
     (how  : int;
      set  : access sigset_t;
      oset : access sigset_t) return int;
   pragma Import (C, pthread_sigmask, "sigthreadmask");

   --------------------------
   -- POSIX.1c  Section 11 --
   --------------------------

   function pthread_mutexattr_init
     (attr : access pthread_mutexattr_t) return int;
   pragma Import (C, pthread_mutexattr_init, "pthread_mutexattr_init");

   function pthread_mutexattr_destroy
     (attr : access pthread_mutexattr_t) return int;
   pragma Import (C, pthread_mutexattr_destroy, "pthread_mutexattr_destroy");

   function pthread_mutex_init
     (mutex : access pthread_mutex_t;
      attr  : access pthread_mutexattr_t) return int;
   pragma Import (C, pthread_mutex_init, "pthread_mutex_init");

   function pthread_mutex_destroy (mutex : access pthread_mutex_t) return int;
   pragma Import (C, pthread_mutex_destroy, "pthread_mutex_destroy");

   function pthread_mutex_lock (mutex : access pthread_mutex_t) return int;
   pragma Import (C, pthread_mutex_lock, "pthread_mutex_lock");

   function pthread_mutex_unlock (mutex : access pthread_mutex_t) return int;
   pragma Import (C, pthread_mutex_unlock, "pthread_mutex_unlock");

   function pthread_condattr_init
     (attr : access pthread_condattr_t) return int;
   pragma Import (C, pthread_condattr_init, "pthread_condattr_init");

   function pthread_condattr_destroy
     (attr : access pthread_condattr_t) return int;
   pragma Import (C, pthread_condattr_destroy, "pthread_condattr_destroy");

   function pthread_cond_init
     (cond : access pthread_cond_t;
      attr : access pthread_condattr_t) return int;
   pragma Import (C, pthread_cond_init, "pthread_cond_init");

   function pthread_cond_destroy (cond : access pthread_cond_t) return int;
   pragma Import (C, pthread_cond_destroy, "pthread_cond_destroy");

   function pthread_cond_signal (cond : access pthread_cond_t) return int;
   pragma Import (C, pthread_cond_signal, "pthread_cond_signal");

   function pthread_cond_wait
     (cond  : access pthread_cond_t;
      mutex : access pthread_mutex_t) return int;
   pragma Import (C, pthread_cond_wait, "pthread_cond_wait");

   function pthread_cond_timedwait
     (cond    : access pthread_cond_t;
      mutex   : access pthread_mutex_t;
      abstime : access timespec) return int;
   pragma Import (C, pthread_cond_timedwait, "pthread_cond_timedwait");

   Relative_Timed_Wait : constant Boolean := False;
   --  pthread_cond_timedwait requires an absolute delay time

   --------------------------
   -- POSIX.1c  Section 13 --
   --------------------------

   PTHREAD_PRIO_PROTECT : constant := 2;

   function PTHREAD_PRIO_INHERIT return int;
   --  Return value of C macro PTHREAD_PRIO_INHERIT. This function is needed
   --  since the value is different between AIX versions.

   function pthread_mutexattr_setprotocol
     (attr     : access pthread_mutexattr_t;
      protocol : int) return int;
   pragma Import (C, pthread_mutexattr_setprotocol);

   function pthread_mutexattr_setprioceiling
     (attr        : access pthread_mutexattr_t;
      prioceiling : int) return int;
   pragma Import (C, pthread_mutexattr_setprioceiling);

   type Array_5_Int is array (0 .. 5) of int;
   type struct_sched_param is record
      sched_priority : int;
      sched_policy   : int;
      sched_reserved : Array_5_Int;
   end record;

   function pthread_setschedparam
     (thread : pthread_t;
      policy : int;
      param  : access struct_sched_param) return int;
   pragma Import (C, pthread_setschedparam, "pthread_setschedparam");

   function pthread_attr_setscope
     (attr            : access pthread_attr_t;
      contentionscope : int) return int;
   pragma Import (C, pthread_attr_setscope, "pthread_attr_setscope");

   function pthread_attr_setinheritsched
     (attr            : access pthread_attr_t;
      inheritsched : int) return int;
   pragma Import (C, pthread_attr_setinheritsched);

   function pthread_attr_setschedpolicy
     (attr   : access pthread_attr_t;
      policy : int) return int;
   pragma Import (C, pthread_attr_setschedpolicy);

   function pthread_attr_setschedparam
     (attr        : access pthread_attr_t;
      sched_param : int) return int;
   pragma Import (C, pthread_attr_setschedparam);

   function sched_yield return int;
   --  AIX have a nonstandard sched_yield

   --------------------------
   -- P1003.1c  Section 16 --
   --------------------------

   function pthread_attr_init (attributes : access pthread_attr_t) return int;
   pragma Import (C, pthread_attr_init, "pthread_attr_init");

   function pthread_attr_destroy
     (attributes : access pthread_attr_t) return int;
   pragma Import (C, pthread_attr_destroy, "pthread_attr_destroy");

   function pthread_attr_setdetachstate
     (attr        : access pthread_attr_t;
      detachstate : int) return int;
   pragma Import (C, pthread_attr_setdetachstate);

   function pthread_attr_setstacksize
     (attr      : access pthread_attr_t;
      stacksize : size_t) return int;
   pragma Import (C, pthread_attr_setstacksize);

   function pthread_create
     (thread        : access pthread_t;
      attributes    : access pthread_attr_t;
      start_routine : Thread_Body;
      arg           : System.Address)
     return int;
   pragma Import (C, pthread_create, "pthread_create");

   procedure pthread_exit (status : System.Address);
   pragma Import (C, pthread_exit, "pthread_exit");

   function pthread_self return pthread_t;
   pragma Import (C, pthread_self, "pthread_self");

   --------------------------
   -- POSIX.1c  Section 17 --
   --------------------------

   function pthread_setspecific
     (key   : pthread_key_t;
      value : System.Address) return int;
   pragma Import (C, pthread_setspecific, "pthread_setspecific");

   function pthread_getspecific (key : pthread_key_t) return System.Address;
   pragma Import (C, pthread_getspecific, "pthread_getspecific");

   type destructor_pointer is access procedure (arg : System.Address);
   pragma Convention (C, destructor_pointer);

   function pthread_key_create
     (key        : access pthread_key_t;
      destructor : destructor_pointer) return int;
   pragma Import (C, pthread_key_create, "pthread_key_create");

private
   type sigset_t is record
      losigs : unsigned_long;
      hisigs : unsigned_long;
   end record;
   pragma Convention (C_Pass_By_Copy, sigset_t);

   type pid_t is new int;

   type time_t is new long;

   type timespec is record
      tv_sec  : time_t;
      tv_nsec : long;
   end record;
   pragma Convention (C, timespec);

   type pthread_attr_t is new System.Address;
   pragma Convention (C, pthread_attr_t);
   --  typedef struct __pt_attr        *pthread_attr_t;

   type pthread_condattr_t is new System.Address;
   pragma Convention (C, pthread_condattr_t);
   --  typedef struct __pt_attr        *pthread_condattr_t;

   type pthread_mutexattr_t is new System.Address;
   pragma Convention (C, pthread_mutexattr_t);
   --  typedef struct __pt_attr        *pthread_mutexattr_t;

   type pthread_t is new System.Address;
   pragma Convention (C, pthread_t);
   --  typedef void    *pthread_t;

   type ptq_queue;
   type ptq_queue_ptr is access all ptq_queue;

   type ptq_queue is record
      ptq_next : ptq_queue_ptr;
      ptq_prev : ptq_queue_ptr;
   end record;

   type Array_3_Int is array (0 .. 3) of int;
   type pthread_mutex_t is record
        link        : ptq_queue;
        ptmtx_lock  : int;
        ptmtx_flags : long;
        protocol    : int;
        prioceiling : int;
        ptmtx_owner : pthread_t;
        mtx_id      : int;
        attr        : pthread_attr_t;
        mtx_kind    : int;
        lock_cpt    : int;
        reserved    : Array_3_Int;
   end record;
   pragma Convention (C, pthread_mutex_t);
   type pthread_mutex_t_ptr is access pthread_mutex_t;

   type pthread_cond_t is record
      link         : ptq_queue;
      ptcv_lock    : int;
      ptcv_flags   : long;
      ptcv_waiters : ptq_queue;
      cv_id        : int;
      attr         : pthread_attr_t;
      mutex        : pthread_mutex_t_ptr;
      cptwait      : int;
      reserved     : int;
   end record;
   pragma Convention (C, pthread_cond_t);

   type pthread_key_t is new unsigned;

end System.OS_Interface;