------------------------------------------------------------------------------
--                                                                          --
--                 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) 1995-2006, Free Software Foundation, Inc.      --
--                                                                          --
-- GNARL 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 2,  or (at your option) any later ver- --
-- sion. GNARL 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.  See the GNU General Public License --
-- for  more details.  You should have  received  a copy of the GNU General --
-- Public License  distributed with GNARL; see file COPYING.  If not, write --
-- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
-- Boston, MA 02110-1301, USA.                                              --
--                                                                          --
-- As a special exception,  if other files  instantiate  generics from this --
-- unit, or you link  this unit with other files  to produce an executable, --
-- this  unit  does not  by itself cause  the resulting  executable  to  be --
-- covered  by the  GNU  General  Public  License.  This exception does not --
-- however invalidate  any other reasons why  the executable file  might be --
-- covered by the  GNU Public License.                                      --
--                                                                          --
-- GNARL was developed by the GNARL team at Florida State University.       --
-- Extensive contributions were provided by Ada Core Technologies, Inc.     --
--                                                                          --
------------------------------------------------------------------------------

--  This is the DEC Unix 4.0/5.1 version of this package

--  This package encapsulates all direct interfaces to OS services
--  that are needed by children of System.

--  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 Interfaces.C;
with Unchecked_Conversion;

package System.OS_Interface is
   pragma Preelaborate;

   pragma Linker_Options ("-lpthread");
   pragma Linker_Options ("-lmach");
   pragma Linker_Options ("-lexc");
   pragma Linker_Options ("-lrt");

   subtype int            is Interfaces.C.int;
   subtype short          is Interfaces.C.short;
   subtype long           is Interfaces.C.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;
   subtype char_array     is Interfaces.C.char_array;

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

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

   EAGAIN    : constant := 35;
   EINTR     : constant := 4;
   EINVAL    : constant := 22;
   ENOMEM    : constant := 12;
   ETIMEDOUT : constant := 60;

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

   Max_Interrupt : constant := 48;
   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)
   SIGABRT    : constant := 6; --  used by abort, replace SIGIOT in the  future
   SIGIOT     : constant := 6; --  abort (terminate) process
   SIGLOST    : constant := 6; --  old BSD signal ??
   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
   SIGURG     : constant := 16; --  urgent condition on IO channel
   SIGIOINT   : constant := 16; --  printer to backend error signal
   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
   SIGCHLD    : constant := 20; --  child status change
   SIGTTIN    : constant := 21; --  background tty read attempted
   SIGTTOU    : constant := 22; --  background tty write attempted
   SIGPOLL    : constant := 23; --  I/O possible, or completed
   SIGIO      : constant := 23; --  STREAMS version of SIGPOLL
   SIGAIO     : constant := 23; --  base lan i/o
   SIGPTY     : constant := 23; --  pty i/o
   SIGXCPU    : constant := 24; --  CPU time limit exceeded
   SIGXFSZ    : constant := 25; --  filesize limit exceeded
   SIGVTALRM  : constant := 26; --  virtual timer expired
   SIGPROF    : constant := 27; --  profiling timer expired
   SIGWINCH   : constant := 28; --  window size change
   SIGINFO    : constant := 29; --  information request
   SIGPWR     : constant := 29; --  Power Fail/Restart -- SVID3/SVR4
   SIGUSR1    : constant := 30; --  user defined signal 1
   SIGUSR2    : constant := 31; --  user defined signal 2
   SIGRESV    : constant := 32; --  reserved by Digital for future use

   SIGADAABORT : constant := SIGABRT;

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

   Unmasked    : constant Signal_Set := (0 .. 0 => SIGTRAP);
   Reserved    : constant Signal_Set := (SIGALRM, SIGABRT, SIGKILL, SIGSTOP);

   type sigset_t is private;

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

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

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

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

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

   type union_type_3 is new String (1 .. 116);
   type siginfo_t is record
      si_signo     : int;
      si_errno     : int;
      si_code      : int;
      X_data       : union_type_3;
   end record;
   for siginfo_t'Size use 8 * 128;
   pragma Convention (C, siginfo_t);

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

   SIG_BLOCK   : constant := 1;
   SIG_UNBLOCK : constant := 2;
   SIG_SETMASK : constant := 3;

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

   SA_NODEFER : constant := 8;
   SA_SIGINFO : constant := 16#40#;

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

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

   type timespec is private;

   function nanosleep (rqtp, rmtp : access timespec)  return int;
   pragma Import (C, nanosleep);

   type clockid_t is private;

   CLOCK_REALTIME : constant clockid_t;

   function clock_gettime
     (clock_id : clockid_t;
      tp       : access timespec) return int;
   pragma Import (C, 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_timeval is private;
   --  This is needed on systems that do not have clock_gettime()
   --  but do have gettimeofday().

   function To_Duration (TV : struct_timeval) return Duration;
   pragma Inline (To_Duration);

   function To_Timeval (D : Duration) return struct_timeval;
   pragma Inline (To_Timeval);

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

   SCHED_FIFO  : constant := 1;
   SCHED_RR    : constant := 2;
   SCHED_OTHER : constant := 3;
   SCHED_LFI   : constant := 5;

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

   type pid_t is private;

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

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

   BIND_NO_INHERIT  : constant := 1;

   function bind_to_cpu
     (pid       : pid_t;
      cpu_mask  : unsigned_long;
      flag      : unsigned_long := BIND_NO_INHERIT) return int;
   pragma Import (C, bind_to_cpu);

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

   type Thread_Body is access
     function (arg : System.Address) return System.Address;

   function Thread_Body_Access is new
     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 := 0;
   PTHREAD_SCOPE_SYSTEM  : constant := 1;

   PTHREAD_EXPLICIT_SCHED : constant := 1;

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

   Stack_Base_Available : constant Boolean := False;
   --  Indicates wether 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, or 0 if this is not relevant on this
   --  target

   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);

   procedure Hide_Yellow_Zone;
   --  Every thread except the initial one features an overflow warning area
   --  just above the overflow guard area on the stack. They are called
   --  the Yellow Zone and the Red Zone respectively. This procedure hides
   --  the former so that the latter could be exposed to stack probing.

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

   procedure pthread_init;
   pragma Inline (pthread_init);
   --  This is a dummy procedure to share some GNULLI files

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

   function sigwait
     (set : access sigset_t;
      sig : access Signal) return int;
   pragma Import (C, sigwait, "__sigwaitd10");

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

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

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

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

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

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

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

   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 struct_sched_param is record
      sched_priority : int;  --  scheduling priority
   end record;

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

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

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

   function sched_yield return int;
   pragma Import (C, sched_yield);

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

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

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

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

private

   type sigset_t is new unsigned_long;

   type pid_t is new int;

   type time_t is new int;

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

   type clockid_t is new int;
   CLOCK_REALTIME : constant clockid_t := 1;

   type struct_timeval is record
      tv_sec  : time_t;
      tv_usec : time_t;
   end record;
   pragma Convention (C, struct_timeval);

   type unsigned_long_array is array (Natural range <>) of unsigned_long;

   type pthread_t is new System.Address;

   type pthread_teb_t is record
      reserved1     : System.Address;
      reserved2     : System.Address;
      size          : unsigned_short;
      version       : unsigned_char;
      reserved3     : unsigned_char;
      external      : unsigned_char;
      reserved4     : char_array (0 .. 1);
      creator       : unsigned_char;
      sequence      : unsigned_long;
      reserved5     : unsigned_long_array (0 .. 1);
      per_kt_area   : System.Address;
      stack_base    : System.Address;
      stack_reserve : System.Address;
      stack_yellow  : System.Address;
      stack_guard   : System.Address;
      stack_size    : unsigned_long;
      tsd_values    : System.Address;
      tsd_count     : unsigned_long;
      reserved6     : unsigned;
      reserved7     : unsigned;
      thread_flags  : unsigned;
      thd_errno     : int;
      stack_hiwater : System.Address;
      home_rad      : unsigned_long;
   end record;
   pragma Convention (C, pthread_teb_t);

   type pthread_cond_t is record
      state     : unsigned;
      valid     : unsigned;
      name      : System.Address;
      arg       : unsigned;
      reserved1 : unsigned;
      sequence  : unsigned_long;
      block     : System.Address;
   end record;
   pragma Convention (C, pthread_cond_t);

   type pthread_attr_t is record
      valid    : long;
      name     : System.Address;
      arg      : unsigned_long;
      reserved : unsigned_long_array (0 .. 18);
   end record;
   pragma Convention (C, pthread_attr_t);

   type pthread_mutex_t is record
      lock     : unsigned;
      valid    : unsigned;
      name     : System.Address;
      arg      : unsigned;
      depth    : unsigned;
      sequence : unsigned_long;
      owner    : unsigned_long;
      block    : System.Address;
   end record;
   for pthread_mutex_t'Size use 8 * 48;
   pragma Convention (C, pthread_mutex_t);

   type pthread_mutexattr_t is record
      valid    : long;
      reserved : unsigned_long_array (0 .. 14);
   end record;
   pragma Convention (C, pthread_mutexattr_t);

   type pthread_condattr_t is record
      valid    : long;
      reserved : unsigned_long_array (0 .. 12);
   end record;
   pragma Convention (C, pthread_condattr_t);

   type pthread_key_t is new unsigned;

end System.OS_Interface;