UNSAFE INTERFACE Uexec;

IMPORT Ctypes, Utypes, Uresource;

Remember that any of the calls which may return an error code in 'Uerror.errno' should be serialized by use of 'UnixMutex.errno'.

<*EXTERNAL*>
PROCEDURE execv(
    name: Ctypes.char_star;
    argv: Ctypes.char_star_star)
    : Ctypes.int
    RAISES {};

<*EXTERNAL*>
PROCEDURE execvp(
    name: Ctypes.char_star;
    argv: Ctypes.char_star_star)
    : Ctypes.int
    RAISES {};

<*EXTERNAL*>
PROCEDURE exect(
    name: Ctypes.char_star;
    argv: Ctypes.char_star_star;
    envp: Ctypes.char_star_star)
    : Ctypes.int
    RAISES {};

CONST
  WNOHANG = 1;			 (* dont hang in wait *)
  WUNTRACED = 2;		 (* tell about stopped, untraced children *)

TYPE
  w_A = Ctypes.unsigned_int;

  (* terminated process status *)
  w_T = RECORD
      w_Termsig : BITS  7 FOR [0..16_7F];  (* termination signal *)
      w_Coredump: BITS  1 FOR [0..16_01];  (* core dump indicator *)
      w_Retcode : BITS  8 FOR [0..16_FF];  (* exit code if w_termsig == 0 *)
      w_Filler  : BITS 16 FOR [0..16_FFFF]; END;

  (* M3 view of return code *)
  w_M3 = RECORD
      w_Retcode : BITS  8 FOR [0..16_FF];  (* exit code if w_termsig == 0 *)
      w_Termsig : BITS  7 FOR [0..16_7F];  (* termination signal *)
      w_Coredump: BITS  1 FOR [0..16_01];  (* core dump indicator *)
      w_Filler  : BITS 16 FOR [0..16_FFFF]; END;

  (* stopped process status *)
  w_S = RECORD
      w_Stopval : BITS  8 FOR [0..16_FF];  (* == W_STOPPED if stopped *)
      w_Stopsig : BITS  8 FOR [0..16_FF];  (* signal that stopped us *)
      w_Filler  : BITS 16 FOR [0..16_FFFF]; END;

  (* union wait is a union of the three types above.  We will use w_A
     in the declarations and do a LOOPHOLE when necessary *)
  w_A_star = UNTRACED REF w_A;

  (* Wait queues (needed for Umsg.i3) *)
  wait_queue = RECORD
     task : Ctypes.void_star;  (* : task_struct;  see below *)
     next : UNTRACED REF wait_queue;
   END;
   (* task_struct - use Ctypes.void_star because task_struct
     should never be touched and is very very hard to emulate in Modula-3
   *)

  wait_queue_star = UNTRACED REF wait_queue;

<*EXTERNAL*>
PROCEDURE wait (status: w_A_star): Utypes.pid_t;

<*EXTERNAL*>
PROCEDURE wait3 (status: w_A_star; options: Ctypes.int;
                 rusage: Uresource.struct_rusage_star): Utypes.pid_t;

<*EXTERNAL*>
PROCEDURE waitpid (pid: Utypes.pid_t; status: w_A_star;
                   options: Ctypes.int): Utypes.pid_t;

END Uexec.