v2.0/source/PROC.ASM

   1 ;
   2 ; process control system calls for MSDOS
   3 ;
   4
   5 INCLUDE DOSSEG.ASM
   6
   7 CODE    SEGMENT BYTE PUBLIC  'CODE'
   8         ASSUME  SS:DOSGROUP,CS:DOSGROUP
   9
  10 .xlist
  11 .xcref
  12 INCLUDE DOSSYM.ASM
  13 INCLUDE DEVSYM.ASM
  14 .cref
  15 .list
  16
  17     i_need  CurrentPDB,WORD
  18     i_need  CreatePDB,BYTE
  19     i_need  NUMIO,BYTE
  20     i_need  Exit_type,BYTE
  21     i_need  INDOS,BYTE
  22     i_need  DMAADD,DWORD
  23     i_need  DidCTRLC,BYTE
  24
  25 SUBTTL $WAIT - return previous process error code
  26 PAGE
  27 ;
  28 ; process control data
  29 ;
  30         i_need  exit_code,WORD          ; code of exit
  31
  32 ;
  33 ;   Assembler usage:
  34 ;           MOV     AH, Wait
  35 ;           INT     int_command
  36 ;         AX has the exit code
  37         procedure   $WAIT,NEAR
  38         ASSUME  DS:NOTHING,ES:NOTHING
  39         MOV     AX,[exit_code]
  40         XOR     DX,DX
  41         MOV     [exit_code],DX
  42         transfer    SYS_RET_OK
  43 $WAIT   ENDP
  44
  45 IF IBM
  46         procedure   $EXEC,NEAR
  47         error   error_invalid_function
  48 $EXEC   ENDP
  49 ENDIF
  50 IF NOT IBM
  51 INCLUDE EXEC.ASM
  52 ENDIF
  53
  54 SUBTTL Terminate and stay resident handler
  55 PAGE
  56 ;
  57 ; Input:    DX is  an  offset  from  CurrentPDB  at which to
  58 ;           truncate the current block.
  59 ;
  60 ; output:   The current block is truncated (expanded) to be [DX+15]/16
  61 ;           paragraphs long.  An exit is simulated via resetting CurrentPDB
  62 ;           and restoring the vectors.
  63 ;
  64         procedure   $Keep_process,NEAR
  65         ASSUME DS:NOTHING,ES:NOTHING,SS:DOSGROUP
  66
  67         PUSH    AX                      ; keep exit code around
  68         MOV     BYTE PTR [Exit_type],Exit_keep_process
  69         MOV     ES,[CurrentPDB]
  70         CMP     DX,6h                   ; keep enough space around for system
  71         JAE     Keep_shrink             ; info
  72         MOV     DX,6h
  73 keep_shrink:
  74         MOV     BX,DX
  75         PUSH    BX
  76         PUSH    ES
  77         invoke  $SETBLOCK               ; ignore return codes.
  78         POP     DS
  79         POP     BX
  80         JC      keep_done               ; failed on modification
  81         MOV     AX,DS
  82         ADD     AX,BX
  83         MOV     DS:[PDB_block_len],AX
  84
  85 keep_done:
  86         POP     AX
  87         JMP     SHORT exit_inner        ; and let abort take care of the rest
  88
  89 $Keep_process   ENDP
  90
  91         procedure   Stay_resident,NEAR
  92         ASSUME  DS:NOTHING,ES:NOTHING,SS:NOTHING
  93         MOV     AX,(Keep_process SHL 8) + 0 ; Lower part is return code
  94         ADD     DX,15
  95         MOV     CL,4
  96         SHR     DX,CL
  97
  98         transfer    COMMAND
  99 Stay_resident   ENDP
 100
 101 SUBTTL $EXIT - return to parent process
 102 PAGE
 103 ;
 104 ;   Assembler usage:
 105 ;           MOV     AL, code
 106 ;           MOV     AH, Exit
 107 ;           INT     int_command
 108 ;   Error return:
 109 ;           None.
 110 ;
 111         procedure   $EXIT,NEAR
 112         ASSUME  DS:NOTHING,ES:NOTHING,SS:DOSGROUP
 113         XOR     AH,AH
 114         XCHG    AH,BYTE PTR [DidCTRLC]
 115         OR      AH,AH
 116         MOV     BYTE PTR [Exit_type],exit_terminate
 117         JZ      exit_inner
 118         MOV     BYTE PTR [Exit_type],exit_ctrl_c
 119
 120 Exit_inner:
 121         invoke  get_user_stack
 122         PUSH    [CurrentPDB]
 123         POP     [SI.user_CS]
 124         transfer    abort_inner
 125 $EXIT   ENDP
 126
 127 do_ext
 128
 129 CODE    ENDS
 130     END