v4.0/src/DOS/LOCK.ASM

   1 ;       SCCSID = @(#)lock.asm   1.1 85/04/10
   2 TITLE   LOCK ROUTINES - Routines for file locking
   3 NAME    LOCK
   4
   5 ;
   6 ;   LOCK_CHECK
   7 ;   LOCK_VIOLATION
   8 ;   $LockOper
   9 ;
  10 ;   Revision history:
  11 ;     A000   version 4.00   Jan. 1988
  12 ;
  13 include dosseg.asm
  14
  15 CODE    SEGMENT BYTE PUBLIC  'CODE'
  16         ASSUME  SS:DOSGROUP,CS:DOSGROUP
  17
  18 .xlist
  19 .xcref
  20 INCLUDE DOSSYM.INC
  21 INCLUDE DEVSYM.INC
  22 include lock.inc                     ;AN000;
  23 .cref
  24 .list
  25
  26 AsmVars <IBM, Installed>
  27
  28 Installed = TRUE
  29
  30         i_need  THISSFT,DWORD
  31         i_need  THISDPB,DWORD
  32         i_need  EXTERR,WORD
  33         i_need  ALLOWED,BYTE
  34         i_need  RetryCount,WORD
  35         I_need  fShare,BYTE
  36         I_Need  EXTERR_LOCUS,BYTE       ; Extended Error Locus
  37         i_need  JShare,DWORD
  38         i_need  Lock_Buffer,DWORD       ;AN000; DOS 4.00
  39         i_need  Temp_Var,WORD           ;AN000; DOS 4.00
  40
  41 BREAK <$LockOper - Lock Calls>
  42
  43 ;
  44 ;   Assembler usage:
  45 ;           MOV     BX, Handle         (DOS 3.3)
  46 ;           MOV     CX, OffsetHigh
  47 ;           MOV     DX, OffsetLow
  48 ;           MOV     SI, LengthHigh
  49 ;           MOV     DI, LengthLow
  50 ;           MOV     AH, LockOper
  51 ;           MOV     AL, Request
  52 ;           INT     21h
  53 ;
  54 ;   Error returns:
  55 ;           AX = error_invalid_handle
  56 ;              = error_invalid_function
  57 ;              = error_lock_violation
  58 ;
  59 ;   Assembler usage:
  60 ;           MOV     AX, 5C??           (DOS 4.00)
  61 ;
  62 ;                                   0? lock all
  63 ;                                   8? lock write
  64 ;                                   ?2 lock multiple
  65 ;                                   ?3 unlock multiple
  66 ;                                   ?4 lock/read
  67 ;                                   ?5 write/unlock
  68 ;                                   ?6 add (lseek EOF/lock/write/unlock)
  69 ;           MOV     BX, Handle
  70 ;           MOV     CX, count or size
  71 ;           LDS     DX, buffer
  72 ;           INT     21h
  73 ;
  74 ;   Error returns:
  75 ;           AX = error_invalid_handle
  76 ;              = error_invalid_function
  77 ;              = error_lock_violation
  78
  79         procedure   $LockOper,NEAR
  80 ASSUME  DS:NOTHING,ES:NOTHING
  81 ;       MOV     BP,AX                   ;MS. BP=AX                              ;AN000;
  82 ;       AND     BP,7FH                  ;MS. clear bit 7                        ;AN000;
  83 ;       CMP     BP,Lock_add             ;MS. supported function ?               ;AN000;
  84 ;       JA      lock_bad_func           ;MS. no,                                ;AN000;
  85
  86         CMP     AL,1                    ;AN000;;MS. no,
  87         JA      lock_bad_func           ;AN000;;MS. no,
  88
  89         PUSH    DI                             ; Save LengthLow
  90         invoke  SFFromHandle                   ; ES:DI -> SFT
  91         JNC     lock_do                        ; have valid handle
  92         POP     DI                             ; Clean stack
  93         error   error_invalid_handle
  94 lock_bad_func:
  95         MOV     EXTERR_LOCUS,errLoc_Unk        ; Extended Error Locus
  96         error   error_invalid_function
  97
  98 ; Align_buffer call has been deleted, since it corrupts the DTA  (6/5/88) P5013
  99
 100 lock_do:
 101 ;       PUSH    AX                      ;AN000;;MS. save ax
 102 ;       PUSH    BX                      ;AN000;;MS. save handle
 103 ;       MOV     [Temp_Var],DX           ;AN000;;MS. save DX
 104 ;       invoke  Align_Buffer            ;AN000;;MS. align ds:dx and set DMAADD
 105 ;       POP     BX                      ;AN000;;MS. restore handle
 106 ;       POP     AX                      ;AN000;;MS. save ax
 107                                         ;AN000;
 108 ;       CMP     BP,Unlock_all           ;AN000;;MS. old function 0 or 1 ?
 109 ;       JA      chk_lock_mul            ;AN000;;MS. no, new function
 110 ;       TEST    AL,80H                  ;AN000;;MS. 80H bit on ?
 111 ;       JZ      old_33                  ;AN000;;MS. no, old DOS 3.3 interface
 112 ;       MOV     CX,1                    ;AN000;;MS. adjust for new interface
 113 ;       ADD     BP,2                    ;AN000;;MS.
 114 ;       JMP     SHORT chk_lock_mul      ;AN000;;MS.
 115 old_33:
 116         MOV     BX,AX                   ;AN000;;MS. save AX
 117                                         ;AN000;
 118 ;;      MOV     DX,[Temp_Var]           ;AN000;;MS. retore DX  (P5013) 6/5/88
 119
 120         MOV     BP, OFFSET DOSGROUP:Lock_Buffer ;AN000;;MS. get DOS LOCK buffer
 121         MOV     WORD PTR [BP.Lock_position],DX  ;AN000;;MS. set low offset
 122         MOV     WORD PTR [BP.Lock_position+2],CX;AN000;;MS. set high offset
 123         POP     CX                              ;AN000;;MS. get low length
 124         MOV     WORD PTR [BP.Lock_length],CX    ;AN000;;MS. set low length
 125         MOV     WORD PTR [BP.Lock_length+2],SI  ;AN000;;MS. set high length
 126         MOV     CX,1                            ;AN000;;MS. one range
 127         PUSH    CS                              ;AN000;;MS.
 128         POP     DS                              ;AN000;;MS. DS:DX points to
 129         MOV     DX,BP                           ;AN000;;MS.   Lock_Buffer
 130         TEST    AL,Unlock_all                   ;AN000;;MS. function 1
 131         JNZ     DOS_Unlock                      ;AN000;;MS. yes
 132         JMP     DOS_Lock                        ;AN000;;MS. function 0
 133 ;;chk_lock_mul:                                 ;AN000;
 134 ;       POP     SI                              ;AN000;;MS. pop low length
 135 ;       TEST    ES:[DI.sf_flags],sf_isnet       ;AN000;;MS. net handle?
 136 ;       JZ      LOCAL_DOS_LOCK                  ;AN000;;MS. no
 137 ;       invoke  OWN_SHARE                       ;AN000;;MS. IFS owns share ?
 138 ;       JNZ     LOCAL_DOS_LOCK                  ;AN000;;MS. no
 139 ;       MOV     BX,AX                           ;AN000;;MS. BX=AX
 140 ;       CallInstall NET_XLock,multNet,10        ;AN000;;MS. issue Net Extended Lock
 141 ;       MOV     [Temp_Var],CX                   ;AN000;;MS. cx= retuened from IFS
 142 ;       JMP     ValChk                          ;AN000;;MS. check return
 143 ;LOCAL_DOS_LOCK:                                ;AN000;
 144 ;       CMP     BP,Lock_mul_range               ;AN000;;MS. lock mul range?
 145 ;       JNZ     unmul                           ;AN000;;MS. lock mul range?
 146 ;       JMP     LOCAL_LOCK                      ;AN000;;MS. yes
 147 ;unmul:
 148 ;       CMP     BP,Unlock_mul_range             ;AN000;;MS. unlock mul range?
 149 ;       JZ      LOCAL_UNLOCK                    ;AN000;;MS. yes
 150 ;       CMP     BP,Lock_read                    ;AN000;;MS. lock read?
 151 ;       JNZ     chk_write_unlock                ;AN000;;MS. no
 152 ;       CALL    Set_Lock_Buffer                 ;AN000;;MS. set DOS lock buffer
 153 ;       CALL    Set_Lock                        ;AN000;;MS. set the lock
 154 ;       JC      lockerror                       ;AN000;;MS. error
 155 ;       invoke  $READ                           ;AN000;;MS. do read
 156 ;       JC      lockerror                       ;AN000;;MS. error
 157 ;lockend:                                       ;AN000;
 158 ;       transfer SYS_RET_OK                     ;AN000;;MS. return
 159 ;chk_write_unlock:                              ;AN000;
 160 ;       CMP     BP,Write_unlock                 ;AN000;;MS. write unlock ?
 161 ;       JNZ     Lock_addf                       ;AN000;;MS. no
 162 ;       CALL    Set_Lock_Buffer                 ;AN000;;MS. set DOS lock buffer
 163 ;WriteUnlock:                                   ;AN000;
 164 ;       PUSH    AX                              ;AN000;;MS. save AX for unlock
 165 ;       invoke  $WRITE                          ;AN000;;MS. do write
 166 ;       MOV     [Temp_Var],AX                   ;AN000;;MS. save number of bytes writ
 167 ;       POP     AX                              ;AN000;;MS. restore AX
 168 ;       JC      lockerror                       ;AN000;;MS. error
 169 ;       MOV     CX,1                            ;AN000;;MS. one range unlock
 170 ;       PUSH    CS                              ;AN000;;MS.
 171 ;       POP     DS                              ;AN000;;MS. DS:DX points to
 172 ;       MOV     DX,OFFSET DOSGROUP:Lock_Buffer  ;AN000;;MS.  Lock_BUffer
 173 ;       JMP     LOCAL_UNLOCK                    ;AN000;;MS. do unlock
 174 ;Lock_addf:                                     ;AN000;
 175 ;       MOV     SI,WORD PTR ES:[DI.SF_Size]      ;AN000;;MS. must be lock add
 176 ;       MOV     WORD PTR ES:[DI.SF_Position],SI  ;AN000;;MS. set file position to
 177 ;       MOV     SI,WORD PTR ES:[DI.SF_Size+2]    ;AN000;;MS. EOF
 178 ;       MOV     WORD PTR ES:[DI.SF_Position+2],SI;AN000;;MS.
 179 ;       CALL    Set_Lock_Buffer                  ;AN000;;MS. set DOS lock buffer
 180 ;       CALL    Set_Lock                         ;AN000;;MS. set the lock
 181 ;       JC      lockerror                        ;AN000;;MS. error
 182 ;       JMP     WriteUnlock                      ;AN000;;MS. do write unlock
 183                                                  ;AN000;;MS.
 184 DOS_Unlock:
 185         TEST    ES:[DI.sf_flags],sf_isnet
 186         JZ      LOCAL_UNLOCK
 187 ;;      invoke  OWN_SHARE                        ;AN000;;MS. IFS owns share ?
 188 ;;      JNZ     LOCAL_UNLOCK                     ;AN000;;MS. no
 189
 190         CallInstall Net_Xlock,multNet,10
 191         JMP     SHORT ValChk
 192 LOCAL_UNLOCK:
 193 if installed
 194         Call    JShare + 7 * 4
 195 else
 196         Call    clr_block
 197 endif
 198 ValChk:
 199         JNC     Lock_OK
 200 lockerror:
 201         transfer SYS_RET_ERR
 202 Lock_OK:
 203         MOV     AX,[Temp_VAR]                    ;AN000;;MS. AX= number of bytes
 204         transfer SYS_Ret_OK
 205 DOS_Lock:
 206         TEST    ES:[DI.sf_flags],sf_isnet
 207         JZ      LOCAL_LOCK
 208 ;;      invoke  OWN_SHARE                        ;AN000;;MS. IFS owns share ?
 209 ;;      JNZ     LOCAL_LOCK                       ;AN000;;MS. no
 210         CallInstall NET_XLock,multNet,10
 211         JMP     ValChk
 212 LOCAL_LOCK:
 213 if installed
 214         Call    JShare + 6 * 4
 215 else
 216         Call    Set_Block
 217 endif
 218         JMP     ValChk
 219
 220 EndProc $LockOper
 221
 222 BREAK <Set_Lock>
 223
 224 ;   Input:
 225 ;          BP = Lock_Buffer addr
 226 ;          CX = lock length
 227 ;   Function:
 228 ;          set the lock
 229 ;   Output:
 230 ;          carry clear ,Lock is set
 231 ;                       DS:DX = addr of
 232 ;          carry set Lock is not set
 233 ;          DS,DX,CX preserved
 234
 235 ;       procedure   Set_Lock,NEAR                                               ;AN000;
 236 ;ASSUME  DS:NOTHING,ES:NOTHING                                                   ;AN000;
 237                                                                                 ;AN000;
 238 ;       PUSH    DS                          ;MS. save regs                      ;AN000;
 239 ;       PUSH    DX                          ;MS.                                ;AN000;
 240 ;       PUSH    CX                          ;MS.                                ;AN000;
 241 ;                                                                               ;AN000;
 242 ;       PUSH    CS                          ;MS.                                ;AN000;
 243 ;       POP     DS                          ;MS. DS:DX poits to Lock_Buffer     ;AN000;
 244 ;       MOV     DX,BP                       ;MS.                                ;AN000;
 245 ;       PUSH    BX                          ;MS. save handle                    ;AN000;
 246 ;       PUSH    AX                          ;MS. save functions                 ;AN000;
 247 ;       MOV     CX,1                        ;MS. set one lock                   ;AN000;
 248 ;if installed                                                                    ;AN000;
 249 ;       Call    JShare + 6 * 4              ;MS. call share set block           ;AN000;
 250 ;else                                                                            ;AN000;
 251 ;       Call    Set_Block                   ;MS.                                ;AN000;
 252 ;endif                                                                           ;AN000;
 253 ;       POP     AX                          ;MS. restore regs                   ;AN000;
 254 ;       POP     BX                          ;MS.                                ;AN000;
 255 ;       POP     CX                          ;MS.                                ;AN000;
 256 ;       POP     DX                          ;MS.                                ;AN000;
 257 ;       POP     DS                          ;MS.                                ;AN000;
 258 ;       return                              ;MS.                                ;AN000;
 259 ;                                                                               ;AN000;
 260 ;EndProc Set_Lock                                                                ;AN000;
 261
 262 BREAK <Set_Lock_Buffer>
 263
 264 ;   Input:
 265 ;          ES:DI = addr of SFT
 266 ;          CX = lock length
 267 ;   Function:
 268 ;          set up the lock buffer
 269 ;   Output:
 270 ;          Lock_Buffer is filled with position and lock length
 271 ;          BP = Lock_Buffer addr
 272 ;
 273
 274 ;       procedure   Set_Lock_Buffer,NEAR
 275 ;ASSUME  DS:NOTHING,ES:NOTHING
 276 ;
 277 ;       MOV     BP, OFFSET DOSGROUP:Lock_Buffer   ;MS. move file position       ;AN000;
 278 ;       MOV     SI,WORD PTR ES:[DI.sf_position]   ;MS. to DOS lock_buffer       ;AN000;
 279 ;       MOV     WORD PTR [BP.Lock_position],SI    ;MS.                          ;AN000;
 280 ;       MOV     SI,WORD PTR ES:[DI.sf_position+2] ;MS.                          ;AN000;
 281 ;       MOV     WORD PTR [BP.Lock_position+2],SI  ;MS.                          ;AN000;
 282 ;       MOV     WORD PTR [BP.Lock_length],CX      ;MS. move cx to lock_buffer   ;AN000;
 283 ;       MOV     WORD PTR [BP.Lock_length+2],0     ;MS.                          ;AN000;
 284 ;       return                                    ;MS.                          ;AN000;
 285 ;
 286 ;EndProc Set_Lock_Buffer
 287
 288 ; Inputs:
 289 ;       Outputs of SETUP
 290 ;       [USER_ID] Set
 291 ;       [PROC_ID] Set
 292 ; Function:
 293 ;       Check for lock violations on local I/O
 294 ;       Retries are attempted with sleeps in between
 295 ; Outputs:
 296 ;    Carry clear
 297 ;       Operation is OK
 298 ;    Carry set
 299 ;       A lock violation detected
 300 ; Outputs of SETUP preserved
 301
 302         procedure   LOCK_CHECK,NEAR
 303         DOSAssume   CS,<DS>,"Lock_Check"
 304         ASSUME  ES:NOTHING
 305
 306         MOV     BX,RetryCount           ; Number retries
 307 LockRetry:
 308         SaveReg <BX,AX>                 ; MS. save regs                         ;AN000;
 309 if installed
 310         call    JShare + 8 * 4
 311 else
 312         Call    chk_block
 313 endif
 314         RestoreReg  <AX,BX>             ; MS. restrore regs                     ;AN000;
 315         retnc                           ; There are no locks
 316         Invoke  Idle                    ; wait a while
 317         DEC     BX                      ; remember a retry
 318         JNZ     LockRetry               ; more retries left...
 319         STC
 320         return
 321 EndProc LOCK_CHECK
 322
 323 ; Inputs:
 324 ;       [THISDPB] set
 325 ;       [READOP] indicates whether error on read or write
 326 ; Function:
 327 ;       Handle Lock violation on compatibility (FCB) mode SFTs
 328 ; Outputs:
 329 ;       Carry set if user says FAIL, causes error_lock_violation
 330 ;       Carry clear if user wants a retry
 331 ;
 332 ; DS, ES, DI, CX preserved, others destroyed
 333
 334         procedure   LOCK_VIOLATION,NEAR
 335         DOSAssume   CS,<DS>,"Lock_Violation"
 336         ASSUME  ES:NOTHING
 337
 338         PUSH    DS
 339         PUSH    ES
 340         PUSH    DI
 341         PUSH    CX
 342         MOV     AX,error_lock_violation
 343         MOV     [ALLOWED],allowed_FAIL + allowed_RETRY
 344         LES     BP,[THISDPB]
 345         MOV     DI,1                            ; Fake some registers
 346         MOV     CX,DI
 347         MOV     DX,ES:[BP.dpb_first_sector]
 348         invoke  HARDERR
 349         POP     CX
 350         POP     DI
 351         POP     ES
 352         POP     DS
 353         CMP     AL,1
 354         retz                    ; 1 = retry, carry clear
 355         STC
 356         return
 357
 358 EndProc LOCK_VIOLATION
 359
 360 IF  INSTALLED
 361 ;
 362 ; do a retz to return error
 363 ;
 364 Procedure   CheckShare,NEAR
 365         ASSUME  CS:DOSGROUP,ES:NOTHING,DS:NOTHING,SS:NOTHING
 366         CMP     fShare,0
 367         return
 368 EndProc CheckShare
 369 ENDIF
 370
 371 CODE    ENDS
 372     END