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; SCCSID = @(#)share.asm 1.1 85/04/10
TITLE SHARING ROUTINES - Routines for file Sharing
NAME SHARE
include dosseg.asm
CODE SEGMENT BYTE PUBLIC 'CODE'
ASSUME SS:DOSGROUP,CS:DOSGROUP
.xlist
.xcref
INCLUDE DOSSYM.INC
INCLUDE DEVSYM.INC
.cref
.list
AsmVars <IBM, Installed>
Installed = True
i_need THISDPB,DWORD
i_need EXTERR,WORD
i_need ReadOp,BYTE
i_need ThisSFT,DWORD
i_need ALLOWED,BYTE
I_need RetryCount,WORD
i_need JShare,DWORD
; Inputs:
; [THISSFT] Points to filled in local file/device SFT for new
; instance of file sf_mode ALWAYS has mode (even on FCB SFTs)
; [WFP_START] has full path of name
; [USER_ID] Set
; [PROC_ID] Set
; Function:
; Check for sharing violations on local file/device access
; Outputs:
; Carry clear
; Sharing approved
; Carry set
; A sharing violation detected
; AX is error code
; USES ALL but DS
procedure SHARE_CHECK,NEAR
DOSAssume CS,<DS>,"Share_Check"
ASSUME ES:NOTHING
if installed
call JShare + 1 * 4
else
Call MFT_Enter
endif
return
EndProc SHARE_CHECK
; Inputs:
; [THISDPB] Set
; AX has error code
; Function:
; Handle Sharing errors
; Outputs:
; Carry set if user says FAIL, causes error_sharing_violation
; Carry clear if user wants a retry
;
; DS, ES, DI preserved, others destroyed
procedure SHARE_VIOLATION,NEAR
DOSAssume CS,<DS>,"Share_Violation"
ASSUME ES:NOTHING
PUSH DS
PUSH ES
PUSH DI
MOV [READOP],0 ; All share errors are reading
MOV [ALLOWED],allowed_FAIL + allowed_RETRY
LES BP,[THISDPB]
MOV DI,1 ; Fake some registers
MOV CX,DI
MOV DX,ES:[BP.dpb_dir_sector]
invoke HARDERR
POP DI
POP ES
POP DS
CMP AL,1
retz ; 1 = retry, carry clear
STC
return
EndProc SHARE_VIOLATION
; ShareEnd - terminate sharing info on a particular SFT/UID/PID. This does
; NOT perform a close, it merely asserts that the sharing information
; for the SFT/UID/PID may be safely released.
;
; Inputs: ES:DI points to an SFT
; Outputs: None
; Registers modified: all except DS,ES,DI
procedure ShareEnd,Near
DOSAssume CS,<DS>,"ShareEnd"
ASSUME ES:NOTHING
if installed
Call JShare + 2 * 4
else
Call MFTClose
endif
return
EndProc ShareEnd
break <ShareEnter - attempt to enter a node into the sharing set>
;
; ShareEnter - perform a retried entry of a nodde into the sharing set. If
; the max number of retries is exceeded, we notify the user via int 24.
;
; Inputs: ThisSFT points to the SFT
; WFP_Start points to the WFP
; Outputs: Carry clear => successful entry
; Carry set => failed system call
; Registers modified: all
Procedure ShareEnter,NEAR
DOSAssume CS,<DS>,"ShareEnter"
assume es:nothing
SaveReg <CX>
retry:
mov cx,RetryCount
attempt:
les di,ThisSFT ; grab sft
XOR AX,AX
MOV ES:[DI.sf_MFT],AX ; indicate free SFT
SaveReg <CX>
call Share_Check ; attempt to enter into the sharing set
RestoreReg <CX>
jnc done ; success, let the user see this
invoke Idle ; wait a while
loop attempt ; go back for another attempt
call Share_violation ; signal the problem to the user
jnc retry ; user said to retry, go do it
done:
RestoreReg <CX>
return
EndProc ShareEnter
CODE ENDS
END
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