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[BUG/PRB.] VFP 9.0 FIX - THE NUMBER OF TIMES TO TRY AGAIN AFTER LOCK FILE FAILED
January 2024
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CCB
1. BUG:
In vfp9 (and vfp6, vfp7, vfp8), somtimes the RLOCK() function runs failed on Windows Vista or later.
2. CAUSE:
There are some compatible problems when the RLOCK() function calls the LockFile Windows API
for the Windows Defender program or the antivirus programs.
Now if the RLOCK() function calls the LockFile Windows API failed,
it will call the LockFile Windows API many times again.
There are some BUGs in the following code.
3. RESOLUTION:
We can write some code to fix the BUG.
Fun41fd5f :: ; proc near
sub esp , 018h ;0x0041fd5f : 83ec18
mov eax , dword ptr [ Data937108 ] ;0x0041fd62 : a108719300
push ebx ;0x0041fd67 : 53
push ebp ;0x0041fd68 : 55
push esi ;0x0041fd69 : 56
mov ebx , ecx ;0x0041fd6a : 8bd9
cmp ebx , eax ;0x0041fd6c : 3bd8
mov esi , edx ;0x0041fd6e : 8bf2
push edi ;0x0041fd70 : 57
mov dword ptr [ esp + 24 ] , esi ;0x0041fd71 : 89742418
mov dword ptr [ esp + 28 ] , ebx ;0x0041fd75 : 895c241c
mov byte ptr [ esp + 22 ] , 00h ;0x0041fd79 : c644241600
jnb Label57fbdd ;0x0041fd7e : 0f8359fe1500
mov ecx , dword ptr [ Data93757c ] ;0x0041fd84 : 8b0d7c759300
mov edi , ebx ;0x0041fd8a : 8bfb
imul edi , edi , 038h ;0x0041fd8c : 6bff38
mov al , byte ptr [ edi + ecx + 44 ] ;0x0041fd8f : 8a440f2c
add edi , ecx ;0x0041fd93 : 03f9
test al , 01h ;0x0041fd95 : a801
mov dword ptr [ esp + 32 ] , edi ;0x0041fd97 : 897c2420
je Label57fbe7 ;0x0041fd9b : 0f8446fe1500
test esi , esi ;0x0041fda1 : 85f6
je Label52445d ;0x0041fda3 : 0f84b4461000
Label41fda9 ::
mov eax , dword ptr [ edi + 44 ] ;0x0041fda9 : 8b472c
mov ecx , dword ptr [esi] ;0x0041fdac : 8b0e
mov ebp , dword ptr [ ecx + 0164h ] ;0x0041fdae : 8ba964010000
shr eax , 0Ah ;0x0041fdb4 : c1e80a
and eax , 03h ;0x0041fdb7 : 83e003
cmp eax , 01h ;0x0041fdba : 83f801
je Label57fbf1 ;0x0041fdbd : 0f842efe1500
Label41fdc3 ::
cmp eax , 03h ;0x0041fdc3 : 83f803
je Label57fc00 ;0x0041fdc6 : 0f8434fe1500
Label41fdcc ::
mov eax , dword ptr [ esp + 48 ] ;0x0041fdcc : 8b442430
test eax , eax ;0x0041fdd0 : 85c0
mov ecx , dword ptr [ esp + 44 ] ;0x0041fdd2 : 8b4c242c
je Label51f010 ;0x0041fdd6 : 0f8434f20f00
Label41fddc ::
or ecx , 040000000h ;0x0041fddc : 81c900000040
test ebp , ebp ;0x0041fde2 : 85ed
mov dword ptr [ esp + 44 ] , ecx ;0x0041fde4 : 894c242c
jne Label57fc50 ;0x0041fde8 : 0f8562fe1500
Label41fdee ::
mov eax , dword ptr [ esp + 52 ] ;0x0041fdee : 8b442434
test eax , eax ;0x0041fdf2 : 85c0
mov eax , dword ptr [ edi + 44 ] ;0x0041fdf4 : 8b472c
je Label41fe33 ;0x0041fdf7 : 743a
test byte ptr ah , 01h ;0x0041fdf9 : f6c401
je Label57ff05 ;0x0041fdfc : 0f8403011600
Label41fe02 ::
mov edx , dword ptr [ esp + 48 ] ;0x0041fe02 : 8b542430
mov edi , dword ptr [ edi + 40 ] ;0x0041fe06 : 8b7f28
;
; -------------------------------------------------------------------------------
; VFP 9.0 FIX - THE NUMBER OF TIMES TO TRY AGAIN AFTER LOCK FILE FAILED
; February 2020
; -------------------------------------------------------------------------------
; CCB
;
; The number of times to try again after lock file failed.
;
; 2020/2/9, by ccb
;
; pushd 00h ;0x0041fe09 : 6a00
; push edx ;0x0041fe0b : 52
; pushd 00h ;0x0041fe0c : 6a00
; push ecx ;0x0041fe0e : 51
; push edi ;0x0041fe0f : 57
; call LockFile ;0x0041fe10 : ff15c0709100
mov dword ptr vfpa_lockfile_lockfile_cnt,00h
mov dword ptr vfpa_lockfile_lockfile_file,edi
mov dword ptr vfpa_lockfile_lockfile_fileoffsetlow,ecx
mov dword ptr vfpa_lockfile_lockfile_fileoffsethigh,00h
mov dword ptr vfpa_lockfile_lockfile_numberofbytestolocklow,edx
mov dword ptr vfpa_lockfile_lockfile_numberofbytestolockhigh,00h
Label41fe09 ::
push dword ptr vfpa_lockfile_lockfile_numberofbytestolockhigh
push dword ptr vfpa_lockfile_lockfile_numberofbytestolocklow
push dword ptr vfpa_lockfile_lockfile_fileoffsethigh
push dword ptr vfpa_lockfile_lockfile_fileoffsetlow
push dword ptr vfpa_lockfile_lockfile_file
call LockFile
test eax , eax
jne Label41fe16
mov ecx,dword ptr vfpa_sys9030_data
inc dword ptr vfpa_lockfile_lockfile_cnt
cmp dword ptr vfpa_lockfile_lockfile_cnt,ecx
ja Label41fe16
push dword ptr vfpa_sys9074_data
call Sleep
jmp Label41fe09
Label41fe16 ::
test eax , eax ;0x0041fe16 : 85c0
je Label57ff23 ;0x0041fe18 : 0f8405011600
Label41fe1e ::
xor eax , eax ;0x0041fe1e : 33c0
Label41fe20 ::
xor ecx , ecx ;0x0041fe20 : 33c9
test eax , eax ;0x0041fe22 : 85c0
sete cl ;0x0041fe24 : 0f94c1
pop edi ;0x0041fe27 : 5f
pop esi ;0x0041fe28 : 5e
pop ebp ;0x0041fe29 : 5d
pop ebx ;0x0041fe2a : 5b
mov eax , ecx ;0x0041fe2b : 8bc1
add esp , 018h ;0x0041fe2d : 83c418
ret 0Ch ;0x0041fe30 : c20c00
4. APPLIES TO:
VFP 6.0.8167.0
VFP 6.0.8961.0 (SP5)
VFP 7.0.0.9262
VFP 7.0.0.9465 (SP1)
VFP 8.0.0.2521
VFP 8.0.0.3117 (SP1)
VFP 9.0.0.2412
VFP 9.0.0.3504 (SP1)
VFP 9.0.0.4611 (SP2)
VFP 9.0.0.5015 (SP2)
VFP 9.0.0.5411 (SP2)
VFP 9.0.0.5721 (SP2)
VFP 9.0.0.5815 (SP2)
VFP 9.0.0.6303 (SP2)
VFP 9.0.0.6602 (SP2)
VFP 9.0.0.7423 (SP2)
The bug has been fixed in VFP Advanced.
5. REFERENCE WEBSITES:
1, baiyujia.com:
http://www.baiyujia.com
http://www.baiyujia.com/vfpdocuments/f_vfp9fix109.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix65.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix66.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix67.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix68.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix69.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix70.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix71.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix72.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix73.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix74.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix84.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix85.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix107.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix108.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix143.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix144.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix145.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix146.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix147.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix148.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix149.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix150.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix203.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix261.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix262.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix269.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix270.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix278.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix279.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix348.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix349.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix350.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix351.asp
2, microsoft.com:
https://devblogs.microsoft.com/oldnewthing/20120907-00/?p=6663
6. OTHER:
For reference only, there is no guarantees.
Any questions or suggestions, please send me an email at ccb2000@163.com.
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