Hi everyone,
I'm having a sporadic problem white pointer address between J and c++.
I'm running a J64-602 that call some function from a DLL written in c++
compiled for x64.
The call look like this.
llxutm =: '"D:\Infodev\c++\RecDLL\x64\release\RecDLL.dll" LL2UTM
+ i * * i i i'&cd
adrY =: mema (#la)*8
adrX =: mema (#lo)*8
NB. calling conversion
llxutm la;lo;adrX;adrY;(#la)
utmx =: _3 ic memr adrX,0,(#la)*8
utmy =: _3 ic memr adrY,0,(#la)*8
memf adrX
memf adrY
C++ prototype:
DllExport int LL2UTM(double *plat, double *plon,unsigned __int64 *px
,unsigned __int64 *py,unsigned __int64 cnt);
In short, I'm allocating memory for the return value in J (mema), C is
calculating the value, and fill in the memory allocated by J. Then J
read the value and free the memory.. pretty straightforward.
This call is made about 500 000 to 1 000 000 times, and once in a while
(once every 25000 - 50000 call). J create a memory allocation somewhere
over the 2^31 boundary . Example : 2552889360 , And then this address
is passed to C. But when C received it, it look like this : -1742077936
(0xffffffff982a0010).
This is way below the 2^64 boundary. I'm wondering if J call the DLL
passing 64bits value correctly, Or if I'm doing something wrong.
This worked like a charm on 32 bits architecture with a J32.
I' running a Windows XP 64 pro SP2, on a Intel Quad Q6600 64bits, 4GB ram.
regards
Jean-Philippe D.
Software Dev.
Infodev EDI
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