Error in Labwindows/CVI dll load in Teststand.

[PRS]

Hi,

I am calling a function from labwindows/CVI dll in one of the sequence step in teststand.The library "UlinkClient",read the data from a file and stores it in a array.There are few2 D arrays defines to acheieve this in the dll Code.

The sequcne step is failing and says "Error -17004, could not load library/dll.".

I noticed that when I reduce the size of the array defined in the dll,this error goes off.Can someone please suggest me how I can eliminate this problem.Does Teststand have any constarints on the dll memory size?If yes how this can be increased?

[dug9000]

If your arrays are on the order of 100's of megs you might be hitting address space limitations of 32-bit processes. It's hard to find contiguous blocks of memory in the 100's of megs range in a 32-bit process. If you can use fewer or smaller arrays you might be able to avoid the problem.

-Doug

[PRS]

The following are the arrays defined :

#define max_num_blocks   255

#define max_block_size    90 

#define Block_Name_Size   90  

#define max_bit_size   256 

#define max_item_size  256

#define max_port 14

char    Project_Name[Block_Name_Size];
int     Num_of_blocks[max_port];
int  Total_num_blocks[max_port];

int     Block_Num[max_port][max_num_blocks];
int     Block_Type[max_port][max_num_blocks];
int     Block_Size[max_port][max_num_blocks];
int     Block_Reply_Bytes[max_port][max_num_blocks];
int     Block_Item_type[max_port][max_num_blocks][max_block_size];
long    Block_Item_Val[max_port][max_num_blocks][max_block_size];
char    Block_Item_Name[max_port][max_num_blocks][max_block_size][Block_Name_Size];
char    Block_Name[max_port][max_num_blocks][Block_Name_Size];
int     Block_Item_Bit[max_port][max_num_blocks][max_block_size][max_bit_size];
int  Block_Item_Bit_Val[max_port][max_num_blocks][max_block_size][max_bit_size];
int  Block_Item_Bit_Loc[max_port][max_num_blocks][max_block_size][max_bit_size];
char  Block_Item_Bit_Name[max_port][1024][Block_Name_Size];

I cannot afford to reduce the array sizes.Is there any other solution to this problem.

[AllenP]

Just this parameter (Block_Item_Bit_Loc) is 93 megabytes.  It looks like there is not enough memory to allocate to call your function.

[dug9000]

Are these data structures generally very sparsely used? If so, rather than allocate all of the memory you could ever possibly need upfront, it might be more efficient to allocate things dynamically when you actually need them. For example, you could have list of ports where you only add the ports when they are actually in use, and where each element in the list is structure that has a list of blocks that are only added when used, etc. I think there are some CVI libraries to help you abstract allocating lists and list elements.

Also, I think you might be allocating a lot more space than you need. For example, do you really have a separate unique 4-byte integer for every combination of portnumber, blocknumber, blockbit, and blocksubbit? What is this array for? It's very easy to end up using huge amounts of memory with high-dimension arrays.

Hope this helps,

-Doug