Re: Using TLSAlloc to read data into a DLL

Sanjay <>
Mon, 31 Dec 2007 12:37:58 -0800 (PST)
On Dec 31, 12:18 pm, "Igor Tandetnik" <> wrote:

"Sanjay" <> wrote in message

Thanks for your response. I was a bit unclear in my earlier message,
which may or may not affect your answer. The DLL I am building is
multi-threaded. I want to be able to read in the data during the
DLL_PROCESS_ATTACH, as you indicate (when the DLL is first loaded). I
then want this data to be available to other threads of the DLL, which
may be called at various times. I thought that you would need to use
TlsAlloc, etc. to be able to do this - that global variables are not
passed between threads. Is this correct?

This is incorrect. All threads have access to global variables. Just do
it, you don't need anything special.
With best wishes,
    Igor Tandetnik

With sufficient thrust, pigs fly just fine. However, this is not
necessarily a good idea. It is hard to be sure where they are going to
land, and it could be dangerous sitting under them as they fly
overhead. -- RFC 1925

How would I go about defining a global variable for this simple
example? (I want "x" to be the global variable):

#define MAX_LENGTH 100

BOOL WINAPI DllMain (HANDLE hInst, ULONG ul_reason_for_call, LPVOID
  static double *x=NULL;
  FILE *in;
  char out[MAX_LENGTH];
     x = malloc(MAX_LENGTH);
     in = fopen("Test.txt", "rt")
     fgets(out, MAX_LENGTH, in);
     x = strtod(out,NULL);
     close (in);
   return TRUE;

int __declspec(dllexport) APIENTRY Test(Data *y)
static double *x, *y;
y = x*x
return 0;

This is just a very simple example, in which I want to read the value
of x from a file, but I only want to read it once, when the DLL is
first loaded. I then want to "pass" this value to the code for
analysis (i.e. calculate x squared). I do not think that I should be
using STATIC variable types, because this doesn't seem to work. Any
help would be greatly appreciated. Thanks for all of your help thus

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