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SETMEM Function Programming Example
 
The following program outlines how SETMEM could be used to free memory for
a C function that uses malloc to get dynamic memory.
 
The C function must be separately compiled and then put in a Quick library
or linked to the BASIC program. The C function is compiled using the
large memory model, so calls to malloc use the far space freed
by the BASIC program.
 
 
'*** Programming example: SETMEM function ***
'
' Do not attempt to run this program unless you have already
' separately compiled the C function, using the large memory model,
' and placed it in a Quick library or linked it to the BASIC program.
'
DECLARE SUB CFunc CDECL (BYVAL X AS INTEGER)
 
' Decrease the size of the far heap so CFunc can use
' malloc to get dynamic memory.
BeforeCall = SETMEM(-2048)
 
' Call the C function.
CFunc(1024%)
 
' Return the memory to the far heap; use a larger value so
' all space goes back into the heap.
AfterCall = SETMEM(3500)
 
IF AfterCall <= BeforeCall THEN PRINT "Memory not reallocated."
 
END
 
void far cfunc(bytes)
int bytes;
{
   char *malloc();
   char *workspace;
 
   /* Allocate working memory using amount BASIC freed. */
   workspace=malloc((unsigned) bytes);
 
   /* Working space would be used here. */
 
   /* Free memory before returning to BASIC. */
   free(workspace);
}