MemCAlloc Function |  |
Allocate static memory buffers of a specified size.
Namespace: XSharp.RT
Assembly: XSharp.RT (in XSharp.RT.dll) Version: 2.21
SyntaxFUNCTION MemCAlloc( wItems AS DWORD, wBytes AS DWORD ) AS IntPtr
public static IntPtr MemCAlloc( uint wItems, uint wBytes )
Parameters
- wItems
- Type: DWord
The number of items to allocate memory for. - wBytes
- Type: DWord
The number of bytes to allocate for each item.
Return Value
Type: IntPtrA pointer to the allocated space if there is sufficient memory available; otherwise, a NULL_PTR. You should always check the return value from MemCAlloc() for a successful allocation.
Remarks
MemCAlloc() is useful in allocating space for several items at one time.
The allocated memory is defined to be static so that it is not moved by the garbage collector. Space allocated by MemCAlloc() is freed by MemFree().
The allocated memory is defined to be static so that it is not moved by the garbage collector. Space allocated by MemCAlloc() is freed by MemFree().
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| This function allows the direct manipulation of a memory location and should be used with extreme care. |
Remarks| Tip |
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The Static Memory Functions (MemAlloc, MemSet etc) are included for compatibility only.
In most cases the static memory blocks can (and should) be replaced with arrays of bytes. Many of the functions in the runtime that take memory blocks as parameter, such as the low level IO functions, now have overloads that take arrays of bytes as parameter. We recommend that you use these overloads, because their performance is somewhat better. |
Examples
This example uses MemCAlloc() to allocate space for ten long integers:
Instead of hard-coding 4 for the size of a long integer, we could have issued:
This next example uses MemCAlloc() to allocate space for five instances of a defined structure:
X#
1LOCAL ptrLongs AS PTR 2ptrLongs := MemCAlloc(10, 4)
X#
1ptrLongs := MemCAlloc(10, _SizeOf(LONG))
X#
1STRUCTURE StatInfo 2 MEMBER wAverageHit AS DWORD 3 MEMBER wMaxHit AS DWORD 4 MEMBER wMinHit AS DWORD 5FUNCTION MemCAlloc2() AS VOID 6 LOCAL ptrStruct AS PTR 7 ptrStruct := MemCAlloc(5, _SizeOf(StatInfo)) 8 IF ptrStruct = NULL_PTR 9 ? "Allocation failed" 10 ELSE 11 MemFree(ptrStruct) 12 ENDIF
See Also