Shorthand Notation for Memory Allocation Flags

ID: Q72459

The information in this article applies to:

Microsoft Windows Software Development Kit (SDK) versions 3.0, 3.1

SUMMARY

Some flags have been defined in the WINDOWS.H file [distributed with the Windows Software Development Kit (SDK)] that are designed to be used instead of common flag combinations for memory allocations. Included below is an explanation of these flags:

Global Memory Allocations

There are two flags defined for global memory allocation: GHND and GPTR. Both are to be used for the wFlags parameter of the GlobalAlloc function.


   Flag      Definition
   ----      ----------

   GHND      (GMEM_MOVEABLE | GMEM_ZEROINIT)
   GPTR      (GMEM_FIXED | GMEM_ZEROINIT)

Local Memory Allocations

Similarly, there are two flags defined for local memory allocation: LHND and LPTR. Both are to be used for the wFlags parameter of the LocalAlloc function:


   Flag      Definition
   ----      ----------

   LHND     (LMEM_MOVEABLE | LMEM_ZEROINIT)
   LPTR     (LMEM_FIXED | LMEM_ZEROINIT)

The LPTR flag returns a pointer that can be used immediately (no need to call the LocalLock function); whereas with the GPTR flag, the GlobalLock function still must be used on the handle that is returned.

For more information on the GlobalAlloc and LocalAlloc functions, refer to the "Microsoft Windows Software Development Kit Reference Volume 1".

Additional query words: 3.00 3.10

Keywords : kb16bitonly
Version : WINDOWS:3.0,3.1
Platform : WINDOWS
Issue type :