Lock a vproc-local, read/write GLOP for reading or writing.
FNC_GLOP_Lock returns an integer that indicates success or failure.
| Value | Meaning |
|---|---|
| 0 | Lock was granted. |
| -1 | The index is not valid or the map does not exist. |
| -2 | The lock attempt timed out. |
| -3 | Cannot lock a read-only GLOP. |
| -4 | The GLOP is already locked by this routine. The routine may only perform one lock of any kind at a time. |