WM_COMPACTING message

Sent to all top-level windows when the system detects more than 12.5 percent of system time over a 30- to 60-second interval is being spent compacting memory. This indicates that system memory is low.

A window receives this message through its WindowProc function.

#define WM_COMPACTING                   0x0041

Parameters

wParam

The ratio of central processing unit (CPU) time currently spent by the system compacting memory to CPU time currently spent by the system performing other operations. For example, 0x8000 represents 50 percent of CPU time spent compacting memory.

lParam

This parameter is not used.

Return value

Type: LRESULT

If an application processes this message, it should return zero.

Remarks

When an application receives this message, it should free as much memory as possible, taking into account the current level of activity of the application and the total number of applications running on the system.

Requirements

See also

Windows Overview