info-mac@uw-beaver (info-mac) (08/20/84)
From: chavez@harvard.ARPA (R. Martin Chavez) Does anyone know why the Memory Manager shouldn't be called by vertical-retrace tasks? R. Martin Chavez (chavez@harvard.ARPA)
info-mac@uw-beaver (info-mac) (08/27/84)
From: winkler@harvard.ARPA (Dan Winkler) The Memory Manager should not be called during vertical retrace tasks because it could trigger a heap compaction. Imagine what that would mean for an application which had just done the first step of dereferencing a handle and, before following the pointer to the actual data, was interrupted by a vertical retrace job which caused a heap compaction and invalidated the pointer.
info-mac@uw-beaver (info-mac) (08/27/84)
From: Michael Rubin <RUBIN@COLUMBIA-20.ARPA> Does anyone know why the Memory Manager shouldn't be called by vertical-retrace tasks? Probably because the Memory Manager isn't reentrant; if it happened to be in the middle of an operation when a vertical-retrace interrupt happened, and the retrace task called it too, its data structures would get trashed. It just wasn't designed for multitasking. -------