UnloadSeg

Unlock a code segment and make it purgeable

#include <SegLoad.h> Segment Loader

void UnloadSeg(rtnAddr );

Ptr rtnAddr ; address of any routine in a segment to unload

UnloadSeg unlocks a code resource (type 'CODE') and makes it purgeable

(unless it is called from code in that same segment). When a memory shortage

occurs, the specified segment will be purged from memory. Any subsequent

call to any routines in the unloaded segment will cause it to be swapped back

into memory.

rtnAddr is the address of any function in the application. The code segment in

which the function resides will be unlocked and made purgeable.

Notes: UnloadSeg ignores calls that would unlock the segment from which the

call was made. Also, the main segment of an application (first segment

executed, the 'CODE' resource whose ID is 1) will always remain locked and

loaded and ready to fire.

Note: It is possible for a function to unload the segment of a function that

called it. If that happens, the eventual return could be disastrous, since

the caller may have been swapped out.

Since the main segment never gets purged, it is OK to unload all other

segments from within that segment, even as often as each time through your

main loop. The unloaded code will be purged only during a memory shortage.

It will be loaded back in as soon as it is needed.

Referenced by (9):