XEmacs

XEmacs is a highly customizable open source text editor and application development system. See http://www.xemacs.org.

I am developing a new memory manager for XEmacs. Here is the work that I already did:

• new mark algorithm: KKCC
• new allocator: MC-ALLOC
• incremental garbage collector: NEWGC

Here are some details:

newgc

Configure with `--enable-newgc' (implies `--enable-mc-alloc' and `--enable-kkcc').

Documentation

• Detailed information can be found in my diploma thesis:
  • A New Garbage Collector for XEmacs

mc-alloc

The new allocator provides size-based allocation (rather than object-based allocation what the old allocator provides). This allows many simplifications: the distinction between lrecords and lcrecords is no longer needed, I merged the two types into one. Thus, the new allocator has a small and straight forward interface.

Configure with `--enable-mc-alloc'.

Documentation

• Detailed information can be found in my term thesis:
  • Ein neuer Speicher-Allokator für XEmacs (sorry, German only)
• This manual provides information about the new allocator in English:
  • New Allocator Manual

kkcc

Together with Markus Kaltenbach I worked on a new marking algorithm using memory descriptions.

The mark algorithm uses an explicit stack that keeps track of the current progress of traversal. Every Lisp object type has a memory layout description. The mark algorithm parses the memory descriptions to determine all live pointers. This way, the traversal is able to follow all pointers from the root set transitively to other objects on the heap.

Configure with `--use-kkcc'.