Fwd: PARC Forum 2/23/95 - Hans-J. Boehm "Garbage Collection for C"

Bill Janssen (janssen@parc.xerox.com)
Fri, 17 Feb 1995 10:23:53 PST

[ Since I've mentioned Hans' garbage collector several times here, I
thought some local list members might be interested in attending... ]

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PARC Forum
Thursday, February 23, 1995, 4:00pm, PARC Auditorium

Garbage Collection for C

Hans-J. Boehm
Xerox PARC

I'll argue briefly that automatic garbage collection (reuse of
inaccessible memory) is important for the construction of reliable
software, and that it can significantly accelerate software
development. Garbage collection is more important for certain kinds of
applications than others. But its utility is largely independent of
the programming language used for development.

We have developed a garbage collector that can usually be used with
unmodified C and C++ programs compiled by standard compilers. It has
been used directly with hand-written code, and with compilers that
translate other languages (notably Cedar, Scheme, ML, and Sather). Its
performance is usually competitive with explicit memory deallocation
(C "free", C++ "delete"), even for code written for explicit
deallocation. Garbage collector pause times are acceptably small for
interactive applications. I'll summarize the techniques needed to
achieve this, and review some performance measurements (mostly
obtained by others). I'll discuss the conditions under which this
style of garbage collection can be guaranteed safe for ANSI C
programs.

* * *

Hans-J. Boehm has been a member of the research staff at Xerox PARC
since 1989. He received his Ph.D. in Computer Science from Cornell
University, and was a member of the faculty at the University of
Washington and at Rice University. His research interests have focused
on a variety of programming language implementations issues. He is the
principal author of the garbage collector described in this talk.

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Some upcoming Forums:
3/2/95, Donald H. Stedman, "Science and Politics of Air Pollution from Cars"
3/9/95, Edward Teller

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John R. Ellis
Xerox PARC