Adding Java and C++ to the MQTT benchmarks or: How I Learned to Stop Worrying and Love the Garbage Collector

[Paulo Pinto]

On Thursday, 9 January 2014 at 23:02:57 UTC, Joseph Rushton 
Wakeling wrote:
> On 08/01/14 21:22, Paulo Pinto wrote:
>> As I shared a few times here, it was Oberon which opened my 
>> eyes
>> to GC enabled systems programming languages, around 1996, 
>> maybe.
>
> What was the GC design for Oberon, and how does that relate to 
> what's in D (and what's in other GC'd languages)?

The original Oberon was a simple mark and sweep collector. 
Initially implemented in Assembly. In later versions it was coded 
in Oberon itself.

Original 1992/2005 edition
http://www.inf.ethz.ch/personal/wirth/ProjectOberon1992.pdf

2013 edition with images of the workstations were Oberon ran
http://www.inf.ethz.ch/personal/wirth/ProjectOberon/PO.System.pdf

EthOS used a mark and sweep GC with support for weak pointers and 
finalization. Running when the system was idle or when not enough 
memory was available.

http://research.microsoft.com/en-us/um/people/cszypers/books/insight-ethos.pdf

Active Oberon implementation used a mark and sweep with 
finalization support.

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.85.5753&rep=rep1&type=pdf

Modula-3 used a compacting GC initially, with an optional 
background one.

https://modula3.elegosoft.com/cm3/doc/help/bib.html
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.36.6890

Cedar used a concurrent reference-counting collector, coupled 
with a mark and sweep one for cycle removals, with finalization 
support

http://www.textfiles.com/bitsavers/pdf/xerox/parc/techReports/CSL-84-7_On_Adding_Garbage_Collection_and_Runtime_Types_to_a_Strongly-Typed_Statically-Checked_Concurrent_Language.pdf

The features are quite similar to D:

- GC
- Allocation of data structures statically in global memory and 
stack
- Escape hatches to allocate memory manually when needed

I cannot say if they also allow for interior pointers like D does.

However the main point about Oberon and other languages wasn't 
only technical, but human. Funny enough that is also Andrew 
Koening's latest post

http://www.drdobbs.com/cpp/social-processes-and-the-design-of-progr/240165221

The people designing such systems believed that it was possible 
to write from the ground up a workstation operating system in a 
GC enabled systems programming language, with minimal Assembly.

They did succeed and built workstations that were usable for 
normal office work, which were then used at ETHZ, Xerox and 
Olivetti for some time.

For games, some more effort would be required I do acknowledge 
that.

However the world at large, ignored these efforts. As Andrew 
nicely puts on his article, many times the social barrier is 
higher than the technical one.

For many developers hearing the GC word, safe coding, bounds 
checking is enough to make them run away as fast as they can.

--
Paulo