564194 - MDC MMGC Documentation Review / Document GC rules

Status: RESOLVED WONTFIX

(Tamarin Graveyard :: Garbage Collection (mmGC), defect, P3)

Description

[Dan Smith]

The Tamarin MMGC documentation should be reviewed for accuracy and updated following the changes in FP 10.1.

https://developer.mozilla.org/en/MMgc

Comment 1

[Lars T Hansen]

See also bug #617395 about a "GC rules" document.

Comment 2

[Lars T Hansen]

We should kill the MDC docs and move everything into html files in the docs/mmgc directory in TR.  There can be a link from the MDC page into the hg repository so no functionality will be lost.

Comment 3

[Lars T Hansen]

Also:

- object invariants for exact tracing
- delete == bad
- safegc rules / usage

Comment 4

[Lars T Hansen]

From bug #617395:

"We need to document (text file in docs directory) all the MMgc rules.   We just
removed the global new operator and have a new rule that all GC allocations
done with new have to inherit from GCObject (enforced with compile error).  
Also we just tightened up the rules around what can be passed to a write
barrier (assertion enforced).  

Something that listed all the rules and how/if they are enforced would be
great.  In an ideal world we could prove that if none of the rules were broken
that a program couldn't crash from a GC problem.  Really though I just want to
point people at something when they say "I didn't know that rule! Where are the
rules written down?"

--------

GC.h needs to include a clear and visible comment at the beginning that points
to that file.

It's not clear to me why that documentation should not be part of the MMgc docs
on MDC, though, since that would allow us to have all the docs in one place and
structured in some useful way.  (Alternatively kill the MDC docs and move
everything into the docs directory.)  See also bug #564194 which is about
cleaning up the MDC docs.

--------

I'm now firmly in favor of killing the MDC docs and moving everything into the
docs directory."

Comment 6

[Tommy Reilly]

Attachment: aborted start

I want to redo this as an HTML document with a table that show for each rule how its enforced (ie compiler, assert, not, telepathy etc).

Comment 7

[Tommy Reilly]

More fodder:

https://acrobat.com/app.html#d=PQPAzjIGxY3XlgI4njJ67w

Comment 8

[Lars T Hansen]

I just landed a fairly extensive "rules" document in doc/mmgc in TR (without review - I figure we can review when it's finished, but there seemed value in landing it today, ahead of the GC tutorial tomorrow).

I also landed a stub "mmgc cookbook", but it really is a stub - hardly anything there.

Comment 9

[Felix S. Klock II [:pnkfelix, :fklock]]

Fixme: allocation of arrays is mentioned under the "dont use GC::Alloc or GC::Calloc", but otherwise unaddressed.

Comment 10

[Lars T Hansen]

Discussions with A Greenblatt on DL-MMgc: We probably want to have a well-developed document on how to use MMgc (notably GC'd storage) effectively.

Comment 11

[Sylvestre Ledru [:Sylvestre]]

No assignee, updating the status.

Comment 12

[Sylvestre Ledru [:Sylvestre]]

Tamarin is a dead project now. Mass WONTFIX.

Comment 13

[Sylvestre Ledru [:Sylvestre]]

Tamarin isn't maintained anymore. WONTFIX remaining bugs.