Re: Pending setup patches (issue 6)

[Igor Pechtchanski <pechtcha at cs dot nyu dot edu>]

On Sun, 9 Mar 2003, Max Bowsher wrote:

> Igor Pechtchanski wrote:
> > On Sun, 9 Mar 2003, Max Bowsher wrote:
> >> But what about:
> >> +    // TODO: free unused map entries
> >
> > Not a show-stopper.  Setup keeps all kinds of memory chunks around.
> > They'll be freed when it exits anyway, it's just cleaner to explicitly
> > manage them.
>
> Fair enough.
>
> >> +    // TODO: detect circular dependences
> >
> > Mmm, I think this one can be done later as an improvement.  Again,
> > not a show stopper, just something that will influence the sort order.
>
> Oh, ok, so at the moment, the order of execution of circular dependencies is
> undefined? It won't get stuck in a loop, or anything terrible?

The dependence propagation step will perform a DFS on the dependence
graph.  No node (FileSpec) will be visited more than once (even with
circular dependences).  As for search order, dependences determine the
partial order of FileSpecs, so a circular dependence breaks irreflexivity
(you'd end up with a FileSpec being less than itself)...

> >> Also, dependences/dependencies: Both are valid words, but the 2nd
> >> seems (to me) more commonly used?
> >
> > Must be my compiler background...  I'll change it if it bothers
> > people.
>
> That would be consistent with elsewhere in setup:
>
> choose.cc:        Dependency *dp = pkg.desired->required;
> package_version.cc:class DependencyProcessor {
> package_version.cc:  DependencyProcessor (trusts const &aTrust, int aDepth=0) : deftrust (aTrust), depth (aDepth) {}
> package_version.cc:select (DependencyProcessor &processor, packagemeta *required, packageversion const &aVersion)
> package_version.cc:processOneDependency(trusts deftrust, size_t depth, PackageSpecification *spec)
> package_version.cc:  DependencyProcessor processor (deftrust, depth);
> package_version.cc:       changed += processOneDependency (deftrust, depth, *i) + 1;
> package_version.cc:       changed += processOneDependency (deftrust, depth, *i) + 1;
>
> Max.

Funny you should mention it, the autotools stuff uses "dependence"...  But
I don't mind changing it (although I may, and probably will, slip up in
regular e-mail).  A new patch is attached (along with the new ChangeLog).
	Igor
==============================================================================
ChangeLog:
2003-03-09  Igor Pechtchanski <pechtcha at cs dot nyu dot edu>

	* postinstall.cc (RunFindVisitor::executeAll): New
	member function that propagates script dependencies,
	topologically sorts the script list, and then executes
	the scripts (via other calls).
	(RunFindVisitor::visitFile): Change to add file to list
	instead of running it immediately.
	(RunFindVisitor::files): New member variable.
	(RunFindVisitor::checkAndLogMissingDependences): New
	member function.
	(FileDesc): New class that extracts and stores
	dependencies from a script file.
	(DEPEND_STR): New #define.
	(do_postinstall): Add executeAll() call.

-- 
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  -- /usr/games/fortune

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