http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/
+What can we offer you in return? Fame, fortune, and everlasting glory? Maybe
+not, but if your patch is incorporated, then we'll add your name to the
+F<AUTHORS> file, which ships in the official distribution. How many other
+programming languages offer you 1 line of immortality?
+=head1 The roadmap to 5.10
+The roadmap to 5.10 envisages feature based releases, as various items in this
+TODO are completed.
+=head2 Needed for a 5.9.3 release
+
+=over
+
+=item *
+Implement L</lexical pragmas>
+
+=back
+
+=head2 Needed for a 5.9.4 release
+
+=over
+
+=item *
+Review assertions. Review syntax to combine assertions. Can assertions take
+advantage of the lexical pragams work? L</What hooks would assertions need?>
+
+=back
+
+=head2 Needed for a 5.9.5 release
+
+=over
+
+=item *
+Implement L</_ prototype character>
+
+=item *
+Implement L</state variables>
+
+=back
+
+=head2 Needed for a 5.9.6 release
+
+Stabilisation. If all goes well, this will be the equivalent of a 5.10-beta.
=head1 Tasks that only need Perl knowledge
errors. See also L</make HTML install work>, as the layout of installation tree
is needed to improve the cross-linking.
+=head2 Parallel testing
+
+The core regression test suite is getting ever more comprehensive, which has
+the side effect that it takes longer to run. This isn't so good. Investigate
+whether it would be feasible to give the harness script the B<option> of
+running sets of tests in parallel. This would be useful for tests in
+F<t/op/*.t> and F<t/uni/*.t> and maybe some sets of tests in F<lib/>.
+
+Questions to answer
+
+=over 4
+
+=item 1
+
+How does screen layout work when you're running more than one test?
+
+=item 2
+
+How does the caller of test specify how many tests to run in parallel?
+
+=item 3
+
+How do setup/teardown tests identify themselves?
+
+=back
+
+Pugs already does parallel testing - can their approach be re-used?
+
=head2 Make Schwern poorer
We should have for everything. When all the core's modules are tested,
=head2 A decent benchmark
-perlbench seems impervious to any recent changes made to the perl core. It
+C<perlbench> seems impervious to any recent changes made to the perl core. It
would be useful to have a reasonable general benchmarking suite that roughly
represented what current perl programs do, and measurably reported whether
tweaks to the core improve, degrade or don't really affect performance, to
Or if you prefer, tasks that you would learn from, and broaden your skills
base...
+=head2 Relocatable perl
+
+The C level patches needed to create a relocatable perl binary are done, as
+is the work on F<Config.pm>. All that's left to do is the C<Configure> tweaking
+to let people specify how they want to do the install.
+
=head2 make HTML install work
There is an C<installhtml> target in the Makefile. It's marked as
=item 2
-Work out how to split perlfunc into chunks, preferably one per function group,
-preferably with general case code that could be used elsewhere. Challenges
-here are correctly identifying the groups of functions that go together, and
-making the right named external cross-links point to the right page. Things to
-be aware of are C<-X>, groups such as C<getpwnam> to C<endservent>, two or
-more C<=items> giving the different parameter lists, such as
+Work out how to split C<perlfunc> into chunks, preferably one per function
+group, preferably with general case code that could be used elsewhere.
+Challenges here are correctly identifying the groups of functions that go
+together, and making the right named external cross-links point to the right
+page. Things to be aware of are C<-X>, groups such as C<getpwnam> to
+C<endservent>, two or more C<=items> giving the different parameter lists, such
+as
=item substr EXPR,OFFSET,LENGTH,REPLACEMENT
a binary distribution better describes the installed machine, when the
installed machine differs from the build machine in some significant way.
-=head2 Relocatable perl
-
-The C level patches needed to create a relocatable perl binary are done, as
-is the work on Config.pm. All that's left to do is the C<Configure> tweaking
-to let people specify how they want to do the install.
-
=head2 make parallel builds work
Currently parallel builds (such as C<make -j3>) don't work reliably. We believe
It would be good if someone were able to track down the causes of these
problems, so that parallel builds worked properly.
+=head2 linker specification files
+
+Some platforms mandate that you provide a list of a shared library's external
+symbols to the linker, so the core already has the infrastructure in place to
+do this for generating shared perl libraries. My understanding is that the
+GNU toolchain can accept an optional linker specification file, and restrict
+visibility just to symbols declared in that file. It would be good to extend
+F<makedef.pl> to support this format, and to provide a means within
+C<Configure> to enable it. This would allow Unix users to test that the
+export list is correct, and to build a perl that does not pollute the global
+namespace with private symbols.
+
+
=head1 Tasks that need a little C knowledge
=head2 Make it clear from -v if this is the exact official release
-Currently perl from p4/rsync ships with a patchlevel.h file that usually
-defines one local patch, of the form "MAINT12345" or "RC1". The output of
-perl -v doesn't report that a perl isn't an official release, and this
+Currently perl from C<p4>/C<rsync> ships with a F<patchlevel.h> file that
+usually defines one local patch, of the form "MAINT12345" or "RC1". The output
+of perl -v doesn't report that a perl isn't an official release, and this
information can get lost in bugs reports. Because of this, the minor version
isn't bumped up until RC time, to minimise the possibility of versions of perl
escaping that believe themselves to be newer than they actually are.
when making a tarball, yet leave the default source saying "I'm not the
official release".
+=head2 Tidy up global variables
+
+There's a note in F<intrpvar.h>
+
+ /* These two variables are needed to preserve 5.8.x bincompat because
+ we can't change function prototypes of two exported functions.
+ Probably should be taken out of blead soon, and relevant prototypes
+ changed. */
+
+So doing this, and removing any of the unused variables still present would
+be good.
+
+=head2 Ordering of "global" variables.
+
+F<thrdvar.h> and F<intrpvarh> define the "global" variables that need to be
+per-thread under ithreads, where the variables are actually elements in a
+structure. As C dictates, the variables must be laid out in order of
+declaration. There is a comment
+C</* Important ones in the first cache line (if alignment is done right) */>
+which implies that at some point in the past the ordering was carefully chosen
+(at least in part). However, it's clear that the ordering is less than perfect,
+as currently there are things such as 7 C<bool>s in a row, then something
+typically requiring 4 byte alignment, and then an odd C<bool> later on.
+(C<bool>s are typically defined as C<char>s). So it would be good for someone
+to review the ordering of the variables, to see how much alignment padding can
+be removed.
+
=head2 bincompat functions
There are lots of functions which are retained for binary compatibility.
Clean these up. Move them to mathom.c, and don't compile for blead?
+=head2 am I hot or not?
+
+The idea of F<pp_hot.c> is that it contains the I<hot> ops, the ops that are
+most commonly used. The idea is that by grouping them, their object code will
+be adjacent in the executable, so they have a greater chance of already being
+in the CPU cache (or swapped in) due to being near another op already in use.
+
+Except that it's not clear if these really are the most commonly used ops. So
+anyone feeling like exercising their skill with coverage and profiling tools
+might want to determine what ops I<really> are the most commonly used. And in
+turn suggest evictions and promotions to achieve a better F<pp_hot.c>.
+
+=head2 emulate the per-thread memory pool on Unix
+
+For Windows, ithreads allocates memory for each thread from a separate pool,
+which it discards at thread exit. It also checks that memory is free()d to
+the correct pool. Neither check is done on Unix, so code developed there won't
+be subject to such strictures, so can harbour bugs that only show up when the
+code reaches Windows.
+
+It would be good to be able to optionally emulate the Window pool system on
+Unix, to let developers who only have access to Unix, or want to use
+Unix-specific debugging tools, check for these problems. To do this would
+involve figuring out how the C<PerlMem_*> macros wrap C<malloc()> access, and
+providing a layer that records/checks the identity of the thread making the
+call, and recording all the memory allocated by each thread via this API so
+that it can be summarily free()d at thread exit. One implementation idea
+would be to increase the size of allocation, and store the C<my_perl> pointer
+(to identify the thread) at the start, along with pointers to make a linked
+list of blocks for this thread. To avoid alignment problems it would be
+necessary to do something like
+
+ union memory_header_padded {
+ struct memory_header {
+ void *thread_id; /* For my_perl */
+ void *next; /* Pointer to next block for this thread */
+ } data;
+ long double padding; /* whatever type has maximal alignment constraint */
+ };
+
+
+although C<long double> might not be the only type to add to the padding
+union.
+
+=head2 reduce duplication in sv_setsv_flags
+
+C<Perl_sv_setsv_flags> has a comment
+C</* There's a lot of redundancy below but we're going for speed here */>
+
+Whilst this was true 10 years ago, the growing disparity between RAM and CPU
+speeds mean that the trade offs have changed. In addition, the duplicate code
+adds to the maintenance burden. It would be good to see how much of the
+redundancy can be pruned, particular in the less common paths. (Profiling
+tools at the ready...). For example, why does the test for
+"Can't redefine active sort subroutine" need to occur in two places?
Clean this up. Check everything in core works
+=head2 shrink C<GV>s, C<CV>s
+
+By removing unused elements and careful re-ordering, the structures for C<AV>s
+and C<HV>s have recently been shrunk considerably. It's probable that the same
+approach would find savings in C<GV>s and C<CV>s, if not all the other
+larger-than-C<PVMG> types.
+
+=head2 merge Perl_sv_2[inpu]v
+
+There's a lot of code shared between C<Perl_sv_2iv_flags>,
+C<Perl_sv_2uv_flags>, C<Perl_sv_2nv>, and C<Perl_sv_2pv_flags>. It would be
+interesting to see if some of it can be merged into common shared static
+functions. In particular, C<Perl_sv_2uv_flags> started out as a cut&paste
+from C<Perl_sv_2iv_flags> around 5.005_50 time, and it may be possible to
+replace both with a single function that returns a value or union which is
+split out by the macros in F<sv.h>
+
=head2 UTF8 caching code
The string position/offset cache is not optional. It should be.
Study the possibility of adding a new prototype character, C<_>, meaning
"this argument defaults to $_".
+=head2 state variables
+
+C<my $foo if 0;> is deprecated, and should be replaced with
+C<state $x = "initial value\n";> the syntax from Perl 6.
+
=head2 @INC source filter to Filter::Simple
The second return value from a sub in @INC can be a source filter. This isn't
=head2 make ithreads more robust
-Generally make ithreads more robust. See also L<iCOW>
+Generally make ithreads more robust. See also L</iCOW>
This task is incremental - even a little bit of work on it will help, and
will be greatly appreciated.
projects / p5sagit/p5-mst-13.2.git / blobdiff