Each of these is explained in further detail below.
-B<NOTE>: starting from the release 5.6.0 Perl will use a version
+B<NOTE>: starting from the release 5.6.0, Perl will use a version
scheme where even-numbered subreleases (like 5.6) are stable
maintenance releases and odd-numbered subreleases (like 5.7) are
unstable development releases. Development releases should not be
a perl that will be binary compatible with the 5.005 release.
However, if you run Configure with any custom options, such as
--Dusethreads, -Dusemultiplicity, -Dusemymalloc, -Ubincompat5005 etc.,
+-Dusethreads, -Dusemultiplicity, -Dusemymalloc, etc.,
the resulting perl will not be binary compatible. Under these
circumstances, if you have dynamically loaded extensions that were
built under perl 5.005, you will need to rebuild and reinstall all
=head2 Selecting File IO mechanisms
-Previous versions of perl used the standard IO mechanisms as defined in
-stdio.h. Versions 5.003_02 and later of perl allowed alternate IO
-mechanisms via a "PerlIO" abstraction, but the stdio mechanism is still
-the default and is the only supported mechanism.
+Executive summary: in Perl 5.8, you should use the default "PerlIO"
+as the IO mechanism unless you have a good reason not to.
-Starting from Perl 5.8 the default mechanism is to use the PerlIO
+In more detail: previous versions of perl used the standard IO
+mechanisms as defined in stdio.h. Versions 5.003_02 and later of perl
+introduced alternate IO mechanisms via a "PerlIO" abstraction, but up
+until and including Perl 5.6, the stdio mechanism was still the default
+and the only supported mechanism.
+
+Starting from Perl 5.8, the default mechanism is to use the PerlIO
abstraction, because it allows better control of I/O mechanisms,
instead of having to work with (often, work around) vendors' I/O
implementations.
-This PerlIO abstraction can be disabled either on the Configure
-command line with
+This PerlIO abstraction can be (but again, unless you know what you
+are doing, should not be) disabled either on the Configure command
+line with
sh Configure -Uuseperlio
=item -DPERL_POLLUTE_MALLOC
-NOTE: This flag is enabled automatically on some platforms if you
-asked for binary compatibility with version 5.005, or if you just
-run Configure to accept all the defaults on those platforms. You
-can refuse the automatic binary compatibility flags wholesale by
-running:
-
- sh Configure -Ubincompat5005
-
-or by answering 'n' at the appropriate prompt.
+NOTE: This flag is enabled automatically on some platforms if you just
+run Configure to accept all the defaults on those platforms.
Perl's malloc family of functions are called Perl_malloc(),
Perl_realloc(), Perl_calloc() and Perl_mfree(). When this flag is
Several tests in the test suite check timing functions, such as
sleep(), and see if they return in a reasonable amount of time.
-If your system is quite busy and doesn't return quickly enough,
-these tests might fail. If possible, try running the tests again with
-the system under a lighter load. These tests include F<t/op/alarm.t>,
-F<ext/Time/HiRes/HiRes.t>, and F<lib/Benchmark.t>.
+If your system is quite busy and doesn't respond quickly enough,
+these tests might fail. If possible, try running the tests again
+with the system under a lighter load. These timing-sensitive
+and load-sensitive tests include F<t/op/alarm.t>,
+F<ext/Time/HiRes/HiRes.t>, F<lib/Benchmark.t>,
+F<lib/Memoize/t/expmod_t.t>, and F<lib/Memoize/t/speed.t>.
=item Out of memory
=head1 Coexistence with earlier versions of perl5
+Perl 5.8 is not binary compatible with earlier versions of Perl.
+In other words, you have to recompile your XS modules.
+
In general, you can usually safely upgrade from one version of Perl (e.g.
5.004_04) to another similar version (e.g. 5.004_05) without re-compiling
all of your add-on extensions. You can also safely leave the old version
projects / p5sagit/p5-mst-13.2.git / blobdiff