Hi Ben,
On 25/09/15 04:09, Ben Roberts wrote:
Hi list,
A colleague and I have noticed that the Perl easyblock forces inclusion of the
“-Dusethreads” compiler directive. This has caused us some difficulty in which
a package requiring threads, forks and MPI dies a gruesome death to do with
pthreads. An experimental build of Perl without “-Dusethreads” doesn’t exhibit
the same problem. We’re therefore looking at ways of using Easybuild to build a
non-threaded Perl, and can think of two options: removing “-Dusethreads” as a
default configuration option and allowing maintainers of easyconfig to add it
in within configopts, or adding an extra option with a corresponding new if
condition in the easyblock itself.
I would prefer the first option. Use of interpreter-based threads in Perl is
noted to be discouraged (http://perldoc.perl.org/threads.html), and the former
option will be easier for writers of new easyconfigs to implement insofar as
they won’t have to consult a strange custom option. However, removing
“-Dusethreads” as the default would affect backwards compatibility, so I was
interested in getting feedback before I commit to one option or the other.
Any thoughts or opinions on the subject?
Removing it from the easyblock and making people add it to 'configopts'
in their easyconfig files is one way, but is indeed backward incompatible.
A better way would be to introduce a new easyconfig parameter that is
specific to the Perl easyblock (for example, 'usethreads'), and have the
default set to True.
If you want to build Perl without it, you can simply add 'usethreads =
False' in your easyconfig file.
When stuff is hardcoded in easyblocks, it's mostly because of laziness
that there's no easyconfig parameter for it yet to turn it off...
Everybody happy: no backwards incompatible changes, and you get the
flexibility you need?
Quick and dirty (and untested), you need to add something like this to
the Perl easyblock:
from easybuild.framework.easyconfig import CUSTOM
...
class EB_Perl(ConfigureMake):
...
@staticmethod
def extra_options(extra_vars=None):
"""Extra easyconfig parameters specific to Perl easyblock."""
extra_vars = EasyBlock.extra_options(extra_vars)
extra_vars.update({
'usethreads': [True, "Configure with -Dusethreads
included", CUSTOM],
})
return extra_vars
...
def configure_step(self):
"""
Configure Perl build: run ./Configure instead of ./configure with
some different options
"""
configopts = [
self.cfg['configopts'],
'-Dcc="%s"' % os.getenv('CC'),
'-Dccflags="%s"' % os.getenv('CFLAGS'),
'-Dinc_version_list=none',
]
if self.cfg['usethreads']:
configopts.append("-Dusethreads")
cmd = './Configure -de %s -Dprefix="%s" ' % (' '.join(configopts),
self.installdir)
run_cmd(cmd, log_all=True, simple=True)
regards,
Kenneth
