python2/python3: fix multiprocessing.BoundedSemaphore not work on qemux86/qemuarm
In upstream, the following commit:
https://github.com/python/cpython/commit/
e711cafab13efc9c1fe6c5cd75826401445eb585
...
commit
e711cafab13efc9c1fe6c5cd75826401445eb585
Author: Benjamin Peterson <benjamin@python.org>
Date: Wed Jun 11 16:44:04 2008 +0000
Merged revisions 64104,64117 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk
...
(see diff in setup.py)
It assigned libraries for multiprocessing module according
the host_platform, but not pass it to Extension.
In glibc, the following commit caused two definition of
sem_getvalue are different.
https://sourceware.org/git/?p=glibc.git;a=commit;h=
042e1521c794a945edc43b5bfa7e69ad70420524
(see diff in nptl/sem_getvalue.c for detail)
`__new_sem_getvalue' is the latest sem_getvalue@@GLIBC_2.1
and `__old_sem_getvalue' is to compat the old version
sem_getvalue@GLIBC_2.0.
If not explicitly link to library pthread (-lpthread), it will
load glibc's sem_getvalue randomly at runtime.
Such as build python on linux x86_64 host and run the python
on linux x86_32 target. If not link library pthread, it caused
multiprocessing bounded semaphore could not work correctly.
...
>>> import multiprocessing
>>> pool_sema = multiprocessing.BoundedSemaphore(value=1)
>>> pool_sema.acquire()
True
>>> pool_sema.release()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ValueError: semaphore or lock released too many times
...
And the semaphore issue also caused multiprocessing.Queue().put() hung.
Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
