From bad7e6a625436402a01d03021fb9ccd58bc9930f Mon Sep 17 00:00:00 2001 From: Alexander Kanavin Date: Thu, 9 Jan 2020 17:44:05 +0100 Subject: [PATCH] setup.py: pass missing libraries to Extension for multiprocessing module In the following commit: ... commit e711cafab13efc9c1fe6c5cd75826401445eb585 Author: Benjamin Peterson 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. To build python for embedded Linux systems: http://www.yoctoproject.org/docs/2.3.1/yocto-project-qs/yocto-project-qs.html 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 "", line 1, in ValueError: semaphore or lock released too many times ... And the semaphore issue also caused multiprocessing.Queue().put() hung. Upstream-Status: Pending Signed-off-by: Hongxu Jia Signed-off-by: Alexander Kanavin --- setup.py | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/setup.py b/setup.py index d92face..f42bcbb 100644 --- a/setup.py +++ b/setup.py @@ -1836,7 +1836,7 @@ class PyBuildExt(build_ext): if (sysconfig.get_config_var('HAVE_SEM_OPEN') and not sysconfig.get_config_var('POSIX_SEMAPHORES_NOT_ENABLED')): multiprocessing_srcs.append('_multiprocessing/semaphore.c') - self.add(Extension('_multiprocessing', multiprocessing_srcs, + self.add(Extension('_multiprocessing', multiprocessing_srcs, libraries=['pthread'], include_dirs=["Modules/_multiprocessing"])) if (not MS_WINDOWS and