Support for multiprocessing broken in python3.1

please recheck with 3.1.2+20100915-0ubuntu1 when the package is built and in the archive

Just checked, I am afraid it's still there.

$ apt-cache policy python3.1python3.1:
  Installed: 3.1.2+20100915-0ubuntu1
  Candidate: 3.1.2+20100915-0ubuntu1
  Version table:
 *** 3.1.2+20100915-0ubuntu1 0
        500 http://archive.ubuntu.com/ubuntu/ maverick/main amd64 Packages
        100 /var/lib/dpkg/status

On 15.09.2010 21:45, Daniele Pighin wrote:
> Just checked, I am afraid it's still there.

do you have a test case which you could attach?

I am attaching a test case (straight from python documentation).

comparing a python3.1 build from sid with one on maverick, same thing when comparing the pyconfig.h from a local build with one from the buildd (both maverick):

--- pyconfig.h.sid 2010-09-09 20:11:48.000000000 +0200
+++ pyconfig.h.mav 2010-07-08 12:19:45.000000000 +0200
@@ -34,9 +34,6 @@
 /* Define if --enable-ipv6 is specified */
 #define ENABLE_IPV6 1

-/* Define if flock needs to be linked with bsd library */
-/* #undef FLOCK_NEEDS_LIBBSD */
-
 /* Define if getpgrp() must be called as getpgrp(0). */
 /* #undef GETPGRP_HAVE_ARG */

@@ -94,7 +91,7 @@
 /* #undef HAVE_BROKEN_PTHREAD_SIGMASK */

 /* define to 1 if your sem_getvalue is broken. */
-/* #undef HAVE_BROKEN_SEM_GETVALUE */
+#define HAVE_BROKEN_SEM_GETVALUE 1

 /* Define this if you have the type _Bool. */
 #define HAVE_C99_BOOL 1
@@ -906,7 +903,7 @@
 /* #undef PACKAGE_VERSION */

 /* Define if POSIX semaphores aren't enabled on your system */
-/* #undef POSIX_SEMAPHORES_NOT_ENABLED */
+#define POSIX_SEMAPHORES_NOT_ENABLED 1

 /* Defined if PTHREAD_SCOPE_SYSTEM supported. */
 #define PTHREAD_SYSTEM_SCHED_SUPPORTED 1

same for lucid :-(

the general issue is that kernel features are checked at build time with a kernel which has nothing to do with the kernel of the release the package is built for.

the configure checks:

# Multiprocessing check for broken sem_getvalue
AC_MSG_CHECKING(for broken sem_getvalue)
AC_TRY_RUN([
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <semaphore.h>
#include <sys/stat.h>

int main(void){
  sem_t *a = sem_open("/autocftw", O_CREAT, S_IRUSR|S_IWUSR, 0);
  int count;
  int res;
  if(a==SEM_FAILED){
    perror("sem_open");
    return 1;

  }
  res = sem_getvalue(a, &count);
  sem_close(a);
  sem_unlink("/autocftw");
  return res==-1 ? 1 : 0;
}
]
,AC_MSG_RESULT(no),
 if test x`lsb_release -sc` = xlucid; then
 AC_MSG_RESULT(no)
 else
 AC_MSG_RESULT(yes)
  AC_DEFINE(HAVE_BROKEN_SEM_GETVALUE, 1, define to 1 if your sem_getvalue is broken.)
 fi
)

# For multiprocessing module, check that sem_open
# actually works. For FreeBSD versions <= 7.2,
# the kernel module that provides POSIX semaphores
# isn't loaded by default, so an attempt to call
# sem_open results in a 'Signal 12' error.
AC_MSG_CHECKING(whether POSIX semaphores are enabled)
AC_CACHE_VAL(ac_cv_posix_semaphores_enabled,
AC_TRY_RUN([
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <semaphore.h>
#include <sys/stat.h>

int main(void) {
  sem_t *a = sem_open("/autoconf", O_CREAT, S_IRUSR|S_IWUSR, 0);
  if (a == SEM_FAILED) {
    perror("sem_open");
    return 1;
  }
  sem_close(a);
  sem_unlink("/autoconf");
  return 0;
}
], ac_cv_posix_semaphores_enabled=yes,
   ac_cv_posix_semaphores_enabled=no,
   ac_cv_posix_semaphores_enabled=yes)
)
if test x`lsb_release -sc` = xlucid; then
  ac_cv_posix_semaphores_enabled=yes
fi
AC_MSG_RESULT($ac_cv_posix_semaphores_enabled)
if test $ac_cv_posix_semaphores_enabled = no
then
  AC_DEFINE(POSIX_SEMAPHORES_NOT_ENABLED, 1,
            [Define if POSIX semaphores aren't enabled on your system])
fi

how do we know that other packages are affected?

when building a package for release N, the buildd should really run the kernel of release N-1

This bug was fixed in the package python3.1 - 3.1.2+20100915-0ubuntu2

---------------
python3.1 (3.1.2+20100915-0ubuntu2) maverick; urgency=low

  * Assume working semaphores, don't rely on running kernel for the check.
    LP: #630511.
 -- Matthias Klose <email address hidden> Thu, 16 Sep 2010 15:19:45 +0200

I can confirm that with the current build I am no longer experiencing the problem.

python3.1:
  Installed: 3.1.2+20100915-0ubuntu3
  Candidate: 3.1.2+20100915-0ubuntu3
  Version table:
 *** 3.1.2+20100915-0ubuntu3 0
        500 http://archive.ubuntu.com/ubuntu/ maverick/main amd64 Packages
        100 /var/lib/dpkg/status

Thanks!

Is there any progress with this bug?

As far as I can say (and I had written in my reply on Sept. 17 2010) the bug
is fixed.

 Daniele

On Sun, Jan 23, 2011 at 11:48 AM, Sardorbek Pulatov (pROCKrammer) <
<email address hidden>> wrote:

> Is there any progress with this bug?
>
>

Any testers of the lucid-proposed package? As this has been in -proposed for about four months, I'll remove the proposed package soon if there is no feedback. Thank you!

Upgrade the following packages:
python3.1-minimal [3.1.2-0ubuntu2 (lucid, now) -> 3.1.2-0ubuntu3
(lucid-proposed)]

Score is 81

Accept this solution? [Y/n/q/?]
The following packages will be upgraded:
  python3.1 python3.1-minimal
2 packages upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 5,303kB of archives. After unpacking 0B will be used.
Do you want to continue? [Y/n/?]
Writing extended state information... Done
Get:1 http://archive.ubuntu.com/ubuntu/ lucid-proposed/main python3.1 3.1.2-0ubuntu3 [3,760kB]
Get:2 http://archive.ubuntu.com/ubuntu/ lucid-proposed/main python3.1-minimal 3.1.2-0ubuntu3 [1,543kB]
Fetched 5,303kB in 8s (643kB/s)
(Reading database ... 47982 files and directories currently installed.)
Preparing to replace python3.1 3.1.2-0ubuntu2 (using .../python3.1_3.1.2-0ubuntu3_amd64.deb) ...
Unpacking replacement python3.1 ...
Preparing to replace python3.1-minimal 3.1.2-0ubuntu2 (using .../python3.1-minimal_3.1.2-0ubuntu3_amd64.deb) ...
Unpacking replacement python3.1-minimal ...
Processing triggers for man-db ...
Setting up python3.1-minimal (3.1.2-0ubuntu3) ...

Setting up python3.1 (3.1.2-0ubuntu3) ...

Reading package lists... Done
Building dependency tree
Reading state information... Done
Reading extended state information
Initializing package states... Done

Current status: 0 updates [-2].
root@spindrift[/etc/apt:54]% python3.1 -c "import multiprocessing; multiprocessing.Pool()"
root@spindrift[/etc/apt:55]% python3.1
Python 3.1.2 (r312:79147, Sep 27 2010, 09:57:50)
[GCC 4.4.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import multiprocessing
>>> multiprocessing.Pool()
<multiprocessing.pool.Pool object at 0x12806d0>
>>>

Thanks for testing!

This bug was fixed in the package python3.1 - 3.1.2-0ubuntu3

---------------
python3.1 (3.1.2-0ubuntu3) lucid-proposed; urgency=low

  * Assume working semaphores, don't rely on running kernel for the check.
    LP: #630511.
  * Disable test_threading test on powerpc, which fail on the buildds.
 -- Matthias Klose <email address hidden> Mon, 20 Sep 2010 14:31:19 +0200