Bugs item #1106262, was opened at 2005-01-20 11:55 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1106262&group_id=5470
Category: None Group: None Status: Open Resolution: None Priority: 5 Submitted By: The Written Word (Albert Chin) (tww-china) Assigned to: Nobody/Anonymous (nobody) Summary: semaphore errors from Python 2.3.x on AIX 5.2 Initial Comment: Newer versions of the AIX 5.2 libc implement POSIX semaphores and thus define _POSIX_SEMAPHORES in <unistd.h>. However, when building Python 2.3.x (and I'm sure any other version with sem_init()), a few semaphore errors are encountered: building 'pcre' extension ./Modules/ld_so_aix gcc -bI:Modules/python.exp -L/opt/TWWfsw/python232/lib/support -Wl,-brtl -Wl,-blibpath:/opt/TWWfsw/python232/lib/support:/usr/lib build/temp.aix-5.2-2.3/pcremodule.o build/temp.aix-5.2-2.3/pypcre.o -L/opt/TWWfsw/python232/lib -o build/lib.aix-5.2-2.3/pcre.so sem_trywait: Permission denied sem_wait: Permission denied sem_post: Permission denied I ran the Python process under truss and saw that the sem_init() from Python/thread_pthread.h worked successfully. fork() was then called and a sem_trywait() operation (probably from PyThread_acquire_lock()) was called. From the sem_init() man page (http://publib.boulder.ibm.com/infocenter/pseries/index.jsp?topic=/com.ibm.aix.doc/libs/basetrf2/sem_init.htm): If the pshared parameter has a nonzero value, the semaphore is shared between processes. In this case, any process that can access the sem parameter can use it for performing sem_wait, sem_trywait, sem_post, and sem_destroy operations. Only the sem parameter itself may be used for performing synchronization. If the pshared parameter is zero, the semaphore is shared between threads of the process. Any thread in this process can use the sem parameter for performing sem_wait, sem_trywait, sem_post, and sem_destroy operations. The use of the semaphore by threads other than those created in the same process returns an error. Setting the 2nd value of sem_init to 1 (was 0) solved the problem. However, I don't know if this is wise for security. Another solution is to set HAVE_BROKEN_POSIX_SEMAPHORES for "AIX/5" like for "SunOS/5.8". ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1106262&group_id=5470 _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
