[Bug 604753] Re: [eglibc] process shared mutex's fail on armel v7 (thumb)
I think this the issue has been fixed by #643171. I do not see this testcase failing using a recent (e)glibc and GCC. Could anyone of the original reporters check if it works for them? Please make sure that you use at least glibc 2.12.1-0ubuntu11 and GCC 4.5. -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to apr in ubuntu. https://bugs.launchpad.net/bugs/604753 Title: [eglibc] process shared mutex's fail on armel v7 (thumb) -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 604753] Re: [eglibc] process shared mutex's fail on armel v7 (thumb)
I had a quick look into the apr sources. Their locks/unix/proc_mutex.c can map the proc_mutex functionality to various methods: 1) Posix sem implemenation (see mutex_posixsem_methods) 2) SysV sem implementation (see mutex_sysv_methods) 3) pthread implementation (see mutex_proc_pthread_methods) 4) fcntl implementation(see mutex_fcntl_methods) 5) flock implementation(see mutex_flock_methods) I think only the pthread implemenation (3) is of interest here. The creation of the pthread_mutex happens at: locks/unix/proc_mutex.c:proc_mutex_proc_pthread_create that calls pthread_mutex_init with the following attributes: PTHREAD_PROCESS_SHARED, PTHREAD_MUTEX_ROBUST_NP, PTHREAD_PRIO_INHERIT The apr-phthread-mutex functionality relies on pthread_mutex_lock and pthread_mutex_trylock. The eglibc implemenation for such a mutex calls atomic_compare_and_exchange_val_acq (see also lll_lock/lll_trylock at ports/sysdeps/unix/sysv/linux/arm/nptl/lowlevellock.h) which goes down to __arch_compare_and_exchange_val_32_acq. Using (e)glibc (= 2.12.1-0ubuntu11) and GCC (=4.5) this expands to __sync_val_compare_and_swap (ports/sysdeps/unix/sysv/linux/arm/nptl/bits/atomic.h) which should be safe even on a SMP system. Some infos regarding the atomic memory operations can be found at: https://wiki.linaro.org/WorkingGroups/ToolChain/AtomicMemoryOperations#implementation%20details The next step would be to check whether the testcase fails using a decent GCC and eglibc (Ubuntu Natty for example). -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to apr in ubuntu. https://bugs.launchpad.net/bugs/604753 Title: [eglibc] process shared mutex's fail on armel v7 (thumb) -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 604753] Re: [eglibc] process shared mutex's fail on armel v7 (thumb)
I ran the testprocmutex test on a panda board using ubuntu natty alpha 2 and it passed: $ ./testall testprocmutex testprocmutex : SUCCESS All tests passed. $ apt-cache show libc6 gcc|grep Version Version: 4:4.5.1-1ubuntu3 Version: 2.12.1-0ubuntu16 -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to apr in ubuntu. https://bugs.launchpad.net/bugs/604753 Title: [eglibc] process shared mutex's fail on armel v7 (thumb) -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 604753] Re: [eglibc] process shared mutex's fail on armel v7 (thumb)
I ran the apr testsuite (svn revision 1071306) several times and I notice that the testlock:test_timeoutcond test fails sometimes because the timer returned to late. Not sure sure if this is related. -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to apr in ubuntu. https://bugs.launchpad.net/bugs/604753 Title: [eglibc] process shared mutex's fail on armel v7 (thumb) -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
