https://svn.boost.org/trac10/ticket/1231 <p> This bug has manifested itself in barrier_test execution on Mac OS (PPC) machines, where POSIX is not sufficiently implemented to support barriers at the kernel level. The [source:trunk/boost/interprocess/sync/emulation@39114 emulated synchronization primitives] are a basic implementation of the necessary primitives, based on spin-locks. Barriers are implemented by having [source:trunk/boost/interprocess/sync/emulation/interprocess_barrier.hpp@39114#L32 m_count] threads wait on a condition variable. When the [source:trunk/boost/interprocess/sync/emulation/interprocess_barrier.hpp@39114#L32 m_count'th] thread arrives, all threads are notified by a call to [source:trunk/boost/interprocess/sync/emulation/interprocess_condition.hpp@39114#L35 interprocess_condition::notify_all()]. </p> <p> The problem has been thus-far reduced to incorrect handling of entry/exit conditions in [source:trunk/boost/interprocess/sync/emulation/interprocess_condition.hpp@39114#L79 interprocess_condition::do_timed_wait()]. Additionally, when [source:trunk/libs/interprocess/test/barrier_test.cpp@38329 barrier_test] is run with a small number of threads (such as [source:trunk/libs/interprocess/test/barrier_test.cpp@38329#L32 N_THREADS]=2), and the help of std::cout, we can more easily see that one thread never completely enters the condition variable, or concurrency problems are causing std::cout calls to be useless. </p> <p> A final note: it appears that Mac OS supports the pthread condition variable. It may be worth allowing the test to run on Mac OS X PPC by using this primitive (known to work). This workaround does not close this ticket, but would solve the problem on that platform and be a valuable optimization. </p> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/1231 Trac 1.4.3 atack2@… Tue, 04 Sep 2007 16:41:33 GMT https://svn.boost.org/trac10/ticket/1231#comment:5 https://svn.boost.org/trac10/ticket/1231#comment:5 <ul> <li><strong>status</strong> <span class="trac-field-old">new</span> → <span class="trac-field-new">closed</span> </li> <li><strong>resolution</strong> → <span class="trac-field-new">fixed</span> </li> </ul> <p> All PPC regressions were failing so I started revising the only platform-dependent file related to interprocess_condition. A bit of intuition and a lot of work ;-) </p> Ticket atack2@… Wed, 02 Jan 2008 06:14:38 GMT