I remember fixing another PPC atomics.hpp issue a while ago, I'll look at it tonight. Where can I read about running the tests? I've not played with that before. -- Tack ---- Original message ----

Date: Tue, 21 Aug 2007 21:33:30 +0200 From: Ion Gaztañaga <igaztanaga@gmail.com> Subject: Re: [boost] [Interprocess] barrier_test hanging on Apple PowerPC To: "boost@lists.boost.org" <boost@lists.boost.org>

Doug Gregor wrote:

...

The problem only seems to occur on PowerPC Mac, because the test is running fine on my Intel Mac. There's a gdb dump of the backtraces for all running threads below.

Removed from SVN.

The main problem is that Mac does not have process-shared barrier/mutexes/condition variables and an emulation using spinlocks is used. Since my knowledge about atomic operations is *zero* my implementation of interprocess_condition might be wrong or just the atomic operations I'm using are not correctly implemented.

I guess I should ask Boost thread-experts (Boost.Thread maintainers willing to help?) to write these synchronization primitives for me or/and beg for a simple atomic operation package in Boost. At least some that implement increment, cas, decrement, atomic read and read (full barrier semantics are enough for me, I just don't understand what acquire and release are ;-) ).

The implementation of the emulated barrier is pretty simple:

inline barrier::barrier(unsigned int count) : m_threshold(count), m_count(count), m_generation(0) { if (count == 0) throw std::invalid_argument("count cannot be zero."); }

inline bool barrier::wait() { scoped_lock<interprocess_mutex> lock(m_mutex); unsigned int gen = m_generation;

if (--m_count == 0){ m_generation++; m_count = m_threshold; m_cond.notify_all(); return true; }

while (gen == m_generation){ m_cond.wait(lock); } return false; }

so I guess there is problem with my emulated condition implementation or with atomic operations (which are taken from apache run-time library).

Regards,

Ion _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/ boost