[Lldb-commits] [PATCH] Skip lldb-mi tests on FreeBSD for now

Ed Maste emaste at freebsd.org
Wed Feb 18 10:38:17 PST 2015

In http://reviews.llvm.org/D7727#125670, @zturner wrote:

> Of course, the correct way to deal with this is to prioritize finding and
>  fixing the underlying race conditions. Presumably they affect not just
>  FreeBSD.

Indeed. On FreeBSD we often encounter threading issues earlier or more often than other platforms, for two reasons.

First, our thread library places stricter demands on POSIX compliance of consumers. For example, `pthread_rwlock_wrlock` and `pthread_rwlock_unlock` must be called from the same thread, but this was originally violated by LLDB. In practice it seemed to work on OS X and Linux, but did not on FreeBSD (which returns EINVAL from the unlock).

Second, we seem to have wider race windows in certain cases due to differences in scheduling or preemption. Issues that show up under these conditions will also happen on other platforms, perhaps just less frequently.



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