BOOST_THREAD_THROW_IF_PRECONDITION_NOT_SATISFIED should not be enabled by default

[Andrew Molyneux <andrew.molyneux@…>]

I just upgraded to Boost 1.52 on Windows using pre-built binaries and encountered a problem. Because BOOST_THREAD_THROW_IF_PRECONDITION_NOT_SATISFIED is enabled by default, any code that uses thread::join() will throw an exception if the target thread has already finished executing. Fortunately this was picked up by our unit tests, but the new behaviour could lead to intermittent race condition bugs that could be difficult to track down.

I've attached a patch (to be applied in libs/thread/build) which comments out the BOOST_THREAD_THROW_IF_PRECONDITION_NOT_SATISFIED defines in the jamfile. Failing that, could someone please explain to me why this feature is enabled by default? It seems like a recipe for disaster. For example, the fix for ticket #7668, which is attempting to work around a bug introduced by this feature, seems to introduce a race condition.

[Andrew Molyneux <andrew.molyneux@…>]

Stop enabling BOOST_THREAD_THROW_IF_PRECONDITION_NOT_SATISFIED by default

[viboes]

Yes, this is abug on 1.52. Version 1.53 lets all (almost all) the uses of BOOST_THREAD_THROW_IF_PRECONDITION_NOT_SATISFIED on the header files

E.g. the thread::join function is defined on boost/detail/thread.hpp as follows

    void thread::join() {
        if (this_thread::get_id() == get_id())
          boost::throw_exception(thread_resource_error(system::errc::resource_deadlock_would_occur, "boost thread: trying joining itself"));

        BOOST_THREAD_VERIFY_PRECONDITION( join_noexcept(),
            thread_resource_error(system::errc::invalid_argument, "boost thread: thread not joinable")
        );
    }

I will however comment the Jamfile.v2 line

<define>BOOST_THREAD_THROW_IF_PRECONDITION_NOT_SATISFIED

[Andrew Molyneux <andrew.molyneux@…>]

Thanks for the quick response Vicente! Glad to hear you're planning to change it. Have you looked at #7668 yet? I'm not sure if Trac notifies you when comments are added to a closed ticket, but I'm pretty sure your fix to thread_group::join_all() has a race condition.

[viboes]

Changeset [82436] by viboes

[viboes]

Committed revision 82491.