[boost] [Interprocess] message_queue should use timed_lock

Subject: [boost] [Interprocess] message_queue should use timed_lock
From: Hartmut Kaiser (hartmut.kaiser_at_[hidden])
Date: 2012-12-05 14:23:49

Hey,

I'm running into a timing issue with interprocess::message_queue even when I
use the timed send and received functions:

One end:

    if (!mq_->timed_receive(&msg, sizeof(msg), recvd_size, priority,
        boost::get_system_time() + boost::posix_time::milliseconds(1)))
    {
        // ...
        return false;
    }
    // ...

The other end:

    while (!mq_->timed_send(&msg, sizeof(msg), 0,
           boost::get_system_time() + boost::posix_time::milliseconds(1)))
    {
        break;
    }

(mq_ is a shared_ptr<message_queue>)

here both ends sit forever inside the timed_receive/timed_send function,
both waiting to acquire a lock (ipc/message_queue.hpp, lines 702 and 799),
which is held by a third participating process. Shouldn't this lock be using
a timed_lock to allow to maintain the API post condition (i.e. returning
after the given amount of time in any case)?

Regards Hartmut
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