hdf5_der

[svn-r19739] Purpose:

    Adjust flush/refresh tests to allow more time 
    for completion, and fix a bug that caused a 
    race condition between the test script and a 
    process it invokes.

Description:

    Flush/refresh testing slows down considerably
    with multiple (other) processes running in the 
    background, such as the case when -j option is
    supplied to gmake when running the test suite. 
    I've extended the amount of time before the test 
    times out due to not receiving a signal, and 
    modified the script so that the timer now resets 
    after receiving a signal so it is not a cumulative 
    timer for the entire test, but rather only per 
    verification process that the script needs to spawn.

    Additionally, I changed the way the test script
    detected that a signal from a process was ready by
    changing detection from 'file exists' to 'non-empty
    file exists'.

    This test may need to undergo further tweaking once 
    we get a feeling for how well it currently runs in 
    a number of different scenarios, particularly with 
    regards to how the script and the processes it spawns
    communicate with each other.

Tested:

    amani, using 'gmake -j 8 check'.
    h5committest