• Daniele Sciascia's avatar
    MDEV-19803 Long semaphore wait error on galera.MW-388 · 7d313214
    Daniele Sciascia authored
    The long semaphore wait appeared to be the caused by the following
    pattern in the MTR test:
    
    ```
    SET DEBUG_SYNC = "now SIGNAL wsrep_after_certification_continue";
    SET DEBUG_SYNC = "now SIGNAL signal.wsrep_apply_cb;
    ```
    
    Raising two signals, one right after another, caused one signal to
    overwrite the other, before the signal was consumed by the thread.
    This caused one thread to be stuck until the debug sync point would
    timeout.
    7d313214
MW-388.result 1.18 KB