A question regarding LWLock in ProcSleep

/*     * Re-acquire the lock table's partition lock.  We have to do this to hold     * off cancel/die interrupts before we can mess with lockAwaited (else we     * might have a missed or duplicated locallock update).     */    LWLockAcquire(partitionLock, LW_EXCLUSIVE);
    /*     * We no longer want LockErrorCleanup to do anything.     */    lockAwaited = NULL;
    /*     * If we got the lock, be sure to remember it in the locallock table.     */    if (MyProc->waitStatus == STATUS_OK)        GrantAwaitedLock();
    /*     * We don't have to do anything else, because the awaker did all the     * necessary update of the lock table and MyProc.     */    return MyProc->waitStatus;