presto-main/src/main/java/io/prestosql/execution/resourcegroups/InternalResourceGroup.java/InternalResourceGroup/setSoftConcurrencyLimit
class InternalResourceGroup:    @Override
    public void setSoftConcurrencyLimit(int softConcurrencyLimit)
    {
        checkArgument(softConcurrencyLimit >= 0, "softConcurrencyLimit is negative");
        synchronized (root) {
            boolean oldCanRun = canRunMore();
            this.softConcurrencyLimit = softConcurrencyLimit;
            if (canRunMore() != oldCanRun) {
                updateEligibility();
            }
        }
    }