@Override
			public void run() {
				try {
					parse1(0, factory, sources, SHUFFLE_FILES_AT_START);
				} catch (InterruptedException ex) {
					Logger.getLogger(TestPerformance.class.getName()).log(Level.SEVERE, null, ex);
				}
			}
Number of parser threads to use.
tool-testsuite/test/org/antlr/v4/test/tool/TestPerformance.java