TestInvocation

/**
	 * {@inheritDoc}
	 */
	@Override
	public void invoke(ITestDevice device, IConfiguration config, IRescheduler rescheduler) throws DeviceNotAvailableException, Throwable {
		try {
			mStatus = "fetching build";
			config.getLogOutput().init();
			getLogRegistry().registerLogger(config.getLogOutput());
			IBuildInfo info = null;
			if (config.getBuildProvider() instanceof IDeviceBuildProvider) {
				info = ((IDeviceBuildProvider) config.getBuildProvider()).getBuild(device);
			} else if (config.getBuildProvider() instanceof IDeviceConfigBuildProvider) {
				// 调用config获得cts.xml文件中的<build_provider>标签中对应的类,然后通过调用getBuild得到IBuildInfo对象
				info = ((IDeviceConfigBuildProvider) config.getBuildProvider()).getBuild(device, config);
			} else {
				info = config.getBuildProvider().getBuild();
			}
			if (info != null) {
				// System.out.println(String.format("setup: %s tearDown: %s",
				// config.getCommandOptions().isNeedPrepare(),
				// config.getCommandOptions().isNeedTearDown()));
				CLog.logAndDisplay(LogLevel.INFO,
						String.format("setup: %s tearDown: %s", config.getCommandOptions().isNeedPrepare(), config.getCommandOptions().isNeedTearDown()));
				// 获取<test>配置项里的测试选项,并注入到info中
				injectBuild(info, config.getTests());
				if (shardConfig(config, info, rescheduler)) {
					CLog.i("Invocation for %s has been sharded, rescheduling", device.getSerialNumber());
				} else {
					device.setRecovery(config.getDeviceRecovery());
					// 准备刷机,启动case
					performInvocation(config, device, info, rescheduler);
					// exit here, depend on performInvocation to deregister
					// logger
					return;
				}
			} else {
				mStatus = "(no build to test)";
				CLog.d("No build to test");
				rescheduleTest(config, rescheduler);
			}
		} catch (BuildRetrievalError e) {
			CLog.e(e);
			/*
			 * because this is BuildRetrievalError, so do not generate test
			 * result // report an empty invocation, so this error is sent to
			 * listeners startInvocation(config, device, e.getBuildInfo()); //
			 * don't want to use #reportFailure, since that will call
			 * buildNotTested for (ITestInvocationListener listener :
			 * config.getTestInvocationListeners()) {
			 * listener.invocationFailed(e); } reportLogs(device,
			 * config.getTestInvocationListeners(), config.getLogOutput());
			 * InvocationSummaryHelper.reportInvocationEnded(
			 * config.getTestInvocationListeners(), 0); return;
			 */
		} catch (IOException e) {
			CLog.e(e);
		}
		// save current log contents to global log
		getLogRegistry().dumpToGlobalLog(config.getLogOutput());
		getLogRegistry().unregisterLogger();
		config.getLogOutput().closeLog();
	}

之所以称为调度室，因为它就是去一步一步的运行9大组件的剩余组件，组件与组件之间并不知道对方的存在，只有TestInvocation自己知道。它通过反射的机制到的对象，别创建对象，然后调用其中的接口方法得到它想要的，然后再传给下一个组件。以上方法就可以看出，它先得到buildprovider对象。调用getBuild对象得到IBuildInfo对象。咱们这个程序中，其实就是调用了CtsBuildProvider的getBuild方法。

如果info不为null：然后给测试任务注入IBuildInfo，判断是否可以分拆任务，如果不能分拆的话，注册设备恢复类，然后跳转到performInvocation方法中。

如果info为null：提示没有可执行的build，调用IRescheduler.rescheduleCommand()重试。

/**
	 * Performs the invocation
	 *
	 * @param config
	 *            the {@link IConfiguration}
	 * @param device
	 *            the {@link ITestDevice} to use. May be <code>null</code>
	 * @param info
	 *            the {@link IBuildInfo}
	 */
	private void performInvocation(IConfiguration config, ITestDevice device, IBuildInfo info, IRescheduler rescheduler) throws Throwable {

		boolean resumed = false;
		long startTime = System.currentTimeMillis();
		long elapsedTime = -1;

		info.setDeviceSerial(device.getSerialNumber());
		startInvocation(config, device, info);
		try {
			device.setOptions(config.getDeviceOptions());
			// 准备build和跑case
			prepareAndRun(config, device, info, rescheduler);
		} catch (BuildError e) {
			CLog.w("Build %s failed on device %s. Reason: %s", info.getBuildId(), device.getSerialNumber(), e.toString());
			takeBugreport(device, config.getTestInvocationListeners(), BUILD_ERROR_BUGREPORT_NAME);
			reportFailure(e, config.getTestInvocationListeners(), config, info, rescheduler);
		} catch (TargetSetupError e) {
			CLog.e("Caught exception while running invocation");
			CLog.e(e);
			reportFailure(e, config.getTestInvocationListeners(), config, info, rescheduler);
			// maybe test device if offline, check it
			device.waitForDeviceOnline();
		} catch (DeviceNotAvailableException e) {
			// log a warning here so its captured before reportLogs is called
			CLog.w("Invocation did not complete due to device %s becoming not available. " + "Reason: %s", device.getSerialNumber(), e.getMessage());
			if ((e instanceof DeviceUnresponsiveException) && TestDeviceState.ONLINE.equals(device.getDeviceState())) {
				// under certain cases it might still be possible to grab a
				// bugreport
				takeBugreport(device, config.getTestInvocationListeners(), DEVICE_UNRESPONSIVE_BUGREPORT_NAME);
			}
			resumed = resume(config, info, rescheduler, System.currentTimeMillis() - startTime);
			if (!resumed) {
				reportFailure(e, config.getTestInvocationListeners(), config, info, rescheduler);
			} else {
				CLog.i("Rescheduled failed invocation for resume");
			}
			throw e;
		} catch (RuntimeException e) {
			// log a warning here so its captured before reportLogs is called
			CLog.w("Unexpected exception when running invocation: %s", e.toString());
			reportFailure(e, config.getTestInvocationListeners(), config, info, rescheduler);
			throw e;
		} catch (AssertionError e) {
			CLog.w("Caught AssertionError while running invocation: ", e.toString());
			reportFailure(e, config.getTestInvocationListeners(), config, info, rescheduler);
		} finally {
			mStatus = "done running tests";
			try {
				//
				reportLogs(device, config.getTestInvocationListeners(), config.getLogOutput());
				elapsedTime = System.currentTimeMillis() - startTime;
				if (!resumed) {
					// 发送报告
					InvocationSummaryHelper.reportInvocationEnded(config.getTestInvocationListeners(), elapsedTime);
				}

			} finally {
				config.getBuildProvider().cleanUp(info);
			}
		}
	}

首先启动所有监听器的start方法，起一个通知开始的作用。

/**
	 * Starts the invocation.
	 * <p/>
	 * Starts logging, and informs listeners that invocation has been started.
	 *
	 * @param config
	 * @param device
	 * @param info
	 */
	private void startInvocation(IConfiguration config, ITestDevice device, IBuildInfo info) {
		logStartInvocation(info, device);
		for (ITestInvocationListener listener : config.getTestInvocationListeners()) {
			try {
				listener.invocationStarted(info);
			} catch (RuntimeException e) {
				// don't let one listener leave the invocation in a bad state
				CLog.e("Caught runtime exception from ITestInvocationListener");
				CLog.e(e);
			}
		}
	}

然后得到device_options对象，设置到ITestDevice中。再调用prepareAndRun(config, device, info, rescheduler);方法。

private void prepareAndRun(IConfiguration config, ITestDevice device, IBuildInfo info, IRescheduler rescheduler) throws Throwable {
		// use the JUnit3 logic for handling exceptions when running tests
		Throwable exception = null;

		try {
			//
			if (config.getCommandOptions().isNeedPrepare()&&!isRepeat) {
				doSetup(config, device, info);
				//下次启动的时候,不再刷机
				isRepeat = true;
			}else{
				CLog.logAndDisplay(LogLevel.DEBUG, String.format("No need to flash,derect to run case"));
			}
			// 跑case
			runTests(device, info, config, rescheduler);
		} catch (Throwable running) {
			exception = running;
		} finally {
			try {
				if (config.getCommandOptions().isNeedTearDown()) {
					doTeardown(config, device, info, exception);
				}
			} catch (Throwable tearingDown) {
				if (exception == null) {
					exception = tearingDown;
				}
			}
		}
		if (exception != null) {
			throw exception;
		}
	}

在该方法中先得到根据cmd_options得到是否需要prepare，如果需要，就调用target_prepare类来做准备工作，如果不需要，直接调用runTests方法

private void runTests(ITestDevice device, IBuildInfo buildInfo, IConfiguration config, IRescheduler rescheduler) throws DeviceNotAvailableException {
		List<ITestInvocationListener> listeners = config.getTestInvocationListeners();
		for (IRemoteTest test : config.getTests()) {
			if (test instanceof IDeviceTest) {
				((IDeviceTest) test).setDevice(device);
			}
			test.run(new ResultForwarder(listeners));
		}
	}

上面的方法调用tests配置的类来追个调用里面的run方法启动测试。测试完成后，来做tearDown的工作。