线程守卫
此类仅在Java中可用
ThreadGuard检查是否仅从创建驱动程序的同一线程中调用了驱动程序.
线程问题 (尤其是在Parallel中运行测试时)
可能遇到神秘并且难以诊断错误.
使用此包装器可以防止此类错误,
并且在发生此类情况时会抛出异常.
以下的示例模拟一种线程冲突的情况:
public class DriverClash {
//thread main (id 1) created this driver
private WebDriver protectedDriver = ThreadGuard.protect(new ChromeDriver());
static {
System.setProperty("webdriver.chrome.driver", "<Set path to your Chromedriver>");
}
//Thread-1 (id 24) is calling the same driver causing the clash to happen
Runnable r1 = () -> {protectedDriver.get("https://selenium.dev");};
Thread thr1 = new Thread(r1);
void runThreads(){
thr1.start();
}
public static void main(String[] args) {
new DriverClash().runThreads();
}
}
结果如下所示:
Exception in thread "Thread-1" org.openqa.selenium.WebDriverException:
Thread safety error; this instance of WebDriver was constructed
on thread main (id 1)and is being accessed by thread Thread-1 (id 24)
This is not permitted and *will* cause undefined behaviour
正如示例所示:
protectedDriver将在主线程中创建- 我们使用Java的
Runnable启动一个新进程, 并使用一个新的Thread运行该进程 - 这两个
Thread都会发生冲突, 因为主线程的内存中没有protectedDriver ThreadGuard.protect会抛出异常
注意:
这不能代替并发运行时使用 ThreadLocal 管理驱动程序的需求.
