我有一个使用 NUnit加载的Selenium Test .DLL 。
在运行测试时，我运行了一个隐藏在进程中的所需Selenium Java Server。
但是，我目前在测试开始时启动服务器，在测试停止时启动服务器。Kill()
这会导致 selenium 服务器为每个 test 启动/停止。
我想要的是 Selenium Server 进程：
- 在DLL 加载/初始化或第一次测试开始时启动
- 了解
Kill()DLL死亡或垃圾收集
我读到 C# 不支持捕获 DLL 初始化和调用代码。（我错了吗？）
我的想法是将 Selenium 服务器托管在一个单例类中，并在第一次测试运行时对其进行初始化。然后，我会将其留给垃圾收集以通过解构函数调用 Dispose 方法。我目前有以下代码来托管 selenium 服务器：
namespace Tests.Server
{
using System;
using System.Diagnostics;
using System.IO;
using System.Security;
using System.Windows.Forms;
using Microsoft.Win32;
/// <summary>
/// A singleton class to host and control the selenium server.
/// </summary>
public class SeleniumServer : IDisposable
{
#region Fields
/// <summary>
/// The singleton instance
/// </summary>
private static volatile SeleniumServer instance;
/// <summary>
/// An object to perform double-check locking upon instance creation to
/// avoid dead-locks.
/// See <see href="SeleniumServer.Instance"/> for more information.
/// </summary>
private static object syncRoot = new Object();
/// <summary>
/// The current selenium server.
/// </summary>
private Process seleniumServer = null;
/// <summary>
/// A flag for the disposal of the class.
/// </summary>
private bool isDisposed = false;
#endregion
#region Constructor
/// <summary>
/// Initializes a new instance of the SeleniumServer class. Starts the
/// Selenium Java server in a background hidden thread.
/// </summary>
private SeleniumServer()
{
// Get the java install folder.
string javaFileLocation = this.GetJavaFileLocation();
// Get the selenium server java executable
string jarFileLocation = '"' + Directory.GetCurrentDirectory() + @"\SeleniumServer\selenium-server.jar""";
// Start the selenium server
seleniumServer = new Process();
seleniumServer.StartInfo.FileName = javaFileLocation;
seleniumServer.StartInfo.Arguments = " -jar " + jarFileLocation + " -browserSessionReuse -trustAllSSLCertification";
seleniumServer.StartInfo.WorkingDirectory = jarFileLocation.Substring(0, jarFileLocation.LastIndexOf("\\"));
seleniumServer.StartInfo.UseShellExecute = true;
seleniumServer.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
seleniumServer.Start();
}
#endregion
#region Deconstructor
~SeleniumServer()
{
Dispose(false);
}
#endregion
#region Properties
/// <summary>
/// A thread safe
/// </summary>
public static SeleniumServer Instance
{
get
{
// This approach ensures that only one instance is created and
// only when the instance is needed. Also, the variable is
// declared to be volatile to ensure that assignment to the
// instance variable completes before the instance variable can
// be accessed. Lastly, this approach uses a syncRoot instance
// to lock on, rather than locking on the type itself, to avoid
// deadlocks.
// This double-check locking approach solves the thread
// concurrency problems while avoiding an exclusive lock in
// every call to the Instance property method. It also allows
// you to delay instantiation until the object is first
// accessed. In practice, an application rarely requires this
// type of implementation. In most cases, the static
// initialization approach is sufficient.
if (instance == null)
{
lock (syncRoot)
{
if (instance == null)
{
instance = new SeleniumServer();
}
}
}
return instance;
}
}
#endregion
#region Methods
/// <summary>
/// Stops the process.
/// </summary>
protected void Dispose(bool disposing)
{
if (disposing)
{
// Code to dispose the managed resources of the class
// Not needed right now.
}
// Code to dispose the un-managed resources of the class
// TODO: Handle the exceptions
Instance.seleniumServer.Kill();
// All done!
isDisposed = true;
}
/// <summary>
/// Dispose of the class and stop the Selenium server process.
/// </summary>
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
/// <summary>
/// Stops the Selenium Server.
/// </summary>
public void Stop()
{
this.Dispose();
}
/// <summary>
/// Attempts to get the Java installation folder from the registry. If
/// it cannot be found the default installation folder is checked before
/// failing.
/// </summary>
/// <returns>The Java executable file path.</returns>
/// <exception cref="System.Exception">
/// Thrown when the user does not have permission to access the
/// registry.
/// </exception>
/// <exception cref="System.ObjectDisposedException">
/// Thrown if the registry key object is disposed of.
/// </exception>
/// <exception cref="System.IOException">
/// Thrown if the registry key object is marked for deletion.
/// </exception>
private string GetJavaFileLocation()
{
string javaFileLocation = string.Empty;
RegistryKey regKey = Registry.LocalMachine;
RegistryKey subKey = null;
try
{
// Check for Java in the native bitness
string javaRegistryLocation = @"SOFTWARE\JavaSoft\Java Runtime Environment\";
subKey = regKey.OpenSubKey(javaRegistryLocation);
// Check if we are running in WOW64 and only 32 bit Java is installed.
if (subKey == null)
{
javaRegistryLocation = @"SOFTWARE\Wow6432Node\JavaSoft\Java Runtime Environment\";
subKey = regKey.OpenSubKey(javaRegistryLocation);
}
// If Java was not found in either of these location the user
// needs to install it. Note that Java 32 bit is a prerequisite
// for the installer so should always be installed.
if (subKey == null)
{
MessageBox.Show(
"You must have Java installed to run the commands server. This allows browser commands to be routed to the browser window.\n\nPlease visit: http://www.java.com/ to download.",
"Please Install Java",
MessageBoxButtons.OK,
MessageBoxIcon.Information);
throw new Exception("No installation of Java was detected to run the selenium server.");
}
// Get all the sub keys (could be multiple versions of Java
// installed) and get the most recent (last one)
string[] subKeyNames = subKey.GetSubKeyNames();
subKey = regKey.OpenSubKey(javaRegistryLocation + subKeyNames[subKeyNames.Length - 1]);
// Specify the java executable location
javaFileLocation = subKey.GetValue("JavaHome").ToString() + @"\bin\java.exe";
}
catch (SecurityException e)
{
// Attempt to find the java executable at the default location.
javaFileLocation = @"C:\Program Files\Java\jre6\bin\java.exe";
if (!File.Exists(javaFileLocation))
{
MessageBox.Show(
"The program did not have permission to access the registry to obtain the installation folder of Java.\n\nThe default location (" + javaFileLocation + ") of Java was used and the Java executable was not found.\n\nPlease install Java in this folder or see the help under the RegistryKey.OpenSubKey method on MSDN.",
"Java Executable Not Found",
MessageBoxButtons.OK,
MessageBoxIcon.Error);
throw new Exception("The program did not have permission to access the registry to obtain the installation folder of Java.", e);
}
}
catch (UnauthorizedAccessException e)
{
// Attempt to find the java executable at the default location.
javaFileLocation = @"C:\Program Files\Java\jre6\bin\java.exe";
if (!File.Exists(javaFileLocation))
{
MessageBox.Show(
"The user does not have the necessary registry rights to obtain the installation folder of Java.\n\nThe default location (" + javaFileLocation + ") of Java was used and the Java executable was not found.\n\nPlease install Java in this folder or see the help under the RegistryKey.OpenSubKey method on MSDN.",
"Java Executable Not Found",
MessageBoxButtons.OK,
MessageBoxIcon.Error);
throw new Exception("The user does not have the necessary registry rights to obtain the installation folder of Java.", e);
}
}
catch (ObjectDisposedException e)
{
// This hopefully shouldn't happen so ask the user to report it.
MessageBox.Show(
"The Java registry object was closed, resulting in the Java server not being started. Please report this error.",
"Error",
MessageBoxButtons.OK,
MessageBoxIcon.Error);
throw new ObjectDisposedException("The Java registry object was closed. Please report this error.", e);
}
catch (IOException e)
{
// This hopefully shouldn't happen so ask the user to report it.
MessageBox.Show(
"The Java registry object was marked for deletion, resulting in the Java server not being started. Please report this error.",
"Error",
MessageBoxButtons.OK,
MessageBoxIcon.Error);
throw new ObjectDisposedException("The Java registry object was marked for deletion. Please report this error.", e);
}
return javaFileLocation;
}
#endregion
}
}
我的问题是：
- 这是在 DLL 生命周期内托管进程的明智方法吗？
- 如何从我的代码中设置这个类？它需要静态/全局吗？您知道使用单例的任何好例子吗？
- 垃圾收集会在 DLL 卸载时处理这个单例吗？
- 我可以将进程作为我的 DLL 的子进程托管，即使 DLL 不会持续活动，因为 NUnit 只会在离散时间点执行 DLL 中的测试？