前几天有一SuperSocket用户报在Linux上面性能日志的各个参数都是0, 由于SuperSocket的性能日志是通过PerformanceCounter实现的，于是我暂时怀疑Mono中的PerformanceCounter在Linux上不被支持。我自己也上Linux上跑了一下，确实有这个问题，performance counter的value都是0. 当时的获取PerformanceCounter的代码如下:

Process process = Process.GetCurrentProcess();

m_CpuUsagePC = new PerformanceCounter("Process", "% Processor Time", process.ProcessName);
m_ThreadCountPC = new PerformanceCounter("Process", "Thread Count", process.ProcessName);
m_WorkingSetPC = new PerformanceCounter("Process", "Working Set", process.ProcessName);

上面这段代码在Windows上是可以取到正确的值的。

Linux上真的不支持PerformanceCounter吗？遍寻网络，唯独只发现Mono网站上有一篇关于PerformanceCounter的权威文章:

http://www.mono-project.com/Mono_Performance_Counters, 上面并没有说PerformanceCounter在Linux上不被支持，网上其它地方也没有找到类似的陈述。

后来又有兄弟说Mono/Linux有个工具可以监控进程的性能，而且他已经在Linux上正常运行了。于是乎我看稍微看了下这个工具的源代码，发现他确实是用PerformanceCounter来获取性能参数的。然后我就尝试在Linux上使用PerformanceCounterCategory来获取intanceName。测试代码如下：

var category = new PerformanceCounterCategory("Process");

foreach(var instance in category.GetInstanceNames())
{
       Console.WriteLine(instance);    
}

运行结果令我大惊:

Linux上PerformanceCounter的instanceName是"ID/NAME"格式的，难怪取出来都是0。

于是我修改SuperSocket获取性能参数的代码为：

var isUnix = Environment.OSVersion.Platform == PlatformID.Unix || Environment.OSVersion.Platform == PlatformID.MacOSX;
var instanceName = isUnix ? string.Format("{0}/{1}", process.Id, process.ProcessName) : process.ProcessName;

m_CpuUsagePC = new PerformanceCounter("Process", "% Processor Time", instanceName);
m_ThreadCountPC = new PerformanceCounter("Process", "Thread Count", instanceName);
m_WorkingSetPC = new PerformanceCounter("Process", "Working Set", instanceName);

在Linux上验证一下:

果然全都拿到了, 大功告成!