vs-threading | xplat library | Architecture library

In short, you can't :(

Dotnet-trace uses a sampling profiler implemented in the .NET runtime. The profiler runs in a separate thread in the application and collects call stack frames of managed threads every few milliseconds. In contrary to most CPU profilers, it collects call stacks even for threads that are waiting. So, by looking at call stacks, you could estimate the waiting time for a managed thread. For example, in the picture below, we may see a managed thread waiting for about 686 ms on a ManualResetEvent.

Of course, this is only an estimate and depends on the sampling interval. You may also enable the CLR ThreadPool events and/or the TplEventSource provider to get events describing the inner-working of the thread pool and TPL.

Now, for the BLOCKED_TIME metric in PerfView. It is based on Context Switch ETW events. You enable them with the 'Thread Time' checkbox in the PerfView collection dialog:

These events are emitted by the system scheduler/dispatcher when a new thread starts running on a CPU. They allow us to measure threads' waiting/running times accurately, but they are also very voluminous.

When you execute a fork you create a copy of the process you are executing with a different PID the variables declared before the fork() execution will appear in both processes. fork returns 0 in the "child" process and returns the pid of the "child" process in the "parent" process (with a switch, you can control the behavior of both processes).

If you want to communicate different processes created by fork() you can declare BEFORE an array of file descriptors such as int fd[2] and execute pipe(fd). If the result of pipe isn't -1, means you have created two "cables" where you can write or read information.

Here you can see an example on how this can work