Cpp Multithreading [closed]

I Have three threads in my cpp program.

thread 1 kick starts the thread 2, and later thread 2 kick starts the thread 3. Both the threads 2 and 3 are executes infinite loops. So expectation is both thread 2 and 3 runs parallelly. But instead thread 3 only executing. Can any one help me why thread 2 is not executing ?

Regards, Srinu