Function num_processors 

pub fn num_processors() -> u32

Determine the approximate number of threads that the system will schedule simultaneously for this process. This is intended to be used as a parameter to g_thread_pool_new() for CPU bound tasks and similar cases.

On platforms where enough information is known, this will be the number of high performance cores and will not include low power ‘efficiency’ cores. Use platform specific APIs to query for low power cores if needed.

Returns

Number of schedulable threads, always greater than 0