Function btck_chainstate_manager_options_set_worker_threads_num 

pub unsafe extern "C" fn btck_chainstate_manager_options_set_worker_threads_num(
    chainstate_manager_options: *mut btck_ChainstateManagerOptions,
    worker_threads: c_int,
)

@brief Set the number of available worker threads used during validation.

@param[in] chainstate_manager_options Non-null, options to be set. @param[in] worker_threads The number of worker threads that should be spawned in the thread pool used for validation. When set to 0 no parallel verification is done. The value range is clamped internally between 0 and 15.