Function configure_thread_pool_once 

pub fn configure_thread_pool_once(max_threads: usize) -> OcrResult<()>

Configures the global rayon thread pool if not already configured.

This function uses std::sync::Once to ensure the global thread pool is only configured once, preventing race conditions and silent failures that can occur when build_global() is called multiple times.

Arguments

• max_threads - Maximum number of threads to use for the thread pool

Returns

A Result indicating success or an OCRError if configuration fails