501 

   502 /// Force the global rayon threadpool to not exceed 16 concurrent threads

   503 /// unless the user has specified a value.

   504 /// This is a stop-gap measure until we figure out why using more than 16

   505 /// threads makes `status` slower for each additional thread.

   506 ///

   507 /// TODO find the underlying cause and fix it, then remove this.

   508 ///

   509 /// # Errors

   510 ///

   511 /// Returns an error if the global threadpool has already been initialized if

   512 /// we try to initialize it.

   513 pub fn cap_default_rayon_threads() -> Result<(), rayon::ThreadPoolBuildError> {

   514     const THREAD_CAP: usize = 16;

   515 

   516     if std::env::var("RAYON_NUM_THREADS").is_err() {

   517         let available_parallelism = std::thread::available_parallelism()

   518             .map(usize::from)

   519             .unwrap_or(1);

   520         let new_thread_count = THREAD_CAP.min(available_parallelism);

   521         let res = rayon::ThreadPoolBuilder::new()

   522             .num_threads(new_thread_count)

   523             .build_global();

   524         if res.is_ok() {

   525             log::trace!(

   526                 "Capped the rayon threadpool to {new_thread_count} threads",

   527             );

   528         }

   529         return res;

   530     }

   531     Ok(())

   532 }