Only spawn request threads if necessary

milli/src/thread_pool_no_abort.rs

@@ -34,7 +34,7 @@ impl ThreadPoolNoAbort {
 }
 
 #[derive(Error, Debug)]
-#[error("A panic occurred. Read the logs to find more information about it")]
+#[error("A panic occured. Read the logs to find more information about it")]
 pub struct PanicCatched;
 
 #[derive(Default)]
@@ -61,28 +61,9 @@ impl ThreadPoolNoAbortBuilder {
     pub fn build(mut self) -> Result<ThreadPoolNoAbort, rayon::ThreadPoolBuildError> {
         let pool_catched_panic = Arc::new(AtomicBool::new(false));
         self.0 = self.0.panic_handler({
-            let catched_panic = Arc::downgrade(&pool_catched_panic);
-            move |_result| {
-                if let Some(catched_panic) = catched_panic.upgrade() {
-                    catched_panic.store(true, Ordering::SeqCst)
-                }
-            }
+            let catched_panic = pool_catched_panic.clone();
+            move |_result| catched_panic.store(true, Ordering::SeqCst)
         });
         Ok(ThreadPoolNoAbort { thread_pool: self.0.build()?, pool_catched_panic })
     }
 }
-
-#[cfg(test)]
-mod test {
-    use std::sync::Arc;
-
-    use crate::ThreadPoolNoAbortBuilder;
-
-    #[test]
-    fn drop_pool() {
-        let pool = ThreadPoolNoAbortBuilder::new().num_threads(10).build().unwrap();
-        let caught_panic = Arc::downgrade(&pool.pool_catched_panic);
-        drop(pool);
-        assert_eq!(caught_panic.strong_count(), 0);
-    }
-}

milli/src/update/index_documents/extract/mod.rs

@@ -229,12 +229,15 @@ fn send_original_documents_data(
     let documents_chunk_cloned = original_documents_chunk.clone();
     let lmdb_writer_sx_cloned = lmdb_writer_sx.clone();
 
-    let request_threads = ThreadPoolNoAbortBuilder::new()
-        .num_threads(crate::vector::REQUEST_PARALLELISM)
-        .thread_name(|index| format!("embedding-request-{index}"))
-        .build()?;
+    let new_embedding_configs = settings_diff.new.embedding_configs.clone();
 
-    if settings_diff.reindex_vectors() || !settings_diff.settings_update_only() {
+    if (settings_diff.reindex_vectors() || !settings_diff.settings_update_only())
+        && new_embedding_configs.get_default().is_some()
+    {
+        let request_threads = ThreadPoolNoAbortBuilder::new()
+            .num_threads(crate::vector::REQUEST_PARALLELISM)
+            .thread_name(|index| format!("embedding-request-{index}"))
+            .build()?;
         let settings_diff = settings_diff.clone();
         rayon::spawn(move || {
             for (name, (embedder, prompt)) in settings_diff.new.embedding_configs.clone() {