From 555933315d2646b298ebeda91c0f3dbf07b28657 Mon Sep 17 00:00:00 2001
From: cyqsimon <28627918+cyqsimon@users.noreply.github.com>
Date: Tue, 15 Jul 2025 11:21:00 +0800
Subject: [PATCH] Only start offload worker thread when there's more than 1
 core (#2956)

* Only start offload worker thread when there's more than 1 core

* Write changelog
---
 CHANGELOG.md       | 1 +
 src/bin/bat/app.rs | 5 ++++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index fbf60912..29ddf751 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,6 +24,7 @@
 - CICD:  CICD: replace windows-2019 runners with windows-2025 #3339 (@cyqsimon)
 - Build script: replace string-based codegen with quote-based codegen #3340 (@cyqsimon)
 - Improve code coverage of `--list-languages` parameter #2942 (@sblondon)
+- Only start offload worker thread when there's more than 1 core #2956 (@cyqsimon)
 
 ## Syntaxes
 
diff --git a/src/bin/bat/app.rs b/src/bin/bat/app.rs
index 946ce5b1..0474e120 100644
--- a/src/bin/bat/app.rs
+++ b/src/bin/bat/app.rs
@@ -3,6 +3,7 @@ use std::env;
 use std::io::IsTerminal;
 use std::path::{Path, PathBuf};
 use std::str::FromStr;
+use std::thread::available_parallelism;
 
 use crate::{
     clap_app,
@@ -149,7 +150,9 @@ impl App {
         // start building glob matchers for builtin mappings immediately
         // this is an appropriate approach because it's statistically likely that
         // all the custom mappings need to be checked
-        syntax_mapping.start_offload_build_all();
+        if available_parallelism()?.get() > 1 {
+            syntax_mapping.start_offload_build_all();
+        }
 
         if let Some(values) = self.matches.get_many::<String>("ignored-suffix") {
             for suffix in values {