add a Mutex to prevent concurrent database sync

Author: coffebar

Cargo.lock

@@ -1,7 +1,7 @@
 [package]
 name = "waybar-module-pacman-updates"
 description = "waybar module for Arch to show system updates available"
-version = "0.2.2"
+version = "0.2.3"
 edition = "2021"
 exclude = ["target", "Cargo.lock", "screenshot.png"]
 readme = "README.md"
@@ -12,3 +12,4 @@ keywords = ["cli", "waybar", "wayland", "linux", "archlinux"]
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+lazy_static = "1.4"

Cargo.toml

@@ -1,7 +1,11 @@
 use std::io::Error;
 use std::process::Command;
+use std::sync::Mutex;
 use std::{thread, time::Duration};
 
+lazy_static::lazy_static! {
+    static ref DATABASE_SYNC_MUTEX: Mutex<()> = Mutex::new(());
+}
 const SLEEP_SECONDS: u16 = 5;
 const SLEEP_DURATION: Duration = Duration::from_secs(SLEEP_SECONDS as u64);
 
@@ -30,6 +34,7 @@ fn main() -> Result<(), Error> {
 
 // check updates from network
 fn sync_database() {
+    let _lock = DATABASE_SYNC_MUTEX.lock().unwrap();
     // checkupdates --nocolor
     Command::new("checkupdates")
         .args(["--nocolor"])