From b239e015c8138b987fae5263f1d2dac99d58b273 Mon Sep 17 00:00:00 2001
From: FliegendeWurst <2012gdwu@web.de>
Date: Sun, 17 May 2020 11:17:38 +0200
Subject: [PATCH] Measure real CPU load

---
 .gitignore  |  1 +
 src/main.rs | 38 +++++++++++++++++++++++++++-----------
 2 files changed, 28 insertions(+), 11 deletions(-)
 create mode 100644 .gitignore

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..eb5a316
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+target
diff --git a/src/main.rs b/src/main.rs
index adade9e..da2dc17 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,15 +1,31 @@
 use std::fs;
 
+const WAIT_MS: u32 = 500;
+
 fn main() {
-    let load = fs::read_to_string("/proc/loadavg").unwrap().split(' ').nth(0).unwrap().parse::<f64>().unwrap();
-    let num_cpus = fs::read_dir("/sys/devices/system/cpu").unwrap()
-        .map(|x| x.unwrap().file_name().into_string().unwrap())
-        .filter(|x| x.starts_with("cpu") && x.chars().nth(3).unwrap().is_numeric())
-        .count() as f64;
-    let temp = fs::read_to_string("/sys/class/hwmon/hwmon0/temp1_input").unwrap().trim().parse::<f64>().unwrap() / 1000.0;
-    let meminfo = fs::read_to_string("/proc/meminfo").unwrap();
-    let mut meminfo = meminfo.split('\n');
-    let total = meminfo.next().unwrap().split_whitespace().nth(1).unwrap().parse::<u64>().unwrap() / 1_000;
-    let available = meminfo.nth(1).unwrap().split_whitespace().nth(1).unwrap().parse::<u64>().unwrap() / 1_000;
-    println!("{:.1}% {:.1}°C {}/{}MB", load / num_cpus * 100.0, temp, total - available, total);
+	let stat_1 = extract_stat();
+	std::thread::sleep_ms(WAIT_MS);
+	let stat_2 = extract_stat();
+	/*
+	let load = fs::read_to_string("/proc/loadavg").unwrap().split(' ').nth(0).unwrap().parse::<f64>().unwrap();
+	let num_cpus = fs::read_dir("/sys/devices/system/cpu").unwrap()
+		.map(|x| x.unwrap().file_name().into_string().unwrap())
+		.filter(|x| x.starts_with("cpu") && x.chars().nth(3).unwrap().is_numeric())
+		.count() as f64;
+	*/
+	let real_load = (stat_2 - stat_1) * 1000 / (WAIT_MS as u64);
+	let temp = fs::read_to_string("/sys/class/hwmon/hwmon0/temp1_input").unwrap().trim().parse::<f64>().unwrap() / 1000.0;
+	let meminfo = fs::read_to_string("/proc/meminfo").unwrap();
+	let mut meminfo = meminfo.split('\n');
+	let total = meminfo.next().unwrap().split_whitespace().nth(1).unwrap().parse::<u64>().unwrap() / 1_000;
+	let available = meminfo.nth(1).unwrap().split_whitespace().nth(1).unwrap().parse::<u64>().unwrap() / 1_000;
+	//println!("{:.1}% {:.1}°C {}/{}MB", load / num_cpus * 100.0, temp, total - available, total);
+	println!("{}% {:.1}°C {}/{}MB", real_load, temp, total - available, total);
+}
+
+fn extract_stat() -> u64 {
+	let stat = fs::read_to_string("/proc/stat").unwrap();
+	let cpu = stat.lines().find(|x| x.starts_with("cpu ")).unwrap();
+	let times = cpu.split(' ');
+	times.skip(1).filter(|x| !x.is_empty()).take(3).map(|x| x.parse::<u64>().unwrap()).sum::<u64>()
 }