make exercise more clear

[rust-101.git] / solutions / src / counter.rs

diff --git a/solutions/src/counter.rs b/solutions/src/counter.rs
index 265fb99d972fcfd6388c6445a207082e42c00320..acf8293acf13aecd2acd5f32446cde12ca80a463 100644 (file)
--- a/solutions/src/counter.rs
+++ b/solutions/src/counter.rs
@@ -1,8 +1,9 @@
 use std::sync::{Arc, RwLock};
 use std::thread;
+use std::time::Duration;
 
 #[derive(Clone)]
-struct ConcurrentCounter(Arc<RwLock<usize>>);
+pub struct ConcurrentCounter(Arc<RwLock<usize>>);
 
 impl ConcurrentCounter {
     // The constructor should not be surprising.
@@ -11,12 +12,19 @@ impl ConcurrentCounter {
     }
 
     pub fn increment(&self, by: usize) {
-        let mut counter = self.0.write().unwrap();
+        let mut counter = self.0.write().unwrap_or_else(|e| e.into_inner());
         *counter = *counter + by;
     }
 
+    pub fn compare_and_inc(&self, test: usize, by: usize) {
+        let mut counter = self.0.write().unwrap_or_else(|e| e.into_inner());
+        if *counter == test {
+            *counter += by;
+        }
+    }
+
     pub fn get(&self) -> usize {
-        let counter = self.0.read().unwrap();
+        let counter = self.0.read().unwrap_or_else(|e| e.into_inner());
         *counter
     }
 }
@@ -29,7 +37,7 @@ pub fn main() {
     let counter1 = counter.clone();
     let handle1 = thread::spawn(move || {
         for _ in 0..10 {
-            thread::sleep_ms(15);
+            thread::sleep(Duration::from_millis(15));
             counter1.increment(2);
         }
     });
@@ -38,14 +46,14 @@ pub fn main() {
     let counter2 = counter.clone();
     let handle2 = thread::spawn(move || {
         for _ in 0..10 {
-            thread::sleep_ms(20);
+            thread::sleep(Duration::from_millis(20));
             counter2.increment(3);
         }
     });
 
     // Now we want to watch the threads working on the counter.
     for _ in 0..50 {
-        thread::sleep_ms(5);
+        thread::sleep(Duration::from_millis(5));
         println!("Current value: {}", counter.get());
     }