threads: Add the no mspc channel account exercice

Signed-off-by: Samuel Ortiz <[email protected]>

Author: sameo

threads/account-no-channel/Cargo.lock

@@ -0,0 +1,8 @@
+[package]
+name = "account-no-channel"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

threads/account-no-channel/Cargo.toml

@@ -0,0 +1,101 @@
+use std::sync::Arc;
+use std::sync::Mutex;
+use std::thread;
+use std::time::Duration;
+
+#[derive(Clone, Debug, Default)]
+struct Account {
+    transactions: Vec<i32>,
+    balance: i32,
+}
+
+impl Account {
+    fn new() -> Self {
+        Account {
+            balance: 0,
+            ..Default::default()
+        }
+    }
+
+    fn withdrawal(&mut self, request: u32) -> u32 {
+        if self.balance <= 0 {
+            return 0;
+        }
+
+        let balance = self.balance as u32;
+        let withdrawal = if balance <= request {
+            self.balance
+        } else {
+            request as i32
+        };
+
+        self.transactions.push(-withdrawal);
+        self.balance -= withdrawal;
+
+        withdrawal as u32
+    }
+
+    fn deposit(&mut self, deposit: i32) {
+        self.transactions.push(deposit);
+        self.balance += deposit;
+    }
+
+    fn balance(&self) -> i32 {
+        self.balance
+    }
+}
+
+const GRAND_TOTAL: u32 = 400;
+
+fn main() {
+    let account = Arc::new(Mutex::new(Account::new()));
+
+    let child_account = Arc::clone(&account);
+    let parent_account = Arc::clone(&account);
+    let banker_account = Arc::clone(&account);
+
+    let child_thread = thread::spawn(move || {
+        let mut total_withdrawal = 0;
+
+        loop {
+            thread::sleep(Duration::from_millis(1500));
+            let mut locked_account = child_account.lock().unwrap();
+            let withdrawal = locked_account.withdrawal(50);
+            total_withdrawal += withdrawal;
+            println!("CHILD <- {}", withdrawal);
+
+            if total_withdrawal >= GRAND_TOTAL {
+                break;
+            }
+        }
+    });
+
+    let parent_thread = thread::spawn(move || {
+        let mut total_deposit = 0;
+
+        loop {
+            thread::sleep(Duration::from_secs(5));
+            let mut locked_account = parent_account.lock().unwrap();
+
+            locked_account.deposit(80);
+            println!("PARENT -> {}", 80);
+            total_deposit += 80;
+
+            if total_deposit >= GRAND_TOTAL {
+                break;
+            }
+        }
+    });
+
+    // Monitoring thread
+    thread::spawn(move || loop {
+        thread::sleep(Duration::from_millis(500));
+        let locked_account = banker_account.lock().unwrap();
+        println!("** Balance {} **", locked_account.balance());
+    });
+
+    child_thread.join().unwrap();
+    parent_thread.join().unwrap();
+
+    println!("Account {:?}", account);
+}