tests/ui/threads-sendsync/no-double-lock-same-thread.rs

//! Regression test for <https://github.com/rust-lang/rust/issues/33770>.
//! Ensure both `Mutex` and `RwLock` cannot be locked twice on same
//! thread.
//!
//! This was possible as mutexes were initialized with `PTHREAD_MUTEX_DEFAULT`
//! for which attempt to relock from the same thread is considered undefined
//! behaviour, and during glibc's lock-elision transaction lock appeared
//! unlocked, which allowed to lock it again from the same thread.
//!
//! This resulted in ability to aquire 2 mutable references at the same time.
//@ run-pass
//@ needs-subprocess

use std::process::{Command, Stdio};
use std::env;
use std::sync::{Mutex, RwLock};
use std::time::Duration;
use std::thread;

fn test_mutex() {
    let m = Mutex::new(0);
    let _g = m.lock().unwrap();
    let _g2 = m.lock().unwrap();
}

fn test_try_mutex() {
    let m = Mutex::new(0);
    let _g = m.lock().unwrap();
    let _g2 = m.try_lock().unwrap();
}

fn test_rwlock_ww() {
    let m = RwLock::new(0);
    let _g = m.write().unwrap();
    let _g2 = m.write().unwrap();
}

fn test_try_rwlock_ww() {
    let m = RwLock::new(0);
    let _g = m.write().unwrap();
    let _g2 = m.try_write().unwrap();
}

fn test_rwlock_rw() {
    let m = RwLock::new(0);
    let _g = m.read().unwrap();
    let _g2 = m.write().unwrap();
}

fn test_try_rwlock_rw() {
    let m = RwLock::new(0);
    let _g = m.read().unwrap();
    let _g2 = m.try_write().unwrap();
}

fn test_rwlock_wr() {
    let m = RwLock::new(0);
    let _g = m.write().unwrap();
    let _g2 = m.read().unwrap();
}

fn test_try_rwlock_wr() {
    let m = RwLock::new(0);
    let _g = m.write().unwrap();
    let _g2 = m.try_read().unwrap();
}

fn main() {
    let args: Vec<String> = env::args().collect();
    if args.len() > 1 {
        match &*args[1] {
            "mutex" => test_mutex(),
            "try_mutex" => test_try_mutex(),
            "rwlock_ww" => test_rwlock_ww(),
            "try_rwlock_ww" => test_try_rwlock_ww(),
            "rwlock_rw" => test_rwlock_rw(),
            "try_rwlock_rw" => test_try_rwlock_rw(),
            "rwlock_wr" => test_rwlock_wr(),
            "try_rwlock_wr" => test_try_rwlock_wr(),
            _ => unreachable!(),
        }
        // If we reach this point then the test failed
        println!("TEST FAILED: {}", args[1]);
    } else {
        let mut v = vec![];
        v.push(Command::new(&args[0]).arg("mutex").stderr(Stdio::null()).spawn().unwrap());
        v.push(Command::new(&args[0]).arg("try_mutex").stderr(Stdio::null()).spawn().unwrap());
        v.push(Command::new(&args[0]).arg("rwlock_ww").stderr(Stdio::null()).spawn().unwrap());
        v.push(Command::new(&args[0]).arg("try_rwlock_ww").stderr(Stdio::null()).spawn().unwrap());
        v.push(Command::new(&args[0]).arg("rwlock_rw").stderr(Stdio::null()).spawn().unwrap());
        v.push(Command::new(&args[0]).arg("try_rwlock_rw").stderr(Stdio::null()).spawn().unwrap());
        v.push(Command::new(&args[0]).arg("rwlock_wr").stderr(Stdio::null()).spawn().unwrap());
        v.push(Command::new(&args[0]).arg("try_rwlock_wr").stderr(Stdio::null()).spawn().unwrap());

        thread::sleep(Duration::new(1, 0));

        // Make sure all subprocesses either panicked or were killed because they deadlocked
        for mut c in v {
            c.kill().ok();
            assert!(!c.wait().unwrap().success());
        }
    }
}