test_unix_msg: Remove thread synchronisation

This refactors the test_unix_msg() test a bit. No change in behaviour is
intended.

Previously, two threads were started in parallel. The server thread used
a mutex and a condition variable to indicate that it set up its
listening socket. The client thread waited for this signal before it
attempted to connect.

This commit makes the code instead bind the server socket before
starting the worker threads. That way, no synchronisation is necessary.

Signed-off-by: Uli Schlachter <[email protected]>

tests/net/unix.rs

@@ -150,31 +150,22 @@ fn test_unix_msg() {
 
     let tmpdir = tempfile::tempdir().unwrap();
     let path = tmpdir.path().join("scp_4804");
-    let ready = Arc::new((Mutex::new(false), Condvar::new()));
+
+    let connection_socket = socket(
+        AddressFamily::UNIX,
+        SocketType::SEQPACKET,
+        Protocol::default(),
+    )
+    .unwrap();
+
+    let name = SocketAddrUnix::new(&path).unwrap();
+    bind_unix(&connection_socket, &name).unwrap();
+    listen(&connection_socket, 1).unwrap();
 
     let server = {
-        let ready = ready.clone();
         let path = path.clone();
 
         move || {
-            let connection_socket = socket(
-                AddressFamily::UNIX,
-                SocketType::SEQPACKET,
-                Protocol::default(),
-            )
-            .unwrap();
-
-            let name = SocketAddrUnix::new(&path).unwrap();
-            bind_unix(&connection_socket, &name).unwrap();
-            listen(&connection_socket, 1).unwrap();
-
-            {
-                let (lock, cvar) = &*ready;
-                let mut started = lock.lock().unwrap();
-                *started = true;
-                cvar.notify_all();
-            }
-
             let mut buffer = vec![0; BUFFER_SIZE];
             'exit: loop {
                 let data_socket = accept(&connection_socket).unwrap();
@@ -214,14 +205,6 @@ fn test_unix_msg() {
     };
 
     let client = move || {
-        {
-            let (lock, cvar) = &*ready;
-            let mut started = lock.lock().unwrap();
-            while !*started {
-                started = cvar.wait(started).unwrap();
-            }
-        }
-
         let addr = SocketAddrUnix::new(path).unwrap();
         let mut buffer = vec![0; BUFFER_SIZE];
         let runs: &[(&[&str], i32)] = &[
@@ -318,31 +301,23 @@ fn test_unix_msg_with_scm_rights() {
 
     let tmpdir = tempfile::tempdir().unwrap();
     let path = tmpdir.path().join("scp_4804");
-    let ready = Arc::new((Mutex::new(false), Condvar::new()));
 
     let server = {
-        let ready = ready.clone();
         let path = path.clone();
 
-        move || {
-            let connection_socket = socket(
-                AddressFamily::UNIX,
-                SocketType::SEQPACKET,
-                Protocol::default(),
-            )
-            .unwrap();
-            let mut pipe_end = None;
+        let connection_socket = socket(
+            AddressFamily::UNIX,
+            SocketType::SEQPACKET,
+            Protocol::default(),
+        )
+        .unwrap();
 
-            let name = SocketAddrUnix::new(&path).unwrap();
-            bind_unix(&connection_socket, &name).unwrap();
-            listen(&connection_socket, 1).unwrap();
+        let name = SocketAddrUnix::new(&path).unwrap();
+        bind_unix(&connection_socket, &name).unwrap();
+        listen(&connection_socket, 1).unwrap();
 
-            {
-                let (lock, cvar) = &*ready;
-                let mut started = lock.lock().unwrap();
-                *started = true;
-                cvar.notify_all();
-            }
+        move || {
+            let mut pipe_end = None;
 
             let mut buffer = vec![0; BUFFER_SIZE];
             let mut cmsg_space = vec![0; rustix::cmsg_space!(ScmRights(1))];
@@ -403,14 +378,6 @@ fn test_unix_msg_with_scm_rights() {
     };
 
     let client = move || {
-        {
-            let (lock, cvar) = &*ready;
-            let mut started = lock.lock().unwrap();
-            while !*started {
-                started = cvar.wait(started).unwrap();
-            }
-        }
-
         let addr = SocketAddrUnix::new(path).unwrap();
         let (read_end, write_end) = pipe().unwrap();
         let mut buffer = vec![0; BUFFER_SIZE];