platform/inprocess: Drop server record after accept(), not on connect()

Invoking `accept()` after `connect()` used to fail, because the server
record was being dropped while doing the `connect()`. Now dropping it
after the `accept()` instead -- which is safe for either invocation
order, because `accept()` is blocking, and thus never finishes before
`connect()` is done.

Also adding a separate `server_connect_first` test case to explicitly
test this situation. (And modifying the original test case to ensure it
always tests the other situation.)

Author: antrik

src/platform/inprocess/mod.rs

@@ -139,7 +139,7 @@ impl OsIpcSender {
     }
 
     pub fn connect(name: String) -> Result<OsIpcSender,MpscError> {
-        let record = ONE_SHOT_SERVERS.lock().unwrap().remove(&name).unwrap();
+        let record = ONE_SHOT_SERVERS.lock().unwrap().get(&name).unwrap().clone();
         record.connect();
         Ok(record.sender)
     }
@@ -285,6 +285,7 @@ impl OsIpcOneShotServer {
     {
         let record = ONE_SHOT_SERVERS.lock().unwrap().get(&self.name).unwrap().clone();
         record.accept();
+        ONE_SHOT_SERVERS.lock().unwrap().remove(&self.name).unwrap();
         let receiver = self.receiver.borrow_mut().take().unwrap();
         let (data, channels, shmems) = receiver.recv().unwrap();
         Ok((receiver, data, channels, shmems))

src/platform/test.rs

@@ -397,11 +397,12 @@ fn receiver_set() {
 
 #[cfg(not(any(feature = "force-inprocess", target_os = "android")))]
 #[test]
-fn server() {
+fn server_accept_first() {
     let (server, name) = OsIpcOneShotServer::new().unwrap();
     let data: &[u8] = b"1234567";
 
     thread::spawn(move || {
+        thread::sleep(Duration::from_millis(30));
         let tx = OsIpcSender::connect(name).unwrap();
         tx.send(data, vec![], vec![]).unwrap();
     });
@@ -413,6 +414,24 @@ fn server() {
                (data, vec![], vec![]));
 }
 
+#[test]
+fn server_connect_first() {
+    let (server, name) = OsIpcOneShotServer::new().unwrap();
+    let data: &[u8] = b"1234567";
+
+    thread::spawn(move || {
+        let tx = OsIpcSender::connect(name).unwrap();
+        tx.send(data, vec![], vec![]).unwrap();
+    });
+
+    thread::sleep(Duration::from_millis(30));
+    let (_, mut received_data, received_channels, received_shared_memory_regions) =
+        server.accept().unwrap();
+    received_data.truncate(7);
+    assert_eq!((&received_data[..], received_channels, received_shared_memory_regions),
+               (data, vec![], vec![]));
+}
+
 #[cfg(not(any(feature = "force-inprocess", target_os = "windows", target_os = "android")))]
 #[test]
 fn cross_process() {