Copy manual linux test from v4

Author: passcod

tests/manual_tests_linux.rs

@@ -0,0 +1,70 @@
+#![cfg(target_os = "linux")]
+#![cfg(feature = "manual_tests")]
+
+use std::{
+    fs::File,
+    io::prelude::*,
+    thread,
+    time::{Duration, Instant},
+};
+
+use crossbeam_channel::{unbounded, TryRecvError};
+use notify::*;
+
+use utils::*;
+mod utils;
+
+const TEMP_DIR: &str = "temp_dir";
+
+#[test]
+// Test preparation:
+// 1. Run `sudo echo 10 > /proc/sys/fs/inotify/max_queued_events`
+// 2. Uncomment the lines near "test inotify_queue_overflow" in inotify watcher
+fn inotify_queue_overflow() {
+    let mut max_queued_events = String::new();
+    let mut f = File::open("/proc/sys/fs/inotify/max_queued_events")
+        .expect("failed to open max_queued_events");
+    f.read_to_string(&mut max_queued_events)
+        .expect("failed to read max_queued_events");
+    assert_eq!(max_queued_events.trim(), "10");
+
+    let tdir = tempfile::Builder::new()
+        .prefix(TEMP_DIR)
+        .tempdir()
+        .expect("failed to create temporary directory");
+
+    let (tx, rx) = unbounded();
+    let mut watcher: RecommendedWatcher =
+        Watcher::new(tx).expect("failed to create recommended watcher");
+    watcher
+        .watch(&tdir.mkpath("."), RecursiveMode::Recursive)
+        .expect("failed to watch directory");
+
+    for i in 0..20 {
+        let filename = format!("file{}", i);
+        tdir.create(&filename);
+        tdir.remove(&filename);
+    }
+
+    sleep(100);
+
+    let start = Instant::now();
+
+    let mut rescan_found = false;
+    while !rescan_found && start.elapsed().as_secs() < 5 {
+        match rx.try_recv() {
+            Ok(Err(Error {
+                // TRANSLATION: this may not be correct
+                kind: ErrorKind::MaxFilesWatch,
+                ..
+            })) => rescan_found = true,
+            Ok(Err(e)) => panic!("unexpected event err: {:?}", e),
+            Ok(Ok(_)) => (),
+            Err(TryRecvError::Empty) => (),
+            Err(e) => panic!("unexpected channel err: {:?}", e),
+        }
+        thread::sleep(Duration::from_millis(10));
+    }
+
+    assert!(rescan_found);
+}