fix(macos): fix race condition in wkwebview implementation of cookie fetching

.changes/fix-cookies-deadlock.md

@@ -0,0 +1,5 @@
+---
+"wry": patch
+---
+
+Fix `Webview::cookies` and `Webview::cookies_for_url` deadlock on macOS.

src/wkwebview/mod.rs

@@ -79,6 +79,7 @@ use std::{
   ptr::{null_mut, NonNull},
   str::{self, FromStr},
   sync::{Arc, Mutex},
+  time::Duration,
 };
 
 #[cfg(feature = "mac-proxy")]
@@ -1054,24 +1055,31 @@ unsafe fn window_position(view: &NSView, x: i32, y: i32, height: f64) -> CGPoint
   CGPoint::new(x as f64, frame.size.height - y as f64 - height)
 }
 
+/// Wait synchronously for the NSRunLoop to run until a receiver has a message.
 unsafe fn wait_for_blocking_operation<T>(rx: std::sync::mpsc::Receiver<T>) -> Result<T> {
-  let interval = 0.0002;
+  let interval = Duration::from_millis(2);
+  let interval_as_secs = interval.as_secs_f64();
   let limit = 1.;
   let mut elapsed = 0.;
   // run event loop until we get the response back, blocking for at most 3 seconds
   loop {
-    let rl = objc2_foundation::NSRunLoop::mainRunLoop();
-    let d = NSDate::dateWithTimeIntervalSinceNow(interval);
-    rl.runUntilDate(&d);
-    if let Ok(response) = rx.try_recv() {
+    if let Ok(response) = rx.recv_timeout(interval) {
       return Ok(response);
     }
-    elapsed += interval;
+    elapsed += interval_as_secs;
     if elapsed >= limit {
       return Err(Error::Io(std::io::Error::new(
         std::io::ErrorKind::TimedOut,
         "timed out waiting for cookies response",
       )));
     }
+
+    // Go progress the event loop if we didn't get the result
+    let rl = objc2_foundation::NSRunLoop::mainRunLoop();
+    let limit_date = NSDate::dateWithTimeIntervalSinceNow(interval_as_secs);
+
+    let mode = NSString::from_str("NSDefaultRunLoopMode");
+
+    rl.acceptInputForMode_beforeDate(&mode, &limit_date);
   }
 }