chore: move event loop recreation check into backends themselves

winit-win32/src/event_loop.rs

@@ -6,7 +6,7 @@ use std::cell::Cell;
 use std::ffi::c_void;
 use std::os::windows::io::{AsRawHandle as _, FromRawHandle as _, OwnedHandle, RawHandle};
 use std::rc::Rc;
-use std::sync::atomic::{AtomicU32, Ordering};
+use std::sync::atomic::{AtomicBool, AtomicU32, Ordering};
 use std::sync::{Arc, LazyLock, Mutex, MutexGuard};
 use std::time::{Duration, Instant};
 use std::{fmt, mem, panic, ptr};
@@ -195,6 +195,12 @@ impl EventLoop {
     pub fn new(
         attributes: &mut PlatformSpecificEventLoopAttributes,
     ) -> Result<Self, EventLoopError> {
+        static EVENT_LOOP_CREATED: AtomicBool = AtomicBool::new(false);
+        if EVENT_LOOP_CREATED.swap(true, Ordering::Relaxed) {
+            // For better cross-platformness.
+            return Err(EventLoopError::RecreationAttempt);
+        }
+
         let thread_id = unsafe { GetCurrentThreadId() };
 
         if !attributes.any_thread && thread_id != main_thread_id() {