Change to using block_on()

src/context.rs

@@ -442,13 +442,20 @@ impl Context {
             typ: event.clone(),
         });
 
-        // `task::spawn()` below is a bit slow, so make sure to only call it if
-        // debug logging is enabled; that's why we have the Context::debug_logging
-        // property. Using `spawn()` also has the disadvantage that the logs might
-        // get out of order.
-        // Both could be solved by using `task::block_on()` instead, but reportedly,
-        // this could lead to deadlocks. A better solution would be to make
-        // `emit_event()` async.
+        // `task::block_on()` below is not how async is meant to be used
+        // since `emit_event()` is often called from an async context.
+        // This could generally lead to deadlocks, so we make sure to only
+        // call it if `debug_logging` is on. It's not that much of a problem
+        // since most of the things we do in the `async` block - esp. the
+        // database access - is blocking anyway.
+        //
+        // A better solution would be to make `emit_event()` async or to
+        // create a debug_logger background loop.
+        //
+        // Alternatively, we could use `task::spawn()`; this would be
+        // non-deterministic, so that the logs might get out of order, and
+        // it could make e.g. backups fail since it could still run in the
+        // background while trying to move/close the database.
         let debug_logging = self.debug_logging.load(atomic::Ordering::Relaxed);
         if debug_logging > 0 {
             let time = SystemTime::now()
@@ -457,7 +464,7 @@ impl Context {
                 .as_millis() as i64;
 
             let context = self.clone();
-            async_std::task::spawn(async move {
+            async_std::task::block_on(async move {
                 let webxdc_instance_id = MsgId::new(debug_logging as u32);
 
                 match context