Freeze managed state before launch.

lib/Cargo.toml

@@ -24,7 +24,7 @@ log = "0.4"
 percent-encoding = "1"
 toml = "0.4.2"
 num_cpus = "1.0"
-state = "0.4"
+state = "0.4.1"
 time = "0.1"
 memchr = "2"
 base64 = "0.9"

lib/src/rocket.rs

@@ -689,6 +689,9 @@ impl Rocket {
             let timeout = self.config.keep_alive.map(|s| Duration::from_secs(s as u64));
             server.keep_alive(timeout);
 
+            // Freeze managed state for synchronization-free accesses later.
+            self.state.freeze();
+
             // Run the launch fairings.
             self.fairings.handle_launch(&self);