Change TRACING_SET to static (paritytech#7607)

* change TRACING_SET to static

* Update primitives/io/src/lib.rs

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* modify test with nested spans

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

client/executor/runtime-test/src/lib.rs

@@ -261,6 +261,17 @@ sp_core::wasm_export_functions! {
 		wasm_tracing::exit(span_id)
 	}
 
+	fn test_nested_spans() {
+		sp_io::init_tracing();
+		let span_id = wasm_tracing::enter_span(Default::default());
+		{
+			sp_io::init_tracing();
+			let span_id = wasm_tracing::enter_span(Default::default());
+			wasm_tracing::exit(span_id);
+		}
+		wasm_tracing::exit(span_id);
+	}
+
 	fn returns_mutable_static() -> u64 {
 		unsafe {
 			MUTABLE_STATIC += 1;

client/executor/src/integration_tests/mod.rs

@@ -719,6 +719,15 @@ fn wasm_tracing_should_work(wasm_method: WasmExecutionMethod) {
 	assert_eq!(span_datum.target, "default");
 	assert_eq!(span_datum.name, "");
 	assert_eq!(values.bool_values.get("wasm").unwrap(), &true);
+
+	call_in_wasm(
+		"test_nested_spans",
+		Default::default(),
+		wasm_method,
+		&mut ext,
+	).unwrap();
+	let len = traces.lock().unwrap().len();
+	assert_eq!(len, 2);
 }
 
 #[test_case(WasmExecutionMethod::Interpreted)]

primitives/io/src/lib.rs

@@ -1093,7 +1093,7 @@ mod tracing_setup {
 	};
 	use super::{wasm_tracing, Crossing};
 
-	const TRACING_SET : AtomicBool = AtomicBool::new(false);
+	static TRACING_SET: AtomicBool = AtomicBool::new(false);
 
 
 	/// The PassingTracingSubscriber implements `tracing_core::Subscriber`