1// Tests that depend on a count of the number of times their filter is evaluated
2// cant exist in the same file with other tests that add subscribers to the
3// registry. The registry was changed so that each time a new dispatcher is
4// added all filters are re-evaluated. The tests being run only in separate
5// threads with shared global state lets them interfere with each other
6#[cfg(not(feature = "std"))]
7extern crate std;
8
9use tracing::{span, Level};
10use tracing_mock::*;
11
12use std::sync::{
13 atomic::{AtomicUsize, Ordering},
14 Arc,
15};
16
17#[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
18#[test]
19fn filters_are_not_reevaluated_for_the_same_span() {
20 // Asserts that the `span!` macro caches the result of calling
21 // `Subscriber::enabled` for each span.
22 let alice_count = Arc::new(AtomicUsize::new(0));
23 let bob_count = Arc::new(AtomicUsize::new(0));
24 let alice_count2 = alice_count.clone();
25 let bob_count2 = bob_count.clone();
26
27 let (subscriber, handle) = subscriber::mock()
28 .with_filter(move |meta| match meta.name() {
29 "alice" => {
30 alice_count2.fetch_add(1, Ordering::Relaxed);
31 false
32 }
33 "bob" => {
34 bob_count2.fetch_add(1, Ordering::Relaxed);
35 true
36 }
37 _ => false,
38 })
39 .run_with_handle();
40
41 // Since this test is in its own file anyway, we can do this. Thus, this
42 // test will work even with no-std.
43 tracing::subscriber::set_global_default(subscriber).unwrap();
44
45 // Enter "alice" and then "bob". The dispatcher expects to see "bob" but
46 // not "alice."
47 let alice = span!(Level::TRACE, "alice");
48 let bob = alice.in_scope(|| {
49 let bob = span!(Level::TRACE, "bob");
50 bob.in_scope(|| ());
51 bob
52 });
53
54 // The filter should have seen each span a single time.
55 assert_eq!(alice_count.load(Ordering::Relaxed), 1);
56 assert_eq!(bob_count.load(Ordering::Relaxed), 1);
57
58 alice.in_scope(|| bob.in_scope(|| {}));
59
60 // The subscriber should see "bob" again, but the filter should not have
61 // been called.
62 assert_eq!(alice_count.load(Ordering::Relaxed), 1);
63 assert_eq!(bob_count.load(Ordering::Relaxed), 1);
64
65 bob.in_scope(|| {});
66 assert_eq!(alice_count.load(Ordering::Relaxed), 1);
67 assert_eq!(bob_count.load(Ordering::Relaxed), 1);
68
69 handle.assert_finished();
70}
71