Vendor dependencies for 0.3.0 release

vendor/crossbeam-epoch/benches/pin.rs

@@ -0,0 +1,31 @@
+#![feature(test)]
+
+extern crate test;
+
+use crossbeam_epoch as epoch;
+use crossbeam_utils::thread::scope;
+use test::Bencher;
+
+#[bench]
+fn single_pin(b: &mut Bencher) {
+    b.iter(epoch::pin);
+}
+
+#[bench]
+fn multi_pin(b: &mut Bencher) {
+    const THREADS: usize = 16;
+    const STEPS: usize = 100_000;
+
+    b.iter(|| {
+        scope(|s| {
+            for _ in 0..THREADS {
+                s.spawn(|_| {
+                    for _ in 0..STEPS {
+                        epoch::pin();
+                    }
+                });
+            }
+        })
+        .unwrap();
+    });
+}