1 files changed, 45 insertions, 0 deletions
diff --git a/vendor/perf-event/examples/group.rs b/vendor/perf-event/examples/group.rs
new file mode 100644
index 000000000..0312485c9
--- /dev/null
+++ b/vendor/perf-event/examples/group.rs
@@ -0,0 +1,45 @@
+use perf_event::{Builder, Group};
+use perf_event::events::{Cache, CacheOp, CacheResult, Hardware, WhichCache};
+
+fn main() -> std::io::Result<()> {
+    const ACCESS: Cache = Cache {
+        which: WhichCache::L1D,
+        operation: CacheOp::READ,
+        result: CacheResult::ACCESS,
+    };
+    const MISS: Cache = Cache { result: CacheResult::MISS, ..ACCESS };
+
+    let mut group = Group::new()?;
+    let access_counter = Builder::new().group(&mut group).kind(ACCESS).build()?;
+    let miss_counter = Builder::new().group(&mut group).kind(MISS).build()?;
+    let branches = Builder::new().group(&mut group).kind(Hardware::BRANCH_INSTRUCTIONS).build()?;
+    let missed_branches = Builder::new().group(&mut group).kind(Hardware::BRANCH_MISSES).build()?;
+
+    // Note that if you add more counters than you actually have hardware for,
+    // the kernel will time-slice them, which means you may get no coverage for
+    // short measurements. See the documentation.
+
+    let vec = (0..=51).collect::<Vec<_>>();
+
+    group.enable()?;
+    println!("{:?}", vec);
+    group.disable()?;
+
+    let counts = group.read()?;
+    println!("L1D cache misses/references: {} / {} ({:.0}%)",
+             counts[&miss_counter],
+             counts[&access_counter],
+             (counts[&miss_counter] as f64 / counts[&access_counter] as f64) * 100.0);
+
+    println!("branch prediction misses/total: {} / {} ({:.0}%)",
+             counts[&missed_branches],
+             counts[&branches],
+             (counts[&missed_branches] as f64 / counts[&branches] as f64) * 100.0);
+
+    // You can iterate over a `Counts` value:
+    for (id, value) in &counts {
+        println!("Counter id {} has value {}", id, value);
+    }
+
+    Ok(())
+}