Add perf energy estimator

2 files changed, 57 insertions, 0 deletions

diff --git a/src/mock.rs b/src/mock.rs
index 81bc32c..c5f8b34 100644
--- a/src/mock.rs
+++ b/src/mock.rs
@@ -1,5 +1,6 @@
 use iocuddle::*;
 use rand::Rng;
+mod perf;
 
 pub trait KernelModule {
     fn start_trace(&mut self, _pid: u64) {}
diff --git a/src/mock/perf.rs b/src/mock/perf.rs
new file mode 100644
index 0000000..4bf87c9
--- /dev/null
+++ b/src/mock/perf.rs
@@ -0,0 +1,56 @@
+use std::collections::HashMap;
+
+use events::Event;
+use perf_event::events::Hardware;
+use perf_event::*;
+
+struct PerfEstimator {
+    registry: HashMap<u64, Counters>,
+}
+
+struct Counters {
+    group: Group,
+    counters: Vec<Counter>,
+}
+
+static EVENT_TYPES: &[(f32, Event)] = &[
+    (1.0, Event::Hardware(Hardware::CPU_CYCLES)),
+    (2.0, Event::Hardware(Hardware::INSTRUCTIONS)),
+];
+
+impl super::KernelModule for PerfEstimator {
+    fn start_trace(&mut self, pid: u64) {
+        let mut group = Group::new().expect("failed to create Group");
+        let counters = EVENT_TYPES
+            .iter()
+            .map(|(_, kind)| {
+                Builder::new()
+                    .group(&mut group)
+                    .kind(kind.clone())
+                    .build()
+                    .unwrap()
+            })
+            .collect();
+
+        group.enable().unwrap();
+        let counters = Counters { counters, group };
+        self.registry.insert(pid, counters);
+    }
+
+    fn stop_trace(&mut self, pid: u64) {
+        self.registry.remove(&pid);
+    }
+
+    fn read_consumption(&mut self, pid: u64) -> u64 {
+        let Some(counters) = self.registry.get_mut(&pid) else {
+            return 0;
+        };
+        let mut sum = 0;
+        let counts = counters.group.read().unwrap();
+        for ((factor, ty), count) in EVENT_TYPES.iter().zip(counts.iter()) {
+            sum += *factor as u64 * count.1;
+        }
+
+        sum
+    }
+}