From e6ec64378136653a75b7b5ebbcf3034623c98050 Mon Sep 17 00:00:00 2001
From: Alwin Berger <alwin.berger@tu-dortmund.de>
Date: Wed, 6 Nov 2024 12:51:39 +0100
Subject: [PATCH] fix release-detection for api -> isr -> app, fix crash on
 empty trace

---
 fuzzers/FRET/src/systemstate/observers.rs | 11 +++++++----
 fuzzers/FRET/src/systemstate/stg.rs       |  3 +++
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/fuzzers/FRET/src/systemstate/observers.rs b/fuzzers/FRET/src/systemstate/observers.rs
index bee3bfbab9..ccb110d541 100644
--- a/fuzzers/FRET/src/systemstate/observers.rs
+++ b/fuzzers/FRET/src/systemstate/observers.rs
@@ -341,19 +341,22 @@ fn get_releases(trace: &Vec<ExecInterval>, states: &HashMap<u64, ReducedFreeRTOS
         }
         // Release driven by an API call. This produces a lot of false positives, as a job may block multiple times per instance. Despite this, aperiodic jobs not be modeled otherwise. If we assume the first release is the real one, we can filter out the rest.
         if i.start_capture.0 == CaptureEvent::APIStart {
-            let api_start = states.get(&i.start_state).expect("State not found");
-            let api_end = {
+            let api_start_state = states.get(&i.start_state).expect("State not found");
+            let api_end_state = {
                 let mut end_index = _n;
                 for n in (_n)..trace.len() {
                     if trace[n].end_capture.0 == CaptureEvent::APIEnd || trace[n].end_capture.0 == CaptureEvent::End {
                         end_index = n;
                         break;
+                    } else if n > _n && trace[n].level == 0 {   // API Start -> ISR Start+End -> APP Continue
+                        end_index = n-1;  // any return to a regular app block is a fair point of comparison for the ready list, because scheduling has been performed
+                        break;
                     }
                 };
                 states.get(&trace[end_index].end_state).expect("State not found")
             };
-            api_end.ready_list_after.iter().for_each(|x| {
-                if x.task_name != api_start.current_task.task_name && !api_start.ready_list_after.iter().any(|y| x.task_name == y.task_name) {
+            api_end_state.ready_list_after.iter().for_each(|x| {
+                if x.task_name != api_start_state.current_task.task_name && !api_start_state.ready_list_after.iter().any(|y| x.task_name == y.task_name) {
                     ret.push((i.end_tick, x.task_name.clone()));
                     // eprintln!("Task {} released by API call at {:.1}ms", x.task_name, crate::time::clock::tick_to_time(i.end_tick).as_micros() as f32/1000.0);
                 }
diff --git a/fuzzers/FRET/src/systemstate/stg.rs b/fuzzers/FRET/src/systemstate/stg.rs
index 77185d4a94..d876aa13f1 100644
--- a/fuzzers/FRET/src/systemstate/stg.rs
+++ b/fuzzers/FRET/src/systemstate/stg.rs
@@ -443,6 +443,9 @@ impl StgFeedback {
         let mut return_edge_trace = vec![];
         let mut interesting = false;
         let mut updated = false;
+        if trace.is_empty() {
+            return (return_node_trace, return_edge_trace, interesting, updated);
+        }
         let mut instance_time = execinterval_to_abb_instances(trace, read_trace);
         // add all missing state+abb combinations to the graph
         for (_i,interval) in trace.iter().enumerate() { // Iterate intervals