experiments

apt install libbpf-dev linux-tools-common linux-tools-$(uname -r)

./scripts/doctor.sh

mvn package
sudo java --enable-native-access=ALL-UNNAMED \
     -cp target/bpf-samples.jar me.bechberger.ebpf.samples.HelloWorld

@BPF(license = "GPL")
public abstract class XDPDropEveryThirdPacket extends BPFProgram implements XDPHook {
    final GlobalVariable<@Unsigned Integer> count = new GlobalVariable<>(0);

    @Override
    public xdp_action xdpHandlePacket(Ptr<xdp_md> ctx) {
        count.set(count.get() + 1);
        return count.get() % 3 == 1 ? xdp_action.XDP_DROP : xdp_action.XDP_PASS;
    }

    public static void main(String[] args) throws InterruptedException {
        try (var p = BPFProgram.load(XDPDropEveryThirdPacket.class)) {
            p.xdpAttach(XDPUtil.getNetworkInterfaceIndex());
            while (true) { System.out.println("Packets: " + p.count.get()); Thread.sleep(1000); }
        }
    }
}

@BPF(license = "GPL")
@Property(name = "sched_name", value = "my_scheduler")
public abstract class MyScheduler extends SchedulerBase implements Scheduler {
    final DispatchQueue shared = DispatchQueue.attach(SHARED_DSQ_ID);

    @Override
    public void enqueue(Ptr<task_struct> p, long enq_flags) {
        shared.insertScaled(p, EnqFlags.passThrough(enq_flags));
    }

    public static void main(String[] args) throws Exception {
        try (var sched = BPFProgram.load(MyScheduler.class)) {
            sched.runSchedulerLoop(); // attach + block until Ctrl-C
        }
    }
}

limactl start hello-ebpf.yaml --mount-writable
limactl shell hello-ebpf sudo bin/install.sh
limactl shell hello-ebpf
sudo -s PATH=$PATH   # root required for BPF program loading

sudo ./scheduler.sh        # starts on port 8087 by default
java samples/Ticker.java & # start a sample process
curl "localhost:8087/taskGroup/$(pgrep -f Ticker)?stopping=true"
# process stops being rescheduled
curl "localhost:8087/taskGroup/$(pgrep -f Ticker)?stopping=false"
# process resumes

# stop 10s, run 5s, stop 10s, run 10s
curl "localhost:8087/taskGroup/plan/$(pgrep -f Ticker)?plan=s10,r5,s10,r10"

curl "localhost:8087/taskGroup/plan/$(pgrep -f Ticker)"

ThreadControl tc = new ThreadControl();         // default port 8087
// ThreadControl tc = new ThreadControl(9000);  // custom port

Thread worker = new WorkerThread();
worker.start();

System.out.println("OS thread id: " + tc.osId(worker));
System.out.println("Status: " + tc.getThreadStatus(worker)); // RUNNING, STOPPED, or UNKNOWN

tc.stopThread(worker);
Thread.sleep(5000);
tc.resumeThread(worker);

sudo ./scheduler.sh -s fifo -p 9000

# 200 BPM, blues scale, only processes with "java" in their name
./scheduler.sh --bpm=200 --scale=BLUES --filter java

# scale the time slice based on number of active tasks
./scheduler.sh --scale-slice

# choose instruments for dispatches vs runtime
./scheduler.sh --dispatches-instrument=PIANO --runtime-instrument=STRINGS

./scheduler.sh -t FIFO      # FIFO scheduler (default)
./scheduler.sh -t LOTTERY   # lottery scheduler
./scheduler.sh -t VTIME     # virtual time scheduler

./scheduler.sh -t VTIME --cores=4

./scheduler.sh samples/run_queue.sh --java --log

./scheduler.sh my_test.sh --java --max-iterations=50

# run threads for 5–50ms, sleep them for 100–500ms
./scheduler.sh my_program --run=5ms,50ms --sleep=100ms,500ms

./scheduler.sh my_program --timeout=60

./scheduler.sh my_program --error-command="grep -q 'ERROR' app.log"
# grep exits 0 when it finds the pattern — that triggers failure detection

./scheduler.sh my_program --error-command="./check.sh" --error-check-interval=1s

java -jar check-language-version.jar src/main/java/ --summary

java -jar check-language-version.jar src/main/java/MyClass.java --verbose

java -jar check-language-version.jar src/ --json > module-a.json
java -jar check-language-version.jar other/src/ --json > module-b.json

java -jar check-language-version.jar summary module-a.json module-b.json

python3 visualize.py module-a.json module-b.json --output-dir charts --open

# Download a model
curl -X POST http://<phone-ip>:8005/ai/models/download \
  -H "Content-Type: application/json" \
  -d '{"modelName": "GEMMA_3_1B_IT"}'

# Run inference
curl -X POST http://<phone-ip>:8005/ai/text \
  -H "Content-Type: application/json" \
  -d '{"text": "Explain eBPF in one sentence", "model": "GEMMA_3_1B_IT", "maxTokens": 150}'

curl -X POST http://<phone-ip>:8005/ai/object_detection \
  -H "Content-Type: application/json" \
  -d '{"side": "rear", "threshold": 0.6, "maxResults": 5, "returnImage": false}'

# Compass orientation
curl http://<phone-ip>:8005/orientation

# Camera snapshot (app must be in foreground)
curl "http://<phone-ip>:8005/capture?side=rear&zoom=2.0"

# Server status, permissions, memory usage
curl http://<phone-ip>:8005/status

# Full API docs
curl http://<phone-ip>:8005/help