fix: list delivered events in order of delivery

Author: joaomlneto

docs/implementing-protocols.md

@@ -4,17 +4,30 @@ This document describes the steps to implement a new BFT protocol in ByzzBench.
 
 A BFT Protocol implementation in ByzzBench consists of the following components:
 
-- A protocol replica that *extends* `Replica<T>`: these are the nodes that run the protocol and communicate with each other
+- A protocol replica that *extends* [`Replica<T>`](../simulator/src/main/java/byzzbench/simulator/Replica.java): these
+  are the nodes that run the protocol and communicate with each other
   via messages. `T` is the type of each of the entries in the commit log (this should be simplified!).
-  - Example: [PBFT-Java Replica](../simulator/src/main/java/byzzbench/simulator/protocols/pbft_java/PbftReplica.java)
-  - The `Replica` constructor requires a `replicaId`, `nodeIds` (set of all replica IDs in the *cluster*), `transport` (the virtualized network instance) and a `commitLog` (instance where all committed operations from the replica are sent to).
-- A set of protocol message POJOs that *implement* `MessagePayload`: these are the messages that are exchanged between replicas.
-  - They just need to have a `String getType()` method that returns e.g. that it is a `PREPARE` message.
-  - Examples from PBFT-Java: [Checkpoint](../simulator/src/main/java/byzzbench/simulator/protocols/pbft_java/message/CheckpointMessage.java), [Commit](../simulator/src/main/java/byzzbench/simulator/protocols/pbft_java/message/CommitMessage.java), [NewView](../simulator/src/main/java/byzzbench/simulator/protocols/pbft_java/message/NewViewMessage.java), [Phase](../simulator/src/main/java/byzzbench/simulator/protocols/pbft_java/message/PhaseMessage.java), [Prepare](../simulator/src/main/java/byzzbench/simulator/protocols/pbft_java/message/PrepareMessage.java), [PrePrepare](../simulator/src/main/java/byzzbench/simulator/protocols/pbft_java/message/PrePrepareMessage.java), [Reply](../simulator/src/main/java/byzzbench/simulator/protocols/pbft_java/message/ReplyMessage.java), [Request](../simulator/src/main/java/byzzbench/simulator/protocols/pbft_java/message/RequestMessage.java), [ViewChange](../simulator/src/main/java/byzzbench/simulator/protocols/pbft_java/message/ViewChangeMessage.java)
+    - Example: [PBFT-Java Replica](../simulator/src/main/java/byzzbench/simulator/protocols/pbft_java/PbftReplica.java)
+    - The `Replica` constructor requires a `replicaId`, `nodeIds` (set of all replica IDs in the
+      *cluster*), `transport` (the virtualized network instance) and a `commitLog` (instance where all committed
+      operations from the replica are sent to).
+- A set of protocol message POJOs that
+  *implement* [`MessagePayload`](../simulator/src/main/java/byzzbench/simulator/transport/MessagePayload.java): these
+  are the messages that are exchanged between
+  replicas.
+    - They just need to have a `String getType()` method that returns e.g. that it is a `PREPARE` message.
+    - Examples from
+      PBFT-Java: [Checkpoint](../simulator/src/main/java/byzzbench/simulator/protocols/pbft_java/message/CheckpointMessage.java), [Commit](../simulator/src/main/java/byzzbench/simulator/protocols/pbft_java/message/CommitMessage.java), [NewView](../simulator/src/main/java/byzzbench/simulator/protocols/pbft_java/message/NewViewMessage.java), [Phase](../simulator/src/main/java/byzzbench/simulator/protocols/pbft_java/message/PhaseMessage.java), [Prepare](../simulator/src/main/java/byzzbench/simulator/protocols/pbft_java/message/PrepareMessage.java), [PrePrepare](../simulator/src/main/java/byzzbench/simulator/protocols/pbft_java/message/PrePrepareMessage.java), [Reply](../simulator/src/main/java/byzzbench/simulator/protocols/pbft_java/message/ReplyMessage.java), [Request](../simulator/src/main/java/byzzbench/simulator/protocols/pbft_java/message/RequestMessage.java), [ViewChange](../simulator/src/main/java/byzzbench/simulator/protocols/pbft_java/message/ViewChangeMessage.java)
 
 ## Communication and Timeouts
 
-Communication between replicas is done via message-passing through the `Transport`. The `Replica` superclass exposes a few methods:
+Using the Actor model, replicas communicate with each other via
+a [`Transport`](../simulator/src/main/java/byzzbench/simulator/transport) instance.
+The `Transport` is a virtualized network that allows replicas to send messages to each other.
+The `Transport` is responsible for delivering messages to the correct recipient, and also for handling timeouts.
+
+Communication between replicas is done via message-passing through the `Transport`. The `Replica` superclass exposes a
+few methods:
 
 - `sendMessage`: send a message to a recipient
 - `multicastMessage`: send a message to a set of replicas
@@ -23,9 +36,12 @@ Communication between replicas is done via message-passing through the `Transpor
 
 Timeouts are implemented via callbacks to a `Runnable`, also handled by the `Transport`:
 
-- `setTimeout(Runnable, timeout)`: Creates a timeout event of `timeout` milliseconds, which will then invoke the `Runnable`. The time is currently being ignored, and is instead triggered just like any other event by the scheduler.
+- `setTimeout(Runnable, timeout)`: Creates a timeout event of `timeout` milliseconds, which will then invoke
+  the `Runnable`. The time is currently being ignored, and is instead triggered just like any other event by the
+  scheduler.
 - `clearAllTimeouts()`: Invalidates all outstanding timeouts for the current replica.
 
 ## Commit Log
 
-Each replica has its own instance of a `CommitLog`: an immutable and total ordered sequence of records. This is used to check whether safety invariants of distributed consensus are broken.
+Each replica has its own instance of a `CommitLog`: an immutable and total ordered sequence of records. This is used to
+check whether safety invariants of distributed consensus are broken.

simulator/src/main/java/byzzbench/simulator/controller/SimulatorController.java

@@ -80,6 +80,15 @@ public List<Long> getDeliveredMessages() {
                 .toList();
     }
 
+    @GetMapping("/schedule")
+    public List<Long> getSchedule() {
+        return simulatorService.getScenarioExecutor().getTransport()
+                .getSchedule()
+                .stream()
+                .map(Event::getEventId)
+                .toList();
+    }
+
     @GetMapping("/event/{eventId}")
     public Event getMessage(@PathVariable Long eventId) {
         return simulatorService.getScenarioExecutor().getTransport().getEvents().get(eventId);

simulator/src/main/java/byzzbench/simulator/transport/Transport.java

@@ -23,6 +23,9 @@ public class Transport<T extends Serializable> {
     @JsonIgnore
     private final Map<Long, Event> events = new TreeMap<>();
 
+    @Getter(onMethod_ = {@Synchronized})
+    private final List<Event> schedule = new ArrayList<>();
+
     @Getter(onMethod_ = {@Synchronized})
     @JsonIgnore
     private final Map<Long, MessageMutator> mutators = new TreeMap<>();
@@ -90,7 +93,10 @@ public void deliverEvent(long eventId) throws Exception {
             throw new RuntimeException("Event not in QUEUED state");
         }
 
+        // deliver the event
+        this.schedule.add(e);
         e.setStatus(Event.Status.DELIVERED);
+
         switch (e) {
             case MessageEvent m -> nodes.get(m.getRecipientId()).handleMessage(m.getSenderId(), m.getPayload());
             case TimeoutEvent t -> t.getTask().run();

webui/app/page.tsx

@@ -22,7 +22,7 @@ export default function Home() {
         <Title order={3}>Nodes</Title>
         <NodeList />
         <br />
-        <Title order={3}>Delivered Messages</Title>
+        <Title order={3}>Schedule</Title>
         <DeliveredMessagesList />
         <br />
         <Title order={3}>Dropped Messages</Title>

webui/components/messages/DeliveredMessagesList.tsx

@@ -1,10 +1,10 @@
 "use client";
 
 import { MessagesList } from "@/components/messages/MessagesList";
-import { useGetDeliveredMessages } from "@/lib/byzzbench-client/generated";
+import { useGetSchedule } from "@/lib/byzzbench-client";
 import React from "react";
 
 export const DeliveredMessagesList = () => {
-  const { data } = useGetDeliveredMessages({ query: { retry: true } });
+  const { data } = useGetSchedule({ query: { retry: true } });
   return <MessagesList messageIds={data?.data ?? []} />;
 };