From 871f0d00ce19e17de3f5d5fd608be3d2f095e4ab Mon Sep 17 00:00:00 2001
From: Kamil Braun <kbraun@scylladb.com>
Date: Thu, 20 Jan 2022 16:14:53 +0100
Subject: [PATCH] test: raft: randomized_nemesis_test: rpc: don't propagate
 `gate_closed_exception` outside

The `raft::rpc` interface functions are called by `raft::server_impl`
and the exceptions may be propagated outside the server, e.g. through
the `add_entry` API.

Translate the internal `gate_closed_exception` to an external
`raft::stopped_error`.
---
 test/raft/randomized_nemesis_test.cc | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/test/raft/randomized_nemesis_test.cc b/test/raft/randomized_nemesis_test.cc
index 620c422db9..ad222cbfb0 100644
--- a/test/raft/randomized_nemesis_test.cc
+++ b/test/raft/randomized_nemesis_test.cc
@@ -369,6 +369,15 @@ private:
     size_t _add_entry_executions = 0;
     size_t _modify_config_executions = 0;
 
+    template <typename F>
+    auto with_gate(F&& f) -> decltype(f()) {
+        try {
+            co_return co_await seastar::with_gate(_gate, std::forward<F>(f));
+        } catch (const gate_closed_exception&) {
+            co_return coroutine::make_exception(raft::stopped_error{});
+        }
+    }
+
 public:
     rpc(raft::server_id id, snapshots_t<State>& snaps, send_message_t send)
         : _id(id), _snapshots(snaps), _send(std::move(send)) {
@@ -557,8 +566,7 @@ public:
         // and push the reply through the promise, which will resolve `f` (see `receive`, `snapshot_reply_message`
         // case).
 
-        co_return co_await with_gate(_gate,
-                [&, guard = std::move(guard), f = std::move(f)] () mutable -> future<raft::snapshot_reply> {
+        co_return co_await with_gate([&, guard = std::move(guard), f = std::move(f)] () mutable -> future<raft::snapshot_reply> {
             // TODO configurable
             static const raft::logical_clock::duration send_snapshot_timeout = 20_t;
 
@@ -585,8 +593,7 @@ public:
             .cmd = cmd,
             .reply_id = id
         });
-        co_return co_await with_gate(_gate,
-                [&, guard = std::move(guard), f = std::move(f)] () mutable -> future<raft::add_entry_reply> {
+        co_return co_await with_gate([&, guard = std::move(guard), f = std::move(f)] () mutable -> future<raft::add_entry_reply> {
             static const raft::logical_clock::duration send_add_entry_timeout = 20_t;
 
             try {
@@ -611,8 +618,7 @@ public:
             .del = del,
             .reply_id = id
         });
-        co_return co_await with_gate(_gate,
-                [&, guard = std::move(guard), f = std::move(f)] () mutable -> future<raft::add_entry_reply> {
+        co_return co_await with_gate([&, guard = std::move(guard), f = std::move(f)] () mutable -> future<raft::add_entry_reply> {
             static const raft::logical_clock::duration send_modify_config_timeout = 200_t;
 
             try {
@@ -634,8 +640,7 @@ public:
             .reply_id = id
         });
 
-        co_return co_await with_gate(_gate,
-                [&, guard = std::move(guard), f = std::move(f)] () mutable -> future<raft::read_barrier_reply> {
+        co_return co_await with_gate([&, guard = std::move(guard), f = std::move(f)] () mutable -> future<raft::read_barrier_reply> {
             // TODO configurable
             static const raft::logical_clock::duration execute_read_barrier_on_leader_timeout = 20_t;