Reduce smoke test flakiness (#258)

### Public-Facing Changes

Reduce smoke test flakiness

### Description
Attempt to fix flaky smoke tests:

**ROS 1**
- Increased timeouts when waiting for channel to be communicated by the
server
- The ROS 1 server does not listen on graph changes, but instead
periodically queries the ROS master for changes regarding available
topics or services. The max. period between two consecutive ROS master
queries is 5 seconds (default), hence we have to use the same timeout in
the test.

**ROS 2**
- Use std::atomic for message handler that may be called concurrently
- Other minor improvements

ros1_foxglove_bridge/tests/smoke_test.cpp

@@ -84,7 +84,7 @@ TEST(SmokeTest, testSubscription) {
     auto client = std::make_shared<foxglove::Client<websocketpp::config::asio_client>>();
     auto channelFuture = foxglove::waitForChannel(client, topic_name);
     ASSERT_EQ(std::future_status::ready, client->connect(URI).wait_for(ONE_SECOND));
-    ASSERT_EQ(std::future_status::ready, channelFuture.wait_for(ONE_SECOND));
+    ASSERT_EQ(std::future_status::ready, channelFuture.wait_for(DEFAULT_TIMEOUT));
     const foxglove::Channel channel = channelFuture.get();
     const foxglove::SubscriptionId subscriptionId = 1;
 
@@ -124,7 +124,7 @@ TEST(SmokeTest, testSubscriptionParallel) {
   for (auto client : clients) {
     auto channelFuture = foxglove::waitForChannel(client, topic_name);
     ASSERT_EQ(std::future_status::ready, client->connect(URI).wait_for(ONE_SECOND));
-    ASSERT_EQ(std::future_status::ready, channelFuture.wait_for(ONE_SECOND));
+    ASSERT_EQ(std::future_status::ready, channelFuture.wait_for(DEFAULT_TIMEOUT));
     const foxglove::Channel channel = channelFuture.get();
     client->subscribe({{subscriptionId, channel.id}});
   }

ros2_foxglove_bridge/tests/smoke_test.cpp

@@ -484,9 +484,9 @@ TEST_F(ServiceTest, testCallServiceParallel) {
 
   auto serviceFuture = foxglove::waitForService(*clients.begin(), SERVICE_NAME);
   for (auto client : clients) {
-    ASSERT_EQ(std::future_status::ready, client->connect(URI).wait_for(std::chrono::seconds(5)));
+    ASSERT_EQ(std::future_status::ready, client->connect(URI).wait_for(ONE_SECOND));
   }
-  ASSERT_EQ(std::future_status::ready, serviceFuture.wait_for(std::chrono::seconds(5)));
+  ASSERT_EQ(std::future_status::ready, serviceFuture.wait_for(DEFAULT_TIMEOUT));
   const foxglove::Service service = serviceFuture.get();
 
   std_srvs::srv::SetBool::Request requestMsg;
@@ -508,7 +508,7 @@ TEST_F(ServiceTest, testCallServiceParallel) {
   }
 
   for (auto& future : futures) {
-    ASSERT_EQ(std::future_status::ready, future.wait_for(std::chrono::seconds(5)));
+    ASSERT_EQ(std::future_status::ready, future.wait_for(DEFAULT_TIMEOUT));
     foxglove::ServiceResponse response;
     EXPECT_NO_THROW(response = future.get());
     EXPECT_EQ(response.serviceId, request.serviceId);
@@ -558,7 +558,7 @@ TEST(SmokeTest, receiveMessagesOfMultipleTransientLocalPublishers) {
 
   // Set up binary message handler to resolve the promise when all nPub message have been received
   std::promise<void> promise;
-  size_t nReceivedMessages = 0;
+  std::atomic<size_t> nReceivedMessages = 0;
   client->setBinaryMessageHandler([&promise, &nReceivedMessages](const uint8_t*, size_t) {
     if (++nReceivedMessages == nPubs) {
       promise.set_value();
@@ -567,8 +567,12 @@ TEST(SmokeTest, receiveMessagesOfMultipleTransientLocalPublishers) {
 
   // Subscribe to the channel and confirm that the promise resolves
   client->subscribe({{subscriptionId, channel.id}});
-  ASSERT_EQ(std::future_status::ready, promise.get_future().wait_for(ONE_SECOND));
+  EXPECT_EQ(std::future_status::ready, promise.get_future().wait_for(DEFAULT_TIMEOUT));
+  EXPECT_EQ(nReceivedMessages, nPubs);
+  client->unsubscribe({subscriptionId});
 
+  pubs.clear();
+  executor.remove_node(node);
   executor.cancel();
   spinnerThread.join();
 }