client: handle connections with ready responses in waitAny

Currently, `waitAny` does not account for connections that already have
ready responses. Let's handle this by going through the set of owned
connections and checking them for ready responses. We should do this before
the timer start, since the checking overhead should not be accounted for
the waiting time.

Closes #132

Author: CuriousGeorgiy

src/Client/Connection.hpp

@@ -85,6 +85,8 @@ struct ConnectionImpl
 	void setError(const std::string &msg, int errno_ = 0);
 	bool hasError() const;
 
+	size_t getFutureCount() const;
+
 	BUFFER &getInBuf();
 	BUFFER &getOutBuf();
 
@@ -161,6 +163,13 @@ ConnectionImpl<BUFFER, NetProvider>::hasError() const
 	return error.has_value();
 }
 
+template <class BUFFER, class NetProvider>
+size_t
+ConnectionImpl<BUFFER, NetProvider>::getFutureCount() const
+{
+	return futures.size();
+}
+
 template <class BUFFER, class NetProvider>
 BUFFER &
 ConnectionImpl<BUFFER, NetProvider>::getInBuf()
@@ -459,7 +468,7 @@ template<class BUFFER, class NetProvider>
 size_t
 Connection<BUFFER, NetProvider>::getFutureCount() const
 {
-	return impl->futures.size();
+	return impl->getFutureCount();
 }
 
 template<class BUFFER, class NetProvider>

src/Client/Connector.hpp

@@ -364,6 +364,10 @@ Connector<BUFFER, NetProvider>::waitAny(int timeout)
 		LOG_DEBUG("waitAny() called on connector without connections");
 		return std::nullopt;
 	}
+	for (auto *conn : m_Connections) {
+		if (conn->getFutureCount() != 0)
+			return conn;
+	}
 	Timer timer{timeout};
 	timer.start();
 	while (m_ReadyToDecode.empty()) {

test/ClientTest.cpp

@@ -1388,13 +1388,10 @@ test_wait(Connector<BUFFER, NetProvider> &client)
 	/* FIXME(gh-143): test solely that we check future readiness before waiting. */
 	fail_unless(client.waitCount(conn, 0) == 0);
 	conn.getResponse(f);
-	/* FIXME(gh-132): waitAny does not check connections for ready futures. */
-#if 0
 	f = conn.ping();
 	fail_unless(client.wait(conn, f, WAIT_TIMEOUT) == 0);
 	fail_unless(client.waitAny(conn).has_value());
 	conn.getResponse(f);
-#endif
 
 #ifdef __linux__
 	TEST_CASE("wait methods internal wait failure (gh-121)");