From 3e3e492f4801df56226a5aff5d82bfa86c9d3812 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tom=C3=A1=C5=A1=20Pecka?= <tomas.pecka@cesnet.cz>
Date: Tue, 3 Dec 2024 13:59:52 +0100
Subject: [PATCH 19/44] tests: fix deadlock in tests
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Organization: Wires

In the case the client never requests (because of misconfiguration or
something else) the test would still be waiting for somebody to
decrement the latch.
Unfortunately std::latch does not allow waiting for specified amount of
time, so this patch replaces it with std::binary_semaphore in which it
is possible to fail the acquiring operation after some time.

Change-Id: I38c007555bb5ab543329d724a16f024a9d80903e
Signed-off-by: Mattias Walström <lazzer@gmail.com>
---
 tests/restconf-notifications.cpp | 10 +++++-----
 tests/restconf_utils.cpp         |  4 ++--
 tests/restconf_utils.h           |  8 +++++---
 3 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/tests/restconf-notifications.cpp b/tests/restconf-notifications.cpp
index 4496b63..04131d7 100644
--- a/tests/restconf-notifications.cpp
+++ b/tests/restconf-notifications.cpp
@@ -7,6 +7,7 @@
 
 #include "trompeloeil_doctest.h"
 static const auto SERVER_PORT = "10088";
+#include <latch>
 #include <libyang-cpp/Time.hpp>
 #include <nghttp2/asio_http2.h>
 #include <spdlog/spdlog.h>
@@ -119,8 +120,7 @@ TEST_CASE("NETCONF notification streams")
             auto notifSession = sysrepo::Connection{}.sessionStart();
             auto ctx = notifSession.getContext();
 
-            // wait until the client sends its HTTP request
-            requestSent.wait();
+            WAIT_UNTIL_SSE_CLIENT_REQUESTS;
 
             SEND_NOTIFICATION(notificationsJSON[0]);
             SEND_NOTIFICATION(notificationsJSON[1]);
@@ -239,7 +239,7 @@ TEST_CASE("NETCONF notification streams")
                     SEND_NOTIFICATION(notificationsJSON[3]);
                     SEND_NOTIFICATION(notificationsJSON[4]);
                     oldNotificationsDone.count_down();
-                    requestSent.wait();
+                    WAIT_UNTIL_SSE_CLIENT_REQUESTS;
 
                     waitForCompletionAndBitMore(seqMod1);
                     waitForCompletionAndBitMore(seqMod2);
@@ -256,7 +256,7 @@ TEST_CASE("NETCONF notification streams")
                     SEND_NOTIFICATION(notificationsJSON[1]);
 
                     oldNotificationsDone.count_down();
-                    requestSent.wait();
+                    WAIT_UNTIL_SSE_CLIENT_REQUESTS;
 
                     SEND_NOTIFICATION(notificationsJSON[2]);
                     SEND_NOTIFICATION(notificationsJSON[3]);
@@ -290,7 +290,7 @@ TEST_CASE("NETCONF notification streams")
                 SEND_NOTIFICATION(notificationsJSON[4]);
 
                 oldNotificationsDone.count_down();
-                requestSent.wait();
+                WAIT_UNTIL_SSE_CLIENT_REQUESTS;
                 waitForCompletionAndBitMore(seqMod1);
                 waitForCompletionAndBitMore(seqMod2);
             }));
diff --git a/tests/restconf_utils.cpp b/tests/restconf_utils.cpp
index 8252bba..c3ff1de 100644
--- a/tests/restconf_utils.cpp
+++ b/tests/restconf_utils.cpp
@@ -164,7 +164,7 @@ SSEClient::SSEClient(
     boost::asio::io_service& io,
     const std::string& server_address,
     const std::string& server_port,
-    std::latch& requestSent,
+    std::binary_semaphore& requestSent,
     const RestconfNotificationWatcher& notification,
     const std::string& uri,
     const std::map<std::string, std::string>& headers,
@@ -192,7 +192,7 @@ SSEClient::SSEClient(
 
         auto req = client->submit(ec, "GET", serverAddressAndPort(server_address, server_port) + uri, "", reqHeaders);
         req->on_response([&, silenceTimeout](const ng_client::response& res) {
-            requestSent.count_down();
+            requestSent.release();
             res.on_data([&, silenceTimeout](const uint8_t* data, std::size_t len) {
                 // not a production-ready code. In real-life condition the data received in one callback might probably be incomplete
                 for (const auto& event : parseEvents(std::string(reinterpret_cast<const char*>(data), len))) {
diff --git a/tests/restconf_utils.h b/tests/restconf_utils.h
index 8b7386e..9efe398 100644
--- a/tests/restconf_utils.h
+++ b/tests/restconf_utils.h
@@ -8,8 +8,8 @@
 
 #pragma once
 #include "trompeloeil_doctest.h"
-#include <latch>
 #include <nghttp2/asio_http2_client.h>
+#include <semaphore>
 #include "event_watchers.h"
 #include "UniqueResource.h"
 
@@ -92,7 +92,7 @@ struct SSEClient {
         boost::asio::io_service& io,
         const std::string& server_address,
         const std::string& server_port,
-        std::latch& requestSent,
+        std::binary_semaphore& requestSent,
         const RestconfNotificationWatcher& notification,
         const std::string& uri,
         const std::map<std::string, std::string>& headers,
@@ -104,7 +104,7 @@ struct SSEClient {
 #define PREPARE_LOOP_WITH_EXCEPTIONS \
     boost::asio::io_service io; \
     std::promise<void> bg; \
-    std::latch requestSent(1);
+    std::binary_semaphore requestSent(0);
 
 #define RUN_LOOP_WITH_EXCEPTIONS \
     do { \
@@ -114,6 +114,8 @@ struct SSEClient {
         fut.get(); \
     } while (false)
 
+#define WAIT_UNTIL_SSE_CLIENT_REQUESTS requestSent.try_acquire_for(std::chrono::seconds(3))
+
 inline auto wrap_exceptions_and_asio(std::promise<void>& bg, boost::asio::io_service& io, std::function<void()> func)
 {
     return [&bg, &io, func]()
-- 
2.43.0