From 4c5ee0dbbfdde5f658706c321ba67741d6657e50 Mon Sep 17 00:00:00 2001
From: "Alexander A. Klimov" <alexander.klimov@icinga.com>
Date: Wed, 3 Apr 2019 09:53:45 +0200
Subject: [PATCH] EventQueue#WaitForEvent(): re-add timeout

---
 lib/remote/eventqueue.cpp    | 13 +++++++++++--
 lib/remote/eventqueue.hpp    |  2 +-
 lib/remote/eventshandler.cpp | 18 +++++++++++-------
 3 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/lib/remote/eventqueue.cpp b/lib/remote/eventqueue.cpp
index ea7474aac..017d3dc57 100644
--- a/lib/remote/eventqueue.cpp
+++ b/lib/remote/eventqueue.cpp
@@ -5,6 +5,7 @@
 #include "base/io-engine.hpp"
 #include "base/singleton.hpp"
 #include "base/logger.hpp"
+#include "base/utility.hpp"
 #include <boost/asio/spawn.hpp>
 
 using namespace icinga;
@@ -102,8 +103,10 @@ Dictionary::Ptr EventQueue::WaitForEvent(void *client, double timeout)
 	}
 }
 
-Dictionary::Ptr EventQueue::WaitForEvent(void *client, boost::asio::yield_context yc)
+Dictionary::Ptr EventQueue::WaitForEvent(void *client, boost::asio::yield_context yc, double timeout)
 {
+	double deadline = -1.0;
+
 	for (;;) {
 		{
 			boost::mutex::scoped_try_lock lock(m_Mutex);
@@ -112,7 +115,13 @@ Dictionary::Ptr EventQueue::WaitForEvent(void *client, boost::asio::yield_contex
 				auto it = m_Events.find(client);
 				ASSERT(it != m_Events.end());
 
-				if (!it->second.empty()) {
+				if (it->second.empty()) {
+					if (deadline == -1.0) {
+						deadline = Utility::GetTime() + timeout;
+					} else if (Utility::GetTime() >= deadline) {
+						return nullptr;
+					}
+				} else {
 					Dictionary::Ptr result = *it->second.begin();
 					it->second.pop_front();
 					return result;
diff --git a/lib/remote/eventqueue.hpp b/lib/remote/eventqueue.hpp
index 8f6a76c0b..1a53baabb 100644
--- a/lib/remote/eventqueue.hpp
+++ b/lib/remote/eventqueue.hpp
@@ -32,7 +32,7 @@ public:
 	void SetFilter(std::unique_ptr<Expression> filter);
 
 	Dictionary::Ptr WaitForEvent(void *client, double timeout = 5);
-	Dictionary::Ptr WaitForEvent(void *client, boost::asio::yield_context yc);
+	Dictionary::Ptr WaitForEvent(void *client, boost::asio::yield_context yc, double timeout = 5);
 
 	static std::vector<EventQueue::Ptr> GetQueuesForType(const String& type);
 	static void UnregisterIfUnused(const String& name, const EventQueue::Ptr& queue);
diff --git a/lib/remote/eventshandler.cpp b/lib/remote/eventshandler.cpp
index 20f655f86..5e8e05901 100644
--- a/lib/remote/eventshandler.cpp
+++ b/lib/remote/eventshandler.cpp
@@ -103,17 +103,21 @@ bool EventsHandler::HandleRequest(
 	asio::const_buffer newLine ("\n", 1);
 
 	for (;;) {
-		String body = JsonEncode(queue->WaitForEvent(&request, yc));
+		auto event (queue->WaitForEvent(&request, yc));
 
-		boost::algorithm::replace_all(body, "\n", "");
+		if (event) {
+			String body = JsonEncode(event);
 
-		asio::const_buffer payload (body.CStr(), body.GetLength());
+			boost::algorithm::replace_all(body, "\n", "");
 
-		IoBoundWorkSlot dontLockTheIoThreadWhileWriting (yc);
+			asio::const_buffer payload (body.CStr(), body.GetLength());
 
-		asio::async_write(stream, payload, yc);
-		asio::async_write(stream, newLine, yc);
-		stream.async_flush(yc);
+			IoBoundWorkSlot dontLockTheIoThreadWhileWriting (yc);
+
+			asio::async_write(stream, payload, yc);
+			asio::async_write(stream, newLine, yc);
+			stream.async_flush(yc);
+		}
 	}
 }
 
-- 
2.40.0