From 65e69fcd37086cad856194d4e274bad72e459199 Mon Sep 17 00:00:00 2001
From: Gunnar Beutner <gunnar@beutner.name>
Date: Tue, 1 Jul 2014 09:38:22 +0200
Subject: [PATCH] Another attempt at fixing the API deadlock

fixes #6617
---
 lib/remote/apiclient.cpp   | 11 +++++++++++
 lib/remote/apiclient.hpp   |  4 ++++
 lib/remote/apilistener.cpp |  4 ++++
 3 files changed, 19 insertions(+)

diff --git a/lib/remote/apiclient.cpp b/lib/remote/apiclient.cpp
index 9203094f1..e7a2c5cb0 100644
--- a/lib/remote/apiclient.cpp
+++ b/lib/remote/apiclient.cpp
@@ -65,6 +65,17 @@ ConnectionRole ApiClient::GetRole(void) const
 }
 
 void ApiClient::SendMessage(const Dictionary::Ptr& message)
+{
+	if (m_WriteQueue.GetLength() > 5000) {
+		Log(LogWarning, "remote", "Closing connection for API identity '" + m_Identity + "': Too many queued messages.");
+		Disconnect();
+		return;
+	}
+
+	m_WriteQueue.Enqueue(boost::bind(&ApiClient::SendMessageSync, this, message));
+}
+
+void ApiClient::SendMessageSync(const Dictionary::Ptr& message)
 {
 	try {
 		ObjectLock olock(m_Stream);
diff --git a/lib/remote/apiclient.hpp b/lib/remote/apiclient.hpp
index b491708c0..b6d87e068 100644
--- a/lib/remote/apiclient.hpp
+++ b/lib/remote/apiclient.hpp
@@ -23,6 +23,7 @@
 #include "remote/endpoint.hpp"
 #include "base/stream.hpp"
 #include "base/timer.hpp"
+#include "base/workqueue.hpp"
 #include "remote/i2-remote.hpp"
 
 namespace icinga
@@ -64,8 +65,11 @@ private:
 	ConnectionRole m_Role;
 	double m_Seen;
 
+	WorkQueue m_WriteQueue;
+
 	bool ProcessMessage(void);
 	void MessageThreadProc(void);
+	void SendMessageSync(const Dictionary::Ptr& request);
 };
 
 }
diff --git a/lib/remote/apilistener.cpp b/lib/remote/apilistener.cpp
index c666a701b..5f981bd60 100644
--- a/lib/remote/apilistener.cpp
+++ b/lib/remote/apilistener.cpp
@@ -364,6 +364,10 @@ void ApiListener::ApiTimerHandler(void)
 				if (endpoint->GetHost().IsEmpty() || endpoint->GetPort().IsEmpty())
 					continue;
 
+				/* don't try to connect if there's already a connection attempt */
+				if (endpoint->GetConnecting())
+					continue;
+
 				Utility::QueueAsyncCallback(boost::bind(&ApiListener::AddConnection, this, endpoint));
 			}
 		}