From 60b59524e7a8b44dab94d69b239d67362f3dbb3d Mon Sep 17 00:00:00 2001
From: Emiel Bruijntjes <emiel.bruijntjes@copernica.com>
Date: Tue, 15 Apr 2014 13:14:16 +0200
Subject: [PATCH] when an error is detected on a channel, all subsequent and
 cached deferred objects are notified about the error too

---
 include/channelimpl.h       |  9 +++++++++
 include/connectionhandler.h |  3 +++
 src/channelimpl.cpp         | 26 ++++++++++++++++++++++++++
 3 files changed, 38 insertions(+)

diff --git a/include/channelimpl.h b/include/channelimpl.h
index 62cc70d..3d77fc2 100644
--- a/include/channelimpl.h
+++ b/include/channelimpl.h
@@ -485,6 +485,12 @@ public:
         if (!next) _newestCallback = nullptr;
     }
 
+    /**
+     *  Report errors to all deferred objects already in an error state
+     *  @param  force           Report errors even for objects not already in error state
+     */
+    void reportErrors(bool force = false);
+
     /**
      *  Report an error message on a channel
      *  @param  message
@@ -514,6 +520,9 @@ public:
         
         // if there was no next callback, the newest callback was just used
         if (!next) _newestCallback = nullptr;
+        
+        // when one error occured, all subsequent messages are in an error state too
+        reportErrors(true);
     }
 
     /**
diff --git a/include/connectionhandler.h b/include/connectionhandler.h
index 220e2dc..0fa28ee 100644
--- a/include/connectionhandler.h
+++ b/include/connectionhandler.h
@@ -31,6 +31,9 @@ public:
      *  @param  connection      the connection that needs the timeout
      *  @param  timeout         number of seconds to wait
      *  @param  callback        function to execute once time runs out
+     * 
+     * 
+     *  @todo   this one should be removed
      */
     virtual void setTimeout(Connection *connection, double seconds, const std::function<void()>& callback) {}
 
diff --git a/src/channelimpl.cpp b/src/channelimpl.cpp
index a3cc37e..27c1bea 100644
--- a/src/channelimpl.cpp
+++ b/src/channelimpl.cpp
@@ -121,6 +121,32 @@ Deferred &ChannelImpl::push(const Frame &frame)
     return push(new Deferred(send(frame)));
 }
 
+/**
+ *  Report errors to all deferred objects already in an error state
+ *  @param  force           Report errors even for objects not already in error state
+ */
+void ChannelImpl::reportErrors(bool force)
+{
+    // keep looping for as long as the oldest callback is in an error state
+    while (_oldestCallback && (force || !*_oldestCallback))
+    {
+        // construct monitor, because channel could be destructed
+        Monitor monitor(this);
+        
+        // report the error
+        auto *next = _oldestCallback->reportError("Frame could not be sent");
+        
+        // leap out if object is no longer valid after the callback was called
+        if (!monitor.valid()) return;
+        
+        // install the next deferred object
+        _oldestCallback.reset(next);
+        
+        // was this also the newest callback
+        if (!next) _newestCallback = nullptr;
+    }
+}
+
 /**
  *  Pause deliveries on a channel
  *