From 508319df28270eccdfa03a880a8604549278a139 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Wed, 26 Nov 2014 11:24:12 +0200
Subject: [PATCH] Pass errors from the resource loading thread to the main
 thread

---
 source/resourcemanager.cpp | 29 +++++++++++++++++++++++++++--
 source/resourcemanager.h   | 12 +++++++++++-
 2 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/source/resourcemanager.cpp b/source/resourcemanager.cpp
index 7bf4412f..c6e3f357 100644
--- a/source/resourcemanager.cpp
+++ b/source/resourcemanager.cpp
@@ -1,4 +1,7 @@
 #include <algorithm>
+#include <typeinfo>
+#include <msp/debug/demangle.h>
+#include <msp/strings/format.h>
 #include <msp/time/utils.h>
 #include "resourcemanager.h"
 #include "resourcewatcher.h"
@@ -8,6 +11,11 @@ using namespace std;
 namespace Msp {
 namespace GL {
 
+resource_load_error::resource_load_error(const string &name, const exception &exc):
+	runtime_error(format("%s: %s: %s", name, Debug::demangle(typeid(exc).name()), exc.what()))
+{ }
+
+
 ResourceManager::ResourceManager():
 	policy(LOAD_ON_DEMAND),
 	async_loads(true),
@@ -329,7 +337,16 @@ void ResourceManager::LoadingThread::main()
 
 		if(ManagedResource *managed = front(async_queue))
 		{
-			managed->process(false);
+			try
+			{
+				managed->process(false);
+			}
+			catch(const exception &e)
+			{
+				MutexLock lock(queue_mutex);
+				error_queue.push_back(resource_load_error(managed->name, e));
+				managed->state = ManagedResource::LOAD_ERROR;
+			}
 
 			MutexLock lock(queue_mutex);
 			sync_queue.splice(sync_queue.end(), async_queue, async_queue.begin());
@@ -398,6 +415,14 @@ bool ResourceManager::LoadingThread::sync()
 {
 	{
 		MutexLock lock(queue_mutex);
+
+		if(!error_queue.empty())
+		{
+			resource_load_error err = error_queue.front();
+			error_queue.pop_front();
+			throw err;
+		}
+
 		unsigned async_size = async_queue.size();
 		if(async_size==0 && size==capacity)
 			++capacity;
@@ -408,7 +433,7 @@ bool ResourceManager::LoadingThread::sync()
 	bool any_finished = false;
 	while(ManagedResource *managed = front(sync_queue))
 	{
-		if(managed->process(true))
+		if(managed->state==ManagedResource::LOAD_ERROR || managed->process(true))
 		{
 			managed->finish_loading();
 			any_finished = true;
diff --git a/source/resourcemanager.h b/source/resourcemanager.h
index a1ff7aee..a2a4975d 100644
--- a/source/resourcemanager.h
+++ b/source/resourcemanager.h
@@ -13,6 +13,14 @@ namespace GL {
 
 class ResourceWatcher;
 
+class resource_load_error: public std::runtime_error
+{
+public:
+	resource_load_error(const std::string &, const std::exception &);
+	virtual ~resource_load_error() throw() { }
+};
+
+
 class ResourceManager
 {
 public:
@@ -32,7 +40,8 @@ private:
 			LOAD_QUEUED,
 			LOADING,
 			LOAD_FINISHED,
-			LOADED
+			LOADED,
+			LOAD_ERROR
 		};
 
 		Resource *resource;
@@ -68,6 +77,7 @@ private:
 		LoadQueue sync_queue;
 		unsigned capacity;
 		unsigned size;
+		std::list<resource_load_error> error_queue;
 		volatile bool done;
 
 	public:
-- 
2.43.0