From 5373cf1cd5e2899c7d9fd7976ec39fbf4e5efc95 Mon Sep 17 00:00:00 2001
From: elsid <elsid.mail@gmail.com>
Date: Sat, 15 May 2021 12:36:37 +0200
Subject: [PATCH] Replace raw pointer by observer_ptr to avoid dangling pointer
dereferencing
When game exit is requests when initial loading screen is active LightManager
can be destructed in the main thread before LightManagerStateAttribute::apply
is completed by different thread. Given that it uses raw pointer at some point
it becomes dangling because object is destructed this leads to UB and eventual
SIGSEGV.
---
components/sceneutil/lightmanager.cpp | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/components/sceneutil/lightmanager.cpp b/components/sceneutil/lightmanager.cpp
index b5c7af780c..00c19dd402 100644
--- a/components/sceneutil/lightmanager.cpp
+++ b/components/sceneutil/lightmanager.cpp
@@ -731,7 +731,7 @@ namespace SceneUtil
META_StateAttribute(NifOsg, LightManagerStateAttribute, osg::StateAttribute::LIGHT)
- void initSharedLayout(osg::GLExtensions* ext, int handle) const
+ void initSharedLayout(osg::GLExtensions* ext, int handle, LightManager& lightManager) const
{
constexpr std::array<unsigned int, 1> index = { static_cast<unsigned int>(Shader::UBOBinding::LightBuffer) };
int totalBlockSize = -1;
@@ -753,13 +753,17 @@ namespace SceneUtil
for (int i = 0; i < 2; ++i)
{
- auto& buf = mLightManager->getLightBuffer(i);
+ auto& buf = lightManager.getLightBuffer(i);
buf->configureLayout(offsets[0], offsets[1], offsets[2], totalBlockSize, stride);
}
}
void apply(osg::State& state) const override
{
+ osg::ref_ptr<LightManager> lightManager;
+ if (!mLightManager.lock(lightManager))
+ return;
+
if (!mInitLayout)
{
mDummyProgram->apply(state);
@@ -772,12 +776,12 @@ namespace SceneUtil
// wait until the UBO binding is created
if (activeUniformBlocks > 0)
{
- initSharedLayout(ext, handle);
+ initSharedLayout(ext, handle, *lightManager);
mInitLayout = true;
}
}
- mLightManager->getLightBuffer(state.getFrameStamp()->getFrameNumber())->uploadCachedSunPos(state.getInitialViewMatrix());
- mLightManager->getLightBuffer(state.getFrameStamp()->getFrameNumber())->dirty();
+ lightManager->getLightBuffer(state.getFrameStamp()->getFrameNumber())->uploadCachedSunPos(state.getInitialViewMatrix());
+ lightManager->getLightBuffer(state.getFrameStamp()->getFrameNumber())->dirty();
}
private:
@@ -807,7 +811,7 @@ namespace SceneUtil
return shader;
}
- LightManager* mLightManager;
+ osg::observer_ptr<LightManager> mLightManager;
osg::ref_ptr<osg::Program> mDummyProgram;
mutable bool mInitLayout;
};