From 1369058280c4cf399d46df1508b80cad99f1247e Mon Sep 17 00:00:00 2001
From: Justin Clark-Casey (justincc)
Date: Wed, 22 Aug 2012 23:04:17 +0100
Subject: Lock disposal of separate gdi+ objects under different threads since
this prevents malloc heap corruption seen under Ubuntu 10.04.1 and 11.04 -
probably a libcairo issue
In testing, it appears that if multiple threads dispose of separate GDI+ objects simultaneously,
the native malloc heap can become corrupted, possibly due to a double free(). This may be due to
bugs in the underlying libcairo used by mono's libgdiplus.dll on Linux/OSX. These problems were
seen with both libcario 1.10.2-6.1ubuntu3 and 1.8.10-2ubuntu1. They go away if disposal is perfomed
under lock.
---
.../Scripting/VectorRender/VectorRenderModule.cs | 68 +++++++++++++---------
1 file changed, 42 insertions(+), 26 deletions(-)
(limited to 'OpenSim/Region')
diff --git a/OpenSim/Region/CoreModules/Scripting/VectorRender/VectorRenderModule.cs b/OpenSim/Region/CoreModules/Scripting/VectorRender/VectorRenderModule.cs
index ca320e1..c48a703 100644
--- a/OpenSim/Region/CoreModules/Scripting/VectorRender/VectorRenderModule.cs
+++ b/OpenSim/Region/CoreModules/Scripting/VectorRender/VectorRenderModule.cs
@@ -308,36 +308,44 @@ namespace OpenSim.Region.CoreModules.Scripting.VectorRender
try
{
- if (alpha == 256)
- bitmap = new Bitmap(width, height, PixelFormat.Format32bppRgb);
- else
- bitmap = new Bitmap(width, height, PixelFormat.Format32bppArgb);
-
- graph = Graphics.FromImage(bitmap);
-
- // this is really just to save people filling the
- // background color in their scripts, only do when fully opaque
- if (alpha >= 255)
+ // XXX: In testing, it appears that if multiple threads dispose of separate GDI+ objects simultaneously,
+ // the native malloc heap can become corrupted, possibly due to a double free(). This may be due to
+ // bugs in the underlying libcairo used by mono's libgdiplus.dll on Linux/OSX. These problems were
+ // seen with both libcario 1.10.2-6.1ubuntu3 and 1.8.10-2ubuntu1. They go away if disposal is perfomed
+ // under lock.
+ lock (this)
{
- using (SolidBrush bgFillBrush = new SolidBrush(bgColor))
+ if (alpha == 256)
+ bitmap = new Bitmap(width, height, PixelFormat.Format32bppRgb);
+ else
+ bitmap = new Bitmap(width, height, PixelFormat.Format32bppArgb);
+
+ graph = Graphics.FromImage(bitmap);
+
+ // this is really just to save people filling the
+ // background color in their scripts, only do when fully opaque
+ if (alpha >= 255)
{
- graph.FillRectangle(bgFillBrush, 0, 0, width, height);
+ using (SolidBrush bgFillBrush = new SolidBrush(bgColor))
+ {
+ graph.FillRectangle(bgFillBrush, 0, 0, width, height);
+ }
}
- }
-
- for (int w = 0; w < bitmap.Width; w++)
- {
- if (alpha <= 255)
+
+ for (int w = 0; w < bitmap.Width; w++)
{
- for (int h = 0; h < bitmap.Height; h++)
+ if (alpha <= 255)
{
- bitmap.SetPixel(w, h, Color.FromArgb(alpha, bitmap.GetPixel(w, h)));
+ for (int h = 0; h < bitmap.Height; h++)
+ {
+ bitmap.SetPixel(w, h, Color.FromArgb(alpha, bitmap.GetPixel(w, h)));
+ }
}
}
+
+ GDIDraw(data, graph, altDataDelim);
}
- GDIDraw(data, graph, altDataDelim);
-
byte[] imageJ2000 = new byte[0];
try
@@ -355,11 +363,19 @@ namespace OpenSim.Region.CoreModules.Scripting.VectorRender
}
finally
{
- if (graph != null)
- graph.Dispose();
-
- if (bitmap != null)
- bitmap.Dispose();
+ // XXX: In testing, it appears that if multiple threads dispose of separate GDI+ objects simultaneously,
+ // the native malloc heap can become corrupted, possibly due to a double free(). This may be due to
+ // bugs in the underlying libcairo used by mono's libgdiplus.dll on Linux/OSX. These problems were
+ // seen with both libcario 1.10.2-6.1ubuntu3 and 1.8.10-2ubuntu1. They go away if disposal is perfomed
+ // under lock.
+ lock (this)
+ {
+ if (graph != null)
+ graph.Dispose();
+
+ if (bitmap != null)
+ bitmap.Dispose();
+ }
}
}
--
cgit v1.1