MantisBT - VTK | |||||
| View Issue Details | |||||
| ID | Project | Category | View Status | Date Submitted | Last Update |
| 0011208 | VTK | (No Category) | public | 2010-09-07 00:24 | 2010-09-08 12:36 |
| Reporter | David Gobbi | ||||
| Assigned To | David Gobbi | ||||
| Priority | high | Severity | crash | Reproducibility | always |
| Status | closed | Resolution | fixed | ||
| Platform | OS | OS Version | |||
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| Target Version | Fixed in Version | ||||
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| Summary | 0011208: Visual Studio 2003 crash for vtkOpenGLExtensionManager::ReadOpenGLExtensions() | ||||
| Description | The ReadOpenGLExtensions() method will call this->RenderWindow->Render() on Win32 machines if Render has not previously been called. This can cause a crash, because Render() in turn calls vtkOpenGLRenderWindow::OpenGLInit(), which calls vtkOpenGLRenderWindow::SetExtensionManager(0) and disassociates the ExtensionManager from the RenderWindow before creating a new ExtensionsManager. | ||||
| Steps To Reproduce | |||||
| Additional Information | This bug was tricky to find because it is hidden by VC80 and newer compilers. Here is a demonstration of how VC80 hides it. I added print statements to vtkOpenGLExtensionManager::ReadOpenGLExtensions() as follows: if (this->RenderWindow) { if (!this->RenderWindow->IsA("vtkOpenGLRenderWindow")) { // If the render window is not OpenGL, then it obviously has no // extensions. this->ExtensionsString = new char[1]; this->ExtensionsString[0] = '\0'; return; } cerr << "calling MakeCurrent " << this << "\n"; // ================ this->RenderWindow->MakeCurrent(); if (!this->RenderWindow->IsCurrent()) { // Really should create a method in the render window to create // the graphics context instead of forcing a full render. cerr << "calling Render " << this << "\n"; // ================ this->RenderWindow->Render(); } cerr << "calling IsCurrent " << this << "\n"; // ================ if (!this->RenderWindow->IsCurrent()) { // this case happens with a headless Mac: a mac with a graphics card // with no monitor attached to it, connected to it with "Screen Sharing" // (VNC-like feature added in Mac OS 10.5) // see bug 8554. this->ExtensionsString = new char[1]; this->ExtensionsString[0] = '\0'; return; } } This is the printout of a test crashing under VC71: bin\ChartsCxxTests.exe TestMultipleScalarsToColors -D E:/Kitware/VTKData Test timeout computed to be: 1500 calling MakeCurrent 04C84C88 calling Render 04C84C88 setting ExtensionManager to 0 created new extension manager 04C85ED0 calling MakeCurrent 04C85ED0 calling IsCurrent 04C85ED0 calling IsCurrent 04C84C88 *** Exception executing: Exit code 0xc0000354 The indentations show where the call to Render causes a new ExtensionManager to be created (I also added print statements to vtkOpenGLRenderWindow). The old ExtensionManager is destructed at the same time, which results in a crash when the call to Render() returns, since the original ExtensionManager has an invalid "this" pointer. It is fairly obvious why the code would crash on VC71. So I had to wonder why it wasn't crashing on all Win32 compilers. To understand, look at the output when VTK is compiled with VC80: bin\ChartsCxxTests.exe TestMultipleScalarsToColors -D E:/Kitware/VTKData created new extension manager 03429150 calling MakeCurrent 03429150 calling Render 03429150 setting ExtensionManager to 0 created new extension manager 03429150 calling MakeCurrent 03429150 calling IsCurrent 03429150 calling IsCurrent 03429150 -- Process completed The VC80 compiler first deletes the ExtensionManager, but then recreates it at exactly the same memory location. In other words, it is doing some memory-management tricks that hide the bug. Update July 8, 2010: Commit 0e84a23372139b50aab77deee9c6865efc2b4643 seems to fix this bug. It makes OpenGLInit call ExtensionManager->Modified() instead of deleting the extension manager. This will force the extension manager to re-read the extensions the next time its Update method is called. | ||||
| Tags | No tags attached. | ||||
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| Issue History | |||||
| Date Modified | Username | Field | Change | ||
| 2010-09-07 00:24 | David Gobbi | New Issue | |||
| 2010-09-07 10:43 | David Gobbi | Note Added: 0022107 | |||
| 2010-09-08 12:28 | David Gobbi | Status | backlog => tabled | ||
| 2010-09-08 12:28 | David Gobbi | Assigned To | => David Gobbi | ||
| 2010-09-08 12:30 | David Gobbi | Note Deleted: 0022107 | |||
| 2010-09-08 12:33 | David Gobbi | Additional Information Updated | |||
| 2010-09-08 12:36 | David Gobbi | Status | tabled => closed | ||
| 2010-09-08 12:36 | David Gobbi | Resolution | open => fixed | ||
| 2011-06-16 13:11 | Zack Galbreath | Category | => (No Category) | ||
| There are no notes attached to this issue. |