Embedding thread names in Windows minidump files - c++

Our 32-bit C++ application names its threads using the standard approach on Windows. We generate minidumps when errors occur, but when the dumps are loaded into Visual Studio 2013 the thread names are missing. This makes it harder to debug the problem given the high number of threads present.
The only way I've heard of to improve this comes from this Microsoft User Voice posting, where the caller suggests embedding them in a custom stream, and writing a custom Visual Studio extension to rename the threads upon loading the dump. However, this seems cumbersome and apparently adds a lot of time to the loading process.
Is there an easier way to embed thread names in the dump so they "just work" when loading them in Visual Studio?
For reference: we use Visual Studio 2013 to build, our apps run on Win7 or higher, and we use Google Breakpad to generate dumps.

Microsoft has indicated that the SetThreadDescription API will be the basis for any proper support they add in the future for thread names in dumps, debuggers, and/or analysis tools.
Unfortunately it appears that this API is rather new and is not yet supported in dumps, WinDbg, Visual Studio Debugger, etc. There is a User Voice request to add this support, so please vote for it if you would like a way to properly give threads a persistent name.

After some more digging, it seems like one way to do this would be to store a pointer to the name in the ArbitraryUserPointer field of the TEB of the thread.
If the TEB was then embedded in the minidump (which can be achieved with the MiniDumpWithProcessThreadData flag, according to this article) then it seems like at the very least we could view the current thread name in the Visual Studio watch window by evaluating
(*(char **)(#TIB+0x14))
Perhaps a Visual Studio debugger add-on could be written to examine the contents of the TEB when a process is attached to, and use the exception 'hack' to set the name of the thread in the Threads window.

Related

Headless debugging on Windows

There is a bug that I would like to fix that only occurs on Windows Server without a GUI running. I have set up a Windows Server 2019 machine on Google Compute Engine that reproduces the bug, and would like to debug it.
Ideally, I would like to use gdb, but seeing as the program was built with Visual Studio 2019, gdb can't read the debugging symbols.
I don't have a Windows machine, so using Visual Studio will be difficult. I could set up a VM, but if there's an in-terminal way to do this that would be preferred.
I did a pretty thorough Google search, but it didn't turn up anything. Is there really no Windows solution for debugging C++ code headlessly?
MS has 2 console debuggers called CDB and NTSD so you don't actually need Visual Studio GUI to do the debugging. In fact there are a lot of debugging environments in Windows from MS beside the usual Visual Studio. Just install them in your Windows Server and control them remotely from your terminal
You can also debug MSVC-compiled code with LLDB since the PDB format has been published long time ago and LLVM on Windows does support it. No idea about current LLDB on Linux though
And since you have the source code, sometimes the old-school printf debugger is the best way to analyze the issue
If you can get a Windows VM it'll be much better to do remote debugging. In fact almost all debuggers support that feature including GDB or LLDB, so even if you don't have the source code you can still run any Windows debugger and step through the instructions instead of high-level code lines from a remote machine
An alternative way is to take a memory dump and debug later. After getting the dump file, just drag it into your VS solution or any debugging tool like WinDbg and then select "Start Debugging". Now you can step through instructions/code lines and examine variables' values, or jump to an arbitrary function's stack frame just as if you're really running the malfunctioning app
There are many ways to dump a process' memory. You can set Windows to automatically save a dump file when your app crashes, or just capture memory snapshots manually during runtime. Comparing 2 snapshots is also useful for detecting leaked memory. For more information on how to do that read
Collecting User-Mode Dumps
Steps to Catch a Simple “Crash Dump” of a Crashing Process
There's also an easy way to take a dump of a live process using task manager (or any other similar tools)

Can the visual studio debugger still be used to debug ppapi trusted plugins when using the --ppapi-out-of-process flag?

I am using the new MessageLoop class introduced in pepper-25 so I can run a background thread with blocking ppapi calls for File IO. Up until now I have been running chrome from visual studio with the flags --single-process and --register-pepper-plugins so I can debug my plugin from within visual studio.
Using these flags I found that the call to PPB_GetInterface get_browser for PPB_MESSAGING_INTERFACE was returning null and after some searching I found this issue which states you must run with the flag --ppapi-out-of-process to get MessageLoop support.
With that flag added get_browser does return a valid interface pointer but I can no longer debug my plugin with the visual studio ide as it cannot attach to the child process that my plugin is run from. Is there anyway to tell it to attach to my plug-in process or a way of running from a single process with support for MessageLoop?
Thanks,
James
To get Visual Studio to attach to child processes automatically, you can use the workarounds described at Can Visual Studio be made to debug child processes like WinDBG?.
A different approach is to use the flags --no-sandbox and --ppapi-startup-dialog when you start Chrome. This will cause a message box to appear with the process id when a plugin process is created. You can then connect the Visual Studio debugger to that process using Debug -> Attach to process... -> pick process id. Of course, you could have attached to the process without the Chrome flags and it's not automatic, so this really just gives you certainty that you're attaching to the right process if you have many running at the same time.
A third approach is to use the free Microsoft-provided debugger WinDbg. It is complex and much less user-friendly than the built-in debugger in Visual Studio, but it does have the ability to attach to child processes automatically. Download is available from http://msdn.microsoft.com/en-us/windows/hardware/gg463009.aspx.
As for MessageLoop it will not be supported for in-process plugins. As the issue you link to mentions, developers should move to out-of-process, even if it adds the inconvenience of not being able to attach the Visual Studio debugger automatically without workarounds.

Problems measuring performance of C++ project in Visual Studio 2010

I am trying to measure the performance of some functions and methods of a console application project in Visual Studio 2010.
I configured the profiling method to instrumentation. The problem is that the performance monitor doesn't work. The message that I get to the output is:
Profiling started.
Instrumenting w:\MyProject\ProfilingTest\Build\Debug\ProfilingTest.exe in place
Info VSP3049: Small functions will be excluded from instrumentation.
Microsoft (R) VSInstr Post-Link Instrumentation 10.0.40219 x64
Copyright (C) Microsoft Corp. All rights reserved.
File to Process:
w:\MyProject\ProfilingTest\Build\Debug\ProfilingTest.exe --> w:\MyProject\ProfilingTest\Build\Debug\ProfilingTest.exe
Original file backed up to w:\MyProject\ProfilingTest\Build\Debug\ProfilingTest.exe.orig
Successfully instrumented file w:\MyProject\ProfilingTest\Build\Debug\ProfilingTest.exe.
The process cannot access the file 'w:\MyProject\ProfilingTest\Build\Debug\ProfilingTest.exe' because it is being used by another process.
Data written to w:\MyProject\ProfilingTest\ProfilingTest110611(17).vsp.
Profiling finished.
File contains no data buffers
File contains no data buffers
Analysis failed
The process cannot access the file 'w:\MyProject\ProfilingTest\Build\Debug\ProfilingTest.exe' because it is being used by another process.
Profiling complete.
I presume that the "root of all evil" is:
The process cannot access the file '...' because it is being used by another process.
Did anybody faced such problems trying to profile native applications developed in Visual Studio 2010 and solve them?
Later add:
If, instead of choosing a project to profile, I am choosing directly the built executable, I succeed to profile, without receiving process blocking, I even received the file analysis. However, the monitoring application is crashing at the end of the profiling. I suspect is related to IDE, but I can't tell for sure.
from the performance wizard choose executable as your target and give the path to the executable. This solved problem for me.
Use process explorer's find handle feature (ctrl + F) to figure out which process has ProfilingTest.exe open. That'll get you to the next step of the troubleshooting process.
Another work-around that I found was to do the following:
1) Launch performance wizard
2) choose your project
3) un-check the box to automatically start your profiling
4) Choose "New Performance Session" and choose your project again (top button on Performance explorer window)
5) Select your performance session from "Targets" and choose "Start Profiling"
I wonder if the nice folks at Redmond have taken notice of this..
Regards.

Visual Studio Questions/C++

I'm a hobbyist developer and have a background with Java (IDE of choice was Eclipse). I'm using Visual Studio Express 2010 and wanting to learn C++.
Few questions:
I create a "HelloWorld" in C++ and compiles/runs in VS/Windows. When I try to compile it under Linux/GCC, it obviously throws tons of errors. Default windows console project includes windows specific files; but if just create an "Empty Project" it throws tons of linker/build errors. What's the best practices here to keep my code portable?
Why is it creating 47 files for 8 lines of code?
How do you format code? You can do Edit->Format Selection, but the hotkeys don't work?
How do I output to VS's 'Output' Window? ( like eclipse does when you run a console java app )
It keeps reverting my "Project Location" to my "home directory" every time I restart. How do you change it? Is it a bug? Because it's Express edition?
Is there a way to keep it from switching to Debug view when it runs?
I create a "HelloWorld" in C++ and
compiles/runs in VS/Windows. When I
try to compile it under Linux/GCC, it
obviously throws tons of errors.
Default windows console project
includes windows specific files; but
if just create an "Empty Project" it
throws tons of linker/build errors.
What's the best practices here to keep
my code portable?
For portable code, avoid VS wizards entirely. Use Make/NMake if you're starting with rocks and sticks, or the portable build system of your preference (Ant, CMake, etc.) Some of these will spit out a VS solution/project file for you to use.
Why is it creating 47 files for 8
lines of code?
Wizards are magical like that.
How do you format code? You can do
Edit->Format Selection, but the
hotkeys don't work?
Ctrl-K Ctrl-F (under Edit, Advanced)
How do I output to VS's 'Output'
Window? ( like eclipse does when you
run a console java app )
Lookup OutputDebugString() for the debug window. Output window should get all cout/cerr output.
It keeps reverting my "Project
Location" to my "home directory" every
time I restart. How do you change it?
Is it a bug? Because it's Express
edition?
Probably hidden in options somewhere - don't know that one, sorry.
Is there a way to keep it from
switching to Debug view when it runs?
Launch using Ctrl+F5 to run without the debugger attached.
Have fun!
I create a "HelloWorld" in C++ and compiles/runs in VS/Windows. When I try to compile it under Linux/GCC, it obviously throws tons of errors. Default windows console project includes windows specific files; but if just create an "Empty Project" it throws tons of linker/build errors. What's the best practices here to keep my code portable?
It's fairly difficult to keep your code truly portable if you're writing Windows applications. Standard C++ will obviously work on either platform, but Linux can't run Windows applications, and vice versa. Remember that console applications are also considered Windows applications. They're not any more "pure" just because they are text-based, rather than graphical. Windows applications have their own entry point, different from the standard main function found in ANSI C++ (technically, main is still there, but it's hidden and called internally by the Windows libraries).
The best thing to do is not to link to any of the Windows headers. Unfortunately, you won't be very satisfied with the results. About all that you'll be able to generate is library code. You can't get a UI on the screen unless you use the Windows functions to do it.
An "Empty Project" is just what it says—empty. I assume the build errors are because you're trying to call functions that aren't defined anywhere. You'll find that you need to include windows.h to get off the ground, which instantly makes your code non-portable.
Why is it creating 47 files for 8 lines of code?
This is obviously an exaggeration; none of the wizards produce anywhere near that many code files. Especially not the "Empty Project", which doesn't create any at all.
A Win32 console application includes the following 5 files:
stdafx.h and stdafx.cpp — these files are used to enable "precompiled headers", meaning that Visual Studio will compile all of your headers once, and only recompile them when they change, rather than recompiling them each time you build the project. This used to provide enormous speed boosts, and still does on large projects. You probably don't need or care about this for small projects, but it's not a bad idea to get familiar with their usage if you're going to be developing in Visual Studio.
A targetver.h file, whose only purpose is to specify the earliest version of Windows that you want your application to run on. This is necessary because later versions of Windows add additional functionality that wasn't available in previous versions. Your app won't run if you link to functions or libraries that don't exist. Set this up once and then forget about it.
A <projectname>.cpp file, which is the implementation code for your application. This is pretty standard stuff—it includes the _tmain function, which is the entry point for a console app.
A ReadMe.txt file, which you can immediately delete. It contains some introductory information and describes the files that have been added to your project. (Yes, reading this yourself could have answered this question.)
A Win32 application would have a few more files, but most of the same ones as well. In particular, you'll see a resource file (with the extension .rc) that contains the icons, dialogs, bitmaps, cursors, etc. used in your program.
If you don't like this structure, you can either forgo the use of a wizard, or modify it yourself. There's nothing set in stone about it.
How do you format code? You can do Edit->Format Selection, but the hotkeys don't work?
Formatting code works fine. I'm not sure why people are telling you that Visual Studio doesn't support this, or that you'll need a third-party plug-in. There's no "Format Document" command as there is in C#, but the "Format Selection" command works just fine. The only difference is, you have to select something in order for it to be enabled.
The default keyboard extension for that command is CtrlK, Ctrl+F. It also works fine, right out of the box. My typical workflow is to hit Ctrl+A first to select all.
How do I output to VS's 'Output' Window? ( like eclipse does when you run a console java app )
I don't know what Eclipse does, nor do I know anything about Java. What do you want this to do? When and what things do you want to get written to the "Output" window? A console application will run in a console window, not in the "Output" window. That's not what it's for.
It's intended for debugging purposes. The OutputDebugString function is one way of utilizing it. The output of the standard cerr keyword should be automatically redirected to the "Output" window.
It keeps reverting my "Project Location" to my "home directory" every time I restart. How do you change it? Is it a bug? Because it's Express edition?
This isn't a bug, it's a feature. Visual Studio is designed for working with projects and solutions, not one-off code files. So by default, it prompts you to specify a project folder, a location to store your files. And what better place for the default location than your home folder?
If you don't like that location, you can change it. Under the "Tools" menu, select "Options". Expand the "Projects and Solutions" category, and click the "General" item. Then, change the path of the "Projects location" (the top textbox). Couldn't get much simpler than that.
Is there a way to keep it from switching to Debug view when it runs?
I frankly don't understand how this question makes any sense at all. When you run an application with the debugger attached, Visual Studio switches to a different window layout specifically optimized for debugging. I just answered a similar question. The upshot is that there's no way of telling Visual Studio to use the same window layout for both design and debug view, but I also can't imagine why you'd want to, either. Different things are useful, depending on what you're currently doing.
The two window layouts are customizable, and your changes are remembered. I've customized mine heavily from the defaults; it's very likely that your tastes vary as well. There are lots of great features, like the "Locals" window, which shows a listing of all the values of the local variables in scope at the point where you break into your program's execution.
Also remember that the default "Debug" and "Release" build configurations have nothing to do with whether or not Visual Studio automatically attaches the debugger to your application's process. If you want to start your app without the debugger attached, select "Start without Debugging" from the Debug menu, or press Ctrl+F5. There are lots of side effects to this though, and it's probably not what you wanted. Without the debugger attached, you lose most of what Visual Studio provides to you as an IDE. You might as well just run the app from Windows Explorer without even launching VS.
Finally, if you prefer Eclipse (or at least are already accustomed to its nuances and prefer not to learn Visual Studio's), you can still use it for C++ development. Download it here.
If you're just wanting to learn C++ and you don't necessarily care about the platform, I would probably avoid using Visual Studio to start with. Visual Studio provides some functionality for managing projects and builds, but honestly, I think you're better off learning how to manage code files and use the compiler on the command line first, then working up from there.
If you're on Windows, I'd recommend installing Cygwin and getting the GNU compiler tools through the Cygwin setup utility (gcc or g++).
This is a bit of an opinionated answer, but my experience with C++ on Windows leads me to believe that you'd be better served trying to learn C++ from more of a unix-like angle. Windows C++ adds a whole layer of crap that will just confuse you when you're getting started.

Visual C++ 2005 hangs during qt builds

At my shop, the main product app is a mongrel built on MFC, QT and other random things devs have thrown in over the years.
In the current stack, Qt toolkit is on the way out, but still features heavily.
If I have SQL 2005 Management studio open and have to do a full build, it usually hangs a CPU (even after the offending process is taken out back and shot...) during the qt specific parts of the build (Moc'ing and UIC'ing)
has anyone seen anything like this? any ideas what the problem could be?
In my experience, some of these tools are capable of looping forever (qt4: lupdate/lrelease for sure).