I've experienced this with every version of Visual Studio starting from 2012 (2012, 2013, 2015 Preview), on multiple computers and multiple projects, but I haven't figured out how to fix it:
Whenever I'm debugging a 64-bit(?) C++ console program, after a few minutes and seemingly completely randomly (when I'm not clicking or typing anything), the console window for the program spontaneously closes and I can no longer debug or step through the program with Visual Studio. When I press Stop and attempt to restart debugging, I usually get ERROR_NETWORK_UNREACHABLE:
// MessageId: ERROR_NETWORK_UNREACHABLE
// MessageText:
// The network location cannot be reached. For information about network troubleshooting, see Windows Help.
#define ERROR_NETWORK_UNREACHABLE 1231L
If I try to attach to the process manually I get the error:
Unable to attach to the process.
The only fix I've found for this is to restart Visual Studio. I can't find any other way to fix it, and I've tried running Process Monitor but haven't found anything.
What causes this problem and how can I fix it?
(?) Upon further checking it seems that this only happens in 64-bit mode, but I'm not 100% sure.
Ok, this is just so wrong
I also have issues with this bug, and in my case it occurred every other debug session. Which meant debug -> stop -> debug -> bug -> restart visual studio -> go to start (repeat every minute during the whole day).
Needless to say I was driven to find a solution. So yesterday I tried procmon, spend hours looking at API monitor differences, looked at plugins, netstat, etc, etc, etc. And found nothing. I gave up.
Today
Until today.
To track down a stupid bug in my program today, I launched appverifier. For my application, I ran the 'basics' tests and clicked save. After a few hours this led me to the bug in my program, which was something like this (extremely simplified version):
void* dst = _aligned_malloc(4096, 32);
memcpy(dst, src, 8192);
Obviously this is a bug and obviously it needed fixing. I noticed the error after putting a breakpoint on the memcpy line, which was not executed.
After a stop and 'debug' again I was surprised to find that I could actually debug the program for the second time. And now, several hours later, this annoying bug here hasn't re-emerged.
So what appears to be going on
So... apparently data from my program is bleeding through into the data or execution space of the debugger, which in turn appears to generate the bug.
I see you thinking: No, this shouldn't happen... you're right; but apparently it does.
So how to fix it? Basically fixing your program (more particular: heap corruption issues) seems to make the VS debugger bug go away. Using appverifier.exe (It's in Debugging tools for Windows) will give you a head start.
Why this works
Since VS2012, VC++ uses a different way to manage the heap. Hans Passant explains it here: Does msvcrt uses a different heap for allocations since (vs2012/2010/2013) .
What basically happens is that heap corruption will break your debugger. The AppVerifier basic settings will ensure that a breakpoint is triggered just before the application does something to corrupt the heap.
So, what happens now is that before the process will break the heap, a breakpoint will trigger instead, which usually means you will terminate the process. The net effect is that the heap will still be in-tact before you terminate your program, which means that your debugger will still function.
"Test"
Before using appverifier -- bug triggered every 2 minutes
While using appverifier -- VS debugger has been stable for 5 days (and counting)
This is an environmental problem of course. Always hard to troubleshoot, SysInternals' utilities like Process Monitor and Process Explorer are your primary weapons of choice. Some non-intuitive ways that a network error can be generated while debugging:
Starting with VS2012, the C runtime library had a pretty drastic modification that can cause very hard to diagnose mis-behavior if your program corrupts the heap. Much like #atlaste describes. Since time memorial, the CRT always created its own heap, underlying call was HeapCreate(). No more, it now uses GetProcessHeap(). This is very convenient, much easier now to deal with DLLs that were built with /MT. But with a pretty sharp edge, you can now easily corrupt the memory owned by Microsoft code. Not strongly indicated if you can't reattach a 64-bit program, you'd have to kill msvsmon.exe to clear up the corruption.
The Microsoft Symbol Server supplies PDBs for Microsoft executables. They normally have their source+line-number info stripped, but not all of them. Notably not for the CRT for example. Those PDBs were built on a build server owned by DevDiv in Redmond that had the source code on the F: drive. A few around that were built from the E: drive, Patterns+Practices uses that (unlikely in a C++ program). Your debugger will go look there to try to find source code. That usually ends well, it gives up quickly, but not if your machine uses those drive letters as well. Diagnose by clearing the symbol cache and disabling the symbol server with Tools + Options, Debugging, Symbols.
The winapi suffers from two nasty viral infections it inherited from another OS that add global state to any process. The PATH environmental variable and the default working directory. Use Control Panel + System + Advanced + Environment to have a look at PATH, copy/paste the content of the intentionally small textboxes into a text editor. Make sure it is squeaky clean, some paralysis at the usual mess is normal btw. Take no prisoners. Having trouble with the default directory is much harder to troubleshoot. Both should pop out when you use Process Monitor.
No slamdunk explanations, it is a tough problem, but dark corners you can look in.
I have the same problem. Thought it was related to 64 bit console apps, where it is very easily triggered with almost any debug session. But, it also happens on 64 bit windows apps too. Now I am seeing it on 32 bit windows apps. I am running Windows 8.1 pro on a single desktop with the latest version of vs 2013 and no remote debugging. My (added) extensions are Visual Assist, Advanced Installer, ClangFormat, Code Alignment, Code Compare, Duplicate Selection, Productivity Power Tools 2013, and Visual SVN.
I discovered that the "Visual Studio 2013\Settings\CurrentSettings.vssettings" file gets corrupted. You can delete this file and recreate it by restarting VS or you can try to edit the XML. I then keep a copy of a good settings file that I use to replace when it gets corrupted again.
In my case, the corrupted line begins with
</ToolsOptionsSubCategory><ToolsOptionsSubCategory name="XAML" RegisteredName="XAML"
... and it is extremely long (I think this is why it is prone to corruption).
I just disabled in the Menu
Tools > Options
Debugging > Edit and Continue
Native-only options > Enable native Edit and Continue
and now it does not give the that stupid error which was preventing the starting of the debuggee application.
I also had the same problem with VS2015. It was so frustrating that a simple Hello World program gave this error when I ran debugger for the second time. Tried uninstall and reinstall and didn't work.
Finally, the solution mentioned in https://social.msdn.microsoft.com/Forums/vstudio/en-US/8dce0952-234f-4c18-a71a-1d614b44f256/visual-studios-2012-cannot-findlaunch-project-exe?forum=vsdebug
worked. Reset all visual studio settings using Tools->Import and Export settings. Now the issue is not occurring.
Related
Question: Can I set up VS2010 so it automatically writes debug output to a file?
Motivation: I have a DirectX 9 application that I'm trying to debug. I've noticed that when my application is fullscreen, it may crash under certain conditions. Normally I would just check my logs or DirectX debug output. However, the way my program crashes prevents that. It freezes and does not respond to any my attempts to end it (including "End Process" from task manager). Moreover, it also freezes my VS2010, and so VS doesn't respond to any commands either. The only way out of this whole thing that I've found is to End VS process. This, however, also destroys the output I'd very much like to read.
Now I see two ways out of this. First is to write all the debug info to a file but I have no idea how to do it. Second is to make my application crash in a more friendly way, but this seems like a difficult task.
Probably MiniDumpWriteMiniDump(..) helps on this. You can at any time dump the current state of the process to a file. After that, you can open the dumps with Visual Studio and analyze the state of the process - this includes callstacks of every thread, variable values...
Try to identify conditions in which your process crashes and write one or more dumps.
Another try is to install the Windows Debugging Tools and use WinDbg to debug your application. This is not as comfortable as Visual Studio, but allows a deeper insight.
Edit:
If there are debug statements made with OutputDebugString(..), you can use DebugView (from Microsoft, earlier Sysinternals) to display it.
after I compiled my project in C++ (VisualStudio) around 3-4 times, I can do it anymore due to LNK1168 that stands for "VisualStudio can't write into the exe". I've looked up in my TaskManager, the exe is NOT running. Normally I have to wait for like 5 minutes but that isn't a real solution. Any ideas?
ProcessExplorer just tells me, that the handle is invalid and though can't be closed. It remains open all the time...
First thing that comes to mind is to use ProcessExplorer to figure out what process is keeping the file open. Download and start up the tool en select Find from the menu. Enter the (partial) file name and it should show up in the search results. Double click to jump to the process and file handle in the main application window.
I'm guessing Visual Studio is the culprit.
Fortunately, you can also use Process Explorer to close the handle. Right-click and choose Close Handle.
Note that it's not a good idea to go around closing file handles on a regular basis. However, whenever you're in a pickle it can really help solve annoying problems.
If I recall correctly, a similar problem existed way back in VS 6. It had to do with incremental compilation. For a more structural solution, try doing a full rebuild from time to time or disabling incremental compilation all together.
I have been experiencing exactly the same problem (For C# and C++). I have just discovered that having the Application Experience Service disabled seems to cause EXPLORER.EXE To keep .exe files hanging around (locked by the SYSTEM) for several minutes after running that executable.
The solution to this problem, for me at least, was to re-enable the Application Experience service. (I had originally disabled it since it seemed unnecessary - Apparently I was wrong!)
Your exe might still be running. Stop it before recompiling it.
When the compiling of a project is complete (or at least when it says it does), I receive no window, no error message, or anything; VC++ freezes up and my computer basically stops responding altogether.
After about five minutes, Task Manager finally pops up and I'm able to close the program. Upon doing that, I see this:
I'm going to take a wild guess here and say something is wrong with the image above. On a side note, the process' (MSBuild.exe) don't (seem) to open all at once, but that may only seem that way because the computer becomes frozen multiple times until I shutdown vc++.
Is this a known issue and if so what should I do so I can compile programs without this issue once again?
Additional Information:
Windows 7
Microsoft Visual C++ 2010 xpress
Project Type(s): I've tried on "Windows Form Application" project and "Win32 Project", both produce the same results.
Compiling projects in VB works as it should. (in case this helps at all)
As suggested by Hans Passant, disabling avast! solved the problem.
Did any error pop up during installation?
The standard thing to do (that almost always helps) is rebooting, reinstalling, (rebooting,) and trying again. Chances are absolutely nobody knows what's going wrong (even MS).
I have a native C++ program which runs more than 20 times slower when started with Debug (F5), but runs at normal speed when using start without debug (Ctrl + F5).
It does not matter whether I use a debug or release build. Also if I use WinDbg the program is a magnitude slower.
Is there some setting I did choose wrong or something?
Set the _NO_DEBUG_HEAP environment variable to 1 (as seen on http://preshing.com/20110717/the-windows-heap-is-slow-when-launched-from-the-debugger).
This can be done from inside Visual Studio, too.
Now this is just a workaround, and I'm curious to know how to refactor a program which suffers from this kind of problem. Do you have many std::map's, shared_ptr, or any other big indirections by any chance?
This is of course not caused by having the _DEBUG symbol defined or compiling the code in the debug configuration. The added debugging code runs whether or not the debugger is attached to the program.
The debugger doesn't normally affect code execution, it stays out of the way by calling WaitForDebugEvent. Which blocks it, until the operating system tells it that something noteworthy happened. That can trigger a bunch of code in the debugger that can slow down your program. You can see the events listed in the DEBUG_EVENT structure documentation.
Annotating them a bit beyond the documentation: the debugger steps in and can slow down your program when:
The program loads or unloads a DLL. Lots of stuff happens during load, the debugger goes hunting for a debug symbol file (.pdb). It may contact a symbol server to download it. Any breakpoints that were set in the DLL source code will get activated. This can be quite slow, but the effect is temporary and generally only slows down the startup. You can see the load/unload notification in the Output window.
The program raises an exception. This activates the debugger at the moment the exception is raised, a "first chance notification". Which can be very helpful, you can use the Debug + Exception, Thrown checkbox to make the debugger stop when the exception is raised. You can see the notification message in the Output window. This does slow down code that raises and catches exceptions tremendously and is quite likely the source of your slowdown. Never use exceptions for flow control.
A thread starts running or terminates. Again, a notification message is printed to the Output window. You'd have to create a lot of threads to make this slow down your program.
When your program uses OutputDebugString() for tracing purposes. Visible in the Output window. Another good candidate for a slow down, output falls in the bit bucket if no debugger is attached. You shouldn't have any trouble diagnosing this as the cause, the obvious side-effect is seeing a lot of messages in the Output window.
When the program hits a breakpoint. Not a lot of reasons to be stumped by that one. But you can set breakpoints that slow down the program a lot yet don't cause a debugger break. Particularly the Conditional breakpoint, Hit counter, Filter and the When Hit operation will be slow. Use Debug + Windows + Breakpoints to review the breakpoints that are defined.
When a process is created under the debugger, the operating system by default uses the debug heap. The debug heap does more verification of your memory, especially at de-alloc.
There are several possible options in order to disable the use of the Debug Heap:
Attach to the process soon after startup. This will allow you to speed up performance in debug mode knowingly so and being fully aware of the mode in which you are running.
Add the environment variable setting _NO_DEBUG_HEAP=1.
This can be set either globally for the machine or for a specific instance of Visual Studio.
a. Globally you would set an environment variable through the Control Panel → System → Advanced system settings → Environment Variables, and there add the variable _NO_DEBUG_HEAP=1.
Note: This will have an affect on EVERY application you debug.
b. For an instance of Visual Studio you can open a command prompt, setting the environment variable _NO_DEBUG_HEAP=1 and then open visual studio from inside that command prompt. This will influence only the processes created from
that instance of Visual Studio will inherit the environment
variable.
Append the behavior of the debugger, this is possible for VS2015. There are 2 ways to override this:
a. To modify for a specific project, go to the project properties Configuration Properties → Debugging and change the Environment property _NO_DEBUG_HEAP to 1
b. To modify for every project in Visual Studio, go to Tools → Options → Debugging and check the option: “Enable Windows debug heap allocator (Native only)”.
Note: f the _NO_DEBUG_HEAP environment variable mentioned in the 'a' is set in a project level it will override this global setting.
For me the difference in performance between debug mode and release mode is about a factor 40. After some digging, it appears several things contribute to the difference in performance, but there is one compiler option that quadruples my debug performance almost for free.
Namely, changing /ZI into /Zi. For a description, see the MSDN page.
I don't use the edit and continue feature anyway.
No one has mentioned closing unused source windows.
After closing 20+ unused windows, debug source stepping went from ~5s back down to ~.2s. This unusually slow project loads a DLL dynamically and that DLL was also the one being stepped through (and having source windows open) so it seems likely related. However this was C# (headline and tags are non-specific).
There are several things that are different if you run the debug build outside the IDE. One is that the IDE takes a while to load symbols, and if you depend on a lot of libraries then that startup time can be significant.
If you are using a symbol server (including the Microsoft public symbol server) then this may add to the startup time, so ensure you have a local symbol cache in your _NT_SYMBOL_PATH variable if that is the case.
Also the IDE runs with the debug heap enabled, but I don't think this happens if you run outside the IDE.
Debugging Visual C++ comes with lots and lots of overhead, especially in the STL. Try not defining _DEBUG, and define NDEBUG.
I'm working on a bug where I have an MFC application that does weird things when installed in when Sophos Safeguard hard drive encryption is installed. I'm sorry to be so vague here, but I'm writing this away from the office so this is all from my (poor) memory.
Three things I've noticed:
AfxGetResourceHandle() doesn't return a consistent resource handle. There is a single case where we try to load a string resource, and for some reason, the resource handle that we get from this method is different to all the other stings.
Can't construct a CDocumentTemplate. There is a trace error which I cant seem to recall. Will edit and post when I'm in tomorrow.
This behaviour appears to manifest in a Visual Studio 2005 version of the project, but not a Visual Studio 2008 version. Unfortunately moving to the 2008 version is not an option.
The bug is not always reproducable if I step through with a debugger. Also, bringing up debug message boxes changes the behaviuor, which leads me to think that either there is some kind of race condition going on with the way MFC events are being handled, but I'm not sure how I'll ever know for sure, or even what I can do about it if I did.
I think there's some underlying reason that the app is behaving weirdly, but what I've posted are more symptoms. Can anyone think of what I should check for?
I've run Windows update on the test environment to ensure everything was up to date, and I've examined the process in procmon to see if the disk encryption stuff was getting in the way and conflicting with files - it didn't appear to be, but it does appear to be involved in some way as our app accesses Sophos related paths in the temp directory.
If your code is multithreaded (which I assume it is, since you mentioned the possibility of a race condition), then the likelihood is that the decryption delays are exposing concurrency flaws. You might want to try running the application off of a network share or similar slow access device to see if it manifests similar problems.
Turned out that the antivirus software was injecting itself in a way where the antivirus' software's resource handles were overridng the app's resource handles. Yuck!