I am trying to debug a windows form application which has a large number of events: button presses, timers, etc..
Is there a way to catch every line of code being executed by the application without setting a break point?
edit:
The program was not written by me, so I am unfamiliar with the code. I wish to step through the entire program, catching every line of code being executed. Setting break points in every event is impractical as various controls are created dynamically.
For debugging a button click without setting breakpoints:
Start the app with the debugger.
Get to the state immediately before the intended click.
Go back to the debugger and press Pause then F11 (Step Into) -- nothing will happen.
Go to the app and press the button -- the debugger should take over and drop you into the event handler.
Note: This will not work if Paint, any Mouse event, or probably some other events are handled. The debugger will drop you into those handlers any time you attempt the steps above.
If you're using the Ultimate edition of your Visual Studio 2010 you can use its new feature called IntelliTrace (previously Historical Debugger). This will allow you to do exactly what you want - be able to see all method calls and events that happened during execution of your program, and you'll be able to jump back to the event which you need.
To enable IntelliTrace, go to Tools → Options → IntelliTrace, and check the "Enable IntelliTrace" checkbox, and select one of two modes: "events only" or "events and call information", then run your application with a debugger (F5).
The difference between the two modes is that the latter uses the profiler to collect all runtime information, so you get a complete call stack, however you won't be able to use edit-and-continue features of the debugger.
You can find more in this series of articles, and of course, on MSDN.
You could also try a code coverage tool.
For example, if you have Resharper and dotCover, you can run your application (via the dotCover->Cover Application... menu item) and when the application finishes, dotCover will show you which lines of code were run in the VS IDE by highlighting them in green. Lines of code which where not run are coloured in red.
I don't know if there are other tools which do this, but it's an option.
I developed the Runtime Flow tool to solve exactly this problem - to understand a large unfamiliar .NET codebase via realtime function calls monitoring. It's similar to IntelliTrace, but places more emphasis on control flow than on debugging.
Why would you want to break on every line? This would be very onerous and time consuming. If you want to see the activity of your program as it executes, use a logging mechanism or Debug.Writeline to output information to the Immediate window.
You cannot trace lines of code, but you can use Trace.TraceInformation calls where you want to have an idea of what's executed. There's also Debug.Write. Both output will write in the output window of Visual Studio.
Another solution would be to add logging to your application, for example with log4net, but that may be overkill for your needs.
This isn't exactly what you're asking for, but in case you didn't know you can toggle an existing breakpoint on or off. In your case, you could add break points at key places throughout your code and just disable them when you don't want to debug them. That way, you'll be able to re-enable them later when you want to use them again.
Enabling/disabling is available through the Breakpoints window found under the Debug > Windows > Breakpoints menu (CTRL+D, B). You can also include "Function" and "File" columns in the window, which might help you identify which breakpoints are in the event handlers that you care about
Not really, but you can set one breakpoint and single-step (F10/F11) through the rest of the code.
Nope 'fraid not - you need to set each breakpoint yourself.
If it helps F9 is the shortcut key for assigning a breakpoint - just set a breakpoint on the start of each method and use step through (F10) / step into (F11) from there.
Related
I am working with Visual Studio 2015.
I have a big c# class file with lot of properties and methods. I want to set breakpoints to all possible lines (set and get of properties, methods) at once. How can I do that?
You could add Debugger.Break() on the end of every single line. Therefore you could use the search and replace function of visual studio and replace \n with Debugger.Break()\n (Remember activating the regular expression option). This would cause the debugger to break at every single line, even though you won't have an indicated breakpoint.
I don't think that there's a method to add normal vs breakpoints to every single line though, due to the fact that it's quite useless, considering that you normally just step through the code with F11.
I think you are looking for this,
steps to follow:
1) Add a break point on the first line of code you want to debug.
2) Run the application.
3) When you want to run the next line of code, Select Debug | Step Into
4) Repeat step #3 for each line of the code
With vim (vsvim) you can set a breakpoint, move down a line, then repeat however many times you like, eg:
{Escape}qq:vsc Debug.ToggleBreakpoint{Enter}jq100#q
will set breakpoints on the next 100 lines
edit: here is example video, wouldnt let me embed gif https://imgur.com/SFhlEr7
Step Into(F11) or use the Debugger.Break() or add breakpoint directly would be the workarounds for you, of course, I suggest you use the Step Into(F11) which was much more convenient.
If you could use the latest VS2017 version, it has a new feature "Run to Click" which is also a better workaround for you during debugging.
Actually you don't have to debug every line code, that's also the reason I suggest you use this new feature.
Run to Click: Simply click the icon next to a line of code while debugging to run to that line. No longer set temporary breakpoints or
perform several steps to execute your code and stop on the line you
want. Now while stopped at a break state under the debugger, the Run
to Click icon subtly appears next to the line of code that your mouse
is hovered over. Move your mouse to the icon and click the button, now
your code will run and stop on that line the next time it is hit in
your code path. Turn it off from Debug> Options > Enable Run to
Click.
Reference:
https://www.visualstudio.com/en-us/news/releasenotes/vs2017-relnotes
Open a feature request with Microsoft https://learn.microsoft.com/en-us/visualstudio/ide/suggest-a-feature?view=vs-2022
There should be a mode that visual studio can be put in so that it automatically stops on every line of code in a particular project. This would be VERY valuable when you attach the debugger to a pre-existing process and you don't know where in the app is the current point of execution is, ie: web apps where you do not know the entry point.
I have a solution with some projects. There are several break-points in different projects. I want to trace the first thread hit one of these break-points and continue tracing that single thread despite of other threads entering the same code-blocks.
I know this is possible through defining a condition on the break-point, that is, thread name = ... or thread Id = ... but my case is a heavy loaded ASP.NET application and as soon as I attach to w3wp.exe many threads will hit the break-points. I need some thing like a ThreadLocal<break-point>.
Is it possible? If so, how?
Here's what I did:
Set a conditional break point that I
knew would only hit on the thread
that I was looking for.
Once the breakpoint hits and you are in the thread you want, in the Visual Studio Threads window (while debugging, Debug -> Windows -> Threads), Ctrl + A (to select all threads), and then Ctrl + click the thread you are currently on. You should have all threads except the one you want to debug selected.
Right-click, and choose "Freeze".
Now, Visual Studio will only step through the thawed thread. It seems to be much slower when doing this, presumably because it has to loop through all of the frozen threads, but it brought some sanity to my multi-threaded debugging.
Freeze/Thaw threads is an incorrect way because other threads don't execute any code.
The most correct and usable way is to:
Hit Ctrl+A in the breakpoints window (select all breakpoints).
Right click and select "Filter...".
Enter "ThreadId=(current thread id)".
In Visual Studio 2015 and newer, the process is similar:
Hit Ctrl+A in the breakpoints window (select all breakpoints).
Right click and select "Settings...".
Check "Conditions" and select "Filter" in the dropdown
Enter "ThreadId=(current thread id)".
So all threads are executed, but the debugger hits on the current thread only.
If multiple threads are being spawned as for a web application, #MattFaus answer's will not work. what I did instead is the following
Set up a breakpoint to interrupt the thread in the function I want.
Once the thread gets to the breakpoint and is paused, I remove the breakpoint and continue debugging using F8,F10 and F11, so that the others threads can run.
I have just released a Visual Studio 2010+ extension that does exactly what you are looking for.
And it's free :).
Presentation
This Visual Studio extension adds two shortcuts and toolbar buttons to allow developers to easily focus on single threads while debugging multi-threaded applications.
It dramatically reduces the need to manually go into the Threads window to freeze/thaw all threads but the one that needs to be followed, and therefore helps improve productivity.
Features
Restrict further execution to the current thread only. Will freeze all other threads. Shortcut: CTRL+T+T or Snowflake button.
Switch to the next single thread (based on ID). Will change current thread and freeze all other threads. Shortcut: CTRL+T+J or Next button.
Check it out here on the Gallery, on the official page or the Github repository.
A slightly different approach which I've used:
Create a normal breakpoint and let it get hit
Look in your threads window for the managed thread ID that you're current debugging
Right click your breakpoint in the breakpoints window and selecter filter
Enter ThreadId=xxx where xxx is the thread ID from 2
You can now debug without stopping other threads and without them hitting your breakpoint
This assumes you have time to do the above before a second thread hits your breakpoint. If not and other threads hit your breakpoint before you've done the above you can right click them in the threads window and choose freeze.
In VS 2019:
Set a breakpoint somewhere.
Hit F5 (Continue) until your thread comes.
Click on breakpoint to remove it.
You can step the thread with F10 or F11.
Set a Breakpoint Condition by right clicking the side bar of the line. Select "Condition" and enter the following with the name of your thread in quotes:
System.Threading.Thread.CurrentThread.Name=="name_of_your_thread"
Alternatively you can do the same by getting the thread's "Managed ID" from the "Threads" Window and use:
System.Threading.Thread.CurrentThread.ManagedThreadId==your_managed_thread_id
I would suggest adding another instance of the application on the live server, either on the same hardware or a new machine (cluster it) and then debug only that instance. I wouldn't add a breakpoint in code users are triggering. If that's not an option, I'd add more tracing.
However, if this is absolutely necessary and you need a solution stat, I'm sure you could add a breakpoint that breaks only if the request is coming from your IP address. You would do this by adding a conditional breakpoint that inspects HttpContext.Request.UserHostAddress. Note however that this slows down your application considerably.
If you don't want to stop all other threads (maybe you are attaching Visual Studio debugger to a running application that needs to answer to requests), you can use a macro that create and remove breakpoints automatically.
This is suggested in an answer to Stack Overflow question "Step over" when debugging multithreaded programs in Visual Studio.
However, the link only explain how to debug line by line. I suggest you modify the macro (if you're comfortable with it) to make it modify all breakpoints (in a given range of line for instance) to stop only on the current thread.
I think this is slightly different in Visual Studio 2015. They've changed a few things in the breakpoints, but here's how to apply the accepted answer from hzdbyte (above):
On the breakpoint in the coding margin, Right-Click > Conditions > Change from 'Conditional Expression' to 'Filter'. This then allows you to filter by ThreadId.
Alternatively on the breakpoint in the Breakpoints window, Right-Click > Settings > tick the Conditions box and do the above.
in VS2019, the conditional breakpoint is tid == xxxxx
this way the breakpoint will be hit only on that thread
TL;DR; Just press F5 when it jumps to the wrong thread.
I'm debugging a multithreaded queue processor in Visual Studio Pro 2022 Preview, I placed a breakpoint at a point where each queue item being processed would hit it. The IDE pauses because it hit the breakpoint. I press F10 (Step Over) a few times to step through the code. Then the another thread hit the breakpoint, and the IDE popped me over to that thread. I pressed F5 (Continue). The second thread continued processing, and the yellow debug-line returned to my original thread.
I have two solutions, one is my main app and the other is a plugin. I am editing the plugin for my app so I have added the plugins project to my apps solution and referenced it instead of the .dll
I am having problems with the breakpoints in the plugin. I have put some breakpoints where the plugin is waiting for a response. The plugin fires off an event once it has processed the data and my main app is subscribed to the event. The debugger always breaks on the event in the main app but in my plugin the debugger will only hit the breakpoints when I first start of the program. When the breakpoints aren't hit I look at the call stack and it shows me that it has gone past that piece of code with the breakpoint in.
I have no idea what is going on here and it has only just started happening. The last thing that I did was add a task into the plugin which would go off and process results when it has received the data.
Can anyone help me?
My code is running in debug
UPDATE
Basically my problem is I am getting data from a list of objects and am getting one, then processing it in my Task while I get another. This was working fine however when the issue with the break points started I noticed that the data that was being return was exactly the same all the time and is always the first element that I get.
I don't know whether that is of any use or not but it may be a caching problem that I can't identify.
You might be able to put a Debugger.Launch() statement in place of a breakpoint. I have had to use this many times when debugging applications that I don't control the application start and need more of a remote debugging scenario. The Debugger.Launch() will allow you to attach a new or existing VS instance to a running application.
By doing that in your scenario, you can start to inspect the threads (both in your current VS, and any new VS you attach with the Debugger.Launch() to ensure that they are both aware of the same threads. Your original VS may be losing access to the threads that your callback are on and thereby is unable to break.
https://msdn.microsoft.com/en-us/library/system.diagnostics.debugger.launch%28v=vs.110%29.aspx
Visual Studio opens source code on top of the stack when I "break all" while debugging; I want to keep the cursor on the document I'm currently working on, without any other document or window (e.g.: no symbols loaded) being opened.
There is a way to stay on the current document, but that requires creating a Visual Studio add-in and a new UI command in the Debug toolbar. Credits for this answer should actually also go to openshac, who posted a similar SO question and also gave a workaround in his OP by using a macro.
The implementation is fairly simple (it took me a few minutes to have it working). First, in the add-in project, modify the Exec method in the Connect.cs file like this:
public void Exec(string commandName, vsCommandExecOption executeOption, ref object varIn, ref object varOut, ref bool handled)
{
handled = false;
if(executeOption == vsCommandExecOption.vsCommandExecOptionDoDefault)
{
if(commandName == "BreakInCurrentDocument.Connect.BreakInCurrentDocument")
{
// here's where the magic happens
// ******************************
var activeWindow = _applicationObject.ActiveWindow;
_applicationObject.Debugger.Break();
if (_applicationObject.ActiveWindow != activeWindow)
{
_applicationObject.ActiveWindow.Close(vsSaveChanges.vsSaveChangesNo);
}
// ******************************
handled = true;
return;
}
}
}
After creating and registering the add-in, just:
click TOOLS on the Visual Studio's menu
Customize
Commands
Choose the "Toolbar" radio button
Select "Debug"
Add Command...
From the "Addins" category, choose your custom add-in.
That's it.
Latest build of VSCommands extension (free version) available from http://visualstudiogallery.msdn.microsoft.com/a83505c6-77b3-44a6-b53b-73d77cba84c8 has just what you want.
It adds a Break In Current Document button to Debug Toolbar and Debug Menu:
http://vscommands.squaredinfinity.com/Media/VSCommands/BlogPost//blog/breakincurrentdocument.png
It's a feature.. when you do "break all" then it is assumed that your process has hung. The first thing you might be interested in such case is - WHERE. Hence, it's directing you right down to the 'current' place that is being executed. IIRC, this is defacto standard for all low-level debuggers. If you don't want the "no symbols loaded" just mark the 'show disasembly' and it will never pop up again:) (of course, instead, you will see the exact point of stop. And yes, this is also a feature that I myself used many times to debug unknown library code)
On the other hand, if you know where you want the code to stop, place the breakpoint there instead.
On yet another hand (as if we had three), if you want to actually stop the application - stop it, don't break, just stop.
I sense that your actual problem lies in the fact that you use one of the features in a wrong way, and therefore another feature bugs you. Please tell me, what do you use the "break all" for and how/why does it collide with your current text-editing. Why can't you stop or break-at-here instead? Or "detach"?
Anyways, I have to admit that as a feature, there should be some option for turning it off, just for the sake of configurability of the IDE.
EDIT
AAhh.. you're right. I've completely forgot about the glorious edit&continue. I'm not joking/teasing, E&C is a great feature that I wish all other platforms had. I've forgot about it, because... I extensively use lambdas, generics, foreachs and etc features that effectively block edit-and-continue.
Anyways, the point is, since that the edit-and-continue is the golden feature that you'd like to use - the application must be in 'break' mode. However, nevertheless how do 'break'/'pause' etc it, the IDE will assume it that the PAUSE was you goal, not editing, hence it will show you where did you pause the app.
There are a few options in MSVS like "show just my code" that may help you a little, but it will not solve the problem: edit-and-continue during debugging was designed for "small, local edits". Like, if(x>0)throw new uncaught() instead if(x<0)throw new uncaught(). Your app stopped on assertion or breakpoint and is about to crash, first-change exception handler fired off and here's your chance! You unwind the crash handler, correct the code, then run. Everything in the same one method which you had the stop occur in, as a way of just-in-time patches..
This is one of the main problems why can't you add methods, classes, modify generics, etc during E&C session: ie. editing your current lambda or current foreach might be OK, but the IDE would be not able to relocate the flows and execute the new code properly. This is a bit similar to why you sometimes see the "stale code" warning, but with those code constructs it is even harder to analyze, and therefore not implemented. And probably will never hit the top of MS's TO-DO list :/
The current boom in .Net/C# is not 'live development' but 'notaliveyet development' heavily supported by modularity and unit testing, where you put the effort to be able to test most of the features of the application off-line.. But that's a paradigm shift and for small projects or for local desktop development sometimes it is simply an overkill.
I know the title is a bit ambitious, but I am wondering if there is a way, after displaying a previous state in the call stack window (Visual Studio 2010) when debugging a C# program, to restart (like when hitting "Continue"/F5) from there.
This would be particularly useful to debug a lambda expression that generates an exception, as there is no way to move outside.
For a real OO code time machine, the historical state of all objects would need to be stored in memory, so I doubt it is feasible at this stage.
Now if the state of all objects has not changed much, then we could keep the current state and jump back in time (as a shortcut to doing the same thing with "edit and continue").
Some times, you can right click on a stack frame and choose "Unwind to here" (or very similar wording). It's not always possible, and I'm not sure what the necessary conditions are, but I'm going to make a guess as to what might prevent it:
A native code frame on the call stack in the middle
Being halted at a StackOverflowException (obviously, death to a process in any case)
Maybe lambda expressions or other things that prevent Edit-and-Continue from working (?)
Basically, anything "unusual".
Other than that, if it works, then there you go!
This is a bit kludgy but:
While viewing the previous state in the call stack window, open the disassembly window (Debug | Windows | Disassembly or CTRL+ALT+D). Now you should be able to create a breakpoint which will stop execution when you get back to that location.
If you don't care what else executes, press F5 and allow the code to run back to your new breakpoint.
Now right click on the statement you want to restart from and select Set Next Statement. Press F5 to restart from there.
If you do care about what else executes on your way back to the new breakpoint you could use Set Next Statement to set the program counter to the end of the function you are in and use Shift+F11 to step out of that function (thus not executing any of the remaining logic in that function). Repeat as needed until you get back to your new breakpoint.
Note the various dire warnings about using Set Next Statement
Edit 6/18 When I tested the above I was running Visual Studio 2010 Ultimate. I just checked Visual Studio Express C# and it does not support the Disassembly Debug Window. When I can I'll check Visual Studio 2010 Professional and update this answer again. If you have Visual Studio Ultimate then the Intellitrace suggestion by #Hans is maybe a better bet.