Vs how to enter chromium subprocess debugging

because Chromium Multi process architecture , So debugging can be challenging . When you select... In the debugger “ function ” when , Only the main browser process will be debugged . Actually render web pages （Renderer） And the plug-in code will be done in a separate process that has not yet been debugged . To debug a subprocess, you need to make some changes , I prefer to use the auto attach to child process method .

1、 Automatically attach to child processes
Microsoft Of Child Process Debugging Power Tool Is an independent extension of this , and VsChromium Is another option bundled with many other additional features . You must also run as an administrator Visual Studio, Otherwise it will not be silently attached to Chrome Some child processes of .

2、 Manually attach to child process
You can use the debugger to attach to a running child process . choice Tools > Attach to process , And then click To attach to chrome.exe process . Before attaching , Please make sure Only native code is selected when attaching to the process . This is through “ Attach to process ” Click in the window “ choice … ” And select only “ This machine ” To complete . If you forget this , It may try to “ WebKit” Mode attach to debug JavaScript, And you will receive an error message “ In the current state ,n Illegal operation ”.

Now? , You can debug them as you would debug two processes . When debugging multiple processes , Please open the “ debugging ”>“ Windows”>“ process ” Window to switch between them .

Sometimes , You are debugging something that only happens at startup , And you want to view the child process immediately after it starts . Use ：

--renderer-startup-dialog  --no-sandbox

You must disable sandbox , Otherwise, the dialog box... Will be suppressed . When the dialog box appears , Please visit “ Tools ”>“ Attach to process ”, Then attach to the display “ Renderer start-up ” Dialog box process . Now? , You are debugging in the renderer , And you can press... In the dialog box “ determine ” To carry on .

There are also startup dialogs for other child process types ：-- gpu-startup-dialog,-- ppapi-startup-dialog,-- plugin-startup-dialog（ be used for NPAPI）.

3、 Semi automatically attach the debugger to the child process
The following parameters make the child process wait in a busy loop 60 second , So that the debugger can attach it to the process . Once any one of the conditions is established , It will continue ; No exceptions were thrown .

--wait-for-debugger-children [= filter ]

filter （ Provided ） Only in the –type Only when the parameter matches the process will it trigger . Values include renderer , plug-in unit （ be used for NPAPI）,ppapi ,gpu-process and Utility .

When using this option , It may be helpful to limit the number of renderer processes generated using the following methods ：

--renderer-process-limit = 1