How to close plugin process?

[zhengyanadws]

I use CEF open a bank website which has a npapi plugin. I find it start an new process, when i close my application this process didn't close.So the app restart.I'm sure the program call the CefShutdown function.

I want to know how to close the process,thank you all.

[ndesktop]

NPAPI plugins are not supported for some time (I assume you are using an older version of CEF).
So, assuming your app is named app.exe, the plugin process should be app.exe --type=plugin (if I remember well).
Normally the plugin subprocess should terminate, but if this is not the case, here is what I've done in the past:
- have a cleanup process (say appcp.exe - CP = cleanup process)
- appcp.exe is launched from app.exe (appcp --pid=app.exe PID) => app.exe PID
- appcp.exe uses the app.exe PID to opens a handle to app.exe (browser, main instance) and waits indefinitely (WaitForSingleObject INFINITE)
- when app.exe closes, the handle is signaled to appcp.exe
- appcp.exe enumerates the processes (CreateToolhelpSnapshot) which (1) have the same path as app.exe and (2) have the parent process PID the one used to launch appcp.exe)
- collects the "orphans" app.exe PIDs, if any
- for each orphan process, appcp.exe
1. (optional) gets the command line if needed (some ntdll things are needed here if you really want to check also if --type=plugin is present in the command line of the orphan process)
this if you need to really validate is a plugin process
2. for each orphan process kill the orphan PID (OpenProcess with TERMINATE and then call TerminateProcess)

I know, is not pleasant, but if for some reason you need this to be done, this is what I've done.

[amaitland]

You don't need to create a new application for cleanup, you can simply pass the main process Id as a command line arg to your sub processes and spawn a thread that waits for the parent process to exit terminating it's self if required. There are examples on this forum.

Just search this forum for WaitForSingleObject you should find example no problem.

[ndesktop]

"when i close my application this process didn't close"
On my comment I assumed the browser process is already terminated and still there are pending orphan processes.
And I saw such cases related to NPAPI plugins (simply said, the plugin process was hung because of the plugin, browser terminates but the subprocess still remained in memory doing nothing).

[zhengyanadws]

Now I create a new app named "cefSubProcess" and use "settings.browser_subprocess_path".So when i visit the website with plugin, it create a new process "cefSubProcess.exe" instead of my main app.It seems perfect.But if there have three or more "cefSubProcess" process, when I use the close button to close my main app, the main process can not exit.Those sub process can not either.

I have to call the ExitProcess() to exit main process now.I'm sure the cefshutdown has been called.How can i deal with it?

[ndesktop]

It is probably a bug on your app. Do not resort on ExitProcess (or its even more evil twin TerminateProcess) unless you are in crt0exe.c or something.
If you say CefShutdown was called for sure, then is either an unsatisfied wait, a re-a-l-l-y slow debug stacktrace (it happened to me to wait ~20 minutes for a DCHECK backtrace to finish, depending on your settings, symbols loading, AV installed etc), or... a bug.
Unless someone else knowing already what can be will help, attach Visual Studio debugger to all processes in cause, hit Break All, and see who's doing what. Otherwise we're fishing.

[zhengyanadws]

Now i find a new way to solve it.In OnBeforePluginLoad i remember the browser and all it's plugin path.And in DoClose()，i check the browser and call CefForceWebPluginShutdown() to shutdown all the plugin,it work so perfect.

But if i use the single_process mode,when the app call the CefForceWebPluginShutdown,it start a new app.

I don't know why my app be started.I faced this problem many times.I want to find the reason.

[ndesktop]

Single process mode is not really supported outside quirky debug.
However, if you want to support this, simply do nothing. In single process mode there is no plugin subprocess, everything is inproc.

[zhengyanadws]

The version i use is 3.2357.1271.And i use cefsetting.single_process = true switch to the single process mode. But when i open a website with npapi plugin,cef create a new process which name is equal with my app's name.I hope the plugin handled in my main process,but it not.Is i do something wrong?

[Czarek]

I don't think plugins are supported in single process mode.