Passing messages between the Render and Browser processes

[palaver]

I am trying to learn about how to pass information between processes using CEF3, and I am a little confused:

With every sample application I look at, it seems that only one type of process (either browser or render) is launched. For example, in the cefclient_win example, we have:

Code: Select all

ClientApp::ProcessType process_type = ClientApp::GetProcessType(command_line);
if (process_type == ClientApp::BrowserProcess)
    app = new ClientAppBrowser();
else if (process_type == ClientApp::RendererProcess)
    app = new ClientAppRenderer();
else if (process_type == ClientApp::OtherProcess)
    app = new ClientAppOther();


Let's say that the first branch of the above conditional is successful and the browser process is initialized. Where then does the communication with the render process happen? Where is the render process launched?

[magreenblatt]

Additional processes are created as needed. When the process is created an IPC channel is established. See https://www.chromium.org/developers/des ... chitecture for details.

[palaver]

Thanks for that. What confused me a little bit was the cefsimple application, which ran without any client implementation of the Render Process handler. In the cefclient example, we check the command line flags, and based on those, we launch either a render or browser process handler, which makes sense to me. But in cefsimple, all we do is create a SimpleApp, which is a CefBrowserProcessHandler, and I wasn't sure where the render process handler came into play there. Am I missing something?

[magreenblatt]

But in cefsimple, all we do is create a SimpleApp, which is a CefBrowserProcessHandler, and I wasn't sure where the render process handler came into play there. Am I missing something?

I see why you're confused. Since SimpleApp does not implement CefRenderProcessHandler it would be clearer if the example program passed NULL to CefExecuteProcess instead of the SimpleApp instance.

[magreenblatt]

But in cefsimple, all we do is create a SimpleApp, which is a CefBrowserProcessHandler, and I wasn't sure where the render process handler came into play there. Am I missing something?

I see why you're confused. Since SimpleApp does not implement CefRenderProcessHandler it would be clearer if the example program passed NULL to CefExecuteProcess instead of the SimpleApp instance.

I've filed https://bitbucket.org/chromiumembedded/cef/issues/1776 for this.

[palaver]

That's perfect, kudos on filing an issue.