while the corresponding page is running any[unload][] listeners, it may become detached as the

newly navigated page replaced it in the frame tree.

A`string` representing the JavaScript call stack of the frame while it's in an unresponsive state.

This can be useful to determine why the frame is unresponsive in cases where there's long-running JavaScript.

For more information, see the[proposed Crash Reporting API.](https://wicg.github.io/crash-reporting/)

const {app }=require('electron')

app.commandLine.appendSwitch('enable-features','DocumentPolicyIncludeJSCallStacksInCrashReports')

app.on('web-contents-created', (_,webContents)=> {

webContents.on('unresponsive', ()=> {

setTimeout(()=> {

constjsCallStack=webContents.mainFrame.unresponsiveDocumentJSCallStack

console.log('Renderer unresponsive\n', jsCallStack)

},10)

})

})

[SCA]:https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Structured_clone_algorithm

[`postMessage`]:https://developer.mozilla.org/en-US/docs/Web/API/Window/postMessage

[`MessagePortMain`]:message-port-main.md

#include<utility>

#include<vector>

#include"base/feature_list.h"

#include"base/logging.h"

#include"base/no_destructor.h"

#include"content/browser/renderer_host/render_frame_host_impl.h"// nogncheck

#include"content/browser/renderer_host/render_process_host_impl.h"// nogncheck

#include"content/public/browser/frame_tree_node_id.h"

#include"content/public/browser/render_frame_host.h"

#include"content/public/common/isolated_world_ids.h"

return frame_hosts;

}

std::stringWebFrameMain::UnresponsiveDocumentJSCallStack()const {

if (!CheckRenderFrame())

return"";

if (!base::FeatureList::IsEnabled(

blink::features::kDocumentPolicyIncludeJSCallStacksInCrashReports)) {

return"";

}

content::RenderProcessHostImpl* rph =

static_cast<content::RenderProcessHostImpl*>(render_frame_->GetProcess());

const std::string& unresponsive_document_javascript_call_stack =

rph->GetUnresponsiveDocumentJavascriptCallStack();

const blink::LocalFrameToken& unresponsive_document_token =

rph->GetUnresponsiveDocumentToken();

if (!unresponsive_document_javascript_call_stack.empty()) {

if (unresponsive_document_token == render_frame_->GetFrameToken()) {

return unresponsive_document_javascript_call_stack;

}

}

return"";

}

voidWebFrameMain::DOMContentLoaded() {

Emit("dom-ready");

}

.SetProperty("parent", &WebFrameMain::Parent)

.SetProperty("frames", &WebFrameMain::Frames)

.SetProperty("framesInSubtree", &WebFrameMain::FramesInSubtree)

.SetProperty("unresponsiveDocumentJSCallStack",

&WebFrameMain::UnresponsiveDocumentJSCallStack)

.Build();

}

std::vector<content::RenderFrameHost*>Frames()const;

std::vector<content::RenderFrameHost*>FramesInSubtree()const;

std::stringUnresponsiveDocumentJSCallStack()const;

voidDOMContentLoaded();

mojo::Remote<mojom::ElectronRenderer> renderer_api_;