UIWebView update in background I've got a EXC_BAD_ACCESS - ios

Question

I study iOS Programming alone and I want make Youtube app.
I want that I can listen when I clicked home button and I want listen many song(like a youtube playlist. but not a list I can chose song in my tablelist.)
I use youtube-ios-player-libarary
https://github.com/youtube/youtube-ios-player-helper and I solved if I press home button app continous play in background.
But I have problem now.
When I listen in background youtube video sound and than video ended don't play next video. In the app is working, but not in background. I don't get any log in Xcode like this. (I tried Zombie)
I tried to work in main thread, like this:
[self performSelectorOnMainThread:#selector(createNewWebView) withObject:nil waitUntilDone:YES];
and
dispatch_async(dispatch_get_main_queue(), ^{
[self.webView removeFromSuperview];
_webView = [self createNewWebView];
[self addSubview:self.webView];
});
But it didn't work, and now I found this device log:
Date/Time: 2016-01-18 15:42:46.46 +0900
Launch Time: 2016-01-18 15:42:33.33 +0900
OS Version: iOS 9.2 (13C75)
Report Version: 105
Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Subtype: KERN_INVALID_ADDRESS at 0x00000001
Triggered by Thread: 13
Thread 13 name: WebThread
Thread 13 Crashed:
0 libGPUSupportMercury.dylib 0x31e3d322 gpus_ReturnNotPermittedKillClient + 10
1 libGPUSupportMercury.dylib 0x31e3de12 gpusSubmitDataBuffers + 118
2 IMGSGX543RC2GLDriver 0x34bd968c 0x34bd6000 + 13964
3 WebCore 0x29260792 WebCore::GraphicsContext3D::reshape(int, int) + 434
4 WebCore 0x299371e2 WebCore::WebGLRenderingContextBase::initializeNewContext() + 502
5 WebCore 0x29936dd0 WebCore::WebGLRenderingContextBase::WebGLRenderingContextBase(WebCore::HTMLCanvasElement*, WTF::PassRefPtr<WebCore::GraphicsContext3D>, WebCore::GraphicsContext3D::Attributes) + 484
6 WebCore 0x29931be0 WebCore::WebGLRenderingContext::WebGLRenderingContext(WebCore::HTMLCanvasElement*, WTF::PassRefPtr<WebCore::GraphicsContext3D>, WebCore::GraphicsContext3D::Attributes) + 48
7 WebCore 0x29936720 WebCore::WebGLRenderingContextBase::create(WebCore::HTMLCanvasElement*, WebCore::WebGLContextAttributes*, WTF::String const&) + 772
8 WebCore 0x28fcfbca WebCore::HTMLCanvasElement::getContext(WTF::String const&, WebCore::CanvasContextAttributes*) + 250
9 WebCore 0x28fcfa46 WebCore::JSHTMLCanvasElement::getContext(JSC::ExecState*) + 154
10 WebCore 0x28fcf988 WebCore::jsHTMLCanvasElementPrototypeFunctionGetContext(JSC::ExecState*) + 88
11 JavaScriptCore 0x28bad71e llint_entry + 21374
12 JavaScriptCore 0x28bad338 llint_entry + 20376
13 JavaScriptCore 0x28bad338 llint_entry + 20376
14 JavaScriptCore 0x28bad338 llint_entry + 20376
15 JavaScriptCore 0x28bad338 llint_entry + 20376
16 JavaScriptCore 0x28ba8190 vmEntryToJavaScript + 336
17 JavaScriptCore 0x28b016da JSC::JITCode::execute(JSC::VM*, JSC::ProtoCallFrame*) + 102
18 JavaScriptCore 0x288eaa18 JSC::Interpreter::executeCall(JSC::ExecState*, JSC::JSObject*, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) + 344
19 JavaScriptCore 0x288ea8bc JSC::call(JSC::ExecState*, JSC::JSValue, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) + 60
20 JavaScriptCore 0x2897d780 JSC::boundFunctionCall(JSC::ExecState*) + 324
21 JavaScriptCore 0x28bad71e llint_entry + 21374
22 JavaScriptCore 0x28bad4ba llint_entry + 20762
23 JavaScriptCore 0x28bad338 llint_entry + 20376
24 JavaScriptCore 0x28bad338 llint_entry + 20376
25 JavaScriptCore 0x28ba8190 vmEntryToJavaScript + 336
26 JavaScriptCore 0x28b016da JSC::JITCode::execute(JSC::VM*, JSC::ProtoCallFrame*) + 102
27 JavaScriptCore 0x288eaa18 JSC::Interpreter::executeCall(JSC::ExecState*, JSC::JSObject*, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) + 344
28 JavaScriptCore 0x288ea8bc JSC::call(JSC::ExecState*, JSC::JSValue, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) + 60
29 JavaScriptCore 0x2897d780 JSC::boundFunctionCall(JSC::ExecState*) + 324
30 JavaScriptCore 0x28bad71e llint_entry + 21374
31 JavaScriptCore 0x28bad338 llint_entry + 20376
32 JavaScriptCore 0x28ba8190 vmEntryToJavaScript + 336
33 JavaScriptCore 0x28b016da JSC::JITCode::execute(JSC::VM*, JSC::ProtoCallFrame*) + 102
34 JavaScriptCore 0x288eaa18 JSC::Interpreter::executeCall(JSC::ExecState*, JSC::JSObject*, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) + 344
35 JavaScriptCore 0x288ea8bc JSC::call(JSC::ExecState*, JSC::JSValue, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) + 60
36 JavaScriptCore 0x2897d780 JSC::boundFunctionCall(JSC::ExecState*) + 324`enter code here`
37 JavaScriptCore 0x28bad71e llint_entry + 21374
38 JavaScriptCore 0x28bad338 llint_entry + 20376
39 JavaScriptCore 0x28ba8190 vmEntryToJavaScript + 336
40 JavaScriptCore 0x28b016da JSC::JITCode::execute(JSC::VM*, JSC::ProtoCallFrame*) + 102
41 JavaScriptCore 0x288eaa18 JSC::Interpreter::executeCall(JSC::ExecState*, JSC::JSObject*, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&) + 344
42 JavaScriptCore 0x289c6f38 JSC::call(JSC::ExecState*, JSC::JSValue, JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&, WTF::NakedPtr<JSC::Exception>&) + 64
43 WebCore 0x28f95df2 WebCore::JSEventListener::handleEvent(WebCore::ScriptExecutionContext*, WebCore::Event*) + 490
44 WebCore 0x291e17d8 WebCore::EventTarget::fireEventListeners(WebCore::Event*, WebCore::EventTargetData*, WTF::Vector<WebCore::RegisteredEventListener, 1ul, WTF::CrashOnOverflow, 16ul>&) + 532
45 WebCore 0x28edb96c WebCore::EventTarget::fireEventListeners(WebCore::Event*) + 232
46 WebCore 0x28fd60a0 WebCore::EventTarget::dispatchEvent(WTF::PassRefPtr<WebCore::Event>) + 64
47 WebCore 0x291aebe6 WebCore::DOMWindow::dispatchMessageEventWithOriginCheck(WebCore::SecurityOrigin*, WTF::PassRefPtr<WebCore::Event>, WTF::PassRefPtr<Inspector::ScriptCallStack>) + 66
48 WebCore 0x291aeb62 WebCore::DOMWindow::postMessageTimerFired(WebCore::PostMessageTimer&) + 98
49 WebCore 0x291b212e WebCore::PostMessageTimer::fired() + 14
50 WebCore 0x28e89898 WebCore::ThreadTimers::sharedTimerFiredInternal() + 136
51 WebCore 0x28e897ec WebCore::timerFired(__CFRunLoopTimer*, void*) + 28
52 CoreFoundation 0x25b919e6 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 14
53 CoreFoundation 0x25b91618 __CFRunLoopDoTimer + 936
54 CoreFoundation 0x25b8f464 __CFRunLoopRun + 1500
55 CoreFoundation 0x25ae1bb8 CFRunLoopRunSpecific + 516
56 CoreFoundation 0x25ae19ac CFRunLoopRunInMode + 108
57 WebCore 0x28ecfcbe RunWebThread(void*) + 422
58 libsystem_pthread.dylib 0x25906c7e _pthread_body + 138
59 libsystem_pthread.dylib 0x25906bf2 _pthread_start + 110
60 libsystem_pthread.dylib 0x25904a08 thread_start + 8
————————————
16.01.19
tried
dispatch_async(dispatch_get_main_queue(), ^{
if (self.webView != nil) {
self.webView removeFromSuperview];
_webView = [self createNewWebView];
[self addSubview:self.webView];
}
});
and
if (self.webView == nil) {
self.webView removeFromSuperview];
_webView = [self createNewWebView];
[self addSubview:self.webView];
}
but It didn’t work.
What can I change or add code ?
Please help me guys..

Answer 1

Its crashing because of open GL in the background.
You will need to disable open GL if the app is in background.
Here is the Code to do that :
typedef void (*CallFuc)(id, SEL, BOOL);
typedef BOOL (*GetFuc)(id, SEL);
-(BOOL)webView:(UIWebView*)view enableGL:(BOOL)bEnable
{
BOOL bRet = NO;
do
{
Ivar internalVar = class_getInstanceVariable([view class], "_internal");
if (!internalVar)
{
NSLog(#"enable GL _internal invalid!");
break;
}
UIWebViewInternal* internalObj = object_getIvar(view, internalVar);
Ivar browserVar = class_getInstanceVariable(object_getClass(internalObj), "browserView");
if (!browserVar)
{
NSLog(#"enable GL browserView invalid!");
break;
}
id webbrowser = object_getIvar(internalObj, browserVar);
Ivar webViewVar = class_getInstanceVariable(object_getClass(webbrowser), "_webView");
if (!webViewVar)
{
NSLog(#"enable GL _webView invalid!");
break;
}
id webView = object_getIvar(webbrowser, webViewVar);
if (!webView)
{
NSLog(#"enable GL webView obj nil!");
}
if(object_getClass(webView) != NSClassFromString(#"WebView"))
{
NSLog(#"enable GL webView not WebView!");
break;
}
SEL selector = NSSelectorFromString(#"_setWebGLEnabled:");
IMP impSet = [webView methodForSelector:selector];
CallFuc func = (CallFuc)impSet;
func(webView, selector, bEnable);
SEL selectorGet = NSSelectorFromString(#"_webGLEnabled");
IMP impGet = [webView methodForSelector:selectorGet];
GetFuc funcGet = (GetFuc)impGet;
BOOL val = funcGet(webView, selector);
bRet = (val == bEnable);
}while(NO);
return bRet;
}
Call [self webView:self.yourWebView enableGL:NO] when app is in background.