MacOS calls CEF when using external message loop

[tarmac]

Hello,

I'm trying to set up CEF with an external message loop on macOS. However, my application's

Code: Select all

[NSApp run]

seems to lead to CEF's runloop observer to get called:

Code: Select all

[1108/110141.158472:FATAL:message_pump_mac.mm(402)] Check failed: nesting_level_ != 0 (0 vs. 0)

(lldb) bt
* thread #1, name = 'CrBrowserMain', queue = 'com.apple.main-thread', stop reason = EXC_BREAKPOINT (code=1, subcode=0x110ddb1c4)
  * frame #0: 0x0000000110ddb1c4 Chromium Embedded Framework`logging::LogMessage::~LogMessage(this=0x0000000103e99640) at logging.cc:951:7 [opt]
    frame #1: 0x0000000110ddb44c Chromium Embedded Framework`logging::LogMessage::~LogMessage() [inlined] logging::LogMessage::~LogMessage(this=<unavailable>) at logging.cc:702:27 [opt]
    frame #2: 0x0000000110ddb448 Chromium Embedded Framework`logging::LogMessage::~LogMessage(this=<unavailable>) at logging.cc:702:27 [opt]
    frame #3: 0x000000010ca8ddf0 Chromium Embedded Framework`scoped_refptr<CefCommandLineImpl>::~scoped_refptr() [inlined] scoped_refptr<CefCommandLineImpl>::Release(ptr=<unavailable>) at scoped_refptr.h:361:8 [opt]
    frame #4: 0x000000010ca8dde4 Chromium Embedded Framework`scoped_refptr<CefCommandLineImpl>::~scoped_refptr() [inlined] scoped_refptr<CefCommandLineImpl>::~scoped_refptr(this=0x000000016fdfe248) at scoped_refptr.h:261:7 [opt]
    frame #5: 0x000000010ca8dddc Chromium Embedded Framework`scoped_refptr<CefCommandLineImpl>::~scoped_refptr(this=0x000000016fdfe248) at scoped_refptr.h:254:20 [opt]
    frame #6: 0x0000000110ea063c Chromium Embedded Framework`base::MessagePumpCFRunLoopBase::PopWorkItemScope(this=0x000000010379e240) at message_pump_mac.mm:402:3 [opt]
    frame #7: 0x0000000110ea01cc Chromium Embedded Framework`base::MessagePumpCFRunLoopBase::EnterExitObserver(observer=<unavailable>, activity=128, info=0x000000010379e240) at message_pump_mac.mm:677:13 [opt]
    frame #8: 0x00000001aafc1bb0 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 36
    frame #9: 0x00000001aafc1a00 CoreFoundation`__CFRunLoopDoObservers + 592
    frame #10: 0x00000001aafc04e4 CoreFoundation`CFRunLoopRunSpecific + 684
    frame #11: 0x00000001b3be0dd8 HIToolbox`RunCurrentEventLoopInMode + 292
    frame #12: 0x00000001b3be0b54 HIToolbox`ReceiveNextEventCommon + 564
    frame #13: 0x00000001b3be0908 HIToolbox`_BlockUntilNextEventMatchingListInModeWithFilter + 72
    frame #14: 0x00000001adb1fbcc AppKit`_DPSNextEvent + 860
    frame #15: 0x00000001adb1e4c4 AppKit`-[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 1328
    frame #16: 0x00000001adb10690 AppKit`-[NSApplication run] + 596
    frame #17: 0x00000001000392f4 cefclient`_sapp_macos_run(desc=0x000000016fdfed60) at sokol_app.h:3347:5
    frame #18: 0x0000000100039078 cefclient`main(argc=1, argv=0x000000016fdff168) at sokol_app.h:3356:5
    frame #19: 0x0000000100201088 dyld`start + 516


(Please note that this is a different program than the `cefclient` in the repo. I called my macOS app bundle `cefclient` just so that I could just copy over the `cefclient Helper`s)

Do I need to make any changes to my application to setup CEF with an external message loop? eg. does CEF make any assumptions about how my application's message loop runs?

[magreenblatt]

You still need to implement the CefAppProtocol interface when using external message loop. If you can't implement it directly, there's an example in injection here that you can follow.

[magreenblatt]

How does your application create the NSApplication instance currently? It would be easiest to follow the cefsimple code example.