1216545 - Crash in libAVFAudio.dylib

Status: VERIFIED FIXED

(Firefox for iOS :: General, defect)

Description

[Aaron Train [:aaronmt]]

Yet another crash in libAVFAudio.dylib

Reproducible.

Steps from ios-mobile-testers

* Visit npr.org, hit play on the live-stream at the top
* Switch out of Firefox, open the timer in the Clock application, set for a min
* Turn off display
* When the alarm goes off, audio suspends in Firefox, on switch back to Firefox we crash
* Re-open Firefox and it crashes again

2015-10-20 10:04:47.390 Client[1476:814824] *** Terminating app due to uncaught exception 'com.apple.coreaudio.avfaudio', reason: 'error 561015905'

* thread #1: tid = 0xc6ee8, 0x0000000198ee31e0 libsystem_kernel.dylib`__pthread_kill + 8, queue = 'com.apple.main-thread', stop reason = signal SIGABRT

Comment 1

[Richard Newman [:rnewman]]

Possibly related, I saw this on my Simulator yesterday after Bug 1215972 landed.

2015-10-19 13:41:06.168 Client[13665:3213222] 13:41:06.168 ERROR:    AVAudioIONodeImpl.mm:365: _GetHWFormat: required condition is false: hwFormat
2015-10-19 13:41:06.169 Client[13665:3213222] *** Terminating app due to uncaught exception 'com.apple.coreaudio.avfaudio', reason: 'required condition is false: hwFormat'
*** First throw call stack:
(
	0   CoreFoundation                      0x0000000106558f65 __exceptionPreprocess + 165
	1   libobjc.A.dylib                     0x0000000105878deb objc_exception_throw + 48
	2   CoreFoundation                      0x0000000106558dca +[NSException raise:format:arguments:] + 106
	3   libAVFAudio.dylib                   0x000000010d427e53 _Z19AVAE_RaiseExceptionP8NSStringz + 176
	4   libAVFAudio.dylib                   0x000000010d4693a7 _ZN13AVAudioIOUnit12_GetHWFormatEjPj + 373
	5   libAVFAudio.dylib                   0x000000010d4690aa ___ZN13AVAudioIOUnit22IOUnitPropertyListenerEPvP28OpaqueAudioComponentInstancejjj_block_invoke_2 + 166

Comment 2

[Stefan Arentz | :st3fan | ⏰ EST | he/him]

Console:

2015-10-20 15:01:52.857 Client[10329:2870709] 15:01:52.820 ERROR:    [0x1a1ed2000] >aurioc> 807: failed: '!pla' (enable 2, outf< 2 ch,  44100 Hz, Float32, non-inter> inf< 2 ch,      0 Hz, Float32, non-inter>)
2015-10-20 15:01:52.891 Client[10329:2870709] 15:01:52.889 ERROR:    [0x1a1ed2000] AVAudioEngineGraph.mm:2510: PerformCommand: error 561015905

Trace:

Thread 1Queue : com.apple.main-thread (serial)
#0	0x000000019ac1ff48 in objc_exception_throw ()
#1	0x0000000186f6744c in __NSThreadPerformPerform ()
#2	0x0000000185fe05a4 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ ()
#3	0x0000000185fe0038 in __CFRunLoopDoSources0 ()
#4	0x0000000185fddd38 in __CFRunLoopRun ()
#5	0x0000000185f0cdc0 in CFRunLoopRunSpecific ()
#6	0x0000000191060088 in GSEventRunModal ()
#7	0x000000018b5e6f44 in UIApplicationMain ()
#8	0x000000010023519c in main at /Users/sarentz/Projects/firefox-ios/Client/Application/main.swift:22
#9	0x000000019b44a8b8 in start ()

Comment 3

[Stefan Arentz | :st3fan | ⏰ EST | he/him]

Thrown from:

        func startEngine() {
            if !engine.running {
                do {
>>>>>>            try engine.start()
                } catch {
                    log.error("Unable to start AVAudioEngine: \(error)")
                }
            }
        }

Comment 4

[Stefan Arentz | :st3fan | ⏰ EST | he/him]

Interesting the catch clause is never called. This may not work as we expect it to.

Comment 5

[Stefan Arentz | :st3fan | ⏰ EST | he/him]

Some notes:

Safari behaviour:

Make sure audio is silent
Open a new tab, go to http://www.relay.fm/mpu/284
Play the podcast
Hit the home button - Audio keeps playing
Open Clock, set an alarm for 1 minute
Lock screen - Audio keeps playing
When alarm goes off, silence it "Tap to Stop"
Audio should still be playing
Unlock phone
Double tap
Switch to Safari - Audio should still be playing

Comment 6

[Stefan Arentz | :st3fan | ⏰ EST | he/him]

We already fail here:

When alarm goes off, silence it "Tap to Stop"
Audio should still be playing

We don't crash, but the audio stops playing. I think we may be using the wrong audio session flags/mode/etc.

Comment 7

[Stefan Arentz | :st3fan | ⏰ EST | he/him]

I have added the 'audio' background mode to the app. This gives us behaviour similar to Safari and stops the crashes.

I don't think this one had anything to do with our AuralProgressBar code. I think this is about the WKWebView playing audio.

Comment 8

[Stefan Arentz | :st3fan | ⏰ EST | he/him]

Attachment: PR: https://github.com/mozilla/firefox-ios/pull/1179

This patch adds audio as a required background mode. This prevents the crash and also makes the app behave similar to Safari wrt audio. You can now for example start a podcast in a tab, answer a phone call, or play a game, and the podcast will be correctly suspended and resumed.

Comment 9

[Aaron Train [:aaronmt]]

Comment on attachment 8676446 [details] [review]
PR: https://github.com/mozilla/firefox-ios/pull/1179

#1180 works for me

https://github.com/mozilla/firefox-ios/pull/1180

Comment 10

[Richard Newman [:rnewman]]

I merged that. 273dcf7

Comment 11

[Richard Newman [:rnewman]]

Comment on attachment 8676446 [details] [review]
PR: https://github.com/mozilla/firefox-ios/pull/1179

sleroux, please post-review!

Comment 12

[Catalin Suciu [:csuciu]]

I can't reproduce the crash using the steps from description.
Verifying as fixed on Beta 1113