We are seeing a strange crash in which it appears that iOS is jettisoning our app along with mediaserverd after receiving a level 2 memory warning. It occurs while streaming DRM content (including, but not limited to, PlayReady encrypted content) about 7-8 minutes into playback – even if we have restarted the device with no other applications running in the background. This does not happen consistently, however, and we can sometimes complete the same piece of content (an entire 2 hour movie) with numerous memory-heavy applications in the background without any issues.
We are seeing this on iPhone 3GS, 4, and 4S devices running iOS 5.1 and 5.1.1, though it appears to be most prominent on a 3GS. The app is be terminated with either “segmentation fault 11” or “signal 9”. Segmentation fault 11 can refer to bad memory access or low memory and signal 9 refers to low memory termination.
We have used both the static analyzer and instruments to find and fix any leaks and nothing alarming shows up in the Leaks instrument.
When analyzing playback using the Memory Monitor instrument, we see a dramatic decrease in available physical memory when we begin streaming, which is to be expected to a certain extent. When the application/os is behaving normally, other applications are removed from the background when memory becomes too low, but occasionally the available physical memory will simply continue to drop until the OS kills our app. No crash logs are generated, although we occasionally receive Low Memory logs, like the one below:
Incident Identifier: 13839D5B-D280-40D8-8C67-6EE3D61394C3
CrashReporter Key: d3746ff556543d6a94e067d82c8fb379a285f543
Hardware Model: iPhone2,1
OS Version: iPhone OS 5.1.1 (9B206)
Kernel Version: Darwin Kernel Version 11.0.0: Sun Apr 8 21:50:49 PDT
2012; root:xnu-1878.11.10~1/RELEASE_ARM_S5L8920X
Date: 2012-06-28 14:09:56 -0400
Time since snapshot: 104 ms
Free pages: 712
Active pages: 1433
Inactive pages: 1012
Throttled pages: 49925
Purgeable pages: 0
Wired pages: 11870
Largest process: SpringBoard
Processes
Name UUID Count resident pages
launchd <5fec01c378a030a8bd23062689abb07f> 79
securekeyvaultd. <78f602d3604c3bf487a27a288dec3bbb> 156
MYAPP <285e46965a91381dad0661443c8be3eb> 4035 (jettisoned) (active)
MobilePhone <8f3f3e982d9235acbff1e33881b0eb13> 749 (jettisoned)
mediaserverd <f03b746f09293fd39a6079c135e7ed00> 3670 (jettisoned)
networkd <80ba40030462385085b5b7e47601d48d> 145
apsd <e7a29f2034083510b5439c0fb5de7ef1> 260
SpringBoard <c74dc89dec1c3392b3f7ac891869644a> 4615 (active)
notifyd <f6a9aa19d33c3962aad3a77571017958> 170
BTServer <31e82dfa7ccd364fb8fcc650f6194790> 259
CommCenterClassi <041d4491826e3c6b911943eddf6aaac9> 421
aggregated <a12fa71e6997362c83e0c23d8b4eb5b7> 329
configd <ee72b01d85c33a24b3548fa40fbe519c> 324
fairplayd.N88 <ecb9495b29543b35a1f2e6c2b432528c> 168
fseventsd <914b28fa8f8a362fabcc47294380c81c> 164
iapd <0a747292a113307abb17216274976be5> 284
imagent <9c3a4f75d1303349a53fc6555ea25cd7> 412
locationd <cf31b0cddd2d3791a2bfcd6033c99045> 493
mDNSResponder <86ccd4633a6c3c7caf44f51ce4aca96d> 182
mediaremoted <327f00bfc10b3820b4a74b9666b0c758> 208
lockdownd <b06de06b9f6939d3afc607b968841ab9> 315
powerd <133b7397f5603cf8bef209d4172d6c39> 143
syslogd <7153b590e0353520a19b74a14654eaaa> 90
wifid <3001cd0a61fe357d95f170247e5458f5> 285
UserEventAgent <dc32e6824fd33bf189b266102751314f> 322
launchd <5fec01c378a030a8bd23062689abb07f> 120
End
According to some older questions I’ve seen on here, it seems that mediaserverd used to have serious problems with memory leaks in previous versions of iOS.
Could this be related to the issue?
How can we prevent this from happening?
Any ideas, theories, feedback, or similar issues would be greatly appreciated!
This is just a blind guess, but aren’t you using AVFoundation’s AVPlayer?
I had an issue like this, it turned out I wasn’t releasing AVPlayers correctly. So for every song I created a new AVPlayer, which is fine if you release the old, but I didn’t.
I found it out by doing an allocation test in Instruments and saw AVPlayers remain living after they supposed to be released.