iOS 7 SDK - MediaPlayer Framework - Rolling back transaction

Question

The following block of code results in the error message:

2013-09-13 15:27:08.449 Mobile[746:5603] {MediaLibrary} Rolling back transaction.

MPMediaQuery *mediaQuery = [MPMediaQuery songsQuery];
NSArray *collections = [mediaQuery collections];

This is in the console as of iOS 7 GM.

This worked without issue in iOS 6.

Does anyone have any idea what this relates to in iOS 7? I have searched all over, and can find nothing about it.

In addition the message is logged on every iteration of this for loop:

for (MPMediaItemCollection *collection in collections) {

    for (MPMediaItem *item in collection.items) {
        //message is written to log here as well

    }
}

Clamworm

Specifically it is running on an iPad gen 3. – Clamworm

I filed a radar with Apple. I will let you know when I hear back – Clamworm

Answer 1

I'm seeing the same issue, though it doesn't seem to cause any problems. I think this is some internal logging that they mistakenly left turned on.

Deste

If this is the case, maybe there is a way to suppress the logging temporarily. When you want to index a 1000 songs, the log gets huge. – Clamworm

Answer 2

In some cases when the MPMediaQuery is loaded the first time you can have

2013-09-19 00:28:10.636 musiXmatch[4498:1303] {MediaLibrary} Database validation succeeded 2013-09-19 00:28:11.240 musiXmatch[4498:7a0b] {MediaLibrary} Rolling back transaction.

Other strange logs on iOS7 GM are the following

2013-09-19 00:28:13.643 musiXmatch[4498:7b0f] CLTilesManagerClient: initialize, sSharedTilesManagerClient 2013-09-19 00:28:13.647 musiXmatch[4498:7b0f] CLTilesManagerClient: init 2013-09-19 00:28:13.649 musiXmatch[4498:7b0f] CLTilesManagerClient: reconnecting, 0x19504c90 2013-09-19 00:28:13.651 musiXmatch[4498:7d03] CLTilesManagerClient: XPC_ERROR_CONNECTION_INVALID!

Specifically the last messagge XPC_ERROR_CONNECTION_INVALID is a value of the xpc event type when doing something like

xpc_connection_set_event_handler(serviceConnection, ^(xpc_object_t event) {
    xpc_type_t type = xpc_get_type(event);

[EDIT]

New interesting CLTilesManagerClient logs.

2013-12-04 15:37:25.695 musiXmatch[274:1303] CLTilesManagerClient: initialize, sSharedTilesManagerClient 2013-12-04 15:37:25.697 musiXmatch[274:1303] CLTilesManagerClient: init 2013-12-04 15:37:25.698 musiXmatch[274:1303] CLTilesManagerClient: reconnecting, 0x1d942d50 2013-12-04 15:37:25.700 musiXmatch[274:7b03] CLTilesManagerClient: XPC_ERROR_CONNECTION_INVALID!

Pug

the problem persists in iOS 7.1 update: {MediaLibrary} Database validation succeeded – Pug

When the app is being closed a new messagge appears in iOS 7.1: {MediaLibrary} Media library service connection invalidated. – Pug