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FYI: The issue will be fixed in the next build, see http://www.ventismedia.com/mantis/view. ... 774#c44176 for details.

Hello Ludek,

Thanks for alerting to me to the workarounds in the Mantis bug tracker. I took a look, and actually I'm not sure the workarounds apply to my situation. For example, I have seen no correlation between the state of my phone's lock screen, and to the slow syncs or to the memory leak. I will study the workarounds carefully however to make sure I'm not missing something.

For me, the memory leak in AppleMobileDeviceService is not the most serious issue. I can work around the memory leak by filling the device with small syncs, and by restarting AppleMobileDeviceService between each sync. This keeps memory usage at ordinary levels.

My real problem is the "slow sync" issue. This is what prevents me from putting tracks on the phone. In my first post in this thread, I wrote:

> As you suggest, I have reproduced the bug with a small set of tracks. For example, with 42.0 GB of
> music already stored on the iPhone, I tried to sync ten tracks totaling 70.2 MB in size. The log for this
> failed sync can be found linked in the Help Desk Ticket.

Tonight I will repeat this test, with just a few tracks, now that I am using 1.11.1783's debug version. I believe that the verbose logs will show many occurrences of the message "Waiting for Asset Manifest." That, I believe, is at the heart of the "slow sync" issue. This error message --

> iPhone: Waiting for Manifest has failed !!!!! , Timeout = 30.

-- indicates that MediaMonkey cannot write tracks to the phone, is my guess. I will attempt to confirm this tonight with a small, controlled sync as I did originally, but this time with verbose debug output written to the log. We shall see what it shows!

EDIT: I just saw your edit to your reply. Thanks very much for the thinking on what's causing the slow sync. I am about to do the small, controlled test of sync speeds now that my phone has 50.1 GB of music data. The verbose logs may reveal what is going on, if anything. Thanks, Tom Davey.

Regards,
Tom Davey

Hi Tom,
thanks for the detailed info, screengrap and logs. I will analyze them and let you know via the ticket.

On the screengraps I see that the memory grows after syncing at least 5000 tracks, after 1600 it stays on 7 MB only, so I will need definetly test with thousands of tracks.

BTW: Does anyone of you know whether the same leak appears when syncing the same tracks using iTunes ??
I also wonder whether one of these workarounds work for you:
http://www.ventismedia.com/mantis/view. ... 774#c42751 ??

EDIT:
Otherwise in your 68 MB log 'dbgview-mediamonkey-sync-2016-02-16-40GB-temp.LOG' I saw that syncing/copying of the 5532 tracks was constantly fast until the unexpected iPhone disconnect appeared at the end of the log (caused by the unexpected iPhone reboot). So it seems that the reboot (caused by the leak) gots the device to a broken state which causes that adding further tracks fails with the AssetManifest timeout. According to my experiment the leaking starts after copying around 1700 files. Workaround could be to restart the "Apple Mobile Service" e.g. after each 1000 files copy. I am going to prepare some stuff/testing DLLs and will post it via the ticket.

Hello everybody,

Last night I performed another test synchronization, yielding some conclusive results. I believe that I have now thoroughly documented the two issues affecting me: the "slow sync" issue that prevents me from filling the iPhone beyond a threshold of 40-50 GB of music tracks, and the memory leak in AppleMobileDeviceService.exe that crashes the iPhone and MediaMonkey over the course of a long slow sync.

RESULTS OF LAST NIGHT'S SYNC

1. The transfer of only 3 GB of data over the course of two hours of syncing, extremely slow
2. During these two hours, RAM consumption ("Private Working Set") in AppleMobileDeviceService.exe from 7k to over 875k. Note that, unlike the earlier syncs described in previous posts to this thread, the RAM growth does not seem to correlated with the amount of data transferred, but seemingly with the amount of time the sync consumed (because the amount of data transferred was small).
3. A spontaneous reboot of the phone, aborting the sync. The phone rebooted in my hands while I happened to be examining it. The phone's UI was noticeably unstable in the minutes leading up to the reboot.
4. At the same time, a MediaMonkey crash -- access violation in d_iPhone.dll -- resulting in a diagnostic report, which was emailed to MediaMonkey support.
5. Upon my manually exiting MediaMonkey, I received an Application Error dialog from Windows, reporting an access violation in iTunesMobileDevice.dll

DOCUMENTATION OF THE CRASHES

I've uploaded a set of files for you to the same Dropbox directory that I earlier shared link in the Help Desk ticket for this forum post. The files are:

1. 4 screen shots of Task Manager, showing the memory leak in AppleMobileDeviceService.exe growing to 875k over the course of the sync, and also the amount of data transferred by MediaMonkey.exe.
2. A debug log captured with DebugView. This log holds more than 400,000 line entries. 56,204 lines contain the string "Waiting for Asset Manifest...". These lines document the "slow sync" issue I believe. The sync is slow because of the waiting.
3. The log contains, in addition, 174 occurrences of the message "iPhone: Waiting for Manifest has failed !!!!! , Timeout = 30." If "30" means 30 seconds, then that's 87 minutes of waiting on the Asset Manifest.
4. 2 screen shots of the access violation dialogs

STEPS TO SET UP THE SYNC

1. I used the same Windows 7 environment and latest MediaMonkey debug version that I reported in my first post to this thread.
2. Unlike the earlier tests, I did NOT "clean" the iPhone first by deleting the music tracks, the iOS MediaLibrary database, etc., but instead preserved the phone's state from last night's sync. 49.2 GB of music was on the device at the start of the most recent test.
3. I selected slightly over 20 GB of music tracks, 3,044 tracks in all.

Last night's results are consistent with my experiences to date: the "slow sync" issue begins to show itself when the iPhone contains around 40 GB of data. Beyond 50 GB of data, MediaMonkey becomes essentially unable to transfer any more music tracks at all.

Please me know what other information I can provide. Thanks again for your interest!

Regards,
Tom Davey

Hello Ludek and other interested folks,

Here's a follow-up on the memory leak issue.

Last night I performed two large syncs, with 42.9 GB and 29.5 GB of music selected for transfer respectively. The memory leak in AppleMobileDeviceService.exe appears to have crashed the iPhone and MediaMonkey both times, although in two different ways. To document the leak, I captured a series of screenshots of Windows Task Manager, and of the Windows error dialogs I received. I also saved the debug logs. I've provided links to these various documents in the Help Desk ticket I opened for this forum post.

THE FIRST SYNC

1. Before starting the sync, I "reset" the phone by deleting all the music and (using iFunBox) a variety of pertinent files in \iTunes_control. Then I rebooted the phone. As a result, the phone had 109 GB of storage available for music.

2. I selected 6,960 tracks, totaling 42.9 GB of music, for the sync. Over the course of the sync, the memory consumed by AppleMobileDeviceService.exe grew from 4,484k to over 1.07 GB. As the Task Manager screen shots show, memory consumpion grows in rough tandem with the amount of data transferred.

3. The iPhone spontaneously rebooted after transferring 34.8 gigs and 5,619 tracks, about 80% of the way through the sync.

4. I also received an Application Error dialog: "Access Violation in module CoreFoundation.dll". See the screen shot linked from the Help Desk ticket.

5. MediaMonkey itself didn't actually crash, but I couldn't exit the program normally because of background processes that wouldn't terminate. I had to kill MediaMonkey.exe using TaskManager.

6. At no time did I detect the "slow syncing" problem, e.g. Asset Manifest timeouts, or the endlessly spinning sync icon on the phone. Slow syncing is what ordinarily prevents me from filling the phone, not crashes.

7. All of the above is illustrated in the zipped debug log (6.84 MB) and the various screen shots.

THE SECOND SYNC

1. I didn't fully reset the iPhone for the second sync, but instead (after the iPhone rebooted) restarted the AppleMobileDeviceService service (to free memory) and MediaMonkey itself.

2. I selected 29.58 GB of music for the sync. Over the course of the sync, the memory consumed by AppleMobileDeviceService.exe grew from 4,484k to a whopping 2.2 GB. I have captured a Task Manager screen shot showing this final memory state.

3. The iPhone spontaneously rebooted after transferring 2,387 tracks and 14.4 GB of music data. At this point, the phone stores 49.2 GB of music; 54.9 GB remains available.

4. I also received an Application Error dialog, different from the first one: "Access Violation in module iPhoneCalc.dll."

5. MediaMonkey itself also crashed. I filled out the MediaMonkey crash report and clicked ok to email it. This crash report should complement the voluminous debug data in the second zipped log file.

6. The "slow syncing" problem manifested itself this time, but only gradually (e.g., increasing frequency of "Waiting for Asset Manifest" messages). Finally, though, the log shows this message: "iPhone: Waiting for Manifest has failed !!!!! , Timeout = 30." I wasn't watching at this point, but it may have been the moment that the phone (and maybe MediaMonkey also) crashed.

I will try more syncing tonight. The iPhone holds nearly 50 GB of stored music right now. This amount of stored music is right about the point that the "slow syncing" issue grows serious, and essentially prevents me from successfully transferring any more music at all. In the past I have worked around the crashes and memory leaks by undertaking small syncs -- 2-3 GB in size -- and then restarting AppleMobileDeviceService.exe to avoid the leaks. I do not have a workaround for the slow syncing issue however.

Hope this helps! Let me know what other information I can provide. I really appreciate everybody's interest in these issues.

Regards,
Tom Davey

Hi Ludek,

Thank you for looking into this. I am delighted to be of help. I will perform more tests later this evening to try to reliably reproduce the memory leak in AppleMobileDeviceService.exe. More to come tomorrow.

You write:

> I see in the log that the device sends "Progress" , but no "AssetManifest" which leads to the failure.

I can see two examples of the "Asset Manifest" failure message in my debug log. Below I have reproduced the exact line in question, and the immediate subsequent lines for context. Both messages occur near the end of the log file. After the second occurrence of the message the syncing process seemed to stall or stop. I waited for about ten minutes, then exited MediaMonkey and finally closed the log.

00027389 241.47232056 [7944] iPhone: Waiting for Asset Manifest...
00027390 241.57238770 [7944] iPhone: Waiting for Manifest has failed !!!!! , Timeout = 30
00027391 241.57244873 [7944] iPhone: close_communication
00027392 241.57250977 [7944] iPhone: closeAirThread
00027393 241.57257080 [7944] iPhone: closeAirThread: 1 thread running
00027394 241.57260132 [7944] iPhone: closeAirThread: signaled
00027395 241.60229492 [7944] iPhone: signal reset
00027396 241.60237122 [7944] iPhone: free ATC data
00027397 241.60249329 [7944] iPhone: closeAirThread: 1 thread finished
00027398 241.60255432 [7944] iPhone: rxThread terminated (12 messages received)
00027399 241.60264587 [7944] iPhone: close_communication finished
00027400 241.60273743 [7944] iPhone: FinishConnection
00027401 241.60494995 [4484] ASL logging to file "C:\Users\tdavey\AppData\Roaming\Apple Computer\Logs\asl.101151_15Feb16.log"
00027402 241.60508728 [4484] [(unknown facility) MediaMonkey64Helper.exe] _send_message (thread 8352): Could not securely send message: SSL_ERROR_SYSCALL errno (No such file or directory).
00027403 241.60691833 [4484] [(unknown facility) MediaMonkey64Helper.exe] AMDeviceStopSession (thread 8352): Could not stop session with device 1: kAMDSendMessageError

And a bit later:

00028734 280.66143799 [7944] iPhone: Waiting for Manifest has failed !!!!! , Timeout = 30
00028735 280.66146851 [7944] iPhone: close_communication
00028736 280.66156006 [7944] iPhone: closeAirThread
00028737 280.66162109 [7944] iPhone: closeAirThread: 1 thread running
00028738 280.66165161 [7944] iPhone: closeAirThread: signaled
00028739 280.69137573 [7944] iPhone: signal reset
00028740 280.69140625 [7944] iPhone: free ATC data
00028741 280.69152832 [7944] iPhone: rxThread terminated (26 messages received)
00028742 280.70126343 [7944] iPhone: closeAirThread: 1 thread finished
00028743 280.70129395 [7944] iPhone: close_communication finished
00028744 280.70132446 [7944] iPhone: FinishConnection
00028745 280.70248413 [4484] [(unknown facility) MediaMonkey64Helper.exe] _send_message (thread 8352): Could not securely send message: SSL_ERROR_SYSCALL errno (No such file or directory).
00028746 280.70336914 [4484] [(unknown facility) MediaMonkey64Helper.exe] AMDeviceStopSession (thread 8352): Could not stop session with device 1: kAMDSendMessageError

Hope this helps! More tomorrow after a 40 GB sync and what promises to be a VERY big log.

Regards,
Tom Davey

Hmm, just testing this with my iTouch 5 powered by iOS 9.2.1 (13D15) , the newest iTunes , Windows 7 x64 and I cannot reproduce the leak at all.

All the time the AppleMobileDeviceService.exe stays only at 7 MB, but I tried to sync only hundreds of files. Is it possible that it starts to grow only after thousands or it grows gradually for you?

Hi, thank you for the detailed info.

I see in the log that the device sends "Progress" , but no "AssetManifest" which leads to the failure.

You noticed that memory leak in AppleMobileDeviceService.exe leading to crashes. The "Private Working Set" can grow to 1 GB over the course of a big sync.
I wonder whether this is also the case now if you want to add just one file to the iPhone that already has 42 GB of tracks ?
Or it was only the case when you let to copy all the 42 GB to the cleaned up iPhone and it crashed at the end of copying the 42 GB ?

Anyway thank you for noticing that there is a leak in AppleMobileDeviceService.exe , I saw several reports of users experiencing the same issue (unexpected iPhone reboot in case of large sync) and had never realized what could cause the crash/reboot.
Now the leak makes quite sense, I will verify and try to eliminate the leak somehow, probably will require some more reverse engineering but hopefully I will be successful.
My guess is that we don't send a message that Apple needs to free the memory.

Thanks again.

Hello everybody,

I have a new iPhone 6s with 128 GB of storage that I've been trying to fill with music. However, I can get to only about 42 GB worth of tracks onto the phone before running into issues similar to other reports here on the forums about "slow syncing" etc. The iPhone has 62 GB of free storage at the moment, but MediaMonkey cannot put any more music on it.

Per your instructions in forum topic #69, I have gathered the needed troubleshooting data (logs etc.) to illustrate the following various symptoms which may occur over the course of my many attempts and experiments in trying to fill the full storage space on the iPhone:

1. Increasingly slow sync as the phone fills up ("Waiting for Asset Manifest . . . ") . Finally "Waiting for Manifest has failed !!!!! , Timeout = 30"
2. Endlessly spinning "sync" icon on the iPhone after MediaMonkey appears to finish the sync; it doesn't stop until I close MediaMonkey.
3. Memory leak in AppleMobileDeviceService.exe, leading to crashes. The "Private Working Set" can grow to 1 GB over the course of a big sync.
4. Application Error dialog: "Exception EAccessVilolation in module iTunesMobileDevice.dll at . . . "
5. iPhone spontaneously rebooting
6. MediaMonkey hanging, requiring me to end the process for MediaMonkey.exe in Task Manager

I have performed my latest tests over the past few days with MediaMonkey debug build 4.1.11.1783 Gold. I do not use iTunes for music syncing, although the latest version of iTunes (12.3.2.35 x64) is installed on my PC. Nor do I enable MediaMonkey's auto-conversion rules when syncing; all tracks are ordinary .m4a or .mp3 formats. The other aspects of my environment are:

1. Windows 7 Professional x64 (6.1.7601 Service Pack 1 Build 7601)
2. Hewlett-Packard 700-515xt with Intel i7-4770 3.4 GHz and 8 GB RAM
3. iPhone 6s Plus with 128 GB storage and iOS 9.2.1.
4. Syncing via cable over USB 3.0 (PC) and Thunderbolt (iPhone)

I have provided links to the relevant iPhone files (from \iTunes_Control\iTunes\) and DebugView logs in a Help Desk ticket. As you suggest, I have reproduced the bug with a small set of tracks. For example, with 42.0 GB of music already stored on the iPhone, I tried to sync ten tracks totaling 70.2 MB in size. The log for this failed sync can be found linked in the Help Desk Ticket.

One other note: before I start another experiment to refill the phone from scratch, I "clean" the iPhone's music configuration by deleting all the music files (using iOS Settings) and a variety of files in iTunes_Control (using iFunBox). This mimics a hard reset, per the following helpful Reddit post. I've done this about ten times as I experiment while watching the logs, trying different batch sizes for the sync, restarting the service AppleMobileDeviceService.exe to recover memory, rebooting the iPhone and/or PC, etc.

https://www.reddit.com/r/iOS8/comments/ ... _crash_pc/

I hope this helps! Let me know what other tests I might perform or information I can provide.

Regards,
Tom Davey