Hi,
i've developed an iPhone program which is kind of an image manipulation program:
The user get an UIImagePickerController and selects an image. Then the program does some heavy calculating in a new thread (for responsiveness of the application). The thread has, of course, its own autorelease pool. When calculation is done, the seperated thread signals the main thread that the result can be presented. The app creates a new view controller, pushes it onto the navigation controller.
In short:
UIImagePickerController
new thread (autorelease pool) does some heavy calculation with image data
signal to main thread that it's done
main thread creates view controller and pushes it onto navigation controller
view controller presents image result
My program works well, but if I dismiss the navigation controller's top view controller by tapping on the back button and repeat the whole process several times, my app crashes. But only on the device!
Instruments cannot find any leaks (except for some minor ones which I don't feel responsible for: thread creation, NSCFString; overall about 10 kB). Even Clang static analyzer tells me that my could seems to be all right.
I know that the UIImage class can cache images and objects returned from convenience methods get freed only whet their autorelease pool gets drained. But most of the time I work with CGImageRef and I use UIImage' alloc, init & release methods to free memory as soon as possible.
Currently, I don't know how to isolate the problem. How would you approach this problem?
Crash Log:
Incident Identifier: F4C202C9-1338-48FC-80AD-46248E6C7154
CrashReporter Key: bb6f526d8b9bb680f25ea8e93bb071566ccf1776
OS Version: iPhone
OS 3.1.1 (7C145)
Date: 2009-09-26 14:18:57 +0200
Free pages: 372
Wired pages: 7754
Purgeable pages: 0
Largest process: _MY_APP_
Processes
Name UUID Count resident pages
_MY_APP_ <032690e5a9b396058418d183480a9ab3> 17766 (jettisoned) (active)
debugserver <ec29691560aa0e2994f82f822181bffd> 107
syslog_relay <21e13fa2b777218bdb93982e23fb65d3> 62
notification_pro <8a7725017106a28b545fd13ed58bf98c> 64
notification_pro <8a7725017106a28b545fd13ed58bf98c> 64
afcd <98b45027fbb1350977bf1ca313dee527> 65
mediaserverd <eb8fe997a752407bea573cd3adf568d3> 319
ptpd <b17af9cf6c4ad16a557d6377378e8a1e> 142
syslogd <ec8a5bc4483638539fa1266363dee8b8> 68
BTServer <1bb74831f93b1d07c48fb46cc31c15da> 119
apsd <a639ba83e666cc1d539223923ce59581> 165
notifyd <2ed3a1166da84d8d8868e64d549cae9d> 101
CommCenter <f4239480a623fb1c35fa6c725f75b166> 161
SpringBoard <8919df8091fdfab94d9ae05f513c0ce5> 2681 (active)
accessoryd <b66bcf6e77c3ee740c6a017f54226200> 90
configd <41e9d763e71dc0eda19b0afec1daee1d> 275
fairplayd <cdce5393153c3d69d23c05de1d492bd4> 108
mDNSResponder <f3ef7a6b24d4f203ed147f476385ec53> 103
lockdownd <6543492543ad16ff0707a46e512944ff> 297
launchd <73ce695fee09fc37dd70b1378af1c818> 71
**End**
