App crashes with no Error

Archives Forums/BlitzMax Bug Reports/App crashes with no Error

shinkiro1

(Posted 2012) [#1]

Hello,

My app seems to crash randomly and also in the debug mode no error is shown. It's a MaxGui app but I don't think it has to do with MaxGUI. The thing is it's a very hard to reproduce error.

The error only occurs when i load a map into my editor. I tested it and it has nothing to do with loading either, it's about the TMap Enumerator. At one point in the loading process I iterate through all Values of a TMap. And that seems to be the problem.

The strange thing is that this error happens only around 10% of the time. It doesn't matter if I just recompile or restart it. When it crashes, i just restart the app, do the exact same thing as before (load the same map) and then in magically works.

I'm using OSX 10.7.3 and this the crash report which also indicates some problem with the enumerator of TMap.

Process:         Editor [2010]
Path:            /Users/USER/*/Editor.app/Contents/MacOS/Editor
Identifier:      Editor
Version:         ??? (???)
Code Type:       X86 (Native)
Parent Process:  launchd [209]

Crashed Thread:  0  Dispatch queue: com.apple.main-thread

Exception Type:  EXC_BAD_ACCESS (SIGBUS)
Exception Codes: KERN_PROTECTION_FAILURE at 0x0000000000000038

VM Regions Near 0x38:
--> __PAGEZERO             0000000000000000-0000000000001000 [    4K] ---/--- SM=NUL  /Users/USER/*/Editor.app/Contents/MacOS/Editor
    __TEXT                 0000000000001000-0000000000145000 [ 1296K] r-x/rwx SM=COW  /Users/USER/*/Editor.app/Contents/MacOS/Editor

Application Specific Information:
objc[2010]: garbage collection is OFF

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   Editor                	0x0008a3d6 _brl_map_TValueEnumerator_NextObject + 23
1   Editor                	0x0000f75d 257 + 19
2   Editor                	0x0000eed9 215 + 11
3   Editor                	0x00003f52 1567 + 55
4   Editor                	0x00004871 1710 + 10
5   Editor                	0x000047d5 1618 + 29
6   Editor                	0x000033ac 357 + 25
7   Editor                	0x00002a5c 4 + 20
8   Editor                	0x00002ca2 -[BlitzMaxAppDelegate applicationDidFinishLaunching:] + 354
9   com.apple.Foundation          	0x96a59e25 __-[NSNotificationCenter addObserver:selector:name:object:]_block_invoke_1 + 49
10  com.apple.CoreFoundation      	0x9199fcb3 ___CFXNotificationPost_block_invoke_1 + 275
11  com.apple.CoreFoundation      	0x9196aa38 _CFXNotificationPost + 2776
12  com.apple.Foundation          	0x96a45012 -[NSNotificationCenter postNotificationName:object:userInfo:] + 92
13  com.apple.AppKit              	0x9894e75d -[NSApplication _postDidFinishNotification] + 259
14  com.apple.AppKit              	0x9894e453 -[NSApplication _sendFinishLaunchingNotification] + 84
15  com.apple.AppKit              	0x9894cf74 -[NSApplication(NSAppleEventHandling) _handleAEOpenEvent:] + 277
16  com.apple.AppKit              	0x9894cc8a -[NSApplication(NSAppleEventHandling) _handleCoreEvent:withReplyEvent:] + 377
17  com.apple.CoreFoundation      	0x919b8298 -[NSObject performSelector:withObject:withObject:] + 72
18  com.apple.Foundation          	0x96a7f0f6 __-[NSAppleEventManager setEventHandler:andSelector:forEventClass:andEventID:]_block_invoke_1 + 121
19  com.apple.Foundation          	0x96a7dea9 -[NSAppleEventManager dispatchRawAppleEvent:withRawReply:handlerRefCon:] + 476
20  com.apple.Foundation          	0x96a7dc7d _NSAppleEventManagerGenericHandler + 234
21  com.apple.AE                  	0x923e6045 aeDispatchAppleEvent(AEDesc const*, AEDesc*, unsigned long, unsigned char*) + 202
22  com.apple.AE                  	0x923cfb67 _ZL25dispatchEventAndSendReplyPK6AEDescPS_ + 43
23  com.apple.AE                  	0x923cfa54 aeProcessAppleEvent + 253
24  com.apple.HIToolbox           	0x93bef5d6 AEProcessAppleEvent + 103
25  com.apple.AppKit              	0x98949d0b _DPSNextEvent + 1301
26  com.apple.AppKit              	0x98949306 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 113
27  com.apple.AppKit              	0x98945675 -[NSApplication run] + 911
28  Editor                	0x000030b0 main + 1024
29  Editor                	0x000025e9 _start + 208
30  Editor                	0x00002518 start + 40

External Modification Summary:
  Calls made by other processes targeting this process:
    task_for_pid: 7
    thread_create: 0
    thread_set_state: 0
  Calls made by this process:
    task_for_pid: 0
    thread_create: 0
    thread_set_state: 0
  Calls made by all processes on this machine:
    task_for_pid: 3290
    thread_create: 1
    thread_set_state: 0

VM Region Summary:
ReadOnly portion of Libraries: Total=193.7M resident=120.8M(62%) swapped_out_or_unallocated=72.9M(38%)
Writable regions: Total=100.1M written=25.4M(25%) resident=50.9M(51%) swapped_out=0K(0%) unallocated=49.2M(49%)
 
REGION TYPE                      VIRTUAL
===========                      =======
CG backing stores                  4292K
CG image                            124K
CG raster data                      272K
CG shared images                   3440K
CoreGraphics                          8K
CoreImage                             4K
CoreServices                       2288K
IOKit                              2808K
MALLOC                             61.8M
MALLOC guard page                    32K
Memory tag=240                        4K
Memory tag=242                       12K
Memory tag=243                        8K
OpenCL                               52K
Stack                              69.1M
VM_ALLOCATE                        16.1M
__CI_BITMAP                          80K
__DATA                             9744K
__DATA/__OBJC                       220K
__IMAGE                             528K
__IMPORT                              4K
__LINKEDIT                         42.8M
__OBJC                             3140K
__OBJC/__DATA                        16K
__PAGEZERO                            4K
__TEXT                            150.9M
__UNICODE                           544K
mapped file                       104.2M
shared memory                      3704K
shared pmap                        6680K
===========                      =======
TOTAL                             482.0M

EDIT: I did a ram test but everything seems fine.

Last edited 2012

Danny

(Posted 2012) [#2]

Check if you're using any recursive routines.
I've only had this type of behavior happening when recursively calling a the same function - that didn't end. And some internal calling stack or whatever would crash instantly without spit or warning.

Floyd

(Posted 2012) [#3]

Exception Type:  EXC_BAD_ACCESS (SIGBUS)
Exception Codes: KERN_PROTECTION_FAILURE at 0x0000000000000038

That looks like the important part.

Nothing in your program should try to access such a low address. In the old days of assembly language or C this would probably mean you were accessing some kind of table with a pointer of the form "base + offset". But base was set to zero instead of the correct address.

I don't know how to go about tracking this down in your BlitzMax code. When it crashes do you always get that same address, or at least some other very low address?

shinkiro1

(Posted 2012) [#4]

Thanks for your replies.
I've narrowed it down to some piece of code of mine which would be too complex to post here.
If if find the bug i'll post it here.