topic Re: Crash when creating geodatabase after closing deleting a geodatabase in File Geodatabase API Questions

Crash when creating geodatabase after closing deleting a geodatabase

PaulAustin — Wed, 25 Sep 2013 21:40:51 GMT

In my App (Java with swig bindings to the API) I create 3 geodatabases. Make some changes to them. Commit those changes to a real database. Then I close the geodatabases and create a new one. I get the following exception running on Windows Server 2008 64 bit running a 32bit app compiled using Visual Studio 2008. I don't get the error on Windows 8 or Mac OS X Lion.

C [ntdll.dll+0x38e19] RtlIntegerToUnicodeString+0x2fc
C [ntdll.dll+0x38d28] RtlIntegerToUnicodeString+0x20b
C [FileGDBAPI.dll+0xe7aff] FileGDBAPI::Envelope::~Envelope+0x687df
C [FileGDBAPI.dll+0x372a1] FileGDBAPI::SpatialReferences::FindSpatialReferenceByName+0x21071
C [FileGDBAPI.dll+0x2271] FileGDBAPI::FieldInfo::FieldInfo+0x861
C [FileGDBAPI.dll+0x5d1e] FileGDBAPI::Geodatabase::CreateGeodatabase+0xce
C [FileGDBAPI.dll+0x8f1f] FileGDBAPI::CreateGeodatabase+0xf

Re: Crash when creating geodatabase after closing deleting a geodatabase

PaulAustin — Sun, 05 Jan 2014 17:00:04 GMT

Further to this it is now occurring on all platforms.

It looks like if I call DeleteGeodatabase then it will crash when I try and create a new one. The geodatabase was closed when calling delete.

Re: Crash when creating geodatabase after closing deleting a geodatabase

PaulAustin — Mon, 06 Jan 2014 13:21:14 GMT

I think this is related to the following issue which talks about thread safety.

http://forums.arcgis.com/threads/76527-CloseDatabase-hanging-on-64-bit-Linux-when-same-File-Geodatabase-opened-twice?highlight=thread

In my application which is written in Java with a Swig binding to the API I use threads extensively.

I had synchronized access to the geodatabase objects so that only one thread could concurrently be accessing that geodatabase and any tables, rows etc created from it. Then I had a separate synchronization on the access to the API to create/open/delete geodatabases. I hadn't thought that once I had a geodatabase open that I'd have to synchronize everything to create/modify tables or anything else hidden in the API that used XML. I'm sure now this is the cause of the problem.

[RANT]I find it kind of crazy that an XML library forces everything to be single thread. Is there not a way to create a new instance of the XML parser per thread to avoid this.[/RANT]

I can understand that for a given table or for management of the database that synchronization is a good idea. However the fact that there is no option for concurrency across any open geodatabases in the same application makes the performance of an application suck. For example I have code where I want to read data from 30 tables and insert them into an Oracle database. In theory I should be able to run that all in parallel, even on a 4 core machine you'd get a lot of concurrency while some threads are blocked for database IO. But when using non-threaded libraries that have every call synchronized that puts a throttle on concurrency as threads will be waiting on monitors most of the time.