[fdo-internals] RE: SDF feature reader

[Haris Kurtagic]

I haven't looked that carefully into GetString but it looks that
BinaryReader do some string buffering.

Anyhow, I am talking now only about single thread use with multiple
feature readers.

Threading is not issue for that case.

 

Also, I would like to understand why SDF provider is not thread safe and
to look into possibilities

I think that sqlite version used with SDF allows thread safe access.

 

Thank you for your help,

 

Haris

 

 

 

 

From: fdo-internals-bounces at lists.osgeo.org
[mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Gavin Cramer
Sent: Wednesday, August 13, 2008 8:23 PM
To: FDO Internals Mail List
Subject: [fdo-internals] RE: SDF feature reader 

 

Yes.  The particular problem that you are seeing can also happen with
String values, since the pointer returned by GetString is to a buffer
owned by the reader.  Per-connection threading for any provider (that
supports this kind of threading, as determined by
FdoIConnectionCapabilities::GetThreadCapability) is the way to go.

 

Gavin

 

 

From: fdo-internals-bounces at lists.osgeo.org
[mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Badreddine
Karoui
Sent: Wednesday, August 13, 2008 2:18 PM
To: FDO Internals Mail List
Subject: [fdo-internals] RE: SDF feature reader 

 

The SDF provider is per connection threaded which means only one thread
can access a reader at a time. You can have many threads using their own
connections/readers at the same time.

 

Badreddine

 

From: fdo-internals-bounces at lists.osgeo.org
[mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Haris
Kurtagic
Sent: Wednesday, August 13, 2008 2:29 PM
To: FDO Internals Mail List
Subject: [fdo-internals] SDF feature reader 

 

Hi,

I have issue when when more than one feature reader is created against
same SDF connection

It looks like same buffer ( created by sqlite cursor ) is shared betwean
feature readers.

This will cause that data returned from feature reader with function
GetGeometry will be corrupted when another reader is used.

Is this a bug or I am not looking into it correctly ?

 

I would like to be able to use multi thread access to sqlite database.

If I am right, SDF provider is not "thread safe" ? if so, what are main
reasons for  it ?

 

Thank you,

Haris

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