These few lines alone are very suspicious indeed. Without further
investigations I'm unable to give any sensible feedback.
On 2016-10-31 11:54, Joe wrote:
Another point is that for any asynchronous appender implementation,
it’s a sine qua non that the LoggingEvent class be thread-safe.
At least for the manipulations an appender might do: layout, accessing
properties, fixing properties.
I had a quick browse through the source and found what looks to me
like a race condition here:
publicobjectLookupProperty(stringkey)
{
if(m_data.Properties != null)
{
returnm_data.Properties[key];
}
if(m_compositeProperties == null)
{
CreateCompositeProperties();
}
returnm_compositeProperties[key];
}
privatevoidCreateCompositeProperties()
{
m_compositeProperties = newCompositeProperties();
if(m_eventProperties != null)
{
m_compositeProperties.Add(m_eventProperties);
}
... etc
If two threads call LookupProperty concurrently, one may start
executing CreateCompositeProperties and the other might access
m_compositeProperties before it’s fully created.
If I’m right, the fix is simple – don’t set m_compositeProperties
until it’s completely created.
