[LOG4NET-551] LockRecursionException when using File Appenders

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.0.7
• Fix Version/s: 2.0.8
• Assignee: Unassigned
• Reporter: Matthew Lefoster
• Created: 01/Feb/17 22:54
• Updated: 14/Mar/17 16:40
• Resolved: 02/Feb/17 19:13

Description

I have been getting the following exception on the console:

log4net:ERROR Exception while logging
System.Threading.LockRecursionException: Recursive read lock acquisitions not allowed in this mode.
at System.Threading.ReaderWriterLockSlim.TryEnterReadLockCore(TimeoutTracker timeout)
at System.Threading.ReaderWriterLockSlim.TryEnterReadLock(TimeoutTracker timeout)
at System.Threading.ReaderWriterLockSlim.EnterReadLock()
at log4net.Util.ReaderWriterLock.AcquireReaderLock()
at log4net.Repository.Hierarchy.Logger.CallAppenders(LoggingEvent loggingEvent)
at log4net.Repository.Hierarchy.Logger.ForcedLog(Type callerStackBoundaryDeclaringType, Level level, Object message, Exception exception)
at log4net.Repository.Hierarchy.Logger.Log(Type callerStackBoundaryDeclaringType, Level level, Object message, Exception exception)

I have a number of different appenders, but this only happens when I am using `log4net.Appender.FileAppender`.

Using a debugger, I was able to narrow it down to this line (I replaced curly brackets with square brackets because otherwise JIRA interprets them as macros):

Logger.DebugFormat("[1] Executing SQL: [0][2][0]With parameters: [3]",
Environment.NewLine, methodName, sql, new ToStringWrapper(parameters));

My first thought was that ToStringWrapper() was throwing an exception or generating another logging call. But If I put breakpoints at the log call and at the first line of ToStringWrapper.ToString, the exception will show up in the console between those two points.

Oddly enough, if I "step into" the logging call instead of just "continuing" and letting the breakpoints handle it, no exception happens.

Issue Links

• duplicates: LOG4NET-550 Logging recursively from an Appender not supported for NET_4_0 and MONO_4_0
• is duplicated by: LOG4NET-466 "LockRecursionException: A read lock may not be acquired with the write lock held in this mode." exception