public void Cleanup()
{
if (_recycleArea.Count == 0 && _scratchBuffers.Count == 1)
{
return;
}
long txIdAllowingToReleaseOldScratches = -1;
// ReSharper disable once LoopCanBeConvertedToQuery
foreach (var scratchBufferItem in _scratchBuffers)
{
if (scratchBufferItem.Value == _current)
{
continue;
}
txIdAllowingToReleaseOldScratches = Math.Max(txIdAllowingToReleaseOldScratches,
scratchBufferItem.Value.File.TxIdAfterWhichLatestFreePagesBecomeAvailable);
}
ByteStringContext byteStringContext;
try
{
byteStringContext = new ByteStringContext(SharedMultipleUseFlag.None);
}
catch (Exception e) when(e is OutOfMemoryException || e is EarlyOutOfMemoryException)
{
return;
}
try
{
while (_env.CurrentReadTransactionId <= txIdAllowingToReleaseOldScratches)
{
// we've just flushed and had no more writes after that, let us bump id of next read transactions to ensure
// that nobody will attempt to read old scratches so we will be able to release more files
try
{
using (var tx = _env.NewLowLevelTransaction(new TransactionPersistentContext(),
TransactionFlags.ReadWrite, timeout: TimeSpan.FromMilliseconds(500), context: byteStringContext))
{
tx.ModifyPage(0);
tx.Commit();
}
}
catch (TimeoutException)
{
break;
}
catch (DiskFullException)
{
break;
}
}
IDisposable exitPreventNewTransactions = null;
try
{
// we need to ensure that no access to _recycleArea and _scratchBuffers will take place in the same time
// and only methods that access this are used within write transaction
using (_env.WriteTransaction())
{
// additionally we must not allow to start any transaction (even read one) to start because it uses GetPagerStatesOfAllScratches() which
// returns _pagerStatesAllScratchesCache that we're updating here
if (_env.TryPreventNewTransactions(TimeSpan.Zero, out exitPreventNewTransactions))
{
var removedInactive = RemoveInactiveScratches(_current, updateCacheBeforeDisposingScratch: false); // no need to update cache because we're going do to it here anyway
var removedInactiveRecycled = RemoveInactiveRecycledScratches();
if (_logger.IsInfoEnabled)
{
_logger.Info(
$"Cleanup of {nameof(ScratchBufferPool)} removed: {removedInactive} inactive scratches and {removedInactiveRecycled} inactive from the recycle area");
}
_forTestingPurposes?.ActionToCallDuringCleanupRightAfterRemovingInactiveScratches?.Invoke();
UpdateCacheForPagerStatesOfAllScratches(); // it's going to be called by Rollback() of the write tx but let's call it explicitly so we can easily find this usage
}
}
}
catch (TimeoutException)
{
}
catch (DiskFullException)
{
}
finally
{
exitPreventNewTransactions?.Dispose();
}
}
finally
{
byteStringContext.Dispose();
}
}