/// <summary>Just do the merges in sequence. We do this
/// "synchronized" so that even if the application is using
/// multiple threads, only one merge may run at a time.
/// </summary>
public override void Merge(IndexWriter writer)
{
lock (this)
{
while (true)
{
MergePolicy.OneMerge merge = writer.GetNextMerge();
if (merge == null)
break;
writer.Merge(merge);
}
}
}
public override void Merge(IndexWriter writer)
{
// TODO: enable this once we are on JRE 1.5
// assert !Thread.holdsLock(writer);
this.writer = writer;
InitMergeThreadPriority();
dir = writer.GetDirectory();
// First, quickly run through the newly proposed merges
// and add any orthogonal merges (ie a merge not
// involving segments already pending to be merged) to
// the queue. If we are way behind on merging, many of
// these newly proposed merges will likely already be
// registered.
if (Verbose())
{
Message("now merge");
Message(" index: " + writer.SegString());
}
// Iterate, pulling from the IndexWriter's queue of
// pending merges, until it's empty:
while (true)
{
// TODO: we could be careful about which merges to do in
// the BG (eg maybe the "biggest" ones) vs FG, which
// merges to do first (the easiest ones?), etc.
MergePolicy.OneMerge merge = writer.GetNextMerge();
if (merge == null)
{
if (Verbose())
Message(" no more merges pending; now return");
return ;
}
// We do this w/ the primary thread to keep
// deterministic assignment of segment names
writer.MergeInit(merge);
bool success = false;
try
{
lock (this)
{
MergeThread merger;
while (MergeThreadCount(true) >= maxThreadCount)
{
if (Verbose())
Message(" too many merge threads running; stalling...");
try
{
System.Threading.Monitor.Wait(this);
}
catch (System.Threading.ThreadInterruptedException ie)
{
// In 3.0 we will change this to throw
// InterruptedException instead
SupportClass.ThreadClass.Current().Interrupt();
throw new System.SystemException(ie.Message, ie);
}
}
if (Verbose())
Message(" consider merge " + merge.SegString(dir));
// OK to spawn a new merge thread to handle this
// merge:
merger = GetMergeThread(writer, merge);
mergeThreads.Add(merger);
if (Verbose())
Message(" launch new thread [" + merger.Name + "]");
merger.Start();
success = true;
}
}
finally
{
if (!success)
{
writer.MergeFinish(merge);
}
}
}
}
