void ConcurrentMergeScheduler::merge(const IndexWriterPtr& writer) {
BOOST_ASSERT(!writer->holdsLock());
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.
message(L"now merge");
message(L" index: " + writer->segString());
// Iterate, pulling from the IndexWriter's queue of pending merges, until it's empty
while (true) {
OneMergePtr merge(writer->getNextMerge());
if (!merge) {
message(L" no more merges pending; now return");
return;
}
// We do this with the primary thread to keep deterministic assignment of segment names
writer->mergeInit(merge);
bool success = false;
LuceneException finally;
try {
SyncLock syncLock(this);
MergeThreadPtr merger;
while (mergeThreadCount() >= maxThreadCount) {
message(L" too many merge threads running; stalling...");
wait(1000);
}
message(L" consider merge " + merge->segString(dir));
BOOST_ASSERT(mergeThreadCount() < maxThreadCount);
// OK to spawn a new merge thread to handle this merge
merger = getMergeThread(writer, merge);
mergeThreads.add(merger);
message(L" launch new thread");
merger->start();
success = true;
} catch (LuceneException& e) {
finally = e;
}
if (!success) {
writer->mergeFinish(merge);
}
finally.throwException();
}
}
void SerialMergeScheduler::merge(const IndexWriterPtr& writer) {
SyncLock syncLock(this);
while (true) {
OneMergePtr merge(writer->getNextMerge());
if (!merge) {
break;
}
writer->merge(merge);
}
}