// SERVER-2068
(function() {

var chunkSize = 25

var s = new ShardingTest({ name: "migrate_cursor1",
                           shards: 2,
                           mongos: 1,
                           other: { chunkSize : chunkSize } });

s.adminCommand( { enablesharding : "test" } );
db = s.getDB( "test" )
s.ensurePrimaryShard('test', 'shard0001');
t = db.foo

bigString = ""
stringSize = 1024;

while ( bigString.length < stringSize )
    bigString += "asdasdas";

stringSize = bigString.length
docsPerChunk = Math.ceil( ( chunkSize * 1024 * 1024 ) / ( stringSize - 12 ) )
numChunks = 5
numDocs = 20 * docsPerChunk

print( "stringSize: " + stringSize + " docsPerChunk: " + docsPerChunk + " numDocs: " + numDocs )

var bulk = t.initializeUnorderedBulkOp();
for (var i = 0; i < numDocs; i++){
    bulk.insert({ _id: i, s: bigString });
}
assert.writeOK(bulk.execute());

s.adminCommand( { shardcollection : "test.foo" , key : { _id : 1 } } );

assert.lt( numChunks ,  s.config.chunks.find().count() , "initial 1" );

primary = s.getServer( "test" ).getDB( "test" ).foo;
secondaryName = s.getOther( primary.name )
secondary = secondaryName.getDB( "test" ).foo;

assert.eq( numDocs , primary.count() , "initial 2" );
assert.eq( 0 , secondary.count() , "initial 3" );
assert.eq( numDocs , t.count() , "initial 4" )

x = primary.find( { _id : { $lt : 500 } } ).batchSize(2)
x.next(); // 1. Create an open cursor

print("start moving chunks...")

// 2. Move chunk from s0 to s1 without waiting for deletion.
// Command returns, but the deletion on s0 will block due to the open cursor.
s.adminCommand( { moveChunk : "test.foo" , find : { _id : 0 } , to : secondaryName.name } )

// 3. Start second moveChunk command from s0 to s1.
// This moveChunk should not observe the above deletion as a 'mod', transfer it to s1 and cause deletion on s1.
// This moveChunk will wait for deletion.
join = startParallelShell( "db.x.insert( {x:1} ); db.adminCommand( { moveChunk : 'test.foo' , find : { _id : " + docsPerChunk * 3 + " } , to : '" + secondaryName.name + "', _waitForDelete: true } )" )
assert.soon( function(){ return db.x.count() > 0; } , "XXX" , 30000 , 1 )

// 4. Close the cursor to enable chunk deletion.
print( "itcount: " + x.itcount() )

x = null;
for ( i=0; i<5; i++ ) gc()

print( "cursor should be gone" )

// 5. Waiting for the second moveChunk to finish its deletion.
// Note the deletion for the first moveChunk may not be finished.
join();

//assert.soon( function(){ return numDocs == t.count(); } , "at end 1" )
// 6. Check the total number of docs on both shards to make sure no doc is lost.
// Use itcount() to ignore orphan docments.
assert.eq( numDocs , t.find().itcount() , "at end 2" )

s.stop();

})();