synchronization

I want to copy many files in one, but using multiThread,supposing that file A is the file in which different threads copy datas, in this case each thread is meant to copy one file in file A, using this procedure: procedure ConcatenateFiles(const InFileNames: array of string; const OutFileName: string); var i: Integer; InStream, OutStream: TFileStream; begin OutStream := TFileStream.Create(OutFileName, fmCreate); try for i := 0 to high(InFileNames) do begin InStream := TFileStream.Create(InFileNames[i], fmOpenRead); try OutStream.CopyFrom(InStream, InStream.Size); finally InStream.Free; end;

Sync way For example, ruby: con = Mysql.new('localhost') rs1 = con.query('select * from test01') # A rs2 = con.query('select * from test02') # B rs = getResult(rs1, rs2) # C con.close so A will block the execution. B will be executed until A is done. So does C Async way for example, nodejs var mysql = require('mysql'); var connection = mysql.createConnection({host : 'localhost',}); connection.connect(); connection.query('SELECT * from test01', function(err, rows, fields) { console.log(rows); }); // A connection.query('SELECT * from test02', function(err, rows, fields) { console.log(rows); });

I have seen usage of synchronized block by this so far but recently I learned that using dummy object is preferable. I found the following topic related to this. Java synchronized method lock on object, or method? As a summary, in the code below, two different object can not run addA and addB concurrently as both uses this for lock. private int a; private int b; public synchronized void addA(){ a++; } public synchronized void addB(){ b++; } I am confused if I use dummy object for lock, what will be different if I use the line below in both method to synchronize? Because still they would have

I am having an issue where Realm sometimes returns me different data every time I do the same query. Currently I am using an SyncAdapter for uploading. The idea is that we are trying to implement offline mode. So when the User creates an item it get's added to Realm db. I am generating the ID for that item manually by getting the maxId and adding 1000 to it. After that I am sending the itemID to the UploadSyncAdapter where I get the itemById and send it to the backend and the backend returns me the item with the real ID. So after that I delete the old item and just insert the new item into