Question

I have several clients, who writes to one socket (not port), when they write together, I receive the garbage, all data from all clients are merged.

all clients are in the same program in Threads.

I need to lock write()

ASocket.Connection.Socket.LOCK; // need to be thread safe
ASocket.Connection.Socket.Write(buf);
ASocket.Connection.Socket.UNLOCK; // need to be thread safe

How can I do it ?

Thanks.

Delphi 2010, Indy 10, Win7

Answer 1

You can use TCriticalSection (SyncObjs unit): put the Write between Enter and Leave:

CriticalSection.Enter;
try
  ASocket.Connection.Socket.Write(buf);
finally
  CriticalSection.Leave;
end;

The methods Acquire and Release do the same (doc). Important: if you write to the socket at multiple points of your code, you must use the same object (the one I called CriticalSection in the above example).