The content that you are sending has nothing to
do with the behavior you are seeing. read()
is supposed to block if there is no data
in the stream - that ought to be your first hint. Since
the problem lies in your code and you don't show
exactly what you're doing, I can only guess that you
are neglecting to do something like flush the output
buffer. In the absence of flushing, the details of the
data buffering depends on the operating system's
TCP/IP implementation. There are a number of other
ways that the sent data could be "delayed" and
not immediately available to the client - your question
doesn't give enough information to narrow it down.