added some thoughts about socket states while reading and writing. This is not h…

…andled very well right now in my code which result in connections to be closed to early.

+each socket can have 4 states while reading or writing...well as far as i can
+say....assuming is is nonblocking.
+These can be checked via errno and return value.
+
+			recv		send		errno
+OK                      >0		>0		NOT SET
+CLOSED REMOTELY		0		-1		(write)ECONNRESET
+E_AGAIN			-1		-1		EAGAIN|EWOULDBLOCK
+ERROR OTHER		-1		-1		AMYTHING ELSE
+
+This means we need a slightly different handling for reading and writing.
+It might be neccessary to distinguish other streams from sockets albeit I
+would like to prevent this...
+This might be tested with small test programs. Well, the only special thing
+is ECONNRESET in write mode...because this is something that would not
+happen to files open for writing.
+We need to be more selective when to close the socket. In fact there are
+some errors, as EINTR which does not mean our socket is closed at all.
+
+Error which does not cause us to close the socket while writing:
+
+EAGAIN  - go to poll
+EINTR   - try again
+ENOBUFS - try again (maybe only a few times....)
+ENOMEM  - try again (maybe only a few times....)
+
+All other errors will cause us to close the socket while writing to it.
+
+Error which does not cause us to close the socket while reading:
+
+EAGAIN - go to poll
+EINTR  - try again
+ENOMEM - try again (maybe only a few times....)
+
+All other errors will cause us to close the socket while reading from it.
+
+From a server view...
+- read or write a socket as long as OK
+- close if either indicated by read or write...maybe read or write themself
+  could do the close.
+- poll if all socket get EAGAIN on read and write.
+
+So...read and write must be able to notify about 3 states at least.
+
+1. I am fine...continue operation on me
+2. I could not continue right now...please poll me
+3. Don't do any further operation on me...please close me.
+
+This could be simply done with return values...
+
+for 1. Return value >= 0
+for 2. Return -1  STREAM_DO_POLL
+for 3. Return -2  STREAM_DO_CLOSE