Re: [MI400] what is a reasonable socket select() wait time?

[Gene_Gaunt@xxxxxxxxxxxxxxx]

Thanks gentlemen.

Sometimes select() fails to detect when more data is truly available.  I'm
not sure why select() fails.  My client receive buffer size is huge; I know
the server never completely fills it.  I know the client sets the fd_set
bits correctly.

The server basically loops like this:

DO FOREVER;
  RC = READ( client );
  RC = WRITE( client );
ENDDO;

and the client basically talks like this:

RC = WRITE( server );
DOU X = 0;
  RC = READ( server );  // size available is huge
  X = SELECT( read_set, wait time=0 );
ENDDO;

If the server sends more than our CHGTCPA TCPRCVBUF(8192) value, the client
loops until X=0.  This works fine---99.9% of the time.  But about once
every thousandth time, select() fails to detect when more data is truly
available, and the DOU ends after one iteration with X=0.

Why does the select() periodically fail?  How can my client truly, TRULY
determine if more data is available from the server?  Do I need a non-zero
wait time?  What is a reasonable value?