> Joseph Reichman > I have wait on ECBLIST when it’s breaks out of the wait one of the > ECB’s has a X’00’ In the first byte > > My question is when going into a wait in let’s say 4 ECB before any > of them get posted with +x’40’ > > Shouldn’t all of them have the x’80’ bit on > > Doesn’t the wait do that until one gets posted with x’40’
> Seymour J Metz > X'80' is set by WAIT and cleared by POST. You should only see the X'80' > from and interrupt or a different dispatching unit. The wait bit x'80' is only on while the task is waiting. This is why long ecb wait lists are a performance problem. application: dynamically builds the ecblist, then issues wait. wait: scans the ecblist, validity checking and turning on the wait bit x'80' in each ECB post: (assuming wait exists on ECB) the targeted ECB to locate the waiting task, scans the ecblist turning off the wait bits in each x'80', marks the target ECB posted (x'40') flag, removes the wait from the waiting task application: wakes up and scans the ecblist to see what to do. So the ecblist gets scanned 4 times for each sleep/wake cycle. As a hint at what can happen picture an application running 10 events/second with 10 ECBs. This might scale up to 100 events/second with 100 ECBs. Not only is the ecblist longer but it's more active. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
