This program illustrates the use of the "Open List" APIs that allows you generate lists asynchronously. That is, instead of generating lists to a user space, a server job generates the list internally and in the background letting your application execute simultaneously. When your app needs one of the items from the list, it calls an API to return it.
Note, only some of the list APIs are supported. The general procedure is:
1. Call the special version of the list API to start a server job that builds the list in the background.
2. Call an API to receive from the server job an item from the list.
3. Repeat step 2 as needed to receive other items or to re-receive items.
4. Close the list. This cleans up the server job by freeing its internal storage. The server job can then be used to process another open list.
d #IgnoreErr c Const(x'0000000800000000') d #ResendErr c Const(x'0000000000000000') d RcvrLen s 10i 0 Inz(0) d SelectDS ds d Direction 10 Inz('*NEXT') d QJobName 26 Inz('*') d IntJobID 16 d StartKey 4 Inz(x'00000000') d MaxMsgLen 10i 0 Inz(-1) d MaxHelpLen 10i 0 Inz(0) d OSFieldIDs 10i 0 Inz(84) d NbrFldIDs 10i 0 Inz(%Elem(FldIDArr)) d OSCallMsgQ 10i 0 Inz(88) d LenCalMsgQ 10i 0 Inz(1) d FldIDArr 85 88b 0 Dim(1) Inz(302) d CallMsgQ 89 90 Inz('*') d LenSelctDS s 10i 0 Inz(%Size(SelectDS)) d ListInfoDS ds d TotalRecs 10i 0 d RecsRtrnd 10i 0 d Handle 4 d RecLength 10i 0 d InfoComplt 1 d DateTime 13 d ListStatus 1 d 1 d InfoLength 10i 0 d FirstRec 10i 0 d 40 d Recs2Rtrn s 10i 0 d Rec#2Rtrn s 10i 0 d MsgEntry ds d OSNextMsg 1 4b 0 d OSFields 5 8b 0 d OSNbrFlds 9 12b 0 d MsgSev 13 16b 0 d MsgID 7 d MsgType 2 d MsgKey 4 d MsgFile 10 d MsgFileLib 10 d DateSent 7 d TimeSent 6 d EntryArr 1 32767 Dim(32767) d EntryFlds ds Based(pEntryFlds) d OSNextFld 1 4b 0 d LenFldInfo 5 8b 0 d FieldID 9 12b 0 d TypeOfData 1 d StsOfData 1 d 14 d LenOfData 10i 0 d Data 32000 d FieldsArr 1 32767 Dim(32767) * Start server job to generate job log messages in the * background (ie, asynchronously). API QGYOLJBL is the * sepcial version of the QMHLJOBL API. c Call 'QGYOLJBL' c Parm Rcvr 1 c Parm 0 RcvrLen c Parm ListInfoDS c Parm 0 Recs2Rtrn c Parm SelectDS c Parm LenSelctDS c Parm #ResendErr Error 8 * At this point, the program can do something else while the list * is being generated in the background, or it can begin processing * the list immediately. * Process list of messages. c Eval Rec#2Rtrn = 1 c DoW ListStatus <> '2' or c Rec#2Rtrn <= TotalRecs * Get a message. c Eval RcvrLen = %Size(MsgEntry) c DoU RecsRtrnd > 0 c Call 'QGYGTLE' c Parm MsgEntry c Parm RcvrLen c Parm Handle c Parm ListInfoDS c Parm 1 Recs2Rtrn c Parm Rec#2Rtrn c Parm #ResendErr Error 8 c EndDo * Point pEntryFlds to the beginning of the fields for * the current message. c Eval pEntryFlds = %Addr(EntryArr(OSFields+1)) * Display message. c If LenOfData > 50 c Z-Add 50 m 5 0 c Else c Z-Add LenOfData m c EndIf c m Subst(P) Data MsgDsply 50 c MsgDsply Dsply r 1 c Eval Rec#2Rtrn = Rec#2Rtrn + 1 c EndDo * Close list (ie, cleanup server job). c Call 'QGYCLST' c Parm Handle c Parm #ResendErr Error 8 c MoveL '1' *InLR c Return