GIV      TITLE 'DMTGIV     (RSCS)      VM/370 - RELEASE 6'              00001000
*.                                                                      00002000
* MODULE NAME -                                                         00003000
*                                                                       00004000
*        DMTGIV                                                         00005000
*                                                                       00006000
* FUNCTION -                                                            00007000
*                                                                       00008000
*        DMTGIV IS A SUPERVISOR SERVICE ROUTINE WHICH ENQUEUES          00009000
*        GIVE REQUESTS FROM TASKS TO BE DELIVERED TO OTHER              00010000
*        TASKS BY DMTAKE.                                               00011000
*                                                                       00012000
* ATTRIBUTES -                                                          00013000
*                                                                       00014000
*        REUSABLE, NON-INTERRUPTABLE                                    00015000
*                                                                       00016000
* ENTRY POINTS -                                                        00017000
*                                                                       00018000
*        DMTGIV -   ENQUEUE A GIVE REQUEST                              00019000
*                                                                       00020000
* ENTRY CONDITIONS -                                                    00021000
*                                                                       00022000
*        GPR1 =  GIVE TABLE ADDRESS IN TASK STORAGE                     00023000
*        GPR14 = RETURN ADDRESS                                         00024000
*        GPR15 = ENTRY ADDRESS                                          00025000
*                                                                       00026000
* EXIT CONDITIONS -                                                     00027000
*                                                                       00028000
*        NORMAL -                                                       00029000
*                                                                       00030000
*        GPR15 = X'00' REQUEST SUCCESSFULLY ENQUEUED                    00031000
*                      (BUT NOT NECESSARILY DELIVERED)                  00032000
*                                                                       00033000
*        ERROR -                                                        00034000
*                                                                       00035000
*        GPR15 = > X'00' ERROR CODE ON RETURN FROM DMTQRQ               00036000
*                                                                       00037000
         EJECT                                                          00038000
*                                                                       00039000
* CALLS TO OTHER ROUTINES -                                             00040000
*                                                                       00041000
*        DMTQRQ -   TO RESERVE AND RELEASE SUP QUEUE ELEMENTS           00042000
*        DMTPST -   TO NOTIFY A TASK OF REQUEST AVAILABILITY            00043000
*                                                                       00044000
* EXTERNAL REFERENCES -                                                 00045000
*                                                                       00046000
*        NONE                                                           00047000
*                                                                       00048000
* TABLES / WORKAREAS -                                                  00049000
*                                                                       00050000
*        DMTVEC -   SUPERVISOR COMMON AREA                              00051000
*        TASK ELEMENT                                                   00052000
*        GIVE ELEMENT                                                   00053000
*                                                                       00054000
* REGISTER USAGE -                                                      00055000
*                                                                       00056000
*        GPR0  = CALLING PARAMETER (POST CODE TO DMTPST)                00057000
*        GPR1  = CALLING PARAMETER (TO DMTQRQ AND DMTPST)               00058000
*        GPR2  = SCRATCH                                                00059000
*        GPR3  = TASK ELEMENT POINTER, TASK SAVE AREA POINTER           00060000
*        GPR4  = GIVE ELEMENT POINTER                                   00061000
*        GPR5  = UNUSED                                                 00062000
*        GPR6  = UNUSED                                                 00063000
*        GPR7  = UNUSED                                                 00064000
*        GPR8  = UNUSED                                                 00065000
*        GPR9  = UNUSED                                                 00066000
*        GPR10 = UNUSED                                                 00067000
*        GPR11 = UNUSED                                                 00068000
*        GPR12 = DMTGIV BASE REGISTER                                   00069000
*        GPR13 = TASK SAVE AREA POINTER                                 00070000
*        GPR14 = LINKAGE RETURN ADDRESS                                 00071000
*        GPR15 = LINKAGE ENTRY ADDRESS                                  00072000
*                                                                       00073000
* NOTES -                                                               00074000
*                                                                       00075000
*        REFER TO MODULE DMTAKE FOR A MORE COMPLETE UNDERSTANDING       00076000
*        OF THE FUNCTION OF THIS ROUTINE.                               00077000
*                                                                       00078000
* OPERATION -                                                           00079000
*                                                                       00080000
*                                                                       00081000
*        DMTGIV  BEGINS  PROCESSING  BY SUSPENDING  CALLING             00082000
*        TASK EXECUTION THROUGH THE  FREEZE SVC FUNCTION. A             00083000
*        SUPERVISOR STATUS QUEUE ELEMENT  IS GOTTEN THROUGH             00084000
*        A  CALL  TO  DMTQRQ,  A  GIVE  REQUEST ELEMENT  IS             00085000
*        BUILT  USING  THE  INFORMATION   SUPPLIED  BY  THE             00086000
*        CALLING TASK, AND  THE ELEMENT IS ENQUEUED  ON THE             00087000
*        GIVE REQUEST QUEUE. THE ADDRESSED TASK IS LOCATED,             00088000
*        AND  IF ITS  REQUEST  ARRIVAL  SYNCH LOCK  IS  NOT             00089000
*        ALREADY POSTED,  IT IS POSTED BY  DMTGIV.  CONTROL             00090000
*        IS RETURNED TO THE DISPATCHER.                                 00091000
*                                                                       00092000
*                                                                       00093000
*.                                                                      00094000
         EJECT                                                          00095000
DMTGIV   CSECT                                                          00096000
         SPACE                                                          00097000
*        ENTRY POINT FOR CALL TO DMTGIV ROUTINE                         00098000
         SPACE                                                          00099000
         FREEZE SAVE            RESUME PSW AND GREGS FOR DISPATCH LATER 00100000
         SPACE                                                          00101000
         LR    R13,R14            REG.13 = SAVE AREA ADDRESS FOR DMTGIV 00102000
         USING TAREA,R13           DEFINE ADDRESSABILITY FOR CALLER'S S 00103000
         USING SVECTORS,0          GET SVECTORS ADDRESSABILTIY          00104000
         USING GIVEE,R4            GET GIVE ELEMENT ADDRESSABILTIY      00105000
         SPACE                                                          00106000
         LA    R12,0(R15)          REG.12 = ENTRY ADDRESS FOR DMTGIV    00107000
         USING DMTGIV,R12          USE ENTRY ADDRESS AS BASE            00108000
         SPACE                                                          00109000
         LA    R3,GIVEQ-(GIVENEXT-GIVEE) INITIALIZE QUEUE SCAN POINTER  00110000
GIVESCAN EQU   *                                                        00111000
         LR    R4,R3            REG.4 = ADDR OF LAST LINK FIELD SCANNED 00112000
         ICM   R3,B'1111',GIVENEXT REG 3 = ADDRESS OF NEXT GIVE ELEMENT 00113000
         BNZ   GIVESCAN        NOPE - KEEP LOOKING FOR THE LAST ELEMENT 00114000
         SPACE                                                          00115000
*        LAST ELEMENT ADDRESS IN REG 4 -- ENQUEUE FIRST IN FIRST OUT    00116000
         SPACE                                                          00117000
         LR    R2,R1               SAVE ADDR OF GIVE TABLE IN REG.2     00118000
         SR    R1,R1      CLEAR REG.1 FOR GET CALL TO SUP QUEUE MANAGER 00119000
         L     R15,QREQ        REG.15 = ENTRY ADDRESS FOR SUP QUEUE REQ 00120000
         BALR  R14,R15    GET A FREE SUP QUEUE ELEMENT FOR NEW GIVE REQ 00121000
         LTR   R15,R15             DID WE GET ONE O.K.?                 00122000
         BNZ   GIVEXIT     EXIT WITH SUP QUEUE MGR'S RETURN CODE IF NOT 00123000
         ST    R1,GIVENEXT       CHAIN NEW ELEMENT TO END OF GIVE QUEUE 00124000
         DROP  R4                                                       00125000
         SPACE                                                          00126000
         USING GIVEE,R1                                                 00127000
         XC    GIVENEXT(4),GIVENEXT CLEAR THE NEW ELEMENT LINK          00128000
         ST    R2,GIVEADDR         SET ADDRESS OF REQUEST INTO ELEMENT  00129000
         MVC   GIVENAME(4),4(R2)   GET RECEIVER'S NAME FROM REQUEST     00130000
         MVI   GIVENID,X'00'       CLEAR TAKER'S ID FIELD UNTIL TAKEN   00131000
         L     R4,ACTIVE           GET THE ACTIVE TASK ELEMENT          00132000
         MVC   GIVERID(1),TASKID-TASKE(R4) MOVE SENDING TASK ID INTO EL 00133000
         ST    R1,4(R2)  SET NEW ELEMENT ADDRESS IN CALLER'S GIVE TABLE 00134000
         EJECT                                                          00135000
         LA    R3,TASKQ-(TASKNEXT-TASKE) INITIALIZE TASK QUEUE SCAN REG 00136000
         USING TASKE,R3            GET TASK ELEMENT ADDRESSABILITY      00137000
GIVESNIF EQU   *                                                        00138000
         ICM   R3,B'1111',TASKNEXT REG 3 = NEXT TASK TABLE IN QUEUE     00139000
         BZ    GIVEDONE         YEP - RECEIVING TASK NOT ACTIVE (YET?)  00140000
         CLC   GIVENAME(4),TASKNAME IS THIS THE ADDRESSED TASK?         00141000
         BNE   GIVESNIF            KEEP SCANNING IF IT ISN'T            00142000
         SPACE                                                          00143000
         DROP  R3                                                       00144000
         DROP  R13                 STOP USING CALLER'S TASK AREA        00145000
         USING TAREA,R3            AND START USING ADDRESSEE'S          00146000
         SPACE                                                          00147000
         L     R3,TASKSAVE-TASKE(R3) REG 3 = ADDRESS OF ADDRESSED TAS   00148000
         CLI   TREQLOCK,X'00'   IS HIS GIVE REQ SYNLOCK POSTED ALREADY? 00149000
         BNE   GIVEDONE            NO NEED TO POST IT AGAIN IF SO       00150000
         SR    R0,R0             CLEAR REG.0 POST CODE FOR CALL TO POST 00151000
         LA    R1,TREQLOCK   REG.1 = ADDRESS OF TASK'S GIVE REQ SYNLOCK 00152000
         L     R15,POSTREQ       REG.15 = ADDR OF ENTRY TO POST ROUTINE 00153000
         BALR  R14,R15             POST RECEIVING TASK'S SYNCH LOCK     00154000
         SPACE                                                          00155000
         DROP  R3           STOP USING ADDRESSEE'S TASK SAVE AREA DSECT 00156000
         USING TAREA,R13           AND RESUME USING CALLER'S TASK AREA  00157000
         SPACE                                                          00158000
GIVEDONE EQU   *                                                        00159000
         SR    R15,R15             CLEAR RETURN CODE FOR RETURN         00160000
         SPACE                                                          00161000
GIVEXIT  EQU   *                                                        00162000
         ST    R15,TGREG15   SET RETURN CODE IN CALLER'S TASK SAVE AREA 00163000
         L     R15,DISPATCH        REG.15 = DISPATCHER ENTRY ADDRESS    00164000
         BALR  R14,R15             GO BACK TO DISPATCHING TASKS         00165000
         EJECT                                                          00166000
         COPY  RSSEQU                                                   00167000
         EJECT                                                          00168000
         COPY  SVECTORS                                                 00169000
         EJECT                                                          00170000
         COPY  TAREA                                                    00171000
         EJECT                                                          00172000
         COPY  TASKE                                                    00173000
         EJECT                                                          00174000
         COPY  GIVEE                                                    00175000
         END                                                            00176000