PST      TITLE 'DMTPST     (RSCS)      VM/370 - RELEASE 6'              00001000
*.                                                                      00002000
* MODULE NAME -                                                         00003000
*                                                                       00004000
*        DMTPST                                                         00005000
*                                                                       00006000
* FUNCTION -                                                            00007000
*                                                                       00008000
*         THE DMTPST MODULE IS A  SERVICE ROUTINE WHICH MAY             00009000
*         BE CALLED FROM ANYWHERE IN THE RSS SYSTEM. DMTPST             00010000
*         IS USED  TO SIGNAL THE  COMPLETION OF AN  EVENT BY            00011000
*         MEANS  OF  POSTING THE  EVENT'S  ASSOCIATED  SYNCH            00012000
*         LOCK. DMTPST IS ENTIRELY  REENTRANT, USES NO MAIN             00013000
*         STORAGE (EXCEPT THE SYNCH  LOCK WHICH IS SPECIFIED            00014000
*         TO  BE  POSTED),  AND  MAY  BE  ENTERED  WITH  PSW            00015000
*         INTERRUPT MASKS ON OR OFF. DMTPST DOES NOT CHANGE             00016000
*         THE STATE OF THE RUNNING PSW IN ANY WAY.                      00017000
*                                                                       00018000
* ATTRIBUTES -                                                          00019000
*                                                                       00020000
*        REENTRANT                                                      00021000
*                                                                       00022000
* ENTRY POINTS -                                                        00023000
*                                                                       00024000
*        DMTPST -   SIGNAL EVENT COMPLETION TO A TASK                   00025000
*                                                                       00026000
* ENTRY CONDITIONS -                                                    00027000
*        GPR0 =  ONE BYTE POST CODE                                     00028000
*        GPR1 =  ADDR OF SYNCH LOCK TO BE POSTED                        00029000
*        GPR14 = RETURN ADDRESS                                         00030000
*                                                                       00031000
* EXIT CONDITIONS -                                                     00032000
*                                                                       00033000
*        NORMAL -                                                       00034000
*                                                                       00035000
*              GPR0 =  ADDR OF POSTED SYNCH LOCK                        00036000
*              GPR1 =  ADDR OF POSTED SYNCH LOCK                        00037000
*                                                                       00038000
*        ERROR -                                                        00039000
*                                                                       00040000
*              NONE                                                     00041000
*                                                                       00042000
         EJECT                                                          00043000
*                                                                       00044000
* CALLS TO OTHER ROUTINES -                                             00045000
*                                                                       00046000
*        NONE                                                           00047000
*                                                                       00048000
* EXTERNAL REFERENCES -                                                 00049000
*                                                                       00050000
*        NONE                                                           00051000
*                                                                       00052000
* TABLES / WORKAREAS -                                                  00053000
*                                                                       00054000
*        TASK ELEMENT (SUPERVISOR QUEUE)                                00055000
*                                                                       00056000
* REGISTER USAGE -                                                      00057000
*                                                                       00058000
*        GPR0  = SCRATCH (SYNCH LOCK ADDR SAVE REG)                     00059000
*        GPR1  = SYNCH LOCK ADDR, TASK ELEMENT POINTER                  00060000
*        GPR2  = UNUSED                                                 00061000
*        GPR3  = UNUSED                                                 00062000
*        GPR4  = UNUSED                                                 00063000
*        GPR5  = UNUSED                                                 00064000
*        GPR6  = UNUSED                                                 00065000
*        GPR7  = UNUSED                                                 00066000
*        GPR8  = UNUSED                                                 00067000
*        GPR9  = UNUSED                                                 00068000
*        GPR10 = UNUSED                                                 00069000
*        GPR11 = UNUSED                                                 00070000
*        GPR12 = UNUSED                                                 00071000
*        GPR13 = UNUSED                                                 00072000
*        GPR14 = RETURN ADDRESS                                         00073000
*        GPR15 = UNUSED                                                 00074000
*                                                                       00075000
* NOTES -                                                               00076000
*                                                                       00077000
*        NONE                                                           00078000
*                                                                       00079000
* OPERATION -                                                           00080000
*                                                                       00081000
*                                                                       00082000
*        DMTPST  POSTS THE SYNCH LOCK SPECIFIED IN THE CALL             00083000
*        BY PLACING THE SPECIFIED ONE-BYTE CODE IN THE HIGH             00084000
*        ORDER BYTE OF THE SYNCH LOCK (AND FORCING THE HIGH             00085000
*        ORDER  BIT  OF THE  SYNCH  LOCK  TO ONE).  IF  THE             00086000
*        SPECIFIED SYNCH LOCK HAS BEEN WAITED ON (IF A TASK             00087000
*        ELEMENT ADDRESS HAS  BEEN SET IN THE  SYNCH LOCK),             00088000
*        THE WAITING TASK'S TASK  ELEMENT ADDRESS IS LOADED             00089000
*        FROM THE SYNCH  LOCK AND THE "WAITING"  BIT IN THE             00090000
*        TASK TABLE  IS SET TO  ZERO. (THIS MAKES  THE TASK             00091000
*        DISPATCHABLE.) THE  LOW ORDER  THREE BYTES  OF THE             00092000
*        SYNCH  LOCK  ARE  SET  TO  ZERO,  AND  CONTROL  IS             00093000
*        RETURNED  DIRECTLY TO  THE CALLER  BY  MEANS OF  A             00094000
*        BRANCH (CONTROL IS NOT PASSED TO THE DISPATCHER).              00095000
*                                                                       00096000
*.                                                                      00097000
         EJECT                                                          00098000
DMTPST   CSECT                                                          00099000
         SPACE                                                          00100000
         USING TASKE,R1            GET TASK ELEMENT ADDRESSABILITY      00101000
         STC   R0,0(R1)         STORE POST CODE IN SYNLOCK TO BE POSTED 00102000
         OI    0(R1),X'80'     AND SET HIGH-ORDER BIT TO FORCE NON-ZERO 00103000
         OC    1(3,R1),1(R1)      IS THERE A TASK ELEMENT ADDRESS HERE? 00104000
         BCR   8,R14            NOPE - MUST BE AN EARLY POST - ALL DONE 00105000
         L     R0,0(R1) REG 0 (SCRATCH REG) = ADDR OF SOME TASK ELEMENT 00106000
         XC    1(3,R1),1(R1) CLEAR TASK ELEMENT ADDRESS FROM THE SYNLOC 00107000
         XR    R0,R1  THIS IS A TRICK TO SWAP THE CONTENTS OF TWO REGS, 00108000
         XR    R1,R0             WITHOUT USING ANY NON-REGISTER STORAGE 00109000
         XR    R0,R1               NEVER THOUGHT I'D NEED TO USE IT     00110000
         NI    TASKSTAT,X'FF'-WAITING SET TASK DISPATCHABLE             00111000
         LR    R1,R0            RESTORE ADDRESS OF THE SYNLOCK TO REG.1 00112000
         BR    R14                 AND RETURN TO THE CALLER             00113000
         EJECT                                                          00114000
         COPY  TASKE                                                    00115000
         EJECT                                                          00116000
         COPY  RSSEQU                                                   00117000
         END                                                            00118000