hschumann2/TempleOS-Source-Code

1 2/*On each core, tasks are linked in a3circular doubly-linked list queue with4the Seth task as the head.  On Core0,5the queue order represents the front-to-back6window stack order with the window mgr7as the wallpaper.8 9The scheduler is round-robin.  It checks10if a task is ready and runs it or skips it.11Swapping tasks just involves storing and12restoring regs (no disk I/O for virtual13memory and no addr map changes).  It is14always fully identity-mapped on all cores.15Tasks can be switched in half a microsecond.16 17The scheduler checks if a task is18waiting for a certain time or waiting19on a message and skips if not ready.20A task runs until it voluntarily yields ctrl21with a call to Yield().  Tasks waiting on I/O22often loop, checking for a status and23Yielding.  This does not really degrade24performance, but pegs the CPU Load.25 26The scheduler checks for a few keys:27 28<CTRL-ALT-x> kill a task.29<CTRL-ALT-DEL> reboots.30<CTRL-ALT-n> Next task.31<CTRL-ALT-c> breaks execution of a program.32 33Each core has its own circular task queue.34For AP processors, they have a "Seth" task35which stays in a loop waiting for jobs or36requests to spawn tasks.  See CoreAPSethTask().37*/38 39U0 TaskFocusNext()40{41  CTask *task,*_task=sys_focus_task;42  sys_focus_task=NULL;43  if (!_task) _task=adam_task;44  task=_task->next_task;45  do {46    if (!Bt(&task->win_inhibit,WIf_SELF_FOCUS)) {47      sys_focus_task=task;48      CallExtNum(EXT_WIN_TO_TOP,task,TRUE);49      return;50    }51    task=task->next_task;52  } while (task!=_task);53}54 55asm {56TASK_CONTEXT_SAVE::57//OUT:  RSI=FS58        PUSH    RSI59        PUSHFD60        XOR     RSI,RSI61        MOV     RSI,FS:CTask.addr[RSI]62        POP     U64 CTask.rflags[RSI]63        POP     U64 CTask.rsi[RSI]64        MOV     U64 CTask.rax[RSI],RAX65 66/*Divert the stk to the Task memory67and push onto it and divert it back.68It's a little faster.69*/70        MOV     RAX,RSP71        LEA     RSP,U64 CTask.r15+8[RSI]72        PUSH    R1573        PUSH    R1474        PUSH    R1375        PUSH    R1276        PUSH    R1177        PUSH    R1078        PUSH    R979        PUSH    R880        PUSH    RDI81        PUSH    RBP82        PUSH    RBX83        PUSH    RDX84        PUSH    RCX85        MOV     RSP,RAX86 87        MOV     RAX,U64 CTask.fpu_mmx[RSI]88        FXSAVE  U64 [RAX]89 90        MOV     RDX,U64 CTask.bpt_lst[RSI]91@@05:   TEST    RDX,RDX92        JZ      @@1093        MOV     RDI,U64 CBpt.addr[RDX]94        MOV     AL,U8 CBpt.val[RDX]95        MOV     U8 [RDI],AL96        MOV     RDX,U64 CBpt.next[RDX]97        JMP     @@0598@@10:   RET99//************************************100_TASK_CONTEXT_RESTORE::101        XOR     RAX,RAX102        INC     U64 GS:CCPU.swap_cnter[RAX]103        MOV     RSI,FS:CTask.addr[RAX]104        BT      U32 CTask.rflags[RSI],RFLAGf_INT105        JNC     @@05106        BTS     U32 GS:CCPU.cpu_flags[RAX],CPUf_RAN_A_TASK107@@05:   BT      U64 CTask.task_flags[RSI],TASKf_DISABLE_BPTS108        JC      @@15109        MOV     RDX,U64 CTask.bpt_lst[RSI]110@@10:   TEST    RDX,RDX111        JZ      @@15112        MOV     RDI,U64 CBpt.addr[RDX]113        MOV     U8 [RDI],OC_BPT114        MOV     RDX,U64 CBpt.next[RDX]115        JMP     @@10116 117@@15:   INC     U64 CTask.swap_cnter[RSI]118 119        MOV     RAX,U64 CTask.fpu_mmx[RSI]120        FXRSTOR U64 [RAX]121 122        MOV     RAX,RSP123        LEA     RSP,U64 CTask.rcx[RSI]124        POP     RCX125        POP     RDX126        POP     RBX127        POP     RBP128        POP     RDI129        POP     R8130        POP     R9131        POP     R10132        POP     R11133        POP     R12134        POP     R13135        POP     R14136        POP     R15137        MOV     RSP,RAX138 139        MOV     RAX,U64 CTask.rax[RSI]140        PUSH    CGDT.ds141        PUSH    U64 CTask.rsp[RSI]142        PUSH    U64 CTask.rflags[RSI]143        PUSH    CGDT.cs64144        PUSH    U64 CTask.rip[RSI]145        MOV     RSI,U64 CTask.rsi[RSI]146        IRET147//************************************148END_RSI_TASK:149        MOV     RAX,RSI150        CALL    SET_FS_BASE151_TASK_END_NOW::152        CALL    &TaskEnd153        MOV     RSI,RAX154        CALL    SET_FS_BASE155        JMP     I8 RESTORE_RSI_TASK156 157_YIELD::158        PUSHFD159        TEST    U8 [SYS_SEMAS+SEMA_SINGLE_USER*DFT_CACHE_LINE_WIDTH],1160        JZ      @@05161        POPFD           //If single user, don't change task.162        RET163 164@@05:   CLI165        CALL    TASK_CONTEXT_SAVE166        MOV     EBX,U32 _RET167        MOV     U64 CTask.rip[RSI],RBX168        POP     U64 CTask.rflags[RSI]169        MOV     U64 CTask.rsp[RSI],RSP170        MOV     RSI,U64 CTask.next_task[RSI]171 172RESTORE_RSI_TASK:173        TEST    U64 [SYS_CTRL_ALT_FLAGS],1<<CTRL_ALT_DEL|1741<<CTRL_ALT_TAB|1<<CTRL_ALT_X|1<<CTRL_ALT_C175        JNZ     HANDLE_SYSF_KEY_EVENT176 177RESTORE_RSI_TASK2:178@@20:   BT      U64 CTask.task_flags[RSI],TASKf_KILL_TASK179        JC      END_RSI_TASK180        TEST    U64 CTask.task_flags[RSI],181                1<<TASKf_AWAITING_MSG|1<<TASKf_SUSPENDED182        JNZ     @@25183 184        MOV     RAX,U64 [&cnts.jiffies]185        CMP     U64 CTask.wake_jiffy[RSI],RAX186        JG      @@25    //Jmp if not ready, yet.187 188        MOV     RAX,RSI189        CALL    SET_FS_BASE190        JMP     I32 _TASK_CONTEXT_RESTORE191 192@@25:   MOV     RSI,U64 CTask.next_task[RSI]193        XOR     RAX,RAX194        CMP     U64 GS:CCPU.seth_task[RAX],RSI195        JNE     @@20    //Jmp if not Seth196        BTR     U32 GS:CCPU.cpu_flags[RAX],CPUf_RAN_A_TASK197        JC      @@20    //Jmp if had chance for IRQ already198        MOV     RAX,U64 GS:CCPU.idle_task[RAX]199        MOV     RSP,U64 CTask.stk[RAX]200        ADD     RSP,MEM_DFT_STK+CTaskStk.stk_base       //Rst to top201        CALL    SET_FS_BASE202        STI     //Restore idle task so we can unmask IRQs.203        HLT204SYS_IDLE_PT::205        CLI206 207RESTORE_SETH_TASK_IF_READY:208        XOR     RAX,RAX209        MOV     RSI,GS:CCPU.seth_task[RAX]210        JMP     RESTORE_RSI_TASK211 212HANDLE_SYSF_KEY_EVENT:213        MOV     RAX,RSI214        CALL    SET_FS_BASE215        XOR     RBX,RBX216        MOV     RAX,GS:CCPU.num[RBX]217        TEST    RAX,RAX218        JNZ     I32 RESTORE_RSI_TASK2219 220        MOV     EAX,U32 SYS_CTRL_ALT_FLAGS221        LOCK222        BTR     U32 [RAX],CTRL_ALT_DEL223        JC      I32 &Reboot224 225        CMP     U64 GS:CCPU.idle_task[RBX],RSI226        JE      RESTORE_SETH_TASK_IF_READY227 228        LOCK229        BTR     U32 [RAX],CTRL_ALT_TAB230        JNC     @@05231        CALL    &TaskFocusNext232        JMP     I32 RESTORE_FS_TASK233 234@@05:   LOCK235        BTR     U32 [RAX],CTRL_ALT_X236        JC      END_FOCUS_USER237        LOCK238        BTR     U32 [RAX],CTRL_ALT_C239        JNC     I32 RESTORE_RSI_TASK240 241BREAK_FOCUS_USER:242        MOV     RSI,U64 [SYS_FOCUS_TASK]243        TEST    RSI,RSI244        JZ      RESTORE_SETH_TASK_IF_READY245        BT      U64 CTask.win_inhibit[RSI],WIf_SELF_FOCUS246        JC      I32 RESTORE_RSI_TASK247        LOCK248        BTR     U64 CTask.task_flags[RSI],TASKf_BREAK_LOCKED249        JNC     @@10250        LOCK251        BTS     U64 CTask.task_flags[RSI],TASKf_PENDING_BREAK252        JMP     I32 RESTORE_RSI_TASK253 254@@10:   MOV     RAX,&Break255        MOV     U64 CTask.rip[RSI],RAX256        BT      U64 CTask.task_flags[RSI],TASKf_BREAK_TO_SHIFT_ESC257        JC      I32 RESTORE_RSI_TASK258 259//Do these now, in case interrupt happens.260        MOV     U64 CTask.wake_jiffy[RSI],0261        PUSH    RSI262        CALL    &TaskRstAwaitingMsg263        JMP     I32 RESTORE_RSI_TASK264 265END_FOCUS_USER:266        MOV     RSI,U64 [SYS_FOCUS_TASK]267        CALL    &TaskFocusNext268        TEST    RSI,RSI269        JZ      I32 RESTORE_SETH_TASK_IF_READY270        MOV     RAX,RSI271        CALL    SET_FS_BASE272        BT      U64 CTask.win_inhibit[RSI],WIf_SELF_FOCUS273        JC      I32 RESTORE_RSI_TASK274        LOCK275        BTS     U64 CTask.task_flags[RSI],TASKf_KILL_TASK276        JMP     I32 END_RSI_TASK277 278RESTORE_FS_TASK:279        XOR     RSI,RSI280        MOV     RSI,FS:CTask.addr[RSI]281        JMP     I32 RESTORE_RSI_TASK282}283 284_extern _TASK_CONTEXT_RESTORE U0 TaskContextRestore(); //Restore a task context.285_extern _YIELD U0 Yield(); //Yield cpu to next task.286_extern _TASK_END_NOW U0 TaskEndNow(); //Terminate current task.287 288U0 TaskQueIns(CTask *task,CTask *pred=NULL)289{//Insert a task in the scheduler running task queue.290//You have no business with this, probably.291  CTask *last;292  PUSHFD293  CLI294  if (!pred) pred=Fs;295  last=pred->last_task;296  last->next_task=pred->last_task=task;297  task->last_task=last;298  task->next_task=pred;299  POPFD300}301 302U0 TaskQueRem(CTask *task)303{//Remove a task from the scheduler running task queue.304//Use Suspend().305  CTask *next,*last;306  PUSHFD307  CLI308  next=task->next_task;309  last=task->last_task;310  last->next_task=next;311  next->last_task=last;312  POPFD313}314 315U0 TaskQueInsChild(CTask *task)316{317  CTask *last,*pred;318  PUSHFD319  CLI320  pred=task->parent_task->last_child_task;321  last=pred->last_sibling_task;322  last->next_sibling_task=pred->last_sibling_task=task;323  task->last_sibling_task=last;324  task->next_sibling_task=pred;325  POPFD326}327