1 / 29

Practical Session 9

Practical Session 9. Co-Routines. Co-routine state. Variable Decleration. STKSZ equ 16*1024 CODEP equ 0 FLAGSP equ 4 SPP equ 8 section .rodata align 16 global numco numco: dd 3 CORS: dd CO1 dd CO2 dd CO3 section .data align 16 ; Structure for first co-routine

sacha-vazquez
Télécharger la présentation

Practical Session 9

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Practical Session 9

  2. Co-Routines

  3. Co-routine state

  4. Variable Decleration STKSZ equ 16*1024 CODEP equ 0 FLAGSP equ 4 SPP equ 8 section .rodata align 16 global numco numco: dd 3 CORS: dd CO1 dd CO2 dd CO3 section .data align 16 ; Structure for first co-routine CO1: dd Function1 Flags1: dd 0 SP1: dd STK1+STKSZ ; Structure for second co-routine CO2: dd Function1 Flags2: dd 0 SP2: dd STK2+STKSZ ; Structure for third co-routine CO3: dd Function2 Flags3: dd 0 SP3: dd STK3+STKSZ ; Counter COUNTER: dd 0 MAX_ITER: dd 3 section .bss align 16 CURR: resd 1 SPT: resd 1 SPMAIN: resd 1 STK1: resb STKSZ STK2: resb STKSZ STK3: resb STKSZ

  5. Co-routine structure

  6. Co-routine structure

  7. Variables • STKSZ – Stack Size • CODEP – Code Position: Offset to code • FLAGP – Flag Position: Offset to flags • SPP – Stack Pointer Position: Offset to stack pointer • numco – Number of Co-Routines: Global • CORS –Co-Routines Array • COi – Function Address of Co-Routine i • Flagsi – Flags of Co-Routine i • SPi – Stack Pointer of Co-Routine i • STKi – The Stack of Co-Routine i • SPMain – Stack Pointer of Main Function • CURR – Current Co-Routine • SPT – Temporary Storage for Stack Pointer

  8. Initializtion section .text align 16 extern printf global init_co_from_c global start_co_from_c global end_co ; Initalize a co-routine number given as an argument from C init_co_from_c: push EBP mov EBP, ESP push EBX mov EBX, [EBP+8] mov EBX, [EBX*4+CORS] call co_init pop EBX pop EBP ret ; EBX is pointer to co-routine structure to initialize co_init: pusha bts dword [EBX+FLAGSP],0 ; test if already initialized jc init_done mov EAX,[EBX+CODEP] ; Get initial PC mov [SPT], ESP mov ESP,[EBX+SPP] ; Get initial SP mov EBP, ESP ; Also use as EBP push EAX ; Push initial "return" address pushf ; and flags pusha ; and all other regs mov [EBX+SPP],ESP ; Save new SP in structure mov ESP, [SPT] ; Restore original SP init_done: popa ret

  9. Co-routine initialization

  10. Co-routine initialization

  11. Co-routine initialization

  12. Function1 ; This function used as code for co-routines 0 and 1 Function1: push dword 0 push dword 1 push dword [CORS+8] push dword [CURR] push dword FMT1 call printf add ESP, 20 mov EBX, [CORS+8] call dword resume mov dword [COUNTER], 0 func1_loop: push dword [COUNTER] push 2 push dword [CORS+8] push dword [CURR] push dword FMT1 call printf add ESP, 20 add dword [COUNTER], 1 mov eax, [MAX_ITER] cmp [COUNTER], eax jne func1_loop mov EBX, [CORS+8] call dword resume jmp end_co

  13. Function2 ; This function used as code for co-routine 2 Function2: push dword 0 push dword 1 push dword [CORS] push dword [CURR] push dword FMT2 call printf add ESP, 16 mov EBX, [CORS] call dword resume mov dword [COUNTER], 0 func2_loop: push dword [COUNTER] push dword 2 push dword [CORS+4] push dword [CURR] push dword FMT2 call printf add ESP, 20 add dword [COUNTER], 1 mov eax, [MAX_ITER] cmp [COUNTER], eax jne func2_loop mov EBX, [CORS+4] call dword resume push dword 3 push dword [CORS] push dword [CURR] push dword FMT2 call printf add ESP, 16 mov EBX, [CORS] call dword resume push dword 4 push dword [CORS+4] push dword [CURR] push dword FMT2 call printf add ESP, 16 mov EBX, [CORS+4] call dword resume jmp end_co

  14. Co-routine code (function)

  15. Co-routine code (function)

  16. Resume ; EBX is pointer to co-init structure of co-routine to be resumed ; CURR holds a pointer to co-init structure of the curent co-routine resume: pushf ; Save state of caller pusha mov EDX, [CURR] mov [EDX+SPP],ESP ; Save current SP do_resume: mov ESP, [EBX+SPP] ; Load SP for resumed co-routine mov [CURR], EBX popa ; Restore resumed co-routine state popf ret ; "return" to resumed co-routine!

  17. Co-routine resume

  18. Co-routine resume

  19. Start and End ; C-callable start of the first co-routine start_co_from_c: push EBP mov EBP, ESP pusha mov [SPMAIN], ESP ; Save SP of main code mov EBX, [EBP+8] ; Get number of co-routine mov EBX, [EBX*4+CORS] ; and pointer to co-routine structure jmp do_resume ; End co-routine mechanism, back to C main end_co: mov ESP, [SPMAIN] ; Restore state of main code popa pop EBP ret

  20. Start Co-routine scheduler

  21. Example

  22. After Init

  23. Resuming resume: pushf pusha mov EDX, [CURR] mov [EDX+SPP],ESP do_resume: mov ESP, [EBX+SPP] mov [CURR], EBX popa popf ret

  24. Resuming – Resume is Called resume: pushf pusha mov EDX, [CURR] mov [EDX+SPP],ESP do_resume: mov ESP, [EBX+SPP] mov [CURR], EBX popa popf ret

  25. Resuming resume: pushf pusha mov EDX, [CURR] mov [EDX+SPP],ESP do_resume: mov ESP, [EBX+SPP] mov [CURR], EBX popa popf ret

  26. Resuming resume: pushf pusha mov EDX, [CURR] mov [EDX+SPP],ESP do_resume: mov ESP, [EBX+SPP] mov [CURR], EBX popa popf ret

  27. Resuming resume: pushf pusha mov EDX, [CURR] mov [EDX+SPP],ESP do_resume: mov ESP, [EBX+SPP] mov [CURR], EBX popa popf ret

  28. Resuming resume: pushf pusha mov EDX, [CURR] mov [EDX+SPP],ESP do_resume: mov ESP, [EBX+SPP] mov [CURR], EBX popa popf ret

  29. Resuming resume: pushf pusha mov EDX, [CURR] mov [EDX+SPP],ESP do_resume: mov ESP, [EBX+SPP] mov [CURR], EBX popa popf ret

More Related