Deprecated: The each() function is deprecated. This message will be suppressed on further calls in /home/zhenxiangba/zhenxiangba.com/public_html/phproxy-improved-master/index.php on line 456
$B%H%i%s%6%/%7%g%s!"(BArgus$B!"Ej5!E*!&3Z4QE*<B9T(B/Transaction,Argus,speculative/optimistic execution
[go: Go Back, main page]

$B%H%i%s%6%/%7%g%s!"(BArgus$B!"Ej5!E*!&3Z4QE*

$BJB9T%7%9%F%`(B

                               $B%7%9%F%`>pJs7O(B/$B>pJs9)3X0h(B,
			       $B%7%9%F%`>pJs9)3X8&5f72(B/$B>pJsM}9)3X0L%W%m%0%i%`(B
			       $B%7%9%F%`>pJs9)3X8&5f2J(B/$B%3%s%T%e!<%?%5%$%(%s%9@l96(B
                               $B?7>k(B $BLw(B
                               <yas@cs.tsukuba.ac.jp>

$B$3$N%Z!<%8$O!" http://www.cs.tsukuba.ac.jp/~yas/cs/csys-2021/2021-06-18
$B$"$k$$$O!" http://www.cs.tsukuba.ac.jp/~yas/cs/
http://www.cs.tsukuba.ac.jp/~yas/

$B"#O"Mm;v9`(B

$B"#:#F|$N=EMW$JOC(B

$B#2$D$NAj(B
$BBh#1Aj(B
$BA4%W%m%;%9$r(B Commit $B$b(B Abort $B$b$G$-$k>uBV$K$9$k!#(B
  1. $B%3!<%G%#%M!<%?$O!"%m%0$K!V=`Hw!W$H=q$/!#(B
  2. $B%3!<%G%#%M!<%?$O!"%5%V%*!<%G%#%M!<%H$K!V=`Hw!W%a%C%;!<%8$rAw$k!#(B
  3. $B%5%V%*!<%G%#%M!<%H$O!"%m%0$K!V=`Hw40N;!W$H=q$/!#(B
  4. $B%5%V%*!<%G%#%M!<%H$O!"%3!<%G%#%M!<%?$K!V=`Hw40N;!W%a%C%;!<%8$rAw$k!#(B
  5. $B%3!<%G%#%M!<%?$O!"A4$F$N%5%V%*!<%G%#%M!<%H$+$i$N1~Ez$rBT$D!#(B
$BBh#2Aj(B
$B
  • $B%3!<%G%#%M!<%?$O!"%m%0$K!V%3%_%C%H!W$H=q$/!#(B
  • $B%3!<%G%#%M!<%?$O!"%5%V%*!<%G%#%M!<%H$K!V%3%_%C%H!W%a%C%;!<%8$rAw$k!#(B
  • $B%5%V%*!<%G%#%M!<%H$O!"%m%0$K!V%3%_%C%H40N;!W$H=q$/!#(B
  • $B%5%V%*!<%G%#%M!<%H$O!"%3!<%G%#%M!<%?$K!V%3%_%C%H40N;!W%a%C%;!<%8$rAw$k!#(B
  • $B%3!<%G%#%M!<%?$O!"A4$F$N%5%V%*!<%G%#%M!<%H$+$i$N1~Ez$rBT$D!#(B
    • $B%/%i%C%7%e$7$?;~$K$O!"%m%0$+$i2sI|$5$;$k!#(B

    $B"!#2AX%3%_%C%H$N@)Ls>r7o(B

    https://www.slideshare.net/kumagi/ss-78765920,$BJ,;6%7%9%F%`$K$D$$$F8l$i$;$F$/$l(B by $B7':j9(
    • (p5, $B$_$s$J$,CN$C$F$$$k$Y$-CM(B by Jeff Dean)
    • p32, 2 Phase Commit$B$O%P%0$C$F$$$k(B

    $B"!%H%i%s%6%/%7%g%sJ,N%%l%Y%k$NNc(B

    ANSI/ISO SQL $BI8=`$GDj5A!#(BSerializable $B$O!"=E$$$N$G!"B?$/$N(B DBMS $B$G$O%G(B $B%U%)%k%H$G$OL58z!#(B
    $BJ,N%%l%Y%k(B $B%@!<%F%#!<%j!<%I(B $B%N%s%j%T!<%?%V%k!&%j!<%I(B $B%U%!%s%H%`!&%j!<%I(B
    Read Uncommitted $BM-(B $BM-(B $BM-(B
    Read Committed $BL5(B $BM-(B $BM-(B
    Repeatable Read $BL5(B $BL5(B $BM-(B
    Serializable $BL5(B $BL5(B $BL5(B
    • $B%@!<%F%#! $B%N%s%j%T!<%?%V%k!&%j!<%I!#(B $BB>$N%H%i%s%6%/%7%g%s$,@h$K=*N;$9$k$H!"ESCf$GCM$,JQ$o$C$?$h$&$K8+$($k!#(B
    • $B%U%!%s%H%`!&%j!<%I!#4X78%G!<%?%Y!<%9$G!"B>$N%H%i%s%6%/%7%g%s$G9T$,(B $BDI2C$5$l!"%3%_%C%H$5$l$?;~!"(Bselect $B$N(B range $B$,JQ$o$C$F$7$^$C$F8+$($F$7(B $B$^$&!#(B

    $B"#(BArgus

    $B%H%i%s%6%/%7%g%s5!G=(B$B$rFbIt$K4^$`8@8l!#(B $BH/2;$O!"1Q8lFI$_$G%"!<%,%9!#%.%j%7%c?@OCFI$_$G$O!"%"%k%4%9!#(B

    Barbara Liskov: "Distributed programming in Argus", Communications of the ACM, Vol.31, No.3, pp.300-312, 1988. https://doi.org/10.1145/42392.42399

    $BJ8K!$O!"(BCLU $B8@8l$K;w$F$$$k!#(B

    $B;29M(B:

    $B"!%,!<%G%#%"%s(B(guardian)

    $BJB9T$KF0:n$9$k%*%V%8%'%/%H(B($B8=:_$NMQ8l$G$O%9%l%C%I(B)$B$r
  • $B%O%s%I%i(B(handler)$B$H8F$P$l$k(B $BB>$N%,!<%G%#%"%s$+$i8F$V$3$H$,$G$-$k $B=i4|2=MQ$K%/%j%(!<%?(B(creator)$B$H8F$P$l$k%(%s%H%j$r;}$D!#(B

    $B"!0BDj$JJQ?t(B(Stable variable)

    $B%,!<%G%#%"%s$O!"#2
    $B0BDj(B(stable)
    $B%/%i%C%7%e!J:F5/F0!K$7$F$b!"@8$-;D$k!#(B
    $B4xH/(B(volatile)
    $B%/%i%C%7%e!J:F5/F0!K$9$k$H!"CM$,<:$o$l$k!#(B

    $B"!%"%/%7%g%s(B(action)

    $B0BDj$JJQ?t$KBP$9$k%H%i%s%6%/%7%g%s$ruBV$+$i!"uBV$XA+0\$5$;$k!#(B( $BESCf$G%/%i%C%7%e$7$?$i!"85$KLa$9!#(B)

    $B%H%C%W%"%/%7%g%s(B
    $B%H%C%W%l%Y%k$N%H%i%s%6%/%7%g%s$r $B%5%V%"%/%7%g%s(B
    $B%M%9%H$7$?%H%i%s%6%/%7%g%s$r $BB>$N%,!<%G%#%"%s$N%O%s%I%i$N8F=P$7(B($B1s3V$B"!(BArgus$B$K$*$1$k%H%i%s%6%/%7%g%s$N
    • $B#2Aj%3%_%C%H(B
    • $B=q9~$_%m%C%/$G!":n6HMQ$N%3%T!<$,:n$i$l$k!#(B

    $B"!%,!<%G%#%"%s$N@k8@(B/Declaration of guardians

    1. $BL>A0(B Name
    2. $B@8@.%k!<%A%s!#0z?t$N $B0BDj$JJQ?t!#(BStable variables
    3. $B4xH/E*$JJQ?t!#(BVolatile variables
    4. $B%O%s%I%i $B%P%C%/%0%i%s%I!&%k!<%A%s!#%,!<%G%#%"%s<+?H$N%W%m%0%i%`!#(B Backgroud routines.
    5. $BI|5luBV$KLa$9!#(B Recovery procedures.
    $B0BDj$JJQ?t$K$D$$$F$O!"%7%9%F%`$,<+F0E*$K@09g@-$,uBV$KI|5l$9$k!#(B

    $B"!6d9T$N;YE9(B/A bank branch in Argus

       1: branch = guardian is create handles total, open, close, deposit, withdraw
   2:   % type definitions
   3:   htable = atomic_array[bucket]
   4:   bucket = atomic_array[pair]
   5:   pair = atomic_record[num: account_number, acct: acct_info]
   6:   acct_info = atomic_record[bal: int]
   7:   account_number = atomic_record[code: string, num: int]
   8:   intcell = atomic_record[val: int]
   9: 
  10:   stable ht: htable    % the table of accounts
  11:   stable code: string  % the code for the branch
  12:   stable seed: intcell % the seed for generating new account numbers
  13: 
  14:   create = creator (c: string, size: int) returns (branch)
  15:     code := c
  16:     seed.val := 0
  17:     ht := htable$new()
  18:     for i: int in int$from_to(1, size) do
  19:       htable$addh(ht, bucket$new())
  20:     end
  21:     return (self)
  22:   end create
  23: 
  24:   total = handler () returns (int)
  25:     sum: int := 0
  26:     for b: bucket in htable$elements(ht) do
  27:       for p: pair in bucket$elements(b) do
  28:         sum := sum + p.acct.bal
  29:       end
  30:     end
  31:     return (sum)
  32:   end total
  33: 
  34:   open = handler () returns (account_number)
  35:     intcell$write_lock(seed) % get a write lock on the seed
  36:     a: account_number := account_number${code: code, num: seed.val}
  37:     seed.val := seed.val + 1
  38:     bucket$addh(ht[hash(a.num)], pair${num: a, acct: acct_info${bal: 0}})
  39:     return (a)
  40:   end open
  41: 
  42:   close = handler (a: account_number) signals (no_such_acct, positive_balance)
  43:     b: bucket := ht[hash(a.num)]
  44:     for i: int in bucket$indexes(b) do
  45:       if b[i].num != a then continue end
  46:       if b[i].acct.bal > 0 then signal positive-balance end
  47:       b[i] := bucket$top(b) % store topmost element in place of closed account
  48:       bucket$remh(b) % discard topmost element
  49:       return
  50:     end
  51:     signal no_such_acct
  52:   end close
  53: 
  54:   lookup = proc (a: account_number) returns (acct_info) signals (no_such__acct)
  55:     for p: pair in bucket$elements(ht[hash(a.num)]) do
  56:       if p.num = a then return (p.acct) end
  57:     end
  58:     signal no_such_acct
  59:     end lookup
  60: 
  61:   deposit = handler (a: account_number, amt: int) signals (no_such_acct, 
  62:                                                                 negativ_amount)
  63:     if amt < 0 then signal negative_amount end
  64:     ainfo: acct_info := lookup(a) resignal no_such_acct
  65:     ainfo.bal := ainfo.bal + amt
  66:   end deposit
  67: 
  68:   withdraw = handler (a: account_number, amt: int) signals (no_such_acct, 
  69:                                          negative_amount, insufficient_funds)
  70:     if amt < 0 then signal negative amount end
  71:     ainfo: acct_info := lookup(a) resignal no_such_acct
  72:     if ainfo.bal < amt then signal insufficient_funds end
  73:     ainfo.bal := ainfo.bal - amt
  74:   end withdraw
  75: end branch
    • $B%,!<%G%#%"%s$rDj5A$7!"(Bbranch $B$H$$$&JQ?t$K%P%$%s%I(B
    • $B%/%j%(!<%?$O!"(Bcreate()
    • $B%O%s%I%i$O!"(Btotal(), open(), close(), deposit(), withdraw()
    • $B7?Dj5A!#(Brecord $B$O!"9=B$BN$NDj5A!#(B
    • atomic $B$J$N$G!"%7%9%F%`$K$h$j%H%i%s%6%/%7%g%s$NBP>]$H$J$k!#(B
    • $BJQ?tDj5A!#(Bstable $B$J$N$G!"A4It0BDj!#(B $B4xH/E*$JJQ?t$,$J$$$N$G!"%/%i%C%7%e$+$i$N2sI|%3!<%I$O$J$$!#(B
    • $B%P%C%/%0%i%s%I$N seed $B$O!"8}:BHV9f$r%f%K!<%/$K$9$k$?$a$N%+%&%s%?!#(B

    $B"#(BEtherium-Solidity

    Etherium $B$O!"%V%m%C%/%A%'!<%s5;=Q$N0l
  • $B%"%+%&%s%H$O!"(Baddress $B$r;}$D!#(B
  • $B%"%+%&%s%H$O!"uBV$r;}$D!#(B
    • balance ($B;D9b(B)
  • $B%"%+%&%s%H$K!"(B2$B
  • EOA$B!J(BExternally Owned Account)$B!#8D?M$N:bI[!#?M$KI3IU$$$F$$$k!#(B $B8x3+80!&HkL)80$NAH$r;}$D!#(B
  • Contract Account$B!#(BSmart contract$B!#%V%m%C%/%A%'!<%s$KIU?o$7$?2>A[7W(B $B;;5!$GuBV$r;}$D!#%V%m%C%/%A%'!<(B $B%s!&%M%C%H%o!<%/$K%G%#%W%m%$$5$l$k!#(B
  • EOA $B$+$iB>$N(B EOA$B!"$^$?$O!"(BEOA $B$+$i(B Contract Account $B$K(B ether $BCM$rAw?.$9$k$3$H$r(B Etherium $B$G$O!"(B $B%H%i%s%6%/%7%g%s$H8@$C$F$$$k!#(B $B%H%i%s%6%/%7%g%s$O!"
  • to: $B data: $B%Z%$%m!<%I(B
  • value: $BAw?.$5$l$k(B ether $BCM(B
  • nonce: $BAw?. gasprice, gasLimit, starttagas: $B (v,r,s): $B%G%#%8%?%k=pL>(B Contract Account$B$+$iH/?.$5$l$k%H%i%s%6%/%7%g%s$O!"%a%C%;!<%8$H8F$P$l$k!#(B
  • $B%H%i%s%6%/%7%g%s$G!"Fs=E;YJ'$$$,5/$-$J$$$h$&$K!"(Bether $B$,A}$($?$j8:$C(B $B$?$j$7$J$$$h$&$K!"%V%m%C%/%A%'!<%s$N%N!<%I(B($B%^%$%J!<(B)$B$,4F;k$7$F$$$k!#(B
  • $B%H%i%s%6%/%7%g%s$N Contract $B$N4X?t$N
  • $B%H%i%s%6%/%7%g%s$G$O!"(Bcontract $B$K!"(Bether $B$r%H%i%s%6%/%7%g%s$GAw$j!"(B Contract $BFbIt$N>uBV$rJQ2=$5$;$k$3$H$,$G$-$k!#>uBV$NJQ2=$O!"%V%m%C%/%A%'!<(B $B%s$K5-O?$5$l$k!#(B
  • $B8F$S=P$7$G$O!"(Bcontract $B$N>uBV$rJQ2=$5$;$i$l$J$$!#%H%i%s%6%/%7%g%s(B $B$G$O$J$$$N$G!"(B($B7Z$$$b$N$O(B)$BuBV$r=8$a$F!"%3!<%I$r!"%m!<%+%k$G

    $B"!6d9T$N8}:B(B/A bank account in Solidity

    contract Bank {

    mapping(address => uint256) public accounts;


    function deposit() {
        accounts[msg.sender] += msg.value;
    }

    function withdraw(uint256 amount) {
        if(amount > accounts[msg.sender])
	    throw;
        accounts[msg.sender] -= amount;
        if(!msg.sender.send(amount))
	    throw;
    }

    function get_balance() {
      return accounts[msg.sender];
    }

}
    • mapping $B$O!"%O%C%7%eI=$N$h$&$J$b$N!#$3$NNc$G$O!"%-!<$,(B address $B$G!"(B $BCM$,(B uint256$B!#JQ?tL>$,(B accounts$B!#(Baddress $B$O!"%"%+%&%s%H$N%"%I%l%9!#(B
    • msg $B$O!"%H%i%s%6%/%7%g%s$GAw$i$F$-$?%a%C%;!<%8!#(B $B
    • msg.sender: $BAw?. msg.value: $BAw$i$l$F$-$?(B ether $B$NCM!#C10L$O(B wei (ether / 1e18)$B!#(B
    deposit() $B$O!"Aw?.85$N%"%+%&%s%H$+$i(B amount $BJ,$N(Bether $B$r
  • $B $B$3$N%H%i%s%6%/%7%g%s$G!"(Bcontract $B$,;}$C$F$$$k(B balance $B$b!"A}$($k!#(B withdraw() $B$O!"%a%C%;!<%8$NAw?.85$K!"MB$+$C$F$$$k(B ether $B$r(B amount $BJ,$@$1JV$9!#(B
    • require() $B$,@.$jN)$?$J$$$H!"%H%i%s%6%/%7%g%s$O!"(Babort $B$5$l$k!#(B
    • $B$^$:!"(Baccounts[msg.sender]$B!!$r8:$i$9!#@h$K8:$i$9$N$,Bg;v!#(B
    • $B $B$3$N%H%i%s%6%/%7%g%s$G!"(Bcontract $B$,;}$C$F$$$k(B balance $B$,8:$k!#(B
    $B;D9b$r3NG'$7!"@h$K(B accounts[msg.sender] $B$r8:$i$7$F$+$i%H%i%s%6%/%7%g%s(B $B$r9T$o$J$$$H!"J#?tF1;~$K(B withdraw() $B$,8F$P$l$?;~$K!"LdBj$,@8$8$k!#(B

    get_balance() $B$O!";D9b>H2q!#(B $B>uBV$rJQ$($J$$$N$G!"%H%i%s%6%/%7%g%s$G$O$J$/(B call $B$G$B"#Ej5!E* $BEj5!E*-MhMxMQ$5$l$k$+MxMQ$5$l$J$$$+3NDj$5(B $B$l$kA0$K

        if( a() ) {
        b();
    }
    else {
        c();
    }

    • $BIaDL$O!"(Ba() $B$,(B true $B$+(B false $B$+$rJV$9$N$rBT$C$F$+$i(B b() $B!"$^$?$O!"(Bc() $B$r3+;O$9$k!#(B
    • $BEj5!E*=hM}$G$O!"(Ba() $B$N40N;$rBT$?$:$K!"@h$K!"(Bb()$B!"$^$?$O!"(Bc() $B$^$?(B $B$O!"(Bb() $B$H(B c() $B$NN>J}$r

      if( a ) then b else c

      $B?^(B? $BEj5!E*

       $B$3$NNc$G$O!"(Ba() $B$,40N;$7$?;~$K$O!"(Bb()$B!"(Bc() $B$,=*$o$C$F$$$?;~$K$O!"8+$+$1(B $B>e!"B(:B$K=*$o$k!#(B
      • $B8=:_$N(BCPU$B$O!"5!3#8lL?Na$NC10L$GEj5!E* $B:G6a$N(BCPU$B$O!"J,4tM=B,$r$7$F!">r7oJ,4tL?Na$N@h$^$G@h$Kr(B $B7o$,K~$?$5$l$J$$;~$K$O7k2L$O $B4X?tC10L!"JEENO$H$OAjH?$9$k!#(B
      • $B4X?tC10L!" then $BIt$d(B else $BIt$N=hM}$K!"I{:nMQ$,$J$$(B($B4X?t7?(B)$B$N;~$K$O!"(B $B $BI{:nMQ$,$"$k;~$K$O!"%H%i%s%6%/%7%g%sE*$J

        $B"!@$3&(BOS/World OS

        $B?7>k$N8&5f@.2L!#(B
        1. $B:,O)LC(B, $BaDbC(B, $B?7>k(B, $B4n20Ip(B, $B2'D9(B: "$BAFN3EYEj5!E*JBNs=hM}$r;Y1g(B $B$9$k%*%Z%l!<%F%#%s%0!&%7%9%F%`$N9=A[(B", SWoPP'94, $B>pJs=hM}3X2q8&5f2qJs(B $B9p(B94-ARC-107-12, Vol.94,No.66, pp.89-96 (1994$BG/(B7$B7n(B).
        2. Jun Sun, Yasushi Shinjo and Kozo Itano: "The Implementation of a Distributed File System Supporting the Parallel World Model", The Third International Workshop on Advanced Parallel Processing Technologies, pp.43-47 (Oct.19-21, 1999).
        3. $B@P0f(B $B9'1R(B, $B?7>k(B $BLw(B, $BHDLn(B $B9N;0(B: "$B%W%m%;%9%H%l!<%95!G=$rMQ$$$?@$3&(B OS$B$NpJs=hM}3X2qO@J8;o(B, Vol.43, No.6, pp.1702-1714 (2002$BG/(B6$B7n(B).
        4. $B:#N$K.IW(B, $BNkLZ??0l(B, $B?7>kLw(B, $BHDLn9N;0(B: "$BF0E*%j%s%/$H%Q%1%C%H%U%#%k(B $B%?$rMQ$$$?@$3&(BOS $B$N%M%C%H%o!<%/5!G=$N Yasushi Shinjo, Wataru Ishida and Jinpeng Wei: "Implementing a parallel world model using Linux containers for efficient system administration", IEEE Second International Workshop on Container Technologies and Container Clouds (WoC 2016), 7 pages (2016).

        SF (Science Fiction) $B$N%Q%i%l%k%o!<%k%I(B(parallel world, parallel universe)$B$r!"%*%Z%l!<%F%#%s%0!&%7%9%F%`$N%l%Y%k$G

        $B%5%$%3%m$r$U$kEY$KCO5e$,#6$D$KJ,Nv$9$k(B

        $B?^(B SF$B$N%Q%i%l%k%o!<%k%I(B

        $B#S#F$G$O!";~!9JL$N@$3&$K%8%c%s%W$7$?$j?M$,F~$lBX$o$C$?$j$9$k!#(B

        $B"!(BUndo $B$G$-$k(BOS/Undoable OS

        Undo $B$H$O!"(Bdo $B$N8z2L$rBG$A>C$7$F!"$b$H$b$H(B do $B$7$J$+$C$?$3$H$K$9$k!#(B (do not $B$H$O0c$&!#(B)

        $B@$3&#O#S$G$O!"%U%!%$%k$NFbMF$rJQ99$9$k$H!"#2$D$N@$3&$,$G$-$k!#(B

        • $BJQ99$5$l$?@$3&(B
        • $BJQ99$5$l$F$$$J$$@$3&(B

        $B@$3&$r:n$j%U%!%$%k$r=q$-49$($&$^$/$$$1$PM;9g!

        $B?^(B $B@$3&(BOS$B$G;H$($k@$3&$NA`:n(B

         $B

        $BIaDL$N2>A[7W;;5!$G$O!"M;9g$O$G$-$J$$!#7Q>5$N%3%9%H$,Bg$-$$!#(B

        $B"!%Q%i%l%k%o!<%k%I$NMxMQ(B/Usage of parallel worlds

        • $B%/%i%C%/%-%s%0!"967b$K$h$kGK2u$+$i$N?WB.$J2sI|!#967b$5$l$k(B $B2DG=@-$,$"$k%W%m%0%i%`!"(B $B2x$7$$%W%m%0%i%`$r;R@$3&$G $B>.5,LO$J%5!<%P$N4IM}!#%Q%C%AEv$F$r!";R@$3&$G $BEj5!E*=hM}!?3Z4QE*=hM}!# $B!V:9J,!W$r(B first class object $B$H$7$F07$&!#(B $BJ#?t$N#P#C$G$N%U%!%$%kFbMF$NE}0l!#J#?t$N@$3&$NFbMF$rHf3S$7$F(B $B99?7$5$l$?ItJ,$rH?1G$5$;$k!#(B A difference as a first class object.

        $B"!(BHOPE

        C. Cowan and H. L. Lutfiyya: "A wait-free algorithm for optimistic programming: Hope realized", In Proceedings of the 16th International Conference on Distributed Computing Systems(ICDCS), pages 484-493, 1996.

        RPC$B$NCY1d$r1#$9!#(B This paper proposes hiding RPC delays by using optimistic execution.

        $B"#2A%"%s%1!<%H(B/Course Evaluation Questionnaire

        CS$B@l96!&>pJsM}9)3X0L%W%m%0%i%`$N653X%^%M%8%a%s%H0Q0w2q$G$O!"(B $B650i$N2~A1$N$?$a$K!"3X@8$N3'$5$s$K2A%"%s%1!<%H$r

        $B%"%s%1!<%H$O(BTWINS$B$+$i2sEz$7$F$/$@$5$$!#(B

        $B$J$*!"3'$5$s$NI>2A$,@.@S$K1F6A$9$k$3$H$O0l@Z$"$j$^$;$s!#(B $B$^$?!"I>2A7k2L$r650i$N2~A10J30$NL\E*$KMxMQ$9$k$3$H$O$"$j$^$;$s$7!"(B $BI>2A7k2L$r8x3+$9$k>l9g$K$O8D?M$rFCDj$G$-$k$h$&$J>pJs$O4^$a$^$;$s!#(B

        $B%"%s%1!<%H$O!"

      • $BJB9T%7%9%F%`(B
      • $BJB9T%7%9%F%`(B-$B8D!9$N2s$4$H$NI>2A(B
      $B2sEz4|4V$O!"(B6$B7n(B17$BF|$+$i(B7$B7n(B14$BF|$G$9!#(B

      The FD Committee of the Department of Computer Science/Master's and Doctoral Programs in Computer Science conducts a survey of all students for the purpose of evaluating and improving instruction. Please complete this questionnaire in TWINS.

      These answers will not affect your academic grades. The result will not be used for any purpose other than instruction evaluation and its further improvement. When the summarized information of this questionnaire is released to the public (for FD activities), no private information about you will be included.

      This class has the following two groups of questionnaires.

      • $BJB9T%7%9%F%`(B (Concurrent Systems)
      • $BJB9T%7%9%F%`(B-$B8D!9$N2s$4$H$NI>2A(B (Concurrent Systems -- Evaluation of individual class)
      Please answer them in Twins between June 17 and July 14.

      $B"#N}=,LdBj(B(exercise)10 $B%H%i%s%6%/%7%g%s!"(BArgus$B!"Ej5!E*!&3Z4QE*

      $B!zLdBj(B(1001) $BD>Ns2=2DG=(B

      $B
    • T1: $B8}:B(B1$B$+$i(B100$B1_$r0z$-=P$9!#(B
    • T2: $B8}:B(B1$B$+$i(B80$B1_$r0z$-=P$9!#(B
    • T3: $B8}:B(B1$B$+$i(B200$B1_$r0z$-=P$9!#(B
    $B8}:B(B1$B$N;D9b$O!"%H%i%s%6%/%7%g%s3+;OA0$K$O(B 200$B1_$@$C$?$H$9$k!#(B $BD>Ns2=2DG=$J%H%i%s%6%/%7%g%s$N%9%1%8%e!<%k$NNc$r(B2$B$D$rEz$($J$5$$!#(B $B$^$?!"3F%9%1%8%e!<%k$K$*$$$F!"%H%i%s%6%/%7%g%s

    Consider the following transactions.

    • T1: Withdraw 100 Yen from Account 1.
    • T2: Withdraw 80 Yen from Account 1.
    • T3: Withdraw 200 Yen from Account 1.
    Suppose that the balance of Account 1 is 200 yen before these transactions are executed. Show two serializable schedules of these transactions. For each schedule, show the balance of Account 1 after the execution of the transactions. Note that the balance should not be negative.

    $B!zLdBj(B(1002) Argus

    Argus $B8@8l$G5-=R$5$l$?6d9T$N;YE9$N%W%m%0%i%`(B$B$O!"%H%i%s%6%/%7%g%s$r

    The profram of a bank branch in Argus performs transactions. Extract a code fragment that executes a transaction from the program. In this code fragment, mark the point that executes the begin_transaction operation implicitly. Mark the point that executes the commit operation implicitly.

    $B!zLdBj(B(1003) $BEj5!E*

    $B

    In the following program in a procedural programming language, answer the place we can perform speculative execution. In this program, the function input_yes_or_no() returns YES or NO. 

    main() {
	int x = 0;
	if( input_yes_or_no() == YES ) {
	    x = time_consuming_computation();
	}
	print(x);
}
    $B$3$NEj5!E*

    In this speculative execution, we need a similar implementation technique to that of transactions. Describe the technique briefly.

    Last updated: 2021/06/16 10:07:31
    Yasushi Shinjo / <yas@cs.tsukuba.ac.jp>