Download - 4. Message Buffer TN

8/18/2019 4. Message Buffer TN

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Message Bufer

Nguyễn Hoàng Tâm 50702111Nguyễn Văn Trọng50702651


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Synchronization and communication ◦ !a""ing #aria$%&'"iz& m&""ag&"◦ Ho%ding m&""ag&" (or "&nding and r&c&i#ing◦ 2 )u&u&" m&""ag&" *aiting to $& "&nt + "&nd

)u&u&,-ta"." *aiting (or m&""ag&" r&c&i/t+ r&c&i#& )u&u&,

Using message bufer


3/16

S&nd&r ◦ o/y m&""ag& to $u&r◦ 3( not &nough "/ac& m&""ag& i" )u&u&d (or "&nding unti% &nough "/ac& i"

a#ai%a$%& ta". *aiting to "&nd i" /ut in "&nd )u&u&

Message sender andreceipt


4/16

4&c&i/t ◦ &""ag& i" (&tch&d (rom $u&r◦ 3( $u&r ha" no m&""ag&" ta". &nt&r ait "tat&

and /ut in r&c&i#& )u&u& hat i( $u&r "iz& i" 0

◦ &""ag& communication (unction i" "ynchronou"◦ Ta". *ait (or "y"t&m ca%% to $& in#o.&d◦ &""ag& i" /a""&d *h&n $oth "id& i""u& "y"t&m

ca%%

Message sender andreceipt


5/16

Synchronou" ommunication $y &""ag& u&r


6/16

t.8cr&8m$( cr&at& m&""ag& $u&r 39 m$:d ; t.8cr&8m$(+T8< =/.8cm$(, /.8cm$( d&tai%"

◦

V! &>in( ?>t&nd&d in(ormation"◦ @T4 m$(atr &""ag& $u&r attri$ut&"◦ 3NT $u("z &""ag& $u&r "iz& + in $yt&" ,◦ 3NT ma>m"z a>imun ma""ag& "iz& +in

$yt&" ,

Functions


7/16

Error code :' ?8AB Norma% com/%&tion

' ?8NA? 3n"uCci&nt m&mory +m&mory (or contro% $%oc. orring $u&r ar&a cannot $& a%%ocat&d,

' ?8D33T Num$&r o( m&""ag& $u&r" &>c&&d" th& "y"t&m %imit

' ?84S@T4 4&"&r#&d attri$ut& +m$(atr i" in#a%id or cannot $&u"&d,

' ?8!@4 !aram&t&r &rror +/. cm$( i" in#a%id- or $u("z orma>m"z i" n&gati#& or in#a%id,

mbatr :' T@8T


8/16

Not&" ◦ Ta"." *aiting (or a m&""ag& to $& "&nt can $&

d&"ignat&d in T@8


9/16

t.8d&%8m$( d&%&t& m&""ag& $u&r ?4 r&cd ; t.8d&%8m$(+39 m$:d,

?rror cod&

' ?8AB Norma% com/%&tion' ?839 3n#a%id 39 num$&r +m$:d i" in#a%idor cannot $& u"&d,' ?8NA?FS A$G&ct do&" not &>i"t +th&m&""ag& $u&r d&"ignat&d in m$:d do&"not &>i"t,

Functions


10/16

h&n thi" (unction" i" ca%%&d 4&%&a"& m&""ag& $u&r "/ac& and contro%

$%oc.

3( th&r&Er& ta"." )u&u&d in m&""ag& $u&r-&rror cod& ?89DT r&turn&d to th& ta"." inait "tat&

3( th&r&Er& m&""ag& in $u&r- it i" d&%&t&d

and no &rror cod& i" r&turn&d

Functions


11/16

t.8"nd8m$( "&nd m&""ag& to m&""ag&$u&r ?4 &rcd ; t.8"nd8m$( + 39 m$:d- V! m"g-

3NT m"g"z- TA tmout , !aram&t&r

' 39 m$:d &""ag& $u&r 39' 3NT m"g"z S&nd m&""ag& "iz& +in $yt&",

' V! m"g Start addr&"" o( "&nd m&""ag&/ac.&t' TA tmout Tim&out d&"ignation

Functions


12/16

Error code :' ?8AB Norma% com/%&tion' ?839 3n#a%id 39 num$&r +m$:d i" in#a%id or cannot $& u"&d,' ?8NA?FS A$G&ct do&" not &>i"t +th& m&""ag& $u&r d&"ignat&din m$:d do&" not &>i"t,

' ?8!@4 !aram&t&r &rror +m"g"z 0- m"g"z I ma>m"z-#a%u& thatcannot $& u"&d in m"g- or tmout +J2,,' ?89DT Th& o$G&ct $&ing *ait&d (or *a" d&%&t&d +m&""ag& $u&r*a" d&%&t&d *hi%& *aiting,' ?84D@3 ait "tat& r&%&a"&d +t. r&% *ai r&c&i#&d in *ait "tat&,

' ?893S@3 ait r&%&a"&d $y *ait di"a$%&d "tat&' ?8TAKT !o%%ing (ai%&d or tim&out' ?8TF ont&>t &rror +i""u&d (rom ta".'ind&/&nd&nt /ortion orin di"/atch di"a$%&d "tat&,

Functions


13/16

9&"cri/tion" ◦ o/y m"g"z $yt&" "tarting at mgz to m&""ag& )u&u&

o( m&""ag& $u&r◦ 3( m"g"z i" %arg&r than ma>m"z - &rror cod& i" r&turn&d◦

3( not &nough "/ac&- ta". i""u&d thi" "y"t&m ca%% go&"to *ait "tat&◦ 3( tmout &%a/"&" $&(or& *ait "tat& r&%&a"&" - "y"t&m

ca%% t&rminat&" and r&turn &rror cod&◦ h&n tmout ; T8!AD - i( th&r&E" &nough "/ac&- &rror

cod& r&turn *ithout &nt&ring *ait "tat&◦ h&n tmout ; T8


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t.8r&c#8m$( r&c&i#& m&""ag& $u&r 3NT m"g"z ; t.8rc#8m$( + 39 m$:d- V! m"g- TA tmout ,

4&turn m&""ag& "iz& or &rror cod&' !aram&t&r- &rror cod& "imi%ar to t.8"nd8m$(

Functions


15/16

t.8r&(8m$( g&t m&""ag& $u&r "tatu" ?4 &rcd ; t.8r&(8m$( + 39 m$:d- T84<

=/.8rm$( ,

!.8rm$( d&tai%" ◦ V! &>in( ?>t&nd&d in(ormation◦ 39 *t". aiting ta". in(ormation◦ 39 "t". S&nd ta". in(ormation◦ 3NT m"g"z Siz& o( th& n&>t m&""ag& to $&

r&c&i#&d +in $yt&",◦ 3NT (r$u("z m"z a>imum m&""ag& "iz& +in $yt&",

Functions


16/16

9&"cri/tion" ◦ 4&(&r&nc& th& "tatu" o( m&""ag& $u&r◦ 3( mu%ti/%& ta"." ar& *aiting - r&turn th& 39 o( ta".

at th& h&ad o( )u&u&◦ 3( no ta". *aiting - 0 i" r&turn&d◦ 3( th&r&E" no m&""ag& at th& )u&u&- m"g"z ; 0 i"

r&turn&d

Functions