Slide Bài Giảng Hệ Diều Hành Chương 3 - UIT

01/2015 Duy Phan

Chng 3: Tin trnh

2 01/2015 Duy Phan

n tp chng 2

3 01/2015 Duy Phan

Mc tiu

Hiu c khi nim v cc trng thi ca tin

trnh

Bit c cc thng s ca tin trnh

Bit c cc khi nim v nh thi tin trnh

Bit c cc tc v c bn ca mt tin trnh

Hiu c cch giao tip gia cc tin trnh

4 01/2015 Duy Phan

Ni dung

Khi nim c bn

Trng thi tin trnh

Khi iu khin tin trnh

nh thi tin trnh

Cc tc v i vi tin trnh

S cng tc gia cc tin trnh

Giao tip gia cc tin trnh

Tiu trnh

5 01/2015 Duy Phan

Khi nim c bn

Cc hot ng ca CPU c gi l g?

H thng b (Batch system): jobs

Time-shared systems: use program,

task

Cc hot ng l tng t gi l process

tin trnh (prcess) l g?

Mt chng trnh ang thc thi

6 01/2015 Duy Phan

Khi nim c bn (tt)

Mt tin trnh bao gm:

Text section (program code)

Data section (cha global variables)

Program counter (PC)

Process status word (PSW)

Stack pointer (SP)

Memory management registers

...

7 01/2015 Duy Phan

Khi nim c bn (tt)

Cc bc np chng trnh vo b nh:

8 01/2015 Duy Phan

Khi nim c bn (tt)

Chng trnh -> tin trnh:

Dng load module biu din chng trnh thc thi c

Layout lun l ca process image

program

code

data

Executable

binary file (load

module) program

code

data

stack

Process image

in main

memory

start address

9 01/2015 Duy Phan

Khi nim c bn (tt)

Cc bc khi to tin trnh:

Cp pht mt nh danh duy nht cho tin trnh

Cp pht khng gian nh np tin trnh

Khi to khi d liu Process Control Block (PCB) cho tin trnh

Thit lp cc mi lin h cn thit (v d: sp PCB vo hng i nh thi, )

10 01/2015 Duy Phan

Trng thi tin trnh

new: tin trnh va c to

ready: tin trnh c ti nguyn, ch cn cn CPU

running: cc lnh ca tin trnh ang c thc thi

waiting: hay l blocked, tin trnh i I/O hon tt, tn hiu

terminated: tin trnh kt thc

11 01/2015 Duy Phan

Trng thi tin trnh (tt)

Chuyn i gia cc trng thi ca tin trnh

ready running

dispatch

interrupt

I/O or event

completion

I/O or

event wait

new terminated

waiting

admit exit

12 01/2015 Duy Phan

Trng thi tin trnh (tt)

/* test.c */

int main(int argc, char** argv)

{

printf(Hello world\n");

exit(0);

}

Bin dch chng trnh trong Linux: gcc test.c o test

Thc thi chng trnh test: ./test

Trong h thng s c mt tin trnh test c to ra, thc thi v kt thc.

Chui trng thi ca tin trnh test nh sau (trng hp tt nht):

new

ready

running

waiting (do ch I/O khi gi printf)

ready

running

terminated

13 01/2015 Duy Phan

Process control block

Mi tin trnh trong h thng u c cp pht mt Process Control Block (PCB)

PCB l mt trong cc cu trc d liu quan trng nht ca h iu hnh

PCB gm:

Trng thi tin trnh: new, ready, running,

B m chng trnh

Cc thanh ghi

Thng tin lp thi biu CPU: u tin,

Thng tin qun l b nh

Thng tin: lng CPU, thi gian s dng,

Thng tin trng thi I/O

14 01/2015 Duy Phan

Process control block (tt)

Lu chuyn CPU t tin trnh ny n tin trnh khc

15 01/2015 Duy Phan

Yu cu i vi h iu hnh v qun l tin trnh

H tr s thc thi lun phin gia nhiu tin trnh

Hiu sut s dng CPU

Thi gian p ng

Phn phi ti nguyn h thng hp l

Trnh deadlock, tr hon v hn nh

Cung cp c ch giao tip v ng b hot ng cc tin

trnh

Cung cp c ch h tr user to/kt thc tin trnh

16 01/2015 Duy Phan

Qun l cc tin trnh: cc hng i

running

ready

waiting

7

11 4 2 17

19 11

process number

cc PCB V d

17 01/2015 Duy Phan

nh thi tin trnh

Ti sao phi nh thi?

a chng

C vi tin trnh chy ti cc thi im

Mc tiu: tn dng ti a CPU

Chia thi

User tng tc vi mi chng trnh ang thc

thi

Mc tiu: ti thiu thi gian p ng

18 01/2015 Duy Phan

Cc hng i nh thi

Hng i cng vic-Job queue

Hng i sn sng-Ready

queue

Hng i thit b-Device queues

19 01/2015 Duy Phan

Cc hng i nh thi (tt)

Lu hng i ca nh thi tin trnh

20 01/2015 Duy Phan

B nh thi

B nh thi cng vic (Job scheduler) hay b nh thi di (long-term scheduler)

B nh thi CPU hay b nh thi ngn

Cc tin trnh c th m t nh:

tin trnh hng I/O

tin trnh hng CPU

Thi gian thc hin khc nhau -> kt hp hi ha gia chng

21 01/2015 Duy Phan

B nh thi trung gian

i khi h iu hnh (nh time-sharing system) c thm medium-term scheduling iu chnh mc a chng ca h thng

Medium-term scheduler

chuyn tin trnh t b nh sang a (swap out)

chuyn tin trnh t a vo b nh (swap in)

22 01/2015 Duy Phan

Cc tc v i vi tin trnh

To tin trnh mi:

Mt tin trnh c th to nhiu tin trnh mi thng qua mt li gi h thng create-process (vd: hm fork trong Unix)

V d: (Unix) Khi user ng nhp h thng, mt command interpreter (shell) s c to ra cho user

tin trnh c to l tin trnh con ca tin trnh to (tin trnh cha)

Quan h cha-con nh ngha mt cy tin trnh

23 01/2015 Duy Phan

Cy tin trnh trong Linux/Unix

init

pid = 1

sshd

pid = 3028

login

pid = 8415kthreadd

pid = 2

sshd

pid = 3610

pdflush

pid = 200

khelper

pid = 6

tcsch

pid = 4005emacs

pid = 9204

bash

pid = 8416

ps

pid = 9298

24 01/2015 Duy Phan

Cc tc v i vi tin trnh (tt)

To tin trnh mi:

tin trnh con nhn ti nguyn: t HH hoc t tin trnh cha

Chia s ti nguyn ca tin trnh cha

tin trnh cha v con chia s mi ti nguyn

tin trnh con chia s mt phn ti nguyn ca cha

Trnh t thc thi

tin trnh cha v con thc thi ng thi (concurrently)

tin trnh cha i n khi cc tin trnh con kt thc

25 01/2015 Duy Phan

V quan h cha/con

Khng gian a ch:

Khng gian a ch ca tin trnh con c nhn bn t cha

Khng gian a ch ca tin trnh con c khi to t tamplate

V d trong Unix/Linux

System call fork() to mt tin trnh mi

System call exec() dng sau fork() np mt chng trnh mi vo khng gian nh ca tin trnh mi

26 01/2015 Duy Phan

V d to process vi fork()

#include

#include

int main (int argc, char *argv[]){

int pid;

/* create a new process */

pid = fork();

if (pid > 0){

printf(This is parent process);

wait(NULL);

exit(0);}

else if (pid == 0) {

printf(This is child process);

execlp(/bin/ls, ls, NULL);

exit(0);}

else { // pid < 0

printf(Fork error\n);

exit(-1);

}

}

27 01/2015 Duy Phan

Cc tc v i vi tin trnh (tt)

Kt thc tin trnh:

tin trnh t kt thc

tin trnh kt thc khi thc thi lnh cui v gi system routine exit

tin trnh kt thc do tin trnh khc (c quyn, vd: tin trnh cha ca n)

Gi system routine abort vi tham s l pid (process identifier) ca tin trnh cn c kt thc

H iu hnh thu hi tt c cc ti nguyn ca tin trnh kt thc (vng nh, I/O buffer,)

28 01/2015 Duy Phan

Cng tc gia cc tin trnh

Trong tin trnh thc thi, cc tin trnh c th cng tc (cooperate) hon thnh cng vic

Cc tin trnh cng tc

Chia s d liu (information sharing)

Tng tc tnh ton (computational speedup)

Nu h thng c nhiu CPU, chia cng vic tnh ton thnh nhiu cng vic tnh ton nh chy song song

Thc hin mt cng vic chung

Xy dng mt phn mm phc tp bng cch chia thnh cc module/process hp tc nhau

S cng tc gia cc tin trnh yu cu h iu hnh h tr c ch giao tip v c ch ng b hot ng ca cc tin trnh

29 01/2015 Duy Phan

Bi ton ngi sn xut-ngi tiu th

Producer to ra cc d liu v consumer tiu th, s dng cc d liu

S trao i thng tin thc hin qua buffer

unbounded buffer: kch thc buffer v hn (khng thc t)

bounded buffer: kch thc buffer c hn

Producer v consumer phi hot ng ng b v

Consumer khng c tiu th khi producer cha sn xut

Producer khng c to thm sn phm khi buffer y

30 01/2015 Duy Phan

Giao tip lin tin trnh

IPC l c ch cung cp bi h iu hnh nhm gip cc tin trnh:

Giao tip vi nhau

ng b hot ng

m khng cn chia s khng gian a ch

IPC c th c cung cp bi message passing system

31 01/2015 Duy Phan

H thng truyn thng ip

Lm th no cc tin trnh giao tip nhau?

t tn (Naming)

Giao tip trc tip

send(P, msg): gi thng ip n tin trnh P

receive(Q, msg): nhn thng ip n t tin trnh Q

Giao tip gin tip: thng qua mailbox hay port

send(A, msg): gi thng ip n mailbox A

receive(Q, msg): nhn thng ip t mailbox B

ng b ha (Synchronization): blocking send, nonblocking send, blocking receive, nonblocking receive

32 01/2015 Duy Phan

H thng truyn thng ip (tt)

Lm th no cc tin trnh giao tip nhau?

To vng m (Buffering): dng queue tm cha cc message

Kh nng cha l 0 (Zero capacity hay no buffering)

Bounded capacity: di ca queue l gii hn

Unbounded capacity: di ca queue l khng gii hn

33 01/2015 Duy Phan

Tiu trnh - Thread

Tiu trnh: l mt n v c bn s dng CPU gm:

Thread ID, PC, Registers, Stack v chia s chung code, data, resourses (files)

34 01/2015 Duy Phan

PCB v TCB trong m hnh multithreads

pid

Threads list

Context

(Mem, global ressources)

Scheduling statistic

Relatives

( Dad, children)

PCB

tid

State

(State, details)

Context

(IP, local stack)

Thread Control Block TCB

35 01/2015 Duy Phan

Li ch ca tin trnh a lung

p ng nhanh: cho php chng trnh tip tc thc

thi khi mt b phn b kha hoc mt hot ng di

Chia s ti nguyn: tit kim khng gian nh

Kinh t: to v chuyn ng cnh nhanh hn tin trnh

V d: Trong Solaris 2, to process chm hn 30 ln,

chuyn chm hn 5 ln so vi thread

Trong multiprocessor: c th thc hin song song

36 01/2015 Duy Phan

Tiu trnh ngi dng (User thread)

Khi nim tiu trnh c h tr bi mt th vin hot ng trong

user mode

T1

Kernel

T2 User

mode

Kernel

mode

T3

LWP1 LWP2

P1 P2

37 01/2015 Duy Phan

Tiu trnh ht nhn (Kernel thread)

Khi nim tiu trnh c xy dng bn trong ht nhn

T1 T2

HDH

System call

User mode

Kernel mode

38 01/2015 Duy Phan

Tng kt

Trng thi tin trnh

Khi iu khin tin trnh

nh thi tin trnh

Cc tc v i vi tin trnh

S cng tc gia cc tin trnh

Giao tip gia cc tin trnh

Tiu trnh

39 01/2015 Duy Phan

Cu hi n tp

01/2015 Duy Phan

Kt thc chng 3