3
3.1 3.2 3.3 3.4 3.5
3.1 3.2 3.3 3.4 3.5
3.1
makefile
output.o cc C output.c
Connect
Process
2144
2145
2146
2147
2142
2143
2144
2145
output.o
output.c
+clock skew: ababambmabab, bc,acconcurrent
Lamport
Process
60
54
48
42
36
30
24
18
12
6
0
80
72
64
56
48
40
32
24
16
8
0
100
90
80
70
60
50
40
30
20
10
0
A
B
C
D
(a)
76
70
48
42
36
30
24
18
12
6
0
85
77
69
61
48
40
32
24
16
8
0
100
90
80
70
60
50
40
30
20
10
0
A
B
C
D
(b)
0
1
2
0
1
2
12 solar-day/86400
9192631770=1TAIUTCTAIWWVGEOS1020
Cp(t), t UTC dC/dt =1 dC/dt 1 dC/dt < 1
Process
,C
UTCt
dC/dt1
Christians -- WWVUTC/2 ,10010
911
Berkeley
Process
State
3:00
3:00
3:00
3:00
3:25
2:50
3:00
0
-10
+25
3:25
2:50
3:05
+5
+15
-20
3:05
3:05
(a)
(b)
(c)
iT0+iR T0+(i+1)R S
OSF DCEUTC
lease
3.1 3.2 3.3 3.4 3.5
3.2 Critical Section
3--
CCC
Win Thread CreateMutex()WaitForSingleObject()ReleaseMutex()
InitializeCriticalSection()EnterCriticalSection()LeaveCriticalSection()
Ricart-Agrawala1. PR 2. PPRRPOKPRPPRPPOK;P3. POKR4. PROK
01202020022
nn2n-1)
322n-12n-110n-1
3.1 3.2 3.3 3.4 3.5
3.3
Bully
PEPQ,PQ456564656
PCEEPPC52
3.1 3.2 3.3 3.4 3.5
3.4 Atomic 1
2
Stable Storage
1BEGIN_TRA NSACTION2END_TRANSACTION3ABORT_TRANSACTION4READ5WRITE
BEGIN TRANSACTION reserve WPJFK reserve JFKNairobi reserve NairobiMalindi END TRANSACTION BEGIN TRANSACTION
reserve WPJFK reserve JFKNairobi NairobiMalindi full
ABORT TRASACTION JFKNairobi
AtomicConsistentIsolatedSerializable:Durable
Isolated
Process
BEGIN_TRANSACTIONx = 0; x = x+1;END_TRANSACTION
BEGIN_TRANSACTIONx = 0; x = x+2;END_TRANSACTION
BEGIN_TRANSACTIONx = 0; x = x+3;END_TRANSACTION
(a)
(b)
(c)
1
2
3
x=0; x=x+1; x=0; x=x+2; x=0; x=x+3;
x=0; x=0; x=x+1; x=x+2; x=0; x=x+3;
x=0; x=0; x=x+1; x=0; x=x+2; x=x+3;
(d)
TWTW03
WALin-place
Rollback:undo,
(a) (b)-(d)
Process
x=0;y=0;BEGIN_TRANSACTION x=x+1; y=y+2; x=y*y;END_TRANSACTION
(a)
x = 0/1
x = 0/1
y = 0/2
x = 1/4
x = 0/1
y = 0/2
(b)
(c)
(d)
two-phase commit protocol
(Concurrency Control)serializable(R)(W)
RWRW
(2PL) 2PL2PCcascaded abort)WFG timeout)
(Optimistic)
(Timestamp)T T;
2PL
3.1 3.2 3.3 3.4 3.5
3.5 [Dijkstra,1965]P, free
-PR:(1)PR; (2) R P;/
BR,TT
(a)0 (b)1(c)(d)
Process
Process name
A
S
R
B
0
(a)
C
T
S
1
(b)
C
S
A
R
(c)
T
B
C
S
(d)
T
A
R
B
ChandyMisraHaasPidPid Pid e.g. 0,2,3,0,4,6,0,5,7 ,0,8,0