求高人帮我解决下这个问题吧画出下列调度的串行化图，指出下列调度中的可串行化调度L1=w2(y)w1(y)r3(y)r1(y)w2(x)r3(x)r3(z)r2(z)L2=r3(z)r3(x)w2(x)r2(z)w1(y)r3(y)w2(y)r1(y)L3=r3(z)w3(y)w2(x)r1(y)r3(y)r2(z)r3(x)w1(y)L4=r

Question

求高人帮我解决下这个问题吧
画出下列调度的串行化图，指出下列调度中的可串行化调度
L1=w2(y)w1(y)r3(y)r1(y)w2(x)r3(x)r3(z)r2(z)
L2=r3(z)r3(x)w2(x)r2(z)w1(y)r3(y)w2(y)r1(y)
L3=r3(z)w3(y)w2(x)r1(y)r3(y)r2(z)r3(x)w1(y)
L4=r2(z)w2(y)w2(x)w1(y)r1(y)r3(y)r3(z)r3(x)

Answer 1

L1:
x: T2->T3, y: T2->T1, T1->T3, z:T3-T2
有环,所以不是可串行化调度
L2:
x: T3->T2, y:T1->T3, T1->T2,T2->T1, T3->T2
有环,所以不是可串行化调度
L3:
x:T2->T3, y: T3->T1,
无环,所以是可串行化调度
L4:
x:T2->T3,y :T2->T1,T2->T3
无环,所以是可串行化调度