信号量

本篇内容只针对个人的概念的简单理解

信号量

信号量 初始值 v = 3

a come

if v < 0 wait

else v = v - 1 //2 in

b come

if v < 0 wait

else v = v - 1 //1 in

c come

if v < 0 wait

else v = v - 1 //0 in

d come

if v < 0 wait

else v = v - 1 //wait

e come

if v < 0 wait

else v = v - 1 //wait

f come

if v < 0 wait

else v = v - 1 //wait

b out

v = v + 1 // 1

if v < 0 wait

else v = v - 1 // 0 f in