semaphore reader = 0; #记录读者个数
semaphore writer = 1; #记录空闲的写者个数
writer(){
while(1){ #当读者为0时,进行写操作
if(reader.value == 0 ){
P(writer);
writing;
V(writer);
}
}
}
reader(){
while(1){ #当写者为1时,进行读操作
if(writer.value == 1 ){
V(reader);
reading;
P(reader);
}
}
}