【正确答案】begin SR,SM₁,SM₂,SP:semaphore;
B₁,B₂:record;
SR:=1;SM₁:=0;SM₂:=1;SP:=0;
Cobegin
process read
X:record;
begin R:(接收来自输入设备上一个记录)
X:=接收的一个记录;
wait(SR);
B₁:=X;
signal(SM₁);
goto R;
end;
Process move
Y:record;
Begin
M:wait(SM₁);
Y:=B₁;
Signal (SR)
加工Y
wait(SM₂);
B₂:=Y;
signal(SP);
goto M;
end;
Process print
Z:record;
Begin
P:wait(SP);
Z:=B₂;
signal(SM₂)
打印Z
go to P;
end;
Coend;
end;