reader and writer

Var rmutex,wmutex: semophore:=1,1;Readcount: integer:=0;beginparbeginReader: beginrepeatwait(rmutex);if Readcount=0 then wait(wmutex);Readcount:=Readcount+1;signal(rmutex);**********************perform read operation;**********************wait(rmutex);Readcount:=Readcount-1;if Readcount=0 then signal(wmutex);//既可以防止在有读者的情况下阻止写者进入，又可以在有写者的情况下堵塞读者自己signal(rmutex);until false;endwriter: beginrepeatwait(wmutex);*********************perform write operation**********************signal(wmutex);until false;end