Reader Writer's question

Readers first:

• Reader Process Execution:
  1. No other reader to write, direct execution
  2. There are written and so on, but other readers are reading and reading directly
  3. There are written by the writer, waiting
• Writer Process Execution:
  1. No other reader and writer, direct execution
  2. There are other readers who are waiting for

Pseudo Code Description:

//R: Semaphore, initial value of 1, for synchronizing between readers
MUTX: semaphore, initial value of 1, for mutually exclusive reader and writer, or writer and writer
RC: Used to count how many reader processes are currently in progress
voidReader () { while(TRUE) {P (R); RC= RC +1; if(rc = =1) P (mutex);            V (R);            Read Operation P (R); RC= RC-1; if(rc = =0) V (mutex);        V (R); Other actions}}voidwriter () { while(TRUE) {P (mutex);    Write operation V (mutex); }}

Write a priority (this is what I think out, not the standard answer, looking to point out the error):

• Reader Process Execution:
  1. If no writer waits at this time, execute directly
  2. If there is a writer waiting, then wait
• Writer Process Execution:
  1. If there is no other writer, then execute
  2. If there are other readers, wait

Pseudo Code Description:

//Mutex semaphore: initial value of 1, Control access to critical section//W semaphore: Initial value of 1 for synchronization between the writer//R semaphore: Initial value of 1 for synchronization between readers//RW semaphore: Initial value of 1 for synchronization between reader and writer//Rcount Initial value is 0: used to count the current number of readers//Wcount Initial value is 0: used to count how many people are currently writtenvoidReader () { while(true) {P (RW);                P (R); Rcount++ ; if(Rcount = =1) P (mutex);        V (R);            V (RW);            Read Operation P (R); Rcount-- ; if(Rcount = =0) V (mutex);    V (R); }}voidwriter () { while(true) {P (W); Wcount++ ; if(Wcount = =1) P (RW);        V (W);            P (Mutex) write operation V (mutex) p (W); Wcount-- ; if(Wcount = =0) V (RW);    V (W); }}

Reader Writer's question