moss.kernel
Class CREWLock

java.lang.Object
  moss.kernel.CREWLock

public class CREWLock
extends java.lang.Object

implementation of a CREW (concurrent read, exclusive write) lock for MOSS processes. Based on Peter Welch's and David Wood's CREW code from occam/KRoC. This is a bit simpler than the algorithm presented in the lecture.

Constructor Summary

CREWLock()
creates and initialises a new CREW lock

Method Summary

void	claim_read() claim a read lock
void	claim_write() claim the write lock
void	release_read() release a read lock
void	release_write() release the write lock

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CREWLock

public CREWLock()

creates and initialises a new CREW lock

Method Detail

claim_read

public void claim_read()

claim a read lock

release_read

public void release_read()

release a read lock

claim_write

public void claim_write()

claim the write lock

release_write

public void release_write()

release the write lock