Threads accessing a program

[sreenath reddy]

Hi

I have a question which needs some expert advise . I have a class which looks like this

class A
{

public int i = 0;

public int read()
{
return i;
}

public void write()
{
i++;
}
}

This program needs to be modified in a such a way that

1. Two threads should be able to read the value of i
2. Two threads should not be able to write at a time
3. Read should not be allowed when write is happening because of some thread

Can any one let me know the best way of doing this ??

[Henry Wong]

This is hardly an advanced topic. In fact, it seems more like a homework questions. Anyway, the Sun tutorial on synchronization should be a good point for you to start.

Henry

[Roy Ben Ami]

Hi there,

I am no expert by if you are using JDK 1.5 there is an easy way of doing that.

Take a look at the ReentranteadWriteLock class and the ReadWriteLock interface.

Using the methods there you can easily implement your criteria.

[Ernest Friedman-Hill]

Moving to "Threads and Synchronization."

[sreenath reddy]

Hi HenryWong

Looks like you are confused and i don't think that is as simple as You think ... It will take some 50 lines if you want to implement that using JDK 1.4 , but JDK 1.5 has introduced ReadWriteLock class to implement this ....