Apologize if it's a too basic questoin
I have a class A with two synchronized methods 1 and 2.
Now class B access Class A's method 1
Class C access Class A's method 2
In this case, whether this two threads can have access on Class A object
Thanks in advance
http://www.cs.brown.edu/courses/cs015/ref/javarefguide/synchronized.html
The object instance can be accessed by only one thread at a time.
> The object instance can be accessed by only one
> thread at a time.
Incorrect.
Synchronization does not prevent "accessing an instance." It prevents obtaining a lock.
> Apologize if it's a too basic questoin
>
> I have a class A with two synchronized methods 1 and
> 2.
>
> Now class B access Class A's method 1
> Class C access Class A's method 2
>
> In this case, whether this two threads can have
> access on Class A object
>
If both B and C are trying to call methods on the same instance of A, then while B is executing method 1, C will be blocked from entering method 2.
> > The object instance can be accessed by only one
> > thread at a time.
>
> Incorrect.
>
> Synchronization does not prevent "accessing an
> instance." It prevents obtaining a lock.
Incorrect.
Synchronization does not prevents obtaining a lock instead it delays obtaining a lock (in the end the method will get the lock ... by preventing something it means it will never occur http://www.fhch.org/ncv/dic/prevent.html). I can admit my formulation was flawed, but so is yours.
> > > The object instance can be accessed by only one
> > > thread at a time.
> >
> > Incorrect.
> >
> > Synchronization does not prevent "accessing an
> > instance." It prevents obtaining a lock.
>
> Incorrect.
>
> Synchronization does not prevents obtaining a lock
> instead it delays obtaining a lock (in the end the
> method will get the lock ... by preventing something
Yes, delay is more accurate than prevent. However "prevent obtaining a lock" is still more accurate than what you originally stated.
> it means it will never occur
I disagree.
http://mw1.merriam-webster.com/dictionary/prevent
3: to keep from happening or existing <steps to prevent war>
4: to hold or keep back : hinder, stop often used with from
intransitive verb
: to interpose an obstacle
Nothing there implies "never".
> http://www.fhch.org/ncv/dic/prevent.html).
verb: keep from happening or arising
Doesn't necessarily mean never.
> I can
> admit my formulation was flawed, but so is yours.
You had the mechanics wrong. I merely wasn't as precise as I should've been. "Temporarily prevent" would have been better, but "prevent" isn't wrong, just unclear.