volatile Vs synchronized

[Kapil Madhok]

Hi,

Can someone please explain me the difference or advantage/disadvantage of using the volatile & synchronized key words?

Thnx,
Kapil

[kri shan]

if the variable is volatile, then it's not possible to serialize

[Henry Wong]

If you just want to do a simple operation like set a flag, (done = true) or check a flag, (if (done != true) { blah } ), there is really little reason to synchronize in order to be thread safe. You can just declare the variable as volatile and avoid synchronization all-together.

Prior to JDK 1.5, this was probably the only useful case. With 1.5 and later, you have atomic variables, which are build using volatile variable. With atomic variables, you can -- in theory -- avoid synchronization all-together.

Henry

[Jim Yingst]

[kri shan]: if the variable is volatile, then it's not possible to serialize

I believe you're thinking of transient, not volatile.

[Ben Hur]

This is a good article about using volatile & synchronised.