How hashCode() method in Object class is implemented?
hashcode, java, object
Solution
It's implemented in the native code. As for implementation, it's a bit more tricky - you can alter default implementation. If you look at the "Open JDK" sources you will see the following options:
-XX:hashCode=n (from 0 to 5).
- 0 – Park-Miller RNG (default)
- 1 – function of address and some global state
- 2 – const 1
- 3 – sequenatial counter
- 4 – address of an object
- 5 – thread specific xor-shift
You can find a detailed implmenetation here: http://hg.openjdk.java.net/jdk7/jdk7/hotspot/file/tip/src/share/vm/runtime/synchronizer.cpp
Consider source code and comments of `static inline intptr_t get_next_hash()` function.
Problem
Possible Duplicate: What’s the implementation of hashCode in java Object? While I was browsing through the Object class, I found that there is only a declaration of the hashCode() method. Where is the implementation part? If there is no implementation how does the hashCode() method return me a result?