java - Interleaving two threads such that one of the thread gets null when called putIfAbsent of concurrentHashMap -

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can explain interleaving of 2 threads such 1 of thread gets null when 2 threads call putifabsent of concurrenthashmap in java?

from javadoc of putifabsent:

returns:
previous value associated specified key, or null if there no mapping key.

so first thread attempting put value in map have null returned it.


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