where it went wrong?

Nothing went wrong.

  1. Your first thread started, locked the variable, slept for 3 seconds, printed its value, got to the end of the block, where the lock was implicitly removed, and then the thread dies.
  2. Your second thread started, checked the value was 'default' -- which it must be -- incremented the count, modifed the variable, tested it for 'default' again -- which it couldn't possibly be -- and exits both the loop and thread.

The only thing that might have stopped the second thread from modifying the variable, is if that second thread had attempted to acquire the lock. Which would have blocked until the first thread completed its sleep and exited its block thus releasing the lock.

Either way, count will only ever be incremented once.

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority". I knew I was on the right track :)
In the absence of evidence, opinion is indistinguishable from prejudice.

In reply to Re: threads::shared: lock a VARIABLE by BrowserUk
in thread threads::shared: lock a VARIABLE by freakcoco

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