[Solved] Identify the problem in this Ruby code using Mutex and how to fix it: require 'thread' mutex = Mutex.new counter = 0 threads = 2.times.map do Thread.new do mutex.lock counter += 1 end end threads.... | Ruby

Ruby - Concurrent Programming

Identify the problem in this Ruby code using Mutex and how to fix it:

require 'thread'
mutex = Mutex.new
counter = 0
threads = 2.times.map do
  Thread.new do
    mutex.lock
    counter += 1
  end
end
threads.each(&:join)
puts counter

AThreads are not joined properly; fix by joining inside the thread block

BMutex is not needed here; remove mutex.lock

Ccounter should be initialized inside the thread

DMissing mutex.unlock causes deadlock; fix by adding mutex.unlock after increment

Step-by-Step Solution

Solution:

Step 1: Check mutex usage
Mutex is locked but never unlocked, causing threads to wait forever (deadlock).
Step 2: Fix by unlocking mutex
After increment, call mutex.unlock or better use mutex.synchronize to auto-handle locking/unlocking.
Final Answer:
Missing mutex.unlock causes deadlock; fix by adding mutex.unlock after increment -> Option D
Quick Check:
Always unlock mutex after lock to avoid deadlock [OK]

Quick Trick: Always unlock mutex or use synchronize block [OK]

Common Mistakes:

Forgetting to unlock mutex
Removing mutex when needed
Initializing shared data inside threads incorrectly

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More Ruby Quizzes

Identify the problem in this Ruby code using Mutex and how to fix it:

Step 1: Check mutex usage

Step 2: Fix by unlocking mutex

Final Answer:

Quick Check:

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