[Solved] You want to safely update a shared hash from multiple threads in Ruby.... shared_hash = {} mutex = Mutex.new threads = 5.times.map do |i| Thread.new do 10.times do |j| # What goes here? | Ruby

Ruby - Concurrent Programming

You want to safely update a shared hash from multiple threads in Ruby. Which approach correctly uses Mutex to avoid race conditions?

shared_hash = {}
mutex = Mutex.new
threads = 5.times.map do |i|
  Thread.new do
    10.times do |j|
      # What goes here?
    end
  end
end
threads.each(&:join)
puts shared_hash.size

Amutex.synchronize { shared_hash[i * 10 + j] = "value" }

Bshared_hash[i * 10 + j] = "value"

Cmutex.lock; shared_hash[i * 10 + j] = "value";

DThread.pass; shared_hash[i * 10 + j] = "value"

Step-by-Step Solution

Solution:

Step 1: Understand thread safety for shared hash
Multiple threads writing to shared_hash need protection to avoid data corruption.
Step 2: Use mutex.synchronize for safe updates
mutex.synchronize { shared_hash[i * 10 + j] = "value" } wraps the update inside mutex.synchronize, ensuring only one thread writes at a time.
Final Answer:
mutex.synchronize { shared_hash[i * 10 + j] = "value" } -> Option A
Quick Check:
Use synchronize block to protect shared hash updates [OK]

Quick Trick: Wrap shared data updates inside mutex.synchronize { } [OK]

Common Mistakes:

Updating shared hash without mutex
Locking mutex without unlocking
Using Thread.pass instead of mutex

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More Ruby Quizzes

You want to safely update a shared hash from multiple threads in Ruby. Which approach correctly uses Mutex to avoid race conditions?

Step 1: Understand thread safety for shared hash

Step 2: Use mutex.synchronize for safe updates

Final Answer:

Quick Check:

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