Queue

Defining a Queue

• A queue is used for threaded programming

• There are three types of queues:

  • A FIFO queue
  • A LIFO queue
  • A priority queue
• A priority queue ensures entries are kept sorted
• Specifically, the lowest-valued entry is retrieved first
• Internally, these queues use locks to temporarily block competing threads

• Specifically, the get() and put() functions are thread-safe

  • Or, these functions are free of race conditions
• However, they are still exposed to experiencing deadlocks

Differentiating between Queue and deque

• Queue.Queue and collections.deque serve different purposes
• Queue.Queue is used for communicating between threads
• collections.queue is used as a data structure only
• In other words, a queue should be used for multithreaded programming
• A deque can be used for singlethreaded programming

References

• Queue Documentation from the Python Standard Library
• Examples of Queue
• Benefits of Queue
• The Internal Locking of the Queue