Class: Concurrent::JavaFixedThreadPool

Inherits:

JavaThreadPoolExecutor

• Object
• JavaThreadPoolExecutor
• Concurrent::JavaFixedThreadPool

Defined in:

lib/concurrent/executor/java_fixed_thread_pool.rb

Overview

Note:

When running on the JVM (JRuby) this class will inherit from ‘JavaFixedThreadPool`. On all other platforms it will inherit from `RubyFixedThreadPool`.

A thread pool with a set number of threads. The number of threads in the pool is set on construction and remains constant. When all threads are busy new tasks ‘#post` to the thread pool are enqueued until a thread becomes available. Should a thread crash for any reason the thread will immediately be removed from the pool and replaced.

The API and behavior of this class are based on Java’s ‘FixedThreadPool`

See Also:

• RubyFixedThreadPool
• JavaFixedThreadPool
• http://docs.oracle.com/javase/tutorial/essential/concurrency/pools.html
• http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/Executors.html
• http://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ExecutorService.html

Constant Summary

Constants inherited from JavaThreadPoolExecutor

Concurrent::JavaThreadPoolExecutor::DEFAULT_MAX_POOL_SIZE, Concurrent::JavaThreadPoolExecutor::DEFAULT_MAX_QUEUE_SIZE, Concurrent::JavaThreadPoolExecutor::DEFAULT_MIN_POOL_SIZE, Concurrent::JavaThreadPoolExecutor::DEFAULT_THREAD_IDLETIMEOUT, Concurrent::JavaThreadPoolExecutor::OVERFLOW_POLICIES

Instance Attribute Summary

Attributes inherited from JavaThreadPoolExecutor

#max_length, #max_queue, #overflow_policy

Instance Method Summary

• #initialize(num_threads, opts = {}) ⇒ JavaFixedThreadPool constructor

  Create a new thread pool.

Methods inherited from JavaThreadPoolExecutor

#can_overflow?, #completed_task_count, #idletime, #largest_length, #length, #min_length, #queue_length, #remaining_capacity, #running?, #scheduled_task_count, #shutdown, #status

Methods included from JavaExecutor

#<<, #kill, #post, #running?, #shutdown, #shutdown?, #shuttingdown?, #wait_for_termination

Methods included from Executor

#can_overflow?

Constructor Details

#initialize(num_threads, opts = {}) ⇒ JavaFixedThreadPool

Create a new thread pool.

Parameters:

• opts (Hash) (defaults to: {}) —

  the options defining pool behavior.

Options Hash (opts):

• :overflow_policy (Symbol) — default: `:abort` —

  the overflow policy

Raises:

• (ArgumentError) —

  if ‘num_threads` is less than or equal to zero

• (ArgumentError) —

  if ‘overflow_policy` is not a known policy

See Also:

• http://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Executors.html#newFixedThreadPool-int-

# File 'lib/concurrent/executor/java_fixed_thread_pool.rb', line 19

def initialize(num_threads, opts = {})
  @overflow_policy = opts.fetch(:overflow_policy, :abort)
  @max_queue = 0

  raise ArgumentError.new('number of threads must be greater than zero') if num_threads < 1
  raise ArgumentError.new("#{@overflow_policy} is not a valid overflow policy") unless OVERFLOW_POLICIES.keys.include?(@overflow_policy)

  @executor = java.util.concurrent.Executors.newFixedThreadPool(num_threads)
  @executor.setRejectedExecutionHandler(OVERFLOW_POLICIES[@overflow_policy].new)

  set_shutdown_hook
end