Class: Concurrent::ThreadPoolExecutor

Inherits:
ThreadPoolExecutorImplementation
  • Object
show all
Defined in:
lib/concurrent/executor/thread_pool_executor.rb

Overview

Note:

Failure to properly shutdown a thread pool can lead to unpredictable results. Please read *Shutting Down Thread Pools* for more information.

An abstraction composed of one or more threads and a task queue. Tasks (blocks or ‘proc` objects) are submitted to the pool and added to the queue. The threads in the pool remove the tasks and execute them in the order they were received.

A ‘ThreadPoolExecutor` will automatically adjust the pool size according to the bounds set by `min-threads` and `max-threads`. When a new task is submitted and fewer than `min-threads` threads are running, a new thread is created to handle the request, even if other worker threads are idle. If there are more than `min-threads` but less than `max-threads` threads running, a new thread will be created only if the queue is full.

Threads that are idle for too long will be garbage collected, down to the configured minimum options. Should a thread crash it, too, will be garbage collected.

‘ThreadPoolExecutor` is based on the Java class of the same name. From the official Java documentation;

> Thread pools address two different problems: they usually provide > improved performance when executing large numbers of asynchronous tasks, > due to reduced per-task invocation overhead, and they provide a means > of bounding and managing the resources, including threads, consumed > when executing a collection of tasks. Each ThreadPoolExecutor also > maintains some basic statistics, such as the number of completed tasks. > > To be useful across a wide range of contexts, this class provides many > adjustable parameters and extensibility hooks. However, programmers are > urged to use the more convenient Executors factory methods > [CachedThreadPool] (unbounded thread pool, with automatic thread reclamation), > [FixedThreadPool] (fixed size thread pool) and [SingleThreadExecutor] (single > background thread), that preconfigure settings for the most common usage > scenarios.

**Thread Pool Options**

Thread pools support several configuration options:

  • ‘idletime`: The number of seconds that a thread may be idle before being reclaimed.

  • ‘max_queue`: The maximum number of tasks that may be waiting in the work queue at any one time. When the queue size reaches `max_queue` and no new threads can be created, subsequent tasks will be rejected in accordance with the configured `fallback_policy`.

  • ‘auto_terminate`: When true (default) an `at_exit` handler will be registered which will stop the thread pool when the application exits. See below for more information on shutting down thread pools.

  • ‘fallback_policy`: The policy defining how rejected tasks are handled.

Three fallback policies are supported:

  • ‘:abort`: Raise a `RejectedExecutionError` exception and discard the task.

  • ‘:discard`: Discard the task and return false.

  • ‘:caller_runs`: Execute the task on the calling thread.

**Shutting Down Thread Pools**

Killing a thread pool while tasks are still being processed, either by calling the ‘#kill` method or at application exit, will have unpredictable results. There is no way for the thread pool to know what resources are being used by the in-progress tasks. When those tasks are killed the impact on those resources cannot be predicted. The best practice is to explicitly shutdown all thread pools using the provided methods:

  • Call ‘#shutdown` to initiate an orderly termination of all in-progress tasks

  • Call ‘#wait_for_termination` with an appropriate timeout interval an allow the orderly shutdown to complete

  • Call ‘#kill` *only when* the thread pool fails to shutdown in the allotted time

On some runtime platforms (most notably the JVM) the application will not exit until all thread pools have been shutdown. To prevent applications from “hanging” on exit all thread pools include an ‘at_exit` handler that will stop the thread pool when the application exits. This handler uses a brute force method to stop the pool and makes no guarantees regarding resources being used by any tasks still running. Registration of this `at_exit` handler can be prevented by setting the thread pool’s constructor ‘:auto_terminate` option to `false` when the thread pool is created. All thread pools support this option.

“‘ruby pool1 = Concurrent::FixedThreadPool.new(5) # an `at_exit` handler will be registered pool2 = Concurrent::FixedThreadPool.new(5, auto_terminate: false) # prevent `at_exit` handler registration “`

See Also:

Direct Known Subclasses

CachedThreadPool, FixedThreadPool

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#completed_task_count ⇒ Integer (readonly)

The number of tasks that have been completed by the pool since construction.

Returns:

  • (Integer) —

    The number of tasks that have been completed by the pool since construction.



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#fallback_policy ⇒ Symbol (readonly)

Returns The fallback policy in effect. Either ‘:abort`, `:discard`, or `:caller_runs`.

Returns:

  • (Symbol) —

    The fallback policy in effect. Either ‘:abort`, `:discard`, or `:caller_runs`.



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#idletime ⇒ Integer (readonly)

The number of seconds that a thread may be idle before being reclaimed.

Returns:

  • (Integer) —

    The number of seconds that a thread may be idle before being reclaimed.



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#largest_length ⇒ Integer (readonly)

The largest number of threads that have been created in the pool since construction.

Returns:

  • (Integer) —

    The largest number of threads that have been created in the pool since construction.



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#length ⇒ Integer (readonly)

The number of threads currently in the pool.

Returns:

  • (Integer) —

    The number of threads currently in the pool.



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#max_length ⇒ Integer (readonly)

The maximum number of threads that may be created in the pool.

Returns:

  • (Integer) —

    The maximum number of threads that may be created in the pool.



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#max_queue ⇒ Integer (readonly)

The maximum number of tasks that may be waiting in the work queue at any one time. When the queue size reaches ‘max_queue` subsequent tasks will be rejected in accordance with the configured `fallback_policy`.

Returns:

  • (Integer) —

    The maximum number of tasks that may be waiting in the work queue at any one time. When the queue size reaches ‘max_queue` subsequent tasks will be rejected in accordance with the configured `fallback_policy`.



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#min_length ⇒ Integer (readonly)

The minimum number of threads that may be retained in the pool.

Returns:

  • (Integer) —

    The minimum number of threads that may be retained in the pool.



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#queue_length ⇒ Integer (readonly)

The number of tasks in the queue awaiting execution.

Returns:

  • (Integer) —

    The number of tasks in the queue awaiting execution.



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#remaining_capacity ⇒ Integer (readonly)

Number of tasks that may be enqueued before reaching ‘max_queue` and rejecting new tasks. A value of -1 indicates that the queue may grow without bound.

Returns:

  • (Integer) —

    Number of tasks that may be enqueued before reaching ‘max_queue` and rejecting new tasks. A value of -1 indicates that the queue may grow without bound.



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#scheduled_task_count ⇒ Integer (readonly)

The number of tasks that have been scheduled for execution on the pool since construction.

Returns:

  • (Integer) —

    The number of tasks that have been scheduled for execution on the pool since construction.



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

Instance Method Details

#<<(task) ⇒ self

Submit a task to the executor for asynchronous processing.

Parameters:

  • task (Proc) —

    the asynchronous task to perform

Returns:

  • (self) —

    returns itself



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#auto_terminate=(value) ⇒ Boolean

Set the auto-terminate behavior for this executor.

Parameters:

  • value (Boolean) —

    The new auto-terminate value to set for this executor.

Returns:

  • (Boolean) —

    ‘true` when auto-termination is enabled else `false`.



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#auto_terminate? ⇒ Boolean

Is the executor auto-terminate when the application exits?

Returns:

  • (Boolean) —

    ‘true` when auto-termination is enabled else `false`.



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#can_overflow? ⇒ Boolean

Does the task queue have a maximum size?

Returns:

  • (Boolean) —

    True if the task queue has a maximum size else false.



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#kill ⇒ Object

Begin an immediate shutdown. In-progress tasks will be allowed to complete but enqueued tasks will be dismissed and no new tasks will be accepted. Has no additional effect if the thread pool is not running.



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#post(*args) { ... } ⇒ Boolean

Submit a task to the executor for asynchronous processing.

Parameters:

  • args (Array) —

    zero or more arguments to be passed to the task

Yields:

  • the asynchronous task to perform

Returns:

  • (Boolean) —

    ‘true` if the task is queued, `false` if the executor is not running

Raises:

  • (ArgumentError) —

    if no task is given



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#running? ⇒ Boolean

Is the executor running?

Returns:

  • (Boolean) —

    ‘true` when running, `false` when shutting down or shutdown



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#serialized? ⇒ Boolean

Does this executor guarantee serialization of its operations?

Returns:

  • (Boolean) —

    True if the executor guarantees that all operations will be post in the order they are received and no two operations may occur simultaneously. Else false.



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#shutdown ⇒ Object

Begin an orderly shutdown. Tasks already in the queue will be executed, but no new tasks will be accepted. Has no additional effect if the thread pool is not running.



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#shutdown? ⇒ Boolean

Is the executor shutdown?

Returns:

  • (Boolean) —

    ‘true` when shutdown, `false` when shutting down or running



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#shuttingdown? ⇒ Boolean

Is the executor shuttingdown?

Returns:

  • (Boolean) —

    ‘true` when not running and not shutdown, else `false`



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end

#wait_for_termination(timeout = nil) ⇒ Boolean

Note:

Does not initiate shutdown or termination. Either ‘shutdown` or `kill` must be called before this method (or on another thread).

Block until executor shutdown is complete or until ‘timeout` seconds have passed.

Parameters:

  • timeout (Integer) (defaults to: nil) —

    the maximum number of seconds to wait for shutdown to complete

Returns:

  • (Boolean) —

    ‘true` if shutdown complete or false on `timeout`



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# File 'lib/concurrent/executor/thread_pool_executor.rb', line 56

class ThreadPoolExecutor < ThreadPoolExecutorImplementation

  # @!macro [new] thread_pool_executor_method_initialize
  #
  #   Create a new thread pool.
  #  
  #   @param [Hash] opts the options which configure the thread pool.
  #  
  #   @option opts [Integer] :max_threads (DEFAULT_MAX_POOL_SIZE) the maximum
  #     number of threads to be created
  #   @option opts [Integer] :min_threads (DEFAULT_MIN_POOL_SIZE) When a new task is submitted
  #      and fewer than `min_threads` are running, a new thread is created
  #   @option opts [Integer] :idletime (DEFAULT_THREAD_IDLETIMEOUT) the maximum
  #     number of seconds a thread may be idle before being reclaimed
  #   @option opts [Integer] :max_queue (DEFAULT_MAX_QUEUE_SIZE) the maximum
  #     number of tasks allowed in the work queue at any one time; a value of
  #     zero means the queue may grow without bound
  #   @option opts [Symbol] :fallback_policy (:abort) the policy for handling new
  #     tasks that are received when the queue size has reached
  #     `max_queue` or the executor has shut down
  #  
  #   @raise [ArgumentError] if `:max_threads` is less than one
  #   @raise [ArgumentError] if `:min_threads` is less than zero
  #   @raise [ArgumentError] if `:fallback_policy` is not one of the values specified
  #     in `FALLBACK_POLICIES`
  #  
  #   @see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ThreadPoolExecutor.html

  # @!method initialize(opts = {})
  #   @!macro thread_pool_executor_method_initialize
end