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== Task module == The `Task` module in Elixir provides a reliable and efficient way to spawn and manage parallel computations. It offers a simple and intuitive interface for working with concurrent tasks, making it easy to build robust and scalable applications. === Creating a Task === To create a task, you can use the `Task.start/1` function, which takes a single argument representing the computation to be performed. The computation should be defined as a function that takes no arguments and returns a value. ```elixir task = Task.start(fn -> 1 + 2 end) ``` The `Task.start/2` function can also be used if you need to specify additional options for the task, such as the name or the priority. === Spawning Multiple Tasks === Elixir provides a convenient way to spawn multiple tasks simultaneously using the `Task.async/1` function. It takes a list of functions and returns a list of corresponding tasks. ```elixir tasks = Task.async([fn -> 1 + 2 end, fn -> 3 * 4 end, fn -> 5 - 6 end]) ``` === Handling Task Results === Once a task is spawned, you can wait for its completion and retrieve the result using the `Task.await/2` function. It takes the task and an optional timeout value in milliseconds. ```elixir result = Task.await(task) ``` By default, if the task fails with an exception, the `Task.await/2` function also raises that exception. To handle failures gracefully, you can use the `Task.await/3` function, which takes an additional argument representing the default value to return in case of failure. ```elixir result = Task.await(task, :default) ``` === Monitoring Tasks === Elixir allows you to monitor tasks for failures or normal termination using the `Task.monitor/1` function. It takes a task as an argument and returns a reference to the monitoring process. ```elixir ref = Task.monitor(task) ``` You can then receive messages about the task's state using the `Process.info/2` function. === Supervising Tasks === In addition to monitoring, Elixir provides a supervision mechanism for managing tasks using the `Task.Supervisor` module. A task supervisor is used to monitor and restart tasks in case of failure. ```elixir children = [ {Task, fn -> long_running_task() end, name: :my_task} ] supervisor = Task.Supervisor.start_link(children, strategy: :one_for_one) ``` The `Task.Supervisor.start_link/2` function takes a list of child specifications and a strategy for managing the tasks. The `:one_for_one` strategy restarts only the failed task, while the `:one_for_all` strategy restarts all tasks under the supervisor. === Conclusion === The `Task` module in Elixir is a powerful tool for concurrent programming, allowing developers to easily spawn and manage parallel computations. By leveraging tasks, it becomes straightforward to build performant and fault-tolerant applications. Take advantage of this module to make your Elixir code more efficient and scalable. == See Also == * [[Concurrency]] * [[Processes]] * [[Supervisor]] * [[Agent module]] == Task Module == [[File:Elixir-logo.svg|thumb|right|150px|Elixir Programming Language]] The '''Task module''' is a core component of the [[Elixir (programming language)|Elixir programming language]]. It provides a simple and powerful way to run concurrent tasks asynchronously. == Overview == The Task module allows developers to spawn tasks that can run concurrently with other parts of their code. These tasks can be used to perform various operations, such as making HTTP requests, reading and writing files, or performing computationally intensive operations. The module includes functions for starting tasks, waiting for their results, and performing error handling. By utilizing the Task module, developers can take advantage of concurrency and parallelism to improve the performance and responsiveness of their applications. == Key Features == The Task module offers several key features, including: === Spawning Tasks === The Task module provides the `Task.start/1` function to spawn new tasks. This allows developers to initiate concurrent operations without blocking the execution of other parts of their code. === Task Supervision === Tasks spawned using the Task module can be supervised, ensuring fault-tolerance and recovery. If a task terminates abnormally, the supervisor can take appropriate actions, such as restarting the task or cleaning up resources. === Asynchronous Execution === Tasks created with the Task module execute asynchronously, allowing other tasks or processes to proceed independently. This enables efficient use of resources and ensures that a single long-running task does not block the overall system. === Error Handling === The Task module provides error handling mechanisms, allowing developers to handle exceptions that occur within tasks. This helps in building robust and resilient applications. === Task Waiting === Developers can use the `Task.await/2` function to wait for the results of a task. This ensures that the execution of specific parts of the code waits until the task completes and returns a value. === Concurrent Programming === The Task module supports concurrent programming paradigms, allowing developers to leverage parallelism and distribute work across multiple cores or nodes within a network. == Usage Examples == Here are a few examples demonstrating the usage of the Task module: === Example 1 === Run a computationally intensive task in the background while executing other code: ```elixir task = Task.start(fn -> 1 + 2 end) # ... code execution continues here ... result = Task.await(task) IO.puts("Result: #{result}") ``` === Example 2 === Perform multiple HTTP requests concurrently: ```elixir urls = ["https://example.com", "https://elixir-lang.org", "https://google.com"] tasks = for url <- urls, do: Task.start(fn -> HTTP.get(url) end) results = Enum.map(tasks, &Task.await/1) IO.inspect(results) ``` == See Also == * [[Concurrency in Elixir]] * [[Supervisor Module]] * [[Parallel Programming in Elixir]] == References == {{Reflist}} [[Category:Elixir]] [[Category:Concurrency]] [[Category:Asynchronous Programming]] [[Category:Programming Languages]] [[Category:Functional Programming]] [[Category:Concurrent Computing]] [[Category:Software Development]]
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