zio.Executor.scala Maven / Gradle / Ivy
/*
* Copyright 2017-2024 John A. De Goes and the ZIO Contributors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package zio
import zio.internal.{DefaultExecutors, ExecutionMetrics}
import zio.stacktracer.TracingImplicits.disableAutoTrace
import java.util.concurrent._
import scala.concurrent.ExecutionContext
/**
* An executor is responsible for executing actions. Each action is guaranteed
* to begin execution on a fresh stack frame.
*/
abstract class Executor extends ExecutorPlatformSpecific { self =>
/**
* Current sampled execution metrics, if available.
*/
def metrics(implicit unsafe: Unsafe): Option[ExecutionMetrics]
/**
* Submits an effect for execution.
*/
def submit(runnable: Runnable)(implicit unsafe: Unsafe): Boolean
/**
* Views this `Executor` as a Scala `ExecutionContext`.
*/
lazy val asExecutionContext: ExecutionContext =
new ExecutionContext {
override def execute(r: Runnable): Unit =
if (!submit(r)(Unsafe.unsafe)) throw new RejectedExecutionException("Rejected: " + r.toString)
override def reportFailure(cause: Throwable): Unit =
cause.printStackTrace
}
/**
* Views this `Executor` as a Java `Executor`.
*/
lazy val asJava: java.util.concurrent.Executor =
command =>
if (submit(command)(Unsafe.unsafe)) ()
else throw new java.util.concurrent.RejectedExecutionException
/**
* Submits an effect for execution and signals that the current fiber is ready
* to yield.
*
* '''NOTE''': The implementation of this method in the ZScheduler will
* attempt to run the runnable on the current thread if the current worker's
* queues are empty. This leads to improved performance as we avoid
* unnecessary parking/un-parking of threads.
*/
def submitAndYield(runnable: Runnable)(implicit unsafe: Unsafe): Boolean =
submit(runnable)
/**
* Submits an effect for execution and signals that the current fiber is ready
* to yield or throws.
*
* @see
* [[submitAndYield]] for an explanation of the implementation in
* ZScheduler.
*/
final def submitAndYieldOrThrow(runnable: Runnable)(implicit unsafe: Unsafe): Unit =
if (!submitAndYield(runnable)) throw new RejectedExecutionException(s"Unable to run ${runnable.toString()}")
/**
* Submits an effect for execution or throws.
*/
final def submitOrThrow(runnable: Runnable)(implicit unsafe: Unsafe): Unit =
if (!submit(runnable)) throw new RejectedExecutionException(s"Unable to run ${runnable.toString()}")
private[zio] def stealWork(depth: Int): Boolean =
false
}
object Executor extends DefaultExecutors with Serializable {
def fromJavaExecutor(executor: java.util.concurrent.Executor): Executor =
new Executor {
override def metrics(implicit unsafe: Unsafe): Option[ExecutionMetrics] = None
override def submit(runnable: Runnable)(implicit unsafe: Unsafe): Boolean =
try {
executor.execute(runnable)
true
} catch {
case t: RejectedExecutionException => false
}
}
/**
* Creates an `Executor` from a Scala `ExecutionContext`.
*/
def fromExecutionContext(ec: ExecutionContext): Executor =
new Executor {
def submit(runnable: Runnable)(implicit unsafe: Unsafe): Boolean =
try {
ec.execute(runnable)
true
} catch {
case _: RejectedExecutionException => false
}
def metrics(implicit unsafe: Unsafe) = None
}
}