Implement IORuntimeMetrics

build.sbt

@@ -668,7 +668,15 @@ lazy val core = crossProject(JSPlatform, JVMPlatform, NativePlatform)
       ProblemFilters.exclude[ReversedMissingMethodProblem]("cats.effect.IOLocal.reset"),
       ProblemFilters.exclude[ReversedMissingMethodProblem]("cats.effect.IOLocal.lens"),
       // this filter is particulary terrible, because it can also mask real issues :(
-      ProblemFilters.exclude[DirectMissingMethodProblem]("cats.effect.IOLocal.lens")
+      ProblemFilters.exclude[DirectMissingMethodProblem]("cats.effect.IOLocal.lens"),
+      // internal API change, makes CpuStarvationMetrics available on all platforms
+      ProblemFilters.exclude[MissingClassProblem](
+        "cats.effect.metrics.JvmCpuStarvationMetrics$NoOpCpuStarvationMetrics"),
+      ProblemFilters.exclude[MissingClassProblem]("cats.effect.metrics.CpuStarvationMetrics"),
+      // package-private classes moved to the `cats.effect.unsafe.metrics` package
+      ProblemFilters.exclude[MissingClassProblem]("cats.effect.metrics.CpuStarvation"),
+      ProblemFilters.exclude[MissingClassProblem]("cats.effect.metrics.CpuStarvation$"),
+      ProblemFilters.exclude[MissingClassProblem]("cats.effect.metrics.CpuStarvationMBean")
     ) ++ {
       if (tlIsScala3.value) {
         // Scala 3 specific exclusions
@@ -835,7 +843,12 @@ lazy val core = crossProject(JSPlatform, JVMPlatform, NativePlatform)
         ProblemFilters.exclude[Problem]("cats.effect.CallbackStackOps.*"),
         // introduced by #3695, which ported fiber monitoring to Native
         // internal API change
-        ProblemFilters.exclude[MissingClassProblem]("cats.effect.unsafe.ES2021FiberMonitor")
+        ProblemFilters.exclude[MissingClassProblem]("cats.effect.unsafe.ES2021FiberMonitor"),
+        // internal API change, makes CpuStarvationMetrics available on all platforms
+        ProblemFilters.exclude[MissingClassProblem](
+          "cats.effect.metrics.JsCpuStarvationMetrics"),
+        ProblemFilters.exclude[MissingClassProblem](
+          "cats.effect.metrics.JsCpuStarvationMetrics$")
       )
     },
     mimaBinaryIssueFilters ++= {
@@ -870,7 +883,12 @@ lazy val core = crossProject(JSPlatform, JVMPlatform, NativePlatform)
       ProblemFilters.exclude[MissingClassProblem](
         "cats.effect.unsafe.PollingExecutorScheduler$SleepTask"),
       ProblemFilters.exclude[MissingClassProblem]("cats.effect.unsafe.QueueExecutorScheduler"),
-      ProblemFilters.exclude[MissingClassProblem]("cats.effect.unsafe.QueueExecutorScheduler$")
+      ProblemFilters.exclude[MissingClassProblem]("cats.effect.unsafe.QueueExecutorScheduler$"),
+      // internal API change, makes CpuStarvationMetrics available on all platforms
+      ProblemFilters.exclude[MissingClassProblem](
+        "cats.effect.metrics.NativeCpuStarvationMetrics"),
+      ProblemFilters.exclude[MissingClassProblem](
+        "cats.effect.metrics.NativeCpuStarvationMetrics$")
     )
   )
 

core/js-native/src/main/scala/cats/effect/unsafe/metrics/IORuntimeMetricsCompanionPlatform.scala

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2020-2024 Typelevel
+ *
+ * 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 cats.effect.unsafe.metrics
+
+import scala.concurrent.ExecutionContext
+
+private[metrics] abstract class IORuntimeMetricsCompanionPlatform {
+  this: IORuntimeMetrics.type =>
+
+  private[unsafe] def apply(ec: ExecutionContext): IORuntimeMetrics = {
+    val _ = ec
+    new IORuntimeMetrics {
+      private[effect] val cpuStarvationSampler: CpuStarvationSampler =
+        CpuStarvationSampler()
+
+      val cpuStarvation: CpuStarvationMetrics =
+        CpuStarvationMetrics(cpuStarvationSampler)
+    }
+  }
+
+}

core/shared/src/main/scala/cats/effect/metrics/CpuStarvationMetrics.scala → core/js-native/src/main/scala/cats/effect/unsafe/metrics/IORuntimeMetricsPlatform.scala

@@ -14,14 +14,6 @@
  * limitations under the License.
  */
 
-package cats.effect.metrics
+package cats.effect.unsafe.metrics
 
-import cats.effect.IO
-
-import scala.concurrent.duration.FiniteDuration
-
-private[effect] trait CpuStarvationMetrics {
-  def incCpuStarvationCount: IO[Unit]
-
-  def recordClockDrift(drift: FiniteDuration): IO[Unit]
-}
+private[metrics] trait IORuntimeMetricsPlatform { this: IORuntimeMetrics => }

core/js/src/main/scala/cats/effect/IOApp.scala

@@ -16,7 +16,7 @@
 
 package cats.effect
 
-import cats.effect.metrics.{CpuStarvationWarningMetrics, JsCpuStarvationMetrics}
+import cats.effect.metrics.CpuStarvationWarningMetrics
 import cats.effect.std.Console
 import cats.effect.tracing.TracingConstants._
 
@@ -260,7 +260,7 @@ trait IOApp {
     val fiber = Spawn[IO]
       .raceOutcome[ExitCode, Nothing](
         CpuStarvationCheck
-          .run(runtimeConfig, JsCpuStarvationMetrics(), onCpuStarvationWarn)
+          .run(runtimeConfig, runtime.metrics.cpuStarvationSampler, onCpuStarvationWarn)
           .background
           .surround(run(argList)),
         keepAlive)

core/jvm/src/main/scala/cats/effect/IOApp.scala

@@ -451,10 +451,10 @@ trait IOApp {
     val queue = this.queue
 
     val fiber =
-      JvmCpuStarvationMetrics()
-        .flatMap { cpuStarvationMetrics =>
+      JvmCpuStarvationMetrics(runtime.metrics.cpuStarvationSampler)
+        .flatMap { _ =>
           CpuStarvationCheck
-            .run(runtimeConfig, cpuStarvationMetrics, onCpuStarvationWarn)
+            .run(runtimeConfig, runtime.metrics.cpuStarvationSampler, onCpuStarvationWarn)
             .background
         }
         .surround(ioa)

core/jvm/src/main/scala/cats/effect/metrics/JvmCpuStarvationMetrics.scala

@@ -18,23 +18,17 @@ package cats.effect.metrics
 
 import cats.effect.{IO, Resource}
 import cats.effect.std.Console
-
-import scala.concurrent.duration.FiniteDuration
+import cats.effect.unsafe.metrics.{CpuStarvation, CpuStarvationSampler}
+import cats.syntax.functor._
 
 import java.io.{PrintWriter, StringWriter}
 import java.lang.management.ManagementFactory
 
 import javax.management.{MBeanServer, ObjectName}
 
-private[effect] class JvmCpuStarvationMetrics private (mbean: CpuStarvation)
-    extends CpuStarvationMetrics {
-  override def incCpuStarvationCount: IO[Unit] = mbean.incStarvationCount
-
-  override def recordClockDrift(drift: FiniteDuration): IO[Unit] = mbean.recordDrift(drift)
-}
-
 private[effect] object JvmCpuStarvationMetrics {
-  private[this] val mBeanObjectName = new ObjectName("cats.effect.metrics:type=CpuStarvation")
+  private[this] val mBeanObjectName = new ObjectName(
+    "cats.effect.unsafe.metrics:type=CpuStarvation")
 
   private[this] def warning(th: Throwable) = {
     val exceptionWriter = new StringWriter()
@@ -46,28 +40,18 @@ private[effect] object JvmCpuStarvationMetrics {
        |""".stripMargin
   }
 
-  private[this] class NoOpCpuStarvationMetrics extends CpuStarvationMetrics {
-    override def incCpuStarvationCount: IO[Unit] = IO.unit
-
-    override def recordClockDrift(drift: FiniteDuration): IO[Unit] = IO.unit
-  }
-
-  private[effect] def apply(): Resource[IO, CpuStarvationMetrics] = {
-    val acquire: IO[(MBeanServer, JvmCpuStarvationMetrics)] = for {
+  private[effect] def apply(metrics: CpuStarvationSampler): Resource[IO, Unit] = {
+    val acquire: IO[MBeanServer] = for {
       mBeanServer <- IO.delay(ManagementFactory.getPlatformMBeanServer)
-      mBean <- CpuStarvation()
+      mBean <- IO.pure(new CpuStarvation(metrics))
       // To allow user-defined program to use the compute pool from the beginning,
       // here we use `IO.delay` rather than `IO.blocking`.
       _ <- IO.delay(mBeanServer.registerMBean(mBean, mBeanObjectName))
-    } yield (mBeanServer, new JvmCpuStarvationMetrics(mBean))
+    } yield mBeanServer
 
     Resource
-      .make(acquire) {
-        case (mbeanServer, _) => IO.blocking(mbeanServer.unregisterMBean(mBeanObjectName))
-      }
-      .map(_._2)
-      .handleErrorWith[CpuStarvationMetrics] { th =>
-        Resource.eval(Console[IO].errorln(warning(th))).map(_ => new NoOpCpuStarvationMetrics)
-      }
+      .make(acquire)(mbeanServer => IO.blocking(mbeanServer.unregisterMBean(mBeanObjectName)))
+      .void
+      .handleErrorWith[Unit](th => Resource.eval(Console[IO].errorln(warning(th))))
   }
 }

core/js/src/main/scala/cats/effect/metrics/JsCpuStarvationMetrics.scala → core/jvm/src/main/scala/cats/effect/unsafe/metrics/CpuStarvation.scala

@@ -14,18 +14,18 @@
  * limitations under the License.
  */
 
-package cats.effect.metrics
+package cats.effect.unsafe.metrics
 
-import cats.effect.IO
+private[effect] final class CpuStarvation(
+    sampler: CpuStarvationSampler
+) extends CpuStarvationMBean {
 
-import scala.concurrent.duration.FiniteDuration
+  def getCpuStarvationCount(): Long =
+    sampler.cpuStarvationCount()
 
-private[effect] class JsCpuStarvationMetrics extends CpuStarvationMetrics {
-  override def incCpuStarvationCount: IO[Unit] = IO.unit
+  def getMaxClockDriftMs(): Long =
+    sampler.clockDriftMaxMs()
 
-  override def recordClockDrift(drift: FiniteDuration): IO[Unit] = IO.unit
-}
-
-private[effect] object JsCpuStarvationMetrics {
-  private[effect] def apply(): CpuStarvationMetrics = new JsCpuStarvationMetrics
+  def getCurrentClockDriftMs(): Long =
+    sampler.clockDriftCurrentMs()
 }

core/jvm/src/main/scala/cats/effect/metrics/CpuStarvationMbean.scala → core/jvm/src/main/scala/cats/effect/unsafe/metrics/CpuStarvationMBean.scala

@@ -14,12 +14,12 @@
  * limitations under the License.
  */
 
-package cats.effect.metrics
+package cats.effect.unsafe.metrics
 
 /**
  * An MBean interfaces for monitoring when CPU starvation occurs.
  */
-private[metrics] trait CpuStarvationMBean {
+private[unsafe] trait CpuStarvationMBean {
 
   /**
    * Returns the number of times CPU starvation has occurred.

core/jvm/src/main/scala/cats/effect/unsafe/metrics/IORuntimeMetricsCompanionPlatform.scala

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2020-2024 Typelevel
+ *
+ * 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 cats.effect.unsafe.metrics
+
+import scala.concurrent.ExecutionContext
+
+private[metrics] abstract class IORuntimeMetricsCompanionPlatform {
+  this: IORuntimeMetrics.type =>
+
+  private[unsafe] def apply(ec: ExecutionContext): IORuntimeMetrics =
+    new IORuntimeMetrics {
+      private[effect] val cpuStarvationSampler: CpuStarvationSampler =
+        CpuStarvationSampler()
+
+      val cpuStarvation: CpuStarvationMetrics =
+        CpuStarvationMetrics(cpuStarvationSampler)
+
+      val workStealingThreadPool: Option[WorkStealingPoolMetrics] =
+        WorkStealingPoolMetrics(ec)
+    }
+
+}

core/native/src/main/scala/cats/effect/metrics/NativeCpuStarvationMetrics.scala → core/jvm/src/main/scala/cats/effect/unsafe/metrics/IORuntimeMetricsPlatform.scala

@@ -14,18 +14,18 @@
  * limitations under the License.
  */
 
-package cats.effect.metrics
+package cats.effect.unsafe.metrics
 
-import cats.effect.IO
+private[metrics] trait IORuntimeMetricsPlatform { this: IORuntimeMetrics =>
 
-import scala.concurrent.duration.FiniteDuration
-
-private[effect] class NativeCpuStarvationMetrics extends CpuStarvationMetrics {
-  override def incCpuStarvationCount: IO[Unit] = IO.unit
-
-  override def recordClockDrift(drift: FiniteDuration): IO[Unit] = IO.unit
-}
-
-private[effect] object NativeCpuStarvationMetrics {
-  private[effect] def apply(): CpuStarvationMetrics = new NativeCpuStarvationMetrics
+  /**
+   * Returns work-stealing thread pool metrics.
+   *
+   * @example
+   *   {{{
+   * val runtime: IORuntime = ???
+   * val totalWorkers = runtime.metrics.workStealingThreadPool.map(_.compute.workerThreadCount())
+   *   }}}
+   */
+  def workStealingThreadPool: Option[WorkStealingPoolMetrics]
 }