Compare concurrency of various SegmentPool strategies

ConcurrencyBenchmark.kt

package okio.samples

import okio.Buffer
import okio.BufferedSink
import okio.BufferedSource
import okio.buffer
import okio.source
import java.io.File
import java.util.concurrent.atomic.AtomicLong

class ConcurrencyBenchmark(
  private val file: File
) {
  private val cycleCount = AtomicLong()

  private fun loop() {
    var a = Buffer()

    file.source().buffer().use { source ->
      a.writeAll(source)
    }

    var b = Buffer()
    while (true) {
      processLines(a, b)
      val c = a
      a = b
      b = c
      cycleCount.incrementAndGet()
    }
  }

  private fun processLines(source: BufferedSource, sink: BufferedSink) {
    while (true) {
      val line = source.readUtf8Line() ?: break
      sink.writeUtf8(line)
      sink.writeUtf8("\n")
    }
  }

  fun printStats() {
    var lastSuccessCount = cycleCount.get()
    var lastTime = System.nanoTime()

    while (true) {
      val currentSuccessCount = cycleCount.get()
      val currentTime = System.nanoTime()

      val elapsedSeconds = (currentTime - lastTime) / 1_000_000_000.0
      val successPerSecond = (currentSuccessCount - lastSuccessCount) / elapsedSeconds
      println(String.format("%10.2f success/sec", successPerSecond))

      lastSuccessCount = currentSuccessCount
      lastTime = currentTime

      Thread.sleep(250)
    }
  }

  fun runThreads(threadCount: Int) {
    for (t in 0 until threadCount) {
      val thread = object : Thread("benchmark-thread-$t") {
        override fun run() {
          loop()
        }
      }
      thread.start()
    }
  }
}

fun main() {
  val concurrencyBenchmark = ConcurrencyBenchmark(
    file = File("/Users/jwilson/Projects/okio/settings.gradle")
  )

  concurrencyBenchmark.runThreads(128)
  concurrencyBenchmark.printStats()
}