Atomic Guard Coordination Report

Record one-shot guard acquisitions and report whether a later attempt was blocked.

Atomic Guard Coordination Report

AtomicGuardCoordinationReport.scala

import java.util.concurrent.atomic.AtomicBoolean

object Main {
  def main(args: Array[String]): Unit = {
    val holds = 
    val guard = new AtomicBoolean(false)
    var acquired = 0
    var blocked = 0

    for (i <- 0 until holds) {
      if (guard.compareAndSet(false, true)) {
        acquired = acquired + 1
      } else {
        blocked = blocked + 1
      }
    }

    var status = "guarded"
    if (acquired == 0) {
      status = "idle"
    }
    if (blocked > 0) {
      status = "blocked"
    }

    println("holds=" + holds + " acquired=" + acquired + " blocked=" + blocked + " " + status)
  }
}

import java.util.concurrent.atomic.AtomicBoolean

object Main {
  def main(args: Array[String]): Unit = {
    val holds = 
    val guard = new AtomicBoolean(false)
    var acquired = 0
    var blocked = 0

    for (i <- 0 until holds) {
      if (guard.compareAndSet(false, true)) {
        acquired = acquired + 1
      } else {
        blocked = blocked + 1
      }
    }

    var status = "guarded"
    if (acquired == 0) {
      status = "idle"
    }
    if (blocked > 0) {
      status = "blocked"
    }

    println("holds=" + holds + " acquired=" + acquired + " blocked=" + blocked + " " + status)
  }
}

import java.util.concurrent.atomic.AtomicBoolean

object Main {
  def main(args: Array[String]): Unit = {
    val holds = 
    val guard = new AtomicBoolean(false)
    var acquired = 0
    var blocked = 0

    for (i <- 0 until holds) {
      if (guard.compareAndSet(false, true)) {
        acquired = acquired + 1
      } else {
        blocked = blocked + 1
      }
    }

    var status = "guarded"
    if (acquired == 0) {
      status = "idle"
    }
    if (blocked > 0) {
      status = "blocked"
    }

    println("holds=" + holds + " acquired=" + acquired + " blocked=" + blocked + " " + status)
  }
}

one-shot guard A coordination report can record nonblocking guard attempts. An `AtomicBoolean` started at `false` acts as an exclusive one-shot guard, and `compareAndSet(false, true)` succeeds only for the first attempt and fails for every later attempt, so it never blocks. The first acquire flips the flag, so a later attempt in the same run is reported as blocked. The status line summarizes whether the section stayed idle, guarded, or blocked a later acquire.