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kturner pushed a commit to branch main
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The following commit(s) were added to refs/heads/main by this push:
new d64bd908d4 adds a new count down timer (#4796)
d64bd908d4 is described below
commit d64bd908d4eb815ceb7b7570666d48f1ff76fac5
Author: Keith Turner <[email protected]>
AuthorDate: Tue Aug 20 14:21:45 2024 -0700
adds a new count down timer (#4796)
Adds a class used to mesure the amount of elapsed
time left from an initial duration.
Co-authored-by: Dom G. <[email protected]>
---
.../org/apache/accumulo/core/fate/ZooStore.java | 11 ++-
.../apache/accumulo/core/util/CountDownTimer.java | 94 +++++++++++++++++++++
.../accumulo/core/util/CountDownTimerTest.java | 97 ++++++++++++++++++++++
3 files changed, 196 insertions(+), 6 deletions(-)
diff --git a/core/src/main/java/org/apache/accumulo/core/fate/ZooStore.java
b/core/src/main/java/org/apache/accumulo/core/fate/ZooStore.java
index c3de5f29df..ac4bf7f876 100644
--- a/core/src/main/java/org/apache/accumulo/core/fate/ZooStore.java
+++ b/core/src/main/java/org/apache/accumulo/core/fate/ZooStore.java
@@ -43,8 +43,8 @@ import java.util.Set;
import org.apache.accumulo.core.fate.zookeeper.ZooReaderWriter;
import org.apache.accumulo.core.fate.zookeeper.ZooUtil.NodeExistsPolicy;
import org.apache.accumulo.core.fate.zookeeper.ZooUtil.NodeMissingPolicy;
+import org.apache.accumulo.core.util.CountDownTimer;
import org.apache.accumulo.core.util.FastFormat;
-import org.apache.accumulo.core.util.time.NanoTime;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.KeeperException.NoNodeException;
import org.apache.zookeeper.KeeperException.NodeExistsException;
@@ -64,7 +64,7 @@ public class ZooStore<T> implements TStore<T> {
private ZooReaderWriter zk;
private String lastReserved = "";
private Set<Long> reserved;
- private Map<Long,NanoTime> deferred;
+ private Map<Long,CountDownTimer> deferred;
private long statusChangeEvents = 0;
private int reservationsWaiting = 0;
@@ -164,7 +164,7 @@ public class ZooStore<T> implements TStore<T> {
}
if (deferred.containsKey(tid)) {
- if (deferred.get(tid).elapsed().compareTo(Duration.ZERO) > 0) {
+ if (deferred.get(tid).isExpired()) {
deferred.remove(tid);
} else {
continue;
@@ -203,9 +203,8 @@ public class ZooStore<T> implements TStore<T> {
if (deferred.isEmpty()) {
this.wait(5000);
} else {
- var now = NanoTime.now();
long minWait = deferred.values().stream()
- .mapToLong(nanoTime ->
nanoTime.subtract(now).toMillis()).min().orElseThrow();
+ .mapToLong(timer ->
timer.timeLeft(MILLISECONDS)).min().orElseThrow();
if (minWait > 0) {
this.wait(Math.min(minWait, 5000));
}
@@ -285,7 +284,7 @@ public class ZooStore<T> implements TStore<T> {
}
if (deferTime.compareTo(Duration.ZERO) > 0) {
- deferred.put(tid, NanoTime.nowPlus(deferTime));
+ deferred.put(tid, CountDownTimer.startNew(deferTime));
}
this.notifyAll();
diff --git
a/core/src/main/java/org/apache/accumulo/core/util/CountDownTimer.java
b/core/src/main/java/org/apache/accumulo/core/util/CountDownTimer.java
new file mode 100644
index 0000000000..3c7c3792c1
--- /dev/null
+++ b/core/src/main/java/org/apache/accumulo/core/util/CountDownTimer.java
@@ -0,0 +1,94 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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
+ *
+ * https://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 org.apache.accumulo.core.util;
+
+import java.time.Duration;
+import java.util.concurrent.TimeUnit;
+
+import com.google.common.base.Preconditions;
+
+/**
+ * A utility class that tracks the time remaining from an initial duration. It
allows the caller to
+ * check how much time is left on the timer and if the countdown has expired.
+ * <p>
+ * Example usage:
+ *
+ * <pre>
+ * CountDownTimer timer = CountDownTimer.startNew(Duration.ofMillis(100));
+ * Thread.sleep(10);
+ * long timeLeft = timer.timeLeft(TimeUnit.MILLISECONDS); // approximately
90ms remaining
+ * boolean expired = timer.isExpired(); // false
+ * Thread.sleep(100);
+ * expired = timer.isExpired(); // true
+ * </pre>
+ */
+public class CountDownTimer {
+ private final long startNanos;
+ private final long durationNanos;
+
+ private CountDownTimer(long durationNanos) {
+ this.startNanos = System.nanoTime();
+ this.durationNanos = durationNanos;
+ }
+
+ /**
+ * Starts a new countdown timer with the specified duration.
+ *
+ * @param duration the countdown duration, must be non-negative.
+ */
+ public static CountDownTimer startNew(Duration duration) {
+ Preconditions.checkArgument(!duration.isNegative());
+ return new CountDownTimer(duration.toNanos());
+ }
+
+ /**
+ * Starts a new countdown timer with the specified duration.
+ *
+ * @param duration the countdown duration, must be non-negative.
+ * @param unit the time unit of the duration.
+ */
+ public static CountDownTimer startNew(long duration, TimeUnit unit) {
+ Preconditions.checkArgument(duration >= 0);
+ return new CountDownTimer(unit.toNanos(duration));
+ }
+
+ /**
+ * @param unit the desired {@link TimeUnit} for the returned time.
+ * @return the remaining time in the specified unit, or zero if expired.
+ */
+ public long timeLeft(TimeUnit unit) {
+ var elapsed = (System.nanoTime() - startNanos);
+ var timeLeft = durationNanos - elapsed;
+ if (timeLeft < 0) {
+ timeLeft = 0;
+ }
+
+ return unit.convert(timeLeft, TimeUnit.NANOSECONDS);
+ }
+
+ /**
+ * Checks if the countdown timer has expired.
+ *
+ * @return true if the elapsed time since creation is greater than or equals
to the initial
+ * duration, otherwise return false.
+ */
+ public boolean isExpired() {
+ return timeLeft(TimeUnit.NANOSECONDS) == 0;
+ }
+}
diff --git
a/core/src/test/java/org/apache/accumulo/core/util/CountDownTimerTest.java
b/core/src/test/java/org/apache/accumulo/core/util/CountDownTimerTest.java
new file mode 100644
index 0000000000..b0ce9953a6
--- /dev/null
+++ b/core/src/test/java/org/apache/accumulo/core/util/CountDownTimerTest.java
@@ -0,0 +1,97 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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
+ *
+ * https://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 org.apache.accumulo.core.util;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.time.Duration;
+import java.util.concurrent.TimeUnit;
+
+import org.junit.jupiter.api.Test;
+
+public class CountDownTimerTest {
+ @Test
+ public void testCountDownTimer() throws Exception {
+
+ var totalTimer = Timer.startNew();
+
+ var cdTimer1 = CountDownTimer.startNew(Duration.ofMillis(100));
+ Thread.sleep(10);
+ var cdTimer2 = CountDownTimer.startNew(100, TimeUnit.MILLISECONDS);
+ Thread.sleep(10);
+ var cdTimer3 = CountDownTimer.startNew(Duration.ofMillis(100));
+ Thread.sleep(10);
+
+ boolean expired1 = cdTimer1.isExpired();
+ boolean expired2 = cdTimer1.isExpired();
+ boolean expired3 = cdTimer1.isExpired();
+
+ var left3 = cdTimer3.timeLeft(TimeUnit.MILLISECONDS);
+ var left2 = cdTimer2.timeLeft(TimeUnit.MILLISECONDS);
+ var left1 = cdTimer1.timeLeft(TimeUnit.MILLISECONDS);
+
+ var elapsed = totalTimer.elapsed();
+
+ assertTrue(left3 <= 90);
+ assertTrue(left2 <= 80);
+ assertTrue(left1 <= 70);
+
+ assertTrue(Math.max(left3 - 10, 0) >= left2);
+ assertTrue(Math.max(left2 - 10, 0) >= left1);
+ assertTrue(left1 >= Duration.ofMillis(100).minus(elapsed).toMillis(),
+ "left1:" + left1 + " elapsed:" + elapsed);
+ assertTrue(left1 >= 0);
+
+ if (left1 > 0) {
+ assertFalse(expired1);
+ } else {
+ assertTrue(expired1);
+ }
+
+ if (left2 > 0) {
+ assertFalse(expired2);
+ } else {
+ assertTrue(expired2);
+ }
+
+ if (left3 > 0) {
+ assertFalse(expired3);
+ } else {
+ assertTrue(expired3);
+ }
+
+ Thread.sleep(92);
+ assertEquals(0, cdTimer1.timeLeft(TimeUnit.MILLISECONDS));
+ assertEquals(0, cdTimer2.timeLeft(TimeUnit.MILLISECONDS));
+ assertEquals(0, cdTimer3.timeLeft(TimeUnit.MILLISECONDS));
+
+ assertTrue(cdTimer1.isExpired());
+ assertTrue(cdTimer2.isExpired());
+ assertTrue(cdTimer3.isExpired());
+ }
+
+ @Test
+ public void testNegative() {
+ assertThrows(IllegalArgumentException.class,
+ () -> CountDownTimer.startNew(Duration.ofMillis(-1)));
+ }
+}
