All bulkheads should be fair

Author: jhalterman

src/main/java/dev/failsafe/Bulkhead.java

@@ -34,7 +34,7 @@
 public interface Bulkhead<R> extends Policy<R> {
   /**
    * Returns a Bulkhead for the {@code maxConcurrency} that has {@link BulkheadBuilder#withMaxWaitTime(Duration) zero
-   * wait} and is {@link BulkheadBuilder#withFairness() not fair} by default.
+   * wait}.
    *
    * @param maxConcurrency controls the max concurrent executions that are permitted within the bulkhead
    */
@@ -43,18 +43,16 @@ static <R> BulkheadBuilder<R> builder(int maxConcurrency) {
   }
 
   /**
-   * Creates a new BulkheadBuilder that will be based on the {@code config}. The built bulkhead is {@link
-   * BulkheadBuilder#withFairness() not fair} by default.
+   * Creates a new BulkheadBuilder that will be based on the {@code config}.
    */
   static <R> BulkheadBuilder<R> builder(BulkheadConfig<R> config) {
     return new BulkheadBuilder<>(config);
   }
 
   /**
    * Returns a Bulkhead for the {@code maxConcurrency} that has {@link BulkheadBuilder#withMaxWaitTime(Duration) zero
-   * wait} and is {@link BulkheadBuilder#withFairness() not fair} by default. Alias for {@code
-   * Bulkhead.builder(maxConcurrency).build()}. To configure additional options on a Bulkhead, use {@link #builder(int)}
-   * instead.
+   * wait}. Alias for {@code Bulkhead.builder(maxConcurrency).build()}. To configure additional options on a Bulkhead,
+   * use {@link #builder(int)} instead.
    *
    * @param maxConcurrency controls the max concurrent executions that are permitted within the bulkhead
    * @see #builder(int)

src/main/java/dev/failsafe/BulkheadBuilder.java

@@ -57,12 +57,4 @@ public BulkheadBuilder<R> withMaxWaitTime(Duration maxWaitTime) {
     config.maxWaitTime = Assert.notNull(maxWaitTime, "maxWaitTime");
     return this;
   }
-
-  /**
-   * Configures the bulkhead to be fair in permitting waiting execution in order.
-   */
-  public BulkheadBuilder<R> withFairness() {
-    config.fair = true;
-    return this;
-  }
 }

src/main/java/dev/failsafe/BulkheadConfig.java

@@ -26,7 +26,6 @@
 public class BulkheadConfig<R> extends PolicyConfig<R> {
   int maxConcurrency;
   Duration maxWaitTime;
-  boolean fair;
 
   BulkheadConfig(int maxConcurrency) {
     this.maxConcurrency = maxConcurrency;
@@ -37,7 +36,6 @@ public class BulkheadConfig<R> extends PolicyConfig<R> {
     super(config);
     maxConcurrency = config.maxConcurrency;
     maxWaitTime = config.maxWaitTime;
-    fair = config.fair;
   }
 
   /**
@@ -58,13 +56,4 @@ public int getMaxConcurrency() {
   public Duration getMaxWaitTime() {
     return maxWaitTime;
   }
-
-  /**
-   * Returns whether the Bulkhead is fair in permitting waiting executions in order.
-   *
-   * @see BulkheadBuilder#withFairness()
-   */
-  public boolean isFair() {
-    return fair;
-  }
 }

src/main/java/dev/failsafe/internal/BulkheadImpl.java

@@ -36,7 +36,7 @@ public class BulkheadImpl<R> implements Bulkhead<R> {
 
   public BulkheadImpl(BulkheadConfig<R> config) {
     this.config = config;
-    semaphore = new Semaphore(config.getMaxConcurrency(), config.isFair());
+    semaphore = new Semaphore(config.getMaxConcurrency(), true);
   }
 
   @Override

src/test/java/dev/failsafe/BulkheadBuilderTest.java

@@ -26,13 +26,11 @@ public class BulkheadBuilderTest {
   public void shouldCreateBuilderFromExistingConfig() {
     BulkheadConfig<Object> initialConfig = Bulkhead.builder(5)
       .withMaxWaitTime(Duration.ofSeconds(10))
-      .withFairness()
       .onSuccess(e -> {
       }).config;
     BulkheadConfig<Object> newConfig = Bulkhead.builder(initialConfig).config;
     assertEquals(newConfig.maxConcurrency, 5);
     assertEquals(newConfig.maxWaitTime, Duration.ofSeconds(10));
-    assertTrue(newConfig.fair);
     assertNotNull(newConfig.successListener);
   }
 }