update at 2019-07-18 18:46:11 by ehlxr

src/main/java/me/ehlxr/BarrierTest.java

@@ -0,0 +1,64 @@
+package me.ehlxr;
+
+import com.google.common.collect.Lists;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * 按比例控制流量
+ *
+ * @author lixiangrong
+ * @since 2019-07-18.
+ */
+public class BarrierTest {
+    public static void main(String[] args) {
+        Barrier barrier = new Barrier(10, 3);
+
+        final Thread[] threads = new Thread[20];
+        for (int i = 0; i < threads.length; i++) {
+            threads[i] = new Thread(() -> {
+                if (barrier.allow()) {
+                    System.out.println("yes");
+                }
+            });
+            threads[i].start();
+        }
+
+        for (Thread t : threads) {
+            try {
+                t.join();
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        }
+
+    }
+}
+
+class Barrier {
+    private AtomicInteger op = new AtomicInteger(0);
+    private List<Integer> sources = Lists.newArrayList();
+    private int base;
+    private int rate;
+
+    public boolean allow() {
+        return sources.get(op.incrementAndGet() % base) < rate;
+    }
+
+    private Barrier() {
+    }
+
+    public Barrier(int base, int rate) {
+        this.base = base;
+        this.rate = rate;
+
+        for (int i = 0; i < 10; i++) {
+            sources.add(i);
+        }
+        Collections.shuffle(sources);
+    }
+
+}
+