add DistributedTracerUseDemo

src/test/java/com/alibaba/mtc/demo/distributed_tracer/DistributedTracerUseDemo.java

+package com.alibaba.mtc.demo.distributed_tracer;
+
+import com.alibaba.mtc.MtContextThreadLocal;
+import com.alibaba.mtc.Utils;
+import com.alibaba.mtc.threadpool.MtContextExecutors;
+
+import java.util.Map;
+import java.util.concurrent.*;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * DistributedTracer(DT) use demo.
+ *
+ * @author Jerry Lee (oldratlee at gmail dot com)
+ */
+public class DistributedTracerUseDemo {
+    static ThreadFactory threadFactory = new ThreadFactory() {
+        @Override
+        public Thread newThread(Runnable r) {
+            Thread thread = new Thread(r, "Executors");
+            thread.setDaemon(true);
+            return thread;
+        }
+    };
+
+
+    static ExecutorService executorService = MtContextExecutors.getMtcExecutorService(Executors.newFixedThreadPool(1, threadFactory));
+
+    static {
+        // 挤满线程, 保证线程不是用的时候new的, 确保验证MTC的传递功能
+        Utils.expandThreadPool(executorService);
+    }
+
+    static class DtTransferInfo {
+        public String traceId;
+        public String baseSpanId;
+
+        public DtTransferInfo(String traceId, String baseSpanId) {
+            this.traceId = traceId;
+            this.baseSpanId = baseSpanId;
+        }
+    }
+
+    private static MtContextThreadLocal<DtTransferInfo> transferInfo = new MtContextThreadLocal<DtTransferInfo>() {
+        @Override
+        protected DtTransferInfo copy(DtTransferInfo parentValue) {
+            increaseSpanIdRefCounter();
+            return super.childValue(parentValue);
+        }
+
+        @Override
+        protected void afterExecute() {
+            decreaseSpanIdRefCounter();
+        }
+    };
+
+    static class LeafSpanIdInfo {
+        AtomicInteger current = new AtomicInteger(1);
+        AtomicInteger refCounter = new AtomicInteger(0);
+    }
+
+
+    private static Map<String, LeafSpanIdInfo> traceId2LeafSpanIdInfo = new ConcurrentHashMap<String, LeafSpanIdInfo>();
+
+    static void increaseSpanIdRefCounter() {
+        DtTransferInfo dtTransferInfo = transferInfo.get();
+        String traceId = dtTransferInfo.traceId;
+        int refCounter = traceId2LeafSpanIdInfo.get(traceId).refCounter.incrementAndGet();
+
+        System.out.printf("DEBUG: Increase reference counter(%s) for traceId %s in thread %s\n", refCounter, traceId, Thread.currentThread().getName());
+    }
+
+    static void decreaseSpanIdRefCounter() {
+        DtTransferInfo dtTransferInfo = transferInfo.get();
+        String traceId = dtTransferInfo.traceId;
+        LeafSpanIdInfo leafSpanIdInfo = traceId2LeafSpanIdInfo.get(traceId);
+
+        int refCounter = leafSpanIdInfo.refCounter.decrementAndGet();
+        System.out.printf("DEBUG: Decrease reference counter(%s) for traceId %s in thread %s\n", refCounter, traceId, Thread.currentThread().getName());
+
+        if (refCounter == 0) {
+            traceId2LeafSpanIdInfo.remove(traceId);
+
+            System.out.printf("DEBUG: Clear traceId2LeafSpanIdInfo for traceId %s in thread %s\n", traceId, Thread.currentThread().getName());
+        } else if (refCounter < 0) {
+            throw new IllegalStateException("Leaf Span Id Info Reference counter has Bug!!");
+        }
+    }
+
+    static int increaseLeafSpanCurrentAndReturn() {
+        DtTransferInfo dtTransferInfo = transferInfo.get();
+        String traceId = dtTransferInfo.traceId;
+        LeafSpanIdInfo leafSpanIdInfo = traceId2LeafSpanIdInfo.get(traceId);
+
+        return leafSpanIdInfo.current.getAndIncrement();
+    }
+
+    public static void main(String[] args) throws Exception {
+        rpcInvokeIn();
+
+        Thread.sleep(1000);
+    }
+
+    static void rpcInvokeIn() {
+        ////////////////////////////////////////////////
+        // DistributedTracer Framework Code
+        ////////////////////////////////////////////////
+
+        // Get Trace Id and Span Id from RPC Context
+        String traceId = "traceId_XXXYYY";
+        String baseSpanId = "1.1";
+
+        transferInfo.set(new DtTransferInfo(traceId, baseSpanId));
+        traceId2LeafSpanIdInfo.put(traceId, new LeafSpanIdInfo());
+
+        increaseSpanIdRefCounter();
+
+        ////////////////////////////////////////////////
+        // Biz Code
+        ////////////////////////////////////////////////
+        syncMethod();
+
+        ////////////////////////////////////////////////
+        // DistributedTracer Framework Code
+        ////////////////////////////////////////////////
+        decreaseSpanIdRefCounter();
+    }
+
+    static void syncMethod() {
+        // async call by MTC Executor, Test OK!
+        executorService.submit(new Runnable() {
+            @Override
+            public void run() {
+                asyncMethod();
+
+            }
+        });
+
+        // async call by new Thread
+        // FIXME Bug!! 没有 Increase/Decrease reference counter操作!
+        new Thread(new Runnable() {
+            @Override
+            public void run() {
+                syncMethod_ByNewThread();
+            }
+        }, "Thread-by-new").start();
+
+        invokeServerWithRpc("server 1");
+    }
+
+    static void asyncMethod() {
+        invokeServerWithRpc("server 2");
+    }
+
+    static void syncMethod_ByNewThread() {
+        invokeServerWithRpc("server 3");
+    }
+
+
+    // RPC invoke
+    static void invokeServerWithRpc(String server) {
+        ////////////////////////////////////////////////
+        // DistributedTracer Framework Code
+        ////////////////////////////////////////////////
+
+        int leafSpanCurrent = increaseLeafSpanCurrentAndReturn();
+
+        // Set RpcContext
+        // Mocked, should use RPC util to get Rpc Context instead
+        Map<String, String> rpcContext = new ConcurrentHashMap<String, String>();
+
+        rpcContext.put("traceId", transferInfo.get().traceId);
+        rpcContext.put("spanId", transferInfo.get().baseSpanId + "." + leafSpanCurrent);
+
+        // Do Rpc
+        // ...
+        System.out.printf("Do Rpc invocation to server %s with %s\n", server, rpcContext);
+    }
+}