Update test cases and demo for async support

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

sentinel-core/src/main/java/com/alibaba/csp/sentinel/context/ContextUtil.java

@@ -190,7 +190,7 @@ public class ContextUtil {
      * @return old context
      * @since 0.2.0
      */
-    private static Context replaceContext(Context newContext) {
+    static Context replaceContext(Context newContext) {
         Context backupContext = contextHolder.get();
         if (newContext == null) {
             contextHolder.remove();

sentinel-core/src/test/java/com/alibaba/csp/sentinel/AsyncEntryIntegrationTest.java

@@ -0,0 +1,224 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * Licensed 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
+ *
+ *      http://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 com.alibaba.csp.sentinel;
+
+import java.util.Set;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+
+import com.alibaba.csp.sentinel.context.ContextUtil;
+import com.alibaba.csp.sentinel.node.DefaultNode;
+import com.alibaba.csp.sentinel.node.EntranceNode;
+import com.alibaba.csp.sentinel.node.Node;
+import com.alibaba.csp.sentinel.slots.block.BlockException;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * Integration test for asynchronous entry, including common scenarios.
+ *
+ * @author Eric Zhao
+ */
+public class AsyncEntryIntegrationTest {
+
+    @Before
+    public void clearContext() {
+        if (ContextUtil.getContext() != null) {
+            ContextUtil.getContext().setCurEntry(null);
+            ContextUtil.exit();
+        }
+    }
+
+    private final ExecutorService pool = Executors.newFixedThreadPool(10);
+
+    private void anotherAsync() {
+        try {
+            final AsyncEntry entry = SphU.asyncEntry("test-another-async");
+
+            runAsync(new Runnable() {
+                @Override
+                public void run() {
+                    ContextUtil.runOnContext(entry.getAsyncContext(), new Runnable() {
+                        @Override
+                        public void run() {
+                            try {
+                                TimeUnit.SECONDS.sleep(2);
+                                anotherSyncInAsync();
+                                System.out.println("Async result: 666");
+                            } catch (InterruptedException e) {
+                                // Ignore.
+                            } finally {
+                                entry.exit();
+                            }
+                        }
+                    });
+                }
+            });
+        } catch (BlockException ex) {
+            ex.printStackTrace();
+        }
+    }
+
+    private void fetchSync() {
+        Entry entry = null;
+        try {
+            entry = SphU.entry("test-sync");
+        } catch (BlockException ex) {
+            ex.printStackTrace();
+        } finally {
+            if (entry != null) {
+                entry.exit();
+            }
+        }
+    }
+
+    private void fetchSyncInAsync() {
+        Entry entry = null;
+        try {
+            entry = SphU.entry("test-sync-in-async");
+        } catch (BlockException ex) {
+            ex.printStackTrace();
+        } finally {
+            if (entry != null) {
+                entry.exit();
+            }
+        }
+    }
+
+    public void anotherSyncInAsync() {
+        Entry entry = null;
+        try {
+            entry = SphU.entry("test-another-in-async");
+        } catch (BlockException ex) {
+            ex.printStackTrace();
+        } finally {
+            if (entry != null) {
+                entry.exit();
+            }
+        }
+    }
+
+    private void doAsyncThenSync() {
+        try {
+            // First we call an asynchronous resource.
+            final AsyncEntry entry = SphU.asyncEntry("test-async");
+            this.invoke("abc", new Consumer<String>() {
+                @Override
+                public void accept(final String resp) {
+                    // The thread is different from original caller thread for async entry.
+                    // So we need to wrap in the async context so that nested sync invocation entry
+                    // can be linked to the parent asynchronous entry.
+                    ContextUtil.runOnContext(entry.getAsyncContext(), new Runnable() {
+                        @Override
+                        public void run() {
+                            try {
+                                // In the callback, we do another async invocation under the async context.
+                                anotherAsync();
+
+                                System.out.println(resp);
+
+                                // Then we do a sync entry under current async context.
+                                fetchSyncInAsync();
+                            } finally {
+                                // Exit the async entry.
+                                entry.exit();
+                            }
+                        }
+                    });
+                }
+            });
+            // Then we call a sync resource.
+            fetchSync();
+        } catch (BlockException ex) {
+            // Request blocked, handle the exception.
+            ex.printStackTrace();
+        }
+    }
+
+    @Test
+    public void testAsyncEntryUnderSyncEntry() throws Exception {
+        // Expected invocation chain:
+        // EntranceNode: machine-root
+        // -EntranceNode: async-context
+        // --test-top
+        // ---test-async
+        // ----test-sync-in-async
+        // ----test-another-async
+        // -----test-another-in-async
+        // ---test-sync
+        ContextUtil.enter(contextName, origin);
+        Entry entry = null;
+        try {
+            entry = SphU.entry("test-top");
+            doAsyncThenSync();
+        } catch (BlockException ex) {
+            ex.printStackTrace();
+        } finally {
+            if (entry != null) {
+                entry.exit();
+            }
+            ContextUtil.exit();
+        }
+
+        TimeUnit.SECONDS.sleep(10);
+        testTreeCorrect();
+    }
+
+    private void testTreeCorrect() {
+        DefaultNode root = Constants.ROOT;
+        Set<Node> childListForRoot = root.getChildList();
+        // TODO: check child tree
+    }
+
+    @After
+    public void shutdown() {
+        pool.shutdownNow();
+        ContextUtil.exit();
+    }
+
+    private void runAsync(Runnable f) {
+        // In Java 8, we can use CompletableFuture.runAsync(f) instead.
+        pool.submit(f);
+    }
+
+    private void invoke(final String arg, final Consumer<String> handler) {
+        runAsync(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    TimeUnit.SECONDS.sleep(3);
+                    String resp = arg + ": " + System.currentTimeMillis();
+                    handler.accept(resp);
+
+                } catch (Exception ex) {
+                    ex.printStackTrace();
+                }
+            }
+        });
+    }
+
+    private interface Consumer<T> {
+        void accept(T t);
+    }
+
+    private final String contextName = "async-context";
+    private final String origin = "originA";
+}

sentinel-core/src/test/java/com/alibaba/csp/sentinel/AsyncEntryTest.java

@@ -0,0 +1,76 @@
+package com.alibaba.csp.sentinel;
+
+import com.alibaba.csp.sentinel.context.Context;
+import com.alibaba.csp.sentinel.context.ContextUtil;
+import com.alibaba.csp.sentinel.slotchain.StringResourceWrapper;
+
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * Test cases for {@link AsyncEntry}.
+ *
+ * @author Eric Zhao
+ * @since 0.2.0
+ */
+public class AsyncEntryTest {
+
+    @Test
+    public void testCleanCurrentEntryInLocal() {
+        final String contextName = "abc";
+        try {
+            ContextUtil.enter(contextName);
+            Context curContext = ContextUtil.getContext();
+            AsyncEntry entry = new AsyncEntry(new StringResourceWrapper("testCleanCurrentEntryInLocal", EntryType.OUT),
+                null, curContext);
+
+            assertSame(entry, curContext.getCurEntry());
+
+            entry.cleanCurrentEntryInLocal();
+            assertNotSame(entry, curContext.getCurEntry());
+        } finally {
+            ContextUtil.getContext().setCurEntry(null);
+            ContextUtil.exit();
+        }
+    }
+
+    @Test
+    public void testInitAndGetAsyncContext() {
+        final String contextName = "abc";
+        final String origin = "xxx";
+        try {
+            ContextUtil.enter(contextName, origin);
+            Context curContext = ContextUtil.getContext();
+            AsyncEntry entry = new AsyncEntry(new StringResourceWrapper("testInitAndGetAsyncContext", EntryType.OUT),
+                null, curContext);
+            assertNull(entry.getAsyncContext());
+
+            entry.initAsyncContext();
+            System.out.println(curContext.getName());
+            System.out.println(curContext.getOrigin());
+
+            Context asyncContext = entry.getAsyncContext();
+            assertNotNull(asyncContext);
+            assertEquals(contextName, asyncContext.getName());
+            assertEquals(origin, asyncContext.getOrigin());
+            assertSame(curContext.getEntranceNode(), asyncContext.getEntranceNode());
+            assertSame(entry, asyncContext.getCurEntry());
+            assertTrue(asyncContext.isAsync());
+        } finally {
+            ContextUtil.getContext().setCurEntry(null);
+            ContextUtil.exit();
+        }
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void testDuplicateInitAsyncContext() {
+        Context context = new Context(null, "abc");
+        AsyncEntry entry = new AsyncEntry(new StringResourceWrapper("testDuplicateInitAsyncContext", EntryType.OUT),
+            null, context);
+        entry.initAsyncContext();
+
+        // Duplicate init.
+        entry.initAsyncContext();
+    }
+}

sentinel-core/src/test/java/com/alibaba/csp/sentinel/ContextTest.java

@@ -1,35 +0,0 @@
-/*
- * Copyright 1999-2018 Alibaba Group Holding Ltd.
- *
- * Licensed 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
- *
- *      http://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 com.alibaba.csp.sentinel;
-
-import org.junit.Test;
-
-import com.alibaba.csp.sentinel.context.ContextUtil;
-
-/**
- * @author jialiang.linjl
- */
-public class ContextTest {
-
-    @Test
-    public void testEnterContext() {
-        // TODO: rewrite this unit test
-        ContextUtil.enter("entry", "origin");
-
-        ContextUtil.exit();
-    }
-
-}

sentinel-core/src/test/java/com/alibaba/csp/sentinel/context/ContextTest.java

@@ -0,0 +1,93 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * Licensed 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
+ *
+ *      http://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 com.alibaba.csp.sentinel.context;
+
+import org.junit.After;
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * Test cases for {@link Context} and {@link ContextUtil}.
+ *
+ * @author jialiang.linjl
+ * @author Eric Zhao
+ */
+public class ContextTest {
+
+    @After
+    public void cleanUp() {
+        ContextUtil.exit();
+    }
+
+    @Test
+    public void testEnterContext() {
+        final String contextName = "contextA";
+        final String origin = "originA";
+        ContextUtil.enter(contextName, origin);
+
+        Context curContext = ContextUtil.getContext();
+        assertEquals(contextName, curContext.getName());
+        assertEquals(origin, curContext.getOrigin());
+        assertFalse(curContext.isAsync());
+
+        ContextUtil.exit();
+        assertNull(ContextUtil.getContext());
+    }
+
+    @Test
+    public void testReplaceContext() {
+        final String contextName = "contextA";
+        final String origin = "originA";
+        ContextUtil.enter(contextName, origin);
+
+        Context contextB = Context.newAsyncContext(null, "contextB")
+            .setOrigin("originA");
+        Context contextA = ContextUtil.replaceContext(contextB);
+        assertEquals(contextName, contextA.getName());
+        assertEquals(origin, contextA.getOrigin());
+        assertFalse(contextA.isAsync());
+
+        Context curContextAfterReplace = ContextUtil.getContext();
+        assertEquals(contextB.getName(), curContextAfterReplace.getName());
+        assertEquals(contextB.getOrigin(), curContextAfterReplace.getOrigin());
+        assertTrue(curContextAfterReplace.isAsync());
+
+        ContextUtil.replaceContext(null);
+        assertNull(ContextUtil.getContext());
+    }
+
+    @Test
+    public void testRunOnContext() {
+        final String contextName = "contextA";
+        final String origin = "originA";
+        ContextUtil.enter(contextName, origin);
+
+        final Context contextB = Context.newAsyncContext(null, "contextB")
+            .setOrigin("originB");
+        assertEquals(contextName, ContextUtil.getContext().getName());
+        ContextUtil.runOnContext(contextB, new Runnable() {
+            @Override
+            public void run() {
+                Context curContext = ContextUtil.getContext();
+                assertEquals(contextB.getName(), curContext.getName());
+                assertEquals(contextB.getOrigin(), curContext.getOrigin());
+                assertTrue(curContext.isAsync());
+            }
+        });
+        assertEquals(contextName, ContextUtil.getContext().getName());
+    }
+}

sentinel-demo/pom.xml

@@ -12,6 +12,11 @@
     <packaging>pom</packaging>
     <name>sentinel-demo</name>
 
+    <properties>
+        <java.source.version>1.8</java.source.version>
+        <java.target.version>1.8</java.target.version>
+    </properties>
+
     <modules>
         <module>sentinel-demo-basic</module>
         <module>sentinel-demo-dynamic-file-rule</module>

sentinel-demo/sentinel-demo-basic/src/main/java/com/alibaba/csp/sentinel/demo/AsyncEntryDemo.java

@@ -0,0 +1,218 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * Licensed 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
+ *
+ *      http://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 com.alibaba.csp.sentinel.demo;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.TimeUnit;
+import java.util.function.Consumer;
+
+import com.alibaba.csp.sentinel.AsyncEntry;
+import com.alibaba.csp.sentinel.Entry;
+import com.alibaba.csp.sentinel.SphU;
+import com.alibaba.csp.sentinel.context.ContextUtil;
+import com.alibaba.csp.sentinel.slots.block.BlockException;
+import com.alibaba.csp.sentinel.slots.block.RuleConstant;
+import com.alibaba.csp.sentinel.slots.block.flow.FlowRule;
+import com.alibaba.csp.sentinel.slots.block.flow.FlowRuleManager;
+
+/**
+ * An example for asynchronous entry in Sentinel.
+ *
+ * @author Eric Zhao
+ * @since 0.2.0
+ */
+public class AsyncEntryDemo {
+
+    private void invoke(String arg, Consumer<String> handler) {
+        CompletableFuture.runAsync(() -> {
+            try {
+                TimeUnit.SECONDS.sleep(3);
+                String resp = arg + ": " + System.currentTimeMillis();
+                handler.accept(resp);
+            } catch (Exception ex) {
+                ex.printStackTrace();
+            }
+        });
+    }
+
+    private void anotherAsync() {
+        try {
+            final AsyncEntry entry = SphU.asyncEntry("test-another-async");
+
+            CompletableFuture.runAsync(() -> {
+                ContextUtil.runOnContext(entry.getAsyncContext(), () -> {
+                    try {
+                        TimeUnit.SECONDS.sleep(2);
+                        anotherSyncInAsync();
+                        System.out.println("Async result: 666");
+                    } catch (InterruptedException e) {
+                        // Ignore.
+                    } finally {
+                        entry.exit();
+                    }
+                });
+            });
+        } catch (BlockException ex) {
+            ex.printStackTrace();
+        }
+    }
+
+    private void fetchSync() {
+        Entry entry = null;
+        try {
+            entry = SphU.entry("test-sync");
+        } catch (BlockException ex) {
+            ex.printStackTrace();
+        } finally {
+            if (entry != null) {
+                entry.exit();
+            }
+        }
+    }
+
+    private void fetchSyncInAsync() {
+        Entry entry = null;
+        try {
+            entry = SphU.entry("test-sync-in-async");
+        } catch (BlockException ex) {
+            ex.printStackTrace();
+        } finally {
+            if (entry != null) {
+                entry.exit();
+            }
+        }
+    }
+
+    private void anotherSyncInAsync() {
+        Entry entry = null;
+        try {
+            entry = SphU.entry("test-another-sync-in-async");
+        } catch (BlockException ex) {
+            ex.printStackTrace();
+        } finally {
+            if (entry != null) {
+                entry.exit();
+            }
+        }
+    }
+
+    private void directlyAsync() {
+        try {
+            final AsyncEntry entry = SphU.asyncEntry("test-async-not-nested");
+
+            CompletableFuture.runAsync(() -> {
+                // If no nested entry later, we don't have to wrap in `ContextUtil.runOnContext()`.
+                try {
+                    TimeUnit.SECONDS.sleep(1);
+                } catch (InterruptedException ex) {
+                    // Ignore.
+                } finally {
+                    // Exit the async entry.
+                    entry.exit();
+                }
+            });
+        } catch (BlockException e) {
+            // Request blocked, handle the exception.
+            e.printStackTrace();
+        }
+    }
+
+    private void doAsyncThenSync() {
+        try {
+            // First we call an asynchronous resource.
+            final AsyncEntry entry = SphU.asyncEntry("test-async");
+            this.invoke("abc", resp -> {
+                // The thread is different from original caller thread for async entry.
+                // So we need to wrap in the async context so that nested sync invocation entry
+                // can be linked to the parent asynchronous entry.
+                ContextUtil.runOnContext(entry.getAsyncContext(), () -> {
+                    try {
+                        // In the callback, we do another async invocation several times under the async context.
+                        for (int i = 0; i < 7; i++) {
+                            anotherAsync();
+                        }
+
+                        System.out.println(resp);
+
+                        // Then we do a sync entry under current async context.
+                        fetchSyncInAsync();
+                    } finally {
+                        // Exit the async entry.
+                        entry.exit();
+                    }
+                });
+            });
+            // Then we call a sync resource.
+            fetchSync();
+        } catch (BlockException ex) {
+            // Request blocked, handle the exception.
+            ex.printStackTrace();
+        }
+    }
+
+    public static void main(String[] args) {
+        initFlowRule();
+
+        AsyncEntryDemo service = new AsyncEntryDemo();
+
+        // Expected invocation chain:
+        //
+        // EntranceNode: machine-root
+        // -EntranceNode: async-context
+        // --test-top
+        // ---test-sync
+        // ---test-async
+        // ----test-another-async
+        // -----test-another-sync-in-async
+        // ----test-sync-in-async
+        ContextUtil.enter("async-context", "originA");
+        Entry entry = null;
+        try {
+            entry = SphU.entry("test-top");
+            System.out.println("Do something...");
+            service.doAsyncThenSync();
+        } catch (BlockException ex) {
+            // Request blocked, handle the exception.
+            ex.printStackTrace();
+        } finally {
+            if (entry != null) {
+                entry.exit();
+            }
+            ContextUtil.exit();
+        }
+    }
+
+    private static void initFlowRule() {
+        // Rule 1 won't take effect as the limitApp doesn't match.
+        FlowRule rule1 = new FlowRule()
+            .setResource("test-another-sync-in-async")
+            .setLimitApp("originB")
+            .as(FlowRule.class)
+            .setCount(4)
+            .setGrade(RuleConstant.FLOW_GRADE_QPS);
+        // Rule 2 will take effect.
+        FlowRule rule2 = new FlowRule()
+            .setResource("test-another-async")
+            .setLimitApp("default")
+            .as(FlowRule.class)
+            .setCount(5)
+            .setGrade(RuleConstant.FLOW_GRADE_QPS);
+        List<FlowRule> ruleList = Arrays.asList(rule1, rule2);
+        FlowRuleManager.loadRules(ruleList);
+    }
+}