Fix timed countdownlatch hang. (#53)

cmu-pasta · Nov 8, 2024 · 98b2e50 · 98b2e50
1 parent 76a3fec
commit 98b2e50
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Showing 5 changed files with 49 additions and 22 deletions.
diff --git a/core/src/main/kotlin/org/pastalab/fray/core/RunContext.kt b/core/src/main/kotlin/org/pastalab/fray/core/RunContext.kt
@@ -517,8 +517,7 @@ class RunContext(val config: Configuration) {
         context.state = ThreadState.Enabled
       }
       is CountDownLatchAwaitBlocking -> {
-        context.pendingOperation = ThreadResumeOperation(false)
-        context.state = ThreadState.Enabled
+        latchManager.unblockThread(pendingOperation.latch, context.thread.id, true, false)
         if (context.thread != Thread.currentThread()) {
           syncManager.createWait(pendingOperation.latch, 1)
           context.thread.interrupt()
@@ -795,10 +794,7 @@ class RunContext(val config: Configuration) {
     if (latchManager.await(latch, true, context)) {
       context.pendingOperation = CountDownLatchAwaitBlocking(latch, timed)
       context.state = ThreadState.Paused
-      checkDeadlock {
-        context.state = ThreadState.Running
-        context.pendingOperation = ThreadResumeOperation(true)
-      }
+      checkDeadlock { latchManager.unblockThread(latch, t, false, false) }
       executor.submit {
         while (registeredThreads[t]!!.thread.state == Thread.State.RUNNABLE) {
           Thread.yield()

diff --git a/core/src/main/kotlin/org/pastalab/fray/core/concurrency/locks/CountDownLatchContext.kt b/core/src/main/kotlin/org/pastalab/fray/core/concurrency/locks/CountDownLatchContext.kt
@@ -19,13 +19,18 @@ class CountDownLatchContext(var count: Long) : Interruptible {
     return false
   }
 
-  override fun interrupt(tid: Long) {
+  fun unblockThread(tid: Long, isTimeout: Boolean, isInterrupt: Boolean) {
     val lockWaiter = latchWaiters[tid] ?: return
-    if (lockWaiter.canInterrupt) {
-      lockWaiter.thread.pendingOperation = ThreadResumeOperation(false)
-      lockWaiter.thread.state = ThreadState.Enabled
-      latchWaiters.remove(tid)
+    if (isInterrupt && !lockWaiter.canInterrupt) {
+      return
     }
+    lockWaiter.thread.pendingOperation = ThreadResumeOperation(!isTimeout)
+    lockWaiter.thread.state = ThreadState.Enabled
+    latchWaiters.remove(tid)
+  }
+
+  override fun interrupt(tid: Long) {
+    unblockThread(tid, false, true)
   }
 
   fun release(): Int {
@@ -35,8 +40,7 @@ class CountDownLatchContext(var count: Long) : Interruptible {
     count = 0
     var threads = 0
     for (lockWaiter in latchWaiters.values) {
-      lockWaiter.thread.pendingOperation = ThreadResumeOperation(true)
-      lockWaiter.thread.state = ThreadState.Enabled
+      unblockThread(lockWaiter.thread.thread.id, false, false)
       threads += 1
     }
     return threads
@@ -55,8 +59,7 @@ class CountDownLatchContext(var count: Long) : Interruptible {
     if (count == 0L) {
       var threads = 0
       for (lockWaiter in latchWaiters.values) {
-        lockWaiter.thread.pendingOperation = ThreadResumeOperation(true)
-        lockWaiter.thread.state = ThreadState.Enabled
+        unblockThread(lockWaiter.thread.thread.id, false, false)
         threads += 1
       }
       return threads

diff --git a/core/src/main/kotlin/org/pastalab/fray/core/concurrency/locks/CountDownLatchManager.kt b/core/src/main/kotlin/org/pastalab/fray/core/concurrency/locks/CountDownLatchManager.kt
@@ -16,6 +16,10 @@ class CountDownLatchManager {
     return latchStore.getContext(latch).await(canInterrupt, thread)
   }
 
+  fun unblockThread(latch: CountDownLatch, tid: Long, isTimeout: Boolean, isInterrupt: Boolean) {
+    latchStore.getContext(latch).unblockThread(tid, isTimeout, isInterrupt)
+  }
+
   /*
    * Returns number of unblocked threads.
    */

diff --git a/...ion-test/src/main/java/org/pastalab/fray/test/success/cdl/CountDownLatchNormalNotify.java b/...ion-test/src/main/java/org/pastalab/fray/test/success/cdl/CountDownLatchNormalNotify.java
@@ -0,0 +1,23 @@
+package org.pastalab.fray.test.success.cdl;
+
+import java.util.concurrent.CountDownLatch;
+
+public class CountDownLatchNormalNotify {
+    public static void main(String[] args) throws InterruptedException {
+        CountDownLatch cdl = new CountDownLatch(1);
+        Thread t = new Thread(() -> {
+            try {
+                cdl.await(1000, java.util.concurrent.TimeUnit.MILLISECONDS);
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        });
+        t.start();
+        Object o = new Object();
+        synchronized (o) {
+            o.wait(1000);
+        }
+        cdl.countDown();
+        t.join();
+    }
+}
diff --git a/integration-test/src/test/java/org/pastalab/fray/test/FrayTestCase.java b/integration-test/src/test/java/org/pastalab/fray/test/FrayTestCase.java
@@ -16,6 +16,7 @@
 import org.pastalab.fray.core.scheduler.POSScheduler;
 import org.pastalab.fray.core.scheduler.RandomScheduler;
 import org.pastalab.fray.runtime.TargetTerminateException;
+import org.pastalab.fray.test.success.cdl.CountDownLatchNormalNotify;
 import org.pastalab.fray.test.success.condition.ConditionAwaitTimeoutInterrupt;
 import org.pastalab.fray.test.success.condition.ConditionAwaitTimeoutNotifyInterrupt;
 
@@ -70,7 +71,11 @@ public void testOne() throws Throwable {
         Configuration config = new Configuration(
                 new ExecutionInfo(
                         new LambdaExecutor(() -> {
-                            ConditionAwaitTimeoutNotifyInterrupt.main(new String[]{});
+                            try {
+                                CountDownLatchNormalNotify.main(new String[]{});
+                            } catch (InterruptedException e) {
+                                throw new RuntimeException(e);
+                            }
                             return null;
                         }),
                         false,
@@ -79,13 +84,9 @@ public void testOne() throws Throwable {
                         -1
                 ),
                 "/tmp/report2",
-                100,
+                1000,
                 60,
-                new RandomScheduler(new ControlledRandom(
-                        new ArrayList<>(List.of(1, 1, 1, 0)),
-                        new ArrayList<>(),
-                        new Random()
-                )),
+                new POSScheduler(),
                 new ControlledRandom(
                         new ArrayList<>(List.of(0, 0, 0, 0, 0, 0)),
                         new ArrayList<>(),