Fixing wakeups caused by Thread.join() interacting with LockSupport.unpark.

This caused several concurrency tests to fail when run with timeouts, since
the tests cause park and unpark to happen frequently.

Also fixing a tiny issue with CoreTestRunnable to use the proper tmp directory
and to include the program of a failed external execution.

1 files changed, 49 insertions, 11 deletions

diff --git a/luni-kernel/src/main/java/java/lang/Thread.java b/luni-kernel/src/main/java/java/lang/Thread.java
index 3cde7e1..89d7ed6 100644
--- a/luni-kernel/src/main/java/java/lang/Thread.java
+++ b/luni-kernel/src/main/java/java/lang/Thread.java
@@ -73,6 +73,8 @@ import org.apache.harmony.security.fortress.SecurityUtils;
  */
 public class Thread implements Runnable {
 
+    private static final int NANOS_PER_MILLI = 1000000;
+
     /** Park states */
     private static class ParkState {
         /** park state indicating unparked */
@@ -973,7 +975,16 @@ public class Thread implements Runnable {
      * @since Android 1.0
      */
     public final void join() throws InterruptedException {
-        join(0, 0);
+        VMThread t = vmThread;
+        if (t == null) {
+            return;
+        }
+
+        synchronized (t) {
+            while (isAlive()) {
+                t.wait();
+            }
+        }
     }
 
     /**
@@ -1008,18 +1019,45 @@ public class Thread implements Runnable {
      * @since Android 1.0
      */
     public final void join(long millis, int nanos) throws InterruptedException {
-        if (millis < 0 || nanos < 0 || nanos > 999999) {
+        if (millis < 0 || nanos < 0 || nanos >= NANOS_PER_MILLI) {
             throw new IllegalArgumentException();
         }
 
-        VMThread t;
+        // avoid overflow: if total > 292,277 years, just wait forever
+        boolean overflow = millis >= (Long.MAX_VALUE - nanos) / NANOS_PER_MILLI;
+        boolean forever = (millis | nanos) == 0;
+        if (forever | overflow) {
+            join();
+            return;
+        }
 
-        t = this.vmThread;
+        VMThread t = vmThread;
+        if (t == null) {
+            return;
+        }
+
+        synchronized (t) {
+            if (!isAlive()) {
+                return;
+            }
+
+            // guaranteed not to overflow
+            long nanosToWait = millis * NANOS_PER_MILLI + nanos;
 
-        if (t != null) {
-            synchronized (t) {
-                if (isAlive())
-                    t.wait(millis, nanos);
+            // wait until this thread completes or the timeout has elapsed
+            long start = System.nanoTime();
+            while (true) {
+                t.wait(millis, nanos);
+                if (!isAlive()) {
+                    break;
+                }
+                long nanosElapsed = System.nanoTime() - start;
+                long nanosRemaining = nanosToWait - nanosElapsed;
+                if (nanosRemaining <= 0) {
+                    break;
+                }
+                millis = nanosRemaining / NANOS_PER_MILLI;
+                nanos = (int) (nanosRemaining - millis * NANOS_PER_MILLI);
             }
         }
     }
@@ -1491,8 +1529,8 @@ public class Thread implements Runnable {
                     break;
                 }
                 case ParkState.UNPARKED: {
-                    long millis = nanos / 1000000;
-                    nanos %= 1000000;
+                    long millis = nanos / NANOS_PER_MILLI;
+                    nanos %= NANOS_PER_MILLI;
 
                     parkState = ParkState.PARKED;
                     try {
@@ -1554,7 +1592,7 @@ public class Thread implements Runnable {
             if (delayMillis <= 0) {
                 parkState = ParkState.UNPARKED;
             } else {
-                parkFor(delayMillis * 1000000);
+                parkFor(delayMillis * NANOS_PER_MILLI);
             }
         }
     }