From 99eafd9c609add7f548fe1f15540634972c9c96c Mon Sep 17 00:00:00 2001
From: Eric House <xwords@eehouse.org>
Date: Sat, 9 Mar 2019 07:17:07 -0800
Subject: [PATCH] add retain()/release()

Seems to work but needs testing!
---
 .../eehouse/android/xw4/BoardDelegate.java    |  1 +
 .../org/eehouse/android/xw4/GameLock.java     | 19 ++++++++++++++++---
 .../eehouse/android/xw4/jni/JNIThread.java    | 12 ++----------
 3 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/BoardDelegate.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/BoardDelegate.java
index e3bcdb9ae..231b4a747 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/BoardDelegate.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/BoardDelegate.java
@@ -595,6 +595,7 @@ public class BoardDelegate extends DelegateBase
                     } else {
                         s_noLockCount = 0;
                         m_jniThreadRef = JNIThread.getRetained( lock );
+                        lock.release();
 
                         // see http://stackoverflow.com/questions/680180/where-to-stop- \
                         // destroy-threads-in-android-service-class
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/GameLock.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/GameLock.java
index a739f878a..606e80325 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/GameLock.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/GameLock.java
@@ -28,6 +28,7 @@ import java.util.Formatter;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Stack;
+import java.util.concurrent.atomic.AtomicInteger;
 
 import android.support.annotation.NonNull;
 
@@ -58,6 +59,7 @@ public class GameLock implements AutoCloseable, Serializable {
     // private static final long ASSERT_TIME = 2000;
     private static final long THROW_TIME = 1000;
     private long m_rowid;
+    private AtomicInteger m_lockCount = new AtomicInteger(1);
 
     private static class Owner {
         Thread mThread;
@@ -314,15 +316,26 @@ public class GameLock implements AutoCloseable, Serializable {
         return getFor( rowid ).lockRO( maxMillis );
     }
 
-    public void unlock()
+    public void release()
     {
-        getFor( m_rowid ).unlock();
+        int count = m_lockCount.decrementAndGet();
+        Log.d( TAG, "%s.release(): count NOW %d", this, count );
+        if ( count == 0 ) {
+            getFor( m_rowid ).unlock();
+        }
+    }
+
+    public GameLock retain()
+    {
+        int count = m_lockCount.incrementAndGet();
+        Log.d( TAG, "%s.retain(): count NOW %d", this, count );
+        return this;
     }
 
     @Override
     public void close()
     {
-        unlock();
+        release();
     }
     
     public long getRowid()
diff --git a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/jni/JNIThread.java b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/jni/JNIThread.java
index 102fd6898..b709f4a3a 100644
--- a/xwords4/android/app/src/main/java/org/eehouse/android/xw4/jni/JNIThread.java
+++ b/xwords4/android/app/src/main/java/org/eehouse/android/xw4/jni/JNIThread.java
@@ -165,7 +165,7 @@ public class JNIThread extends Thread implements AutoCloseable {
 
     private JNIThread( GameLock lock )
     {
-        m_lock = lock;
+        m_lock = lock.retain();
         m_rowid = lock.getRowid();
         m_queue = new LinkedBlockingQueue<QueueElem>();
     }
@@ -273,7 +273,7 @@ public class JNIThread extends Thread implements AutoCloseable {
     private synchronized void unlockOnce()
     {
         if ( null != m_lock ) {
-            m_lock.unlock();
+            m_lock.release();
             m_lock = null;
         }
     }
@@ -866,14 +866,6 @@ public class JNIThread extends Thread implements AutoCloseable {
             if ( null == result && null != lock ) {
                 result = new JNIThread( lock );
                 s_instances.put( rowid, result );
-            } else if ( null != lock ) {
-                // unlock if we're not using it. This is a hack needed because
-                // we don't have retain/release semantics. The caller is done
-                // with the lock and expects us to keep it. If we don't need
-                // it we need to unlock it. Fix is for JNIThread.__init() to
-                // be able to retain() it and caller to release() it after we
-                // return.
-                lock.unlock();
             }
             if ( null != result ) {
                 result.retain_sync();