From 891c73a1b74d9dc62680828db67e2e59d28ea015 Mon Sep 17 00:00:00 2001
From: Eric House <xwords@eehouse.org>
Date: Tue, 18 Dec 2018 06:55:23 -0800
Subject: [PATCH] make run() wait for gamePtr before starting loop

Was seeing race condition on slowest device where JNIThread init hadn't
finished before the event loop tried to use the gamePtr. So use
wait()/notifyAll() to fix.
---
 .../eehouse/android/xw4/jni/JNIThread.java    | 47 +++++++++++++------
 1 file changed, 32 insertions(+), 15 deletions(-)

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 3f197f307..3c90325e1 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
@@ -216,23 +216,29 @@ public class JNIThread extends Thread {
             if ( null != m_jniGamePtr ) {
                 Log.d( TAG, "configure(): m_jniGamePtr not null; that ok?" );
             }
-            m_jniGamePtr = null;
-            if ( null != stream ) {
-                m_jniGamePtr = XwJNI.initFromStream( m_rowid, stream, m_gi,
-                                                     dictNames, pairs.m_bytes,
-                                                     pairs.m_paths,
-                                                     m_gi.langName( m_context ),
-                                                     utils, null, cp, m_xport );
+
+            synchronized ( this ) {
+                m_jniGamePtr = null;
+                if ( null != stream ) {
+                    m_jniGamePtr = XwJNI.initFromStream( m_rowid, stream, m_gi,
+                                                         dictNames, pairs.m_bytes,
+                                                         pairs.m_paths,
+                                                         m_gi.langName( m_context ),
+                                                         utils, null, cp, m_xport );
+                }
+                if ( null == m_jniGamePtr ) {
+                    m_jniGamePtr = XwJNI.initNew( m_gi, dictNames, pairs.m_bytes,
+                                                  pairs.m_paths,
+                                                  m_gi.langName(m_context),
+                                                  utils, null, cp, m_xport );
+                }
+                Assert.assertNotNull( m_jniGamePtr );
+                notifyAll();
             }
-            if ( null == m_jniGamePtr ) {
-                m_jniGamePtr = XwJNI.initNew( m_gi, dictNames, pairs.m_bytes,
-                                              pairs.m_paths,
-                                              m_gi.langName(m_context),
-                                              utils, null, cp, m_xport );
-            }
-            Assert.assertNotNull( m_jniGamePtr );
+
             m_lastSavedState = Arrays.hashCode( stream );
         }
+        Log.d( TAG, "configure() => %b", success );
         return success;
     }
 
@@ -417,13 +423,24 @@ public class JNIThread extends Thread {
     }
 
     @SuppressWarnings("fallthrough")
+    @Override
     public void run()
     {
+        Log.d( TAG, "run() starting" );
         boolean[] barr = new boolean[2]; // scratch boolean
         for ( ; ; ) {
             synchronized ( this ) {
                 if ( m_stopped ) {
                     break;
+                } else if ( null == m_jniGamePtr ) {
+                    try {
+                        wait();
+                    } catch ( InterruptedException iex ) {
+                        Log.d( TAG, "exiting run() on interrupt: %s",
+                               iex.getMessage() );
+                        break;
+                    }
+                    continue;
                 }
             }
 
@@ -728,6 +745,7 @@ public class JNIThread extends Thread {
             m_jniGamePtr.release();
             m_jniGamePtr = null;
         }
+        Log.d( TAG, "run() finished" );
     } // run
 
     public void handleBkgrnd( JNICmd cmd, Object... args )
@@ -815,7 +833,6 @@ public class JNIThread extends Thread {
             result = s_instances.get( rowid );
             if ( null == result && makeNew ) {
                 result = new JNIThread( new GameLock( rowid, true ).lock() );
-                Assert.assertNotNull( result );
                 s_instances.put( rowid, result );
             }
             if ( null != result ) {