From f90d76329b561f26bc4be84c1a50fcd3f0bfb334 Mon Sep 17 00:00:00 2001
From: Eric House <xwords@eehouse.org>
Date: Wed, 30 Sep 2020 17:21:18 -0700
Subject: [PATCH] use semaphore to protect known players data

Requires adding a common method called by platform code on creating a
new dutil ctxt.
---
 xwords4/android/jni/Android.mk    | 1 +
 xwords4/android/jni/utilwrapper.c | 3 +--
 xwords4/common/config.mk          | 2 ++
 xwords4/common/dutil.h            | 7 ++++++-
 xwords4/common/knownplyr.c        | 4 ++++
 xwords4/linux/lindutil.c          | 4 +++-
 6 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/xwords4/android/jni/Android.mk b/xwords4/android/jni/Android.mk
index a5ed47bc4..deac3ef65 100644
--- a/xwords4/android/jni/Android.mk
+++ b/xwords4/android/jni/Android.mk
@@ -86,6 +86,7 @@ COMMON_SRC_FILES +=        \
 	$(COMMON_PATH)/dbgutil.c    \
 	$(COMMON_PATH)/nli.c    	\
 	$(COMMON_PATH)/smsproto.c  	\
+	$(COMMON_PATH)/dutil.c  	\
 	$(COMMON_PATH)/device.c  	\
 	$(COMMON_PATH)/knownplyr.c  \
 
diff --git a/xwords4/android/jni/utilwrapper.c b/xwords4/android/jni/utilwrapper.c
index c704bb54b..29e13cbb6 100644
--- a/xwords4/android/jni/utilwrapper.c
+++ b/xwords4/android/jni/utilwrapper.c
@@ -1006,6 +1006,7 @@ makeDUtil( MPFORMAL JNIEnv* env,
            JNIUtilCtxt* jniutil, void* closure )
 {
     AndDUtil* dutil = (AndDUtil*)XP_CALLOC( mpool, sizeof(*dutil) );
+    dutil_super_init( MPPARM(mpool) &dutil->dutil );
 #ifdef MAP_THREAD_TO_ENV
     dutil->ti = ti;
 #endif
@@ -1017,8 +1018,6 @@ makeDUtil( MPFORMAL JNIEnv* env,
         dutil->jdutil = (*env)->NewGlobalRef( env, jdutil );
     }
 
-    MPASSIGN( dutil->dutil.mpool, mpool );
-
     DUtilVtable* vtable = &dutil->dutil.vtable;
 #define SET_DPROC(nam) vtable->m_dutil_##nam = and_dutil_##nam
     SET_DPROC(getCurSeconds);
diff --git a/xwords4/common/config.mk b/xwords4/common/config.mk
index e34e9c41a..2991d5907 100644
--- a/xwords4/common/config.mk
+++ b/xwords4/common/config.mk
@@ -49,6 +49,7 @@ COMMONSRC = \
 	$(COMMONDIR)/dictmgr.c \
 	$(COMMONDIR)/dbgutil.c \
 	$(COMMONDIR)/smsproto.c \
+	$(COMMONDIR)/dutil.c \
 	$(COMMONDIR)/device.c \
 
 # PENDING: define this in terms of above!!!
@@ -88,6 +89,7 @@ COMMON5 = \
 	$(COMMONOBJDIR)/dictmgr.o \
 	$(COMMONOBJDIR)/dbgutil.o \
 	$(COMMONOBJDIR)/smsproto.o \
+	$(COMMONOBJDIR)/dutil.o \
 	$(COMMONOBJDIR)/device.o \
 	$(COMMONOBJDIR)/knownplyr.o \
 
diff --git a/xwords4/common/dutil.h b/xwords4/common/dutil.h
index 308e502ef..c21351a1a 100644
--- a/xwords4/common/dutil.h
+++ b/xwords4/common/dutil.h
@@ -84,11 +84,16 @@ struct XW_DUtilCtxt {
     DUtilVtable vtable;
     void* closure;
     void* devCtxt;              /* owned by device.c */
-    void* kpCtxt;               /* owned by knownplyr.c */
+#ifdef XWFEATURE_KNOWNPLAYERS   /* owned by knownplyr.c */
+    void* kpCtxt;
+    pthread_mutex_t kpMutex;
+#endif
     VTableMgr* vtMgr;
     MPSLOT
 };
 
+void dutil_super_init( MPFORMAL XW_DUtilCtxt* dutil );
+
 /* This one cheats: direct access */
 #define dutil_getVTManager(duc) (duc)->vtMgr
 
diff --git a/xwords4/common/knownplyr.c b/xwords4/common/knownplyr.c
index 536588b75..e299428e5 100644
--- a/xwords4/common/knownplyr.c
+++ b/xwords4/common/knownplyr.c
@@ -64,6 +64,8 @@ static KPState*
 loadState( XW_DUtilCtxt* dutil, XWEnv xwe )
 {
     LOG_FUNC();
+    pthread_mutex_lock( &dutil->kpMutex );
+
     KPState* state = (KPState*)dutil->kpCtxt;
     if ( NULL == state ) {
         dutil->kpCtxt = state = XP_CALLOC( dutil->mpool, sizeof(*state) );
@@ -107,6 +109,8 @@ releaseState( XW_DUtilCtxt* dutil, XWEnv xwe, KPState* state )
     XP_ASSERT( state->inUse );
     saveState( dutil, xwe, state );
     state->inUse = XP_FALSE;
+
+    pthread_mutex_unlock( &dutil->kpMutex );
 }
 
 static const XP_UCHAR*
diff --git a/xwords4/linux/lindutil.c b/xwords4/linux/lindutil.c
index b2876ae6c..125b112a0 100644
--- a/xwords4/linux/lindutil.c
+++ b/xwords4/linux/lindutil.c
@@ -133,6 +133,9 @@ XW_DUtilCtxt*
 dutils_init( MPFORMAL VTableMgr* vtMgr, void* closure )
 {
     XW_DUtilCtxt* result = XP_CALLOC( mpool, sizeof(*result) );
+
+    dutil_super_init( MPPARM(mpool) result );
+
     result->vtMgr = vtMgr;
     result->closure = closure;
 
@@ -170,7 +173,6 @@ dutils_init( MPFORMAL VTableMgr* vtMgr, void* closure )
 
     assertTableFull( &result->vtable, sizeof(result->vtable), "lindutil" );
 
-    MPASSIGN( result->mpool, mpool );
     return result;
 }