From 2afcbb4bc815e02f8b0c2e42f0047387b6bddb49 Mon Sep 17 00:00:00 2001
From: curt <curt>
Date: Sun, 20 May 2001 06:49:06 +0000
Subject: [PATCH] We can't remove ssg branches in the threaded tile page
 because if we happen to have attached an ssg loaded object to this branch,
 then plib will remove it and all it's states (and textures) which will call
 opengl api commands which will crash the program if run from a separate
 thread from the main render thread.

---
 src/Scenery/FGTileLoader.cxx | 5 +++++
 src/Scenery/FGTileLoader.hxx | 6 ++++--
 src/Scenery/newcache.cxx     | 5 +++--
 src/Scenery/tileentry.cxx    | 4 ++++
 src/Scenery/tileentry.hxx    | 2 ++
 src/Scenery/tilemgr.hxx      | 2 ++
 6 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/src/Scenery/FGTileLoader.cxx b/src/Scenery/FGTileLoader.cxx
index 8f04c78c8..661833e28 100644
--- a/src/Scenery/FGTileLoader.cxx
+++ b/src/Scenery/FGTileLoader.cxx
@@ -89,6 +89,7 @@ FGTileLoader::add( FGTileEntry* tile )
     tile_load_queue.push( tile );
 }
 
+#ifdef WISH_PLIB_WAS_THREADED // but it isn't
 /**
  * 
  */
@@ -97,6 +98,7 @@ FGTileLoader::remove( FGTileEntry* tile )
 {
     tile_free_queue.push( tile );
 }
+#endif
 
 /**
  * 
@@ -156,6 +158,7 @@ FGTileLoader::LoaderThread::run()
 
   	FGTileMgr::ready_to_attach( tile );
 
+#ifdef WISH_PLIB_WAS_THREADED // but it isn't
 	// Handle and pending removals
 	while ( !loader->tile_free_queue.empty() ) {
 	    cout << "freeing next tile ..." << endl;
@@ -164,6 +167,8 @@ FGTileLoader::LoaderThread::run()
 	    tile->free_tile();
 	    delete tile;
 	}
+#endif
+
     }
     pthread_cleanup_pop(1);
 }
diff --git a/src/Scenery/FGTileLoader.hxx b/src/Scenery/FGTileLoader.hxx
index 258232a52..f8d1ba03b 100644
--- a/src/Scenery/FGTileLoader.hxx
+++ b/src/Scenery/FGTileLoader.hxx
@@ -60,11 +60,13 @@ public:
      */
     void add( FGTileEntry* tile );
 
+#ifdef WISH_PLIB_WAS_THREADED // but it isn't
     /**
      * Remove a tile from memory.
      * @param tile The tile to be removed from memory.
      */
     void remove( FGTileEntry* tile );
+#endif
 
     /**
      * The tile loader thread will only load one tile per call to the
@@ -89,10 +91,10 @@ private:
      * FIFO queue of tiles to load from data files.
      */
     SGBlockingQueue< FGTileEntry * > tile_load_queue;
-    SGBlockingQueue< FGTileEntry * > tile_free_queue;
+    // SGBlockingQueue< FGTileEntry * > tile_free_queue;
 #else
     queue< FGTileEntry * > tile_load_queue;
-    queue< FGTileEntry * > tile_free_queue;
+    // queue< FGTileEntry * > tile_free_queue;
 #endif
 
     /**
diff --git a/src/Scenery/newcache.cxx b/src/Scenery/newcache.cxx
index c7e59195e..841fb4bac 100644
--- a/src/Scenery/newcache.cxx
+++ b/src/Scenery/newcache.cxx
@@ -64,9 +64,10 @@ void FGNewCache::entry_free( long cache_index ) {
     SG_LOG( SG_TERRAIN, SG_DEBUG, "FREEING CACHE ENTRY = " << cache_index );
     FGTileEntry *tile = tile_cache[cache_index];
     tile->disconnect_ssg_nodes();
-    tile->sched_removal();
 
-#if 0
+#ifdef WISH_PLIB_WAS_THREADED
+    tile->sched_removal();
+#else // plib isn't threaded so we always go here
     tile->free_tile();
     delete tile;
 #endif
diff --git a/src/Scenery/tileentry.cxx b/src/Scenery/tileentry.cxx
index 4bc931ae1..5ba0900d8 100644
--- a/src/Scenery/tileentry.cxx
+++ b/src/Scenery/tileentry.cxx
@@ -105,11 +105,15 @@ static void my_remove_branch( ssgBranch * branch ) {
 }
 
 
+#ifdef WISH_PLIB_WAS_THREADED // but it isn't
+
 // Schedule tile to be freed/removed
 void FGTileEntry::sched_removal() {
     global_tile_mgr.ready_to_delete( this );
 }
 
+#endif
+
 
 // Clean up the memory used by this tile and delete the arrays used by
 // ssg as well as the whole ssg branch
diff --git a/src/Scenery/tileentry.hxx b/src/Scenery/tileentry.hxx
index 5199f8f92..d1fdb93e2 100644
--- a/src/Scenery/tileentry.hxx
+++ b/src/Scenery/tileentry.hxx
@@ -177,8 +177,10 @@ public:
     // Destructor
     ~FGTileEntry();
 
+#ifdef WISH_PLIB_WAS_THREADED // but it isn't
     // Schedule tile to be freed/removed
     void sched_removal();
+#endif
 
     // Clean up the memory used by this tile and delete the arrays
     // used by ssg as well as the whole ssg branch
diff --git a/src/Scenery/tilemgr.hxx b/src/Scenery/tilemgr.hxx
index 0dfc968ed..b4ae8ac1d 100644
--- a/src/Scenery/tilemgr.hxx
+++ b/src/Scenery/tilemgr.hxx
@@ -143,10 +143,12 @@ public:
      */
     static void ready_to_attach( FGTileEntry *t ) { attach_queue.push( t ); }
 
+#ifdef WISH_PLIB_WAS_THREADED // but it isn't
     /**
      * Tile is detatched from scene graph and is ready to delete
      */
     inline void ready_to_delete( FGTileEntry *t ) { loader.remove( t ); }
+#endif
 
     /**
      * Add a pending model to the 'deferred model load' queue
-- 
2.39.5