Nuked the segfault on exit bug everyone was seeing. The material lib could

have multiple ptrs to individual entries (aliases) but the destructor was
trying to delete every ptr so it would delete already freed memory for aliases.
I implimented a simple ref counting scheme (similar to the plib mechanism) to
track references to material lib entries and only "delete" them when the last
reference is removed.

diff --git a/src/Objects/matlib.cxx b/src/Objects/matlib.cxx
index 7103d976eeeee9188ca6a51c16884bfbda6a9d86..9d110bd692d762b0fc86cfec8882faba095b882d 100644 (file)
--- a/src/Objects/matlib.cxx
+++ b/src/Objects/matlib.cxx
@@ -72,18 +72,6 @@ static bool local_file_exists( const string& path ) {
     } else {
        return true;
     }
-
-#if 0
-    cout << path << " ";
-    FILE *fp = fopen( path.c_str(), "r" );
-    if ( fp == NULL ) {
-       cout << " doesn't exist\n";
-       return false;
-    } else {
-       cout << " exists\n";
-       return true;
-    }
-#endif
 }
 
 
@@ -123,6 +111,7 @@ bool FGMaterialLib::load( const string& mpath ) {
            FGNewMat *m = matlib[src_mat];
             if ( m != NULL ) {
                 matlib[dst_mat] = m;
+               m->ref();
             } else {
                 SG_LOG( SG_GENERAL, SG_ALERT,
                         "Bad material alias pointing to nonexistant material" );
@@ -139,6 +128,7 @@ bool FGMaterialLib::load( const string& mpath ) {
                 // create a pointer to a heap allocated copy of the structure
                FGNewMat *m = new FGNewMat;
                 *m = tmp;
+               m->ref();
 
                // build the ssgSimpleState
                SGPath tex_path( globals->get_fg_root() );
@@ -277,9 +267,9 @@ FGMaterialLib::~FGMaterialLib ( void ) {
     // Free up all the material entries first
     for ( material_map_iterator it = begin(); it != end(); it++ ) {
        FGNewMat *slot = it->second;
-        if ( slot != NULL ) {
+       slot->deRef();
+       if ( slot->getRef() <= 0 ) {
             delete slot;
-           it->second = NULL;
         }
     }
 }

diff --git a/src/Objects/newmat.cxx b/src/Objects/newmat.cxx
index 2fa702d61907d1ef04880f359ab9ff09a9a5c128..451b344ef59bf37c024834ac175afe283745b556 100644 (file)
--- a/src/Objects/newmat.cxx
+++ b/src/Objects/newmat.cxx
@@ -43,6 +43,7 @@ FGNewMat::FGNewMat ( void ) {
     wrapu = wrapv = 1;
     mipmap = 1;
     light_coverage = -1.0;
+    refcount = 0;
 }
 
 
@@ -67,6 +68,7 @@ FGNewMat::FGNewMat ( const string &mat_name, const string &tex_name )
     specular[0] = specular[1] = specular[2] = specular[3] = 1.0;
     emission[0] = emission[1] = emission[2] = emission[3] = 1.0;
     light_coverage = -1.0;
+    refcount = 0;
 }
 
 

diff --git a/src/Objects/newmat.hxx b/src/Objects/newmat.hxx
index acd9169bed0bdff875590824db086cbf404914ab..72a92ecc3232815d5cbfb9cdf3406e91cfa80749 100644 (file)
--- a/src/Objects/newmat.hxx
+++ b/src/Objects/newmat.hxx
@@ -92,6 +92,10 @@ private:
     // true if texture loading deferred, and not yet loaded
     bool texture_loaded;
 
+    // ref count so we can properly delete if we have multiple
+    // pointers to this record
+    int refcount;
+
 public:
 
     // Constructor
@@ -144,6 +148,10 @@ public:
 
     inline ssgStateSelector *get_state() const { return state; }
 
+    inline void ref() { refcount++; }
+    inline void deRef() { refcount--; }
+    inline int getRef() const { return refcount; }
+
     void dump_info();
 };