Hack to make RCCpp work on Linux.

We need to change the name of the library every time we call dlopen because otherwise even after closing it dlopen returns the same handler.
pamarcos · Jun 26, 2014 · 2ae5db3 · 2ae5db3
1 parent 5b24910
commit 2ae5db3
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Showing 3 changed files with 34 additions and 3 deletions.
diff --git a/Source/Engine/RCCpp/RCCppUnix.cpp b/Source/Engine/RCCpp/RCCppUnix.cpp
@@ -1,4 +1,4 @@
-//
+//
 // Copyright (c) 2008-2014 the Urho3D project.
 //
 // Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -40,7 +40,8 @@ RCCppUnix::RCCppUnix(Context* context) :
     library_(NULL),
     createObject_(NULL),
     destroyObject_(NULL),
-    compiler_(new RCCppGppCompiler(context_))
+    compiler_(new RCCppGppCompiler(context_)),
+    fileSystem_(context_->GetSubsystem<FileSystem>())
 {
 }
 
@@ -84,7 +85,23 @@ void RCCppUnix::DestroyObject(RCCppObject *object)
 
 bool RCCppUnix::LoadLib(const String& libraryPath)
 {
+    if (library_ != NULL)
+    {
+        UnloadLib();
+    }
+#ifdef __linux__
+    // Hack in case it's Linux. It seems dlopen caches the library name and in case
+    // the same library name is opened again (even after closing the library), it returns
+    // the same handler (memory address). Hence, every time we need to load the library we
+    // use a different name to avoid that happening.
+    static unsigned counter = 0;
+    String tmpLibraryPath = libraryPath + "." + String(counter++);
+    fileSystem_->Rename(libraryPath, tmpLibraryPath);
+    library_ = dlopen(tmpLibraryPath.CString(), RTLD_LAZY);
+    fileSystem_->Rename(tmpLibraryPath, libraryPath);
+#else
     library_ = dlopen(libraryPath.CString(), RTLD_LAZY);
+#endif
     if (library_ != NULL)
     {
         String name = GetFileName(libraryPath);
@@ -94,6 +111,7 @@ bool RCCppUnix::LoadLib(const String& libraryPath)
     }
     else
     {
+        LOGERROR("Error loading library " + libraryPath + ": " + dlerror());
         return false;
     }
 }
@@ -102,9 +120,14 @@ void RCCppUnix::UnloadLib()
 {
     if (library_ != NULL)
     {
-        dlclose(library_);
+        if (dlclose(library_) != 0)
+        {
+            LOGERROR("Error closing library: " + String(dlerror()));
+        }
         library_ = NULL;
         mainObject_ = NULL;
+        createObject_ = NULL;
+        destroyObject_ = NULL;
     }
 }
 

diff --git a/Source/Engine/RCCpp/RCCppUnix.h b/Source/Engine/RCCpp/RCCppUnix.h
@@ -36,6 +36,7 @@ namespace Urho3D
 class RCCppMainObject;
 class RCCppObject;
 class RCCppCompiler;
+class FileSystem;
 
 class URHO3D_API RCCppUnix : public RCCppImpl
 {
@@ -57,6 +58,7 @@ class URHO3D_API RCCppUnix : public RCCppImpl
     void* library_;
     PCreateRCCppObject createObject_;
     PDestroyRCCppObject destroyObject_;
+    FileSystem* fileSystem_;
 };
 
 }

diff --git a/Source/Engine/RCCpp/RCCppWin.cpp b/Source/Engine/RCCpp/RCCppWin.cpp
@@ -103,6 +103,10 @@ void RCCppWin::DestroyObject(RCCppObject *object)
 
 bool RCCppWin::LoadLib(const String& libraryPath)
 {
+    if (library_ != NULL)
+    {
+        UnloadLib();
+    }
     library_ = LoadLibrary(libraryPath.CString());
     if (library_ != NULL)
     {
@@ -124,6 +128,8 @@ void RCCppWin::UnloadLib()
         FreeLibrary(library_);
         library_ = NULL;
         mainObject_ = NULL;
+        createObject_ = NULL;
+        destroyObject_ = NULL;
 
         if (!oldLibPath_.Empty())
         {