[Bug classpath/22734] classpath0.08: java.lang.Runtime.loadLibrary : causes UnsatisfiedLinkException when VM is intializing

[gcc-bugzilla at gcc dot gnu dot org]

Hi,
While dealing with JAMVM I came across an exceptions related problem with
java.lang.Runtime.loadLibrary.

Issue is that when scanning java.library.path dirs to find the required lib
"loadLibrary" uses "load". In its turn "load" raise exeception if lib is not
find.

In case of JAMVM when this exeception hapens during intialization it aborts VM.
Because of that LD_LIBRARY_PATH is not scanned completely and lib is not
located at all.

This also could be attributed to JAMVM specifics and probably it is true. Yet,
I can understand also that VM exception handling may not be that "accurate"
during VM build-up therefore I'd see it as Classpath issue as well.

Attached is a patch against Runtime.java which overcomes the problem by doing
exactly what "load" does but without mentioned exception problem.

See sf.net/projects/jamvm:Forums-Help where this issues has been raised too.

-- niki


------- Comment #1 from from-classpath at savannah dot gnu dot org  2004-04-18 
22:07 -------
THis is JamVM specific.  THe patch should be rejected, and JamVM fixed.


------- Comment #2 from from-classpath at savannah dot gnu dot org  2004-04-30 
15:14 -------
Thanks. I made your suggestion a bit more abstract which cleaned up library
loading a bit. Hopefully this prevents early bootstrap triggering of exception
handling and it is hopefully be a little more efficient if your library path is
large.

2004-04-30  Mark Wielaard  <address@hidden>

        Reported by Nikolay Fiykov [bugs #8611]
        * java/lang/Runtime.java (loadLib): New private method.
        (load): Call loadLib.
        (loadLibrary): Call loadLib.

diff -u -r1.6 Runtime.java
--- java/lang/Runtime.java      17 Apr 2004 17:08:22 -0000      1.6
+++ java/lang/Runtime.java      30 Apr 2004 15:08:12 -0000
@@ -670,11 +664,20 @@
    */
   public void load(String filename)
   {
+    if (loadLib(filename) == 0)
+      throw new UnsatisfiedLinkError("Could not load library " + filename);
+  }
+
+  // Private version of load(String) that doesn't throw Exception on
+  // load error, but it does do security checks (which can throw
+  // SecurityExceptions). Convenience method for early bootstrap
+  // process.
+  private int loadLib(String filename)
+  {
     SecurityManager sm = securityManager; // Be thread-safe!
     if (sm != null)
       sm.checkLink(filename);
-    if (VMRuntime.nativeLoad(filename) == 0)
-      throw new UnsatisfiedLinkError("Could not load library " + filename);
+    return VMRuntime.nativeLoad(filename);
   }

   /**
@@ -706,21 +709,18 @@
         filename = cl.findLibrary(libname);
         if (filename != null)
           {
-            load(filename);
-            return;
+           // Use loadLib so no UnsatisfiedLinkError are thrown.
+            if (loadLib(filename) != 0)
+             return;
           }
       }
+
     filename = System.mapLibraryName(libname);
     for (int i = 0; i < libpath.length; i++)
-      try
-        {
-          load(libpath[i] + filename);
-          return;
-        }
-      catch (UnsatisfiedLinkError e)
-        {
-          // Try next path element.
-        }
+      // Use loadLib so no UnsatisfiedLinkError are thrown.
+      if (loadLib(libpath[i] + filename) != 0)
+       return;
+
     throw new UnsatisfiedLinkError("Could not find library " + libname + ".");
   }



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22734