* gnu/gcj/runtime/natFinalizerThread.cc: New file.

	* java/lang/natRuntime.cc: Include FinalizerThread.h.
	(runFinalization): Call finalizerReady.
	* nogc.cc (_Jv_GCInitializeFinalizers): New function.
	* prims.cc: Include VirtualMachineError.h, FinalizerThread.h.
	(_Jv_CreateJavaVM): Start the finalizer thread.
	* no-threads.cc: Include InternalError.h.
	(_Jv_ThreadStart): Throw InternalError.
	(_Jv_ThreadInitData): Don't throw error if this is not the first
	thread.
	* Makefile.in: Rebuilt.
	* Makefile.am (ordinary_java_source_files): Added
	FinalizerThread.java.
	(nat_source_files): Added natFinalizerThread.cc.
	* include/jvm.h (_Jv_GCInitializeFinalizers): Declare.
	* boehm.cc (_Jv_GCInitializeFinalizers): New function.
	* gnu/gcj/runtime/FirstThread.java (run): Start finalizer thread.
	* gnu/gcj/runtime/FinalizerThread.java: New file.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@46163 138bc75d-0d04-0410-961f-82ee72b054a4

12 files changed, 210 insertions, 39 deletions

diff --git a/libjava/ChangeLog b/libjava/ChangeLog
index 6807a7b0fff..37ef2aa6a24 100644
--- a/libjava/ChangeLog
+++ b/libjava/ChangeLog
@@ -1,3 +1,24 @@
+2001-10-10  Tom Tromey  <tromey@redhat.com>
+
+	* gnu/gcj/runtime/natFinalizerThread.cc: New file.
+	* java/lang/natRuntime.cc: Include FinalizerThread.h.
+	(runFinalization): Call finalizerReady.
+	* nogc.cc (_Jv_GCInitializeFinalizers): New function.
+	* prims.cc: Include VirtualMachineError.h, FinalizerThread.h.
+	(_Jv_CreateJavaVM): Start the finalizer thread.
+	* no-threads.cc: Include InternalError.h.
+	(_Jv_ThreadStart): Throw InternalError.
+	(_Jv_ThreadInitData): Don't throw error if this is not the first
+	thread.
+	* Makefile.in: Rebuilt.
+	* Makefile.am (ordinary_java_source_files): Added
+	FinalizerThread.java.
+	(nat_source_files): Added natFinalizerThread.cc.
+	* include/jvm.h (_Jv_GCInitializeFinalizers): Declare.
+	* boehm.cc (_Jv_GCInitializeFinalizers): New function.
+	* gnu/gcj/runtime/FirstThread.java (run): Start finalizer thread.
+	* gnu/gcj/runtime/FinalizerThread.java: New file.
+
 2001-10-09  Per Bothner  <per@bothner.com>
 
 	* strtod.c (_strtod_r):  Logic to check for missing digits
diff --git a/libjava/Makefile.am b/libjava/Makefile.am
index 91d437fed9d..3b5541260f5 100644
--- a/libjava/Makefile.am
+++ b/libjava/Makefile.am
@@ -1137,6 +1137,7 @@ gnu/gcj/protocol/http/Handler.java \
 gnu/gcj/protocol/jar/Connection.java \
 gnu/gcj/protocol/jar/Handler.java \
 gnu/gcj/runtime/FileDeleter.java \
+gnu/gcj/runtime/FinalizerThread.java \
 gnu/gcj/runtime/FirstThread.java \
 gnu/gcj/runtime/SharedLibLoader.java \
 gnu/gcj/runtime/VMClassLoader.java \
@@ -1495,6 +1496,7 @@ gnu/gcj/convert/natOutput_SJIS.cc \
 gnu/gcj/io/natSimpleSHSStream.cc \
 gnu/gcj/io/shs.cc \
 gnu/gcj/protocol/core/natCoreInputStream.cc \
+gnu/gcj/runtime/natFinalizerThread.cc \
 gnu/gcj/runtime/natFirstThread.cc \
 gnu/gcj/runtime/natSharedLibLoader.cc \
 java/io/natFile.cc \
diff --git a/libjava/Makefile.in b/libjava/Makefile.in
index 1c605a20e49..5204ced139f 100644
--- a/libjava/Makefile.in
+++ b/libjava/Makefile.in
@@ -123,26 +123,38 @@ libgcj_basedir = @libgcj_basedir@
 mkinstalldirs = @mkinstalldirs@
 
 AUTOMAKE_OPTIONS = foreign
-@TESTSUBDIR_TRUE@SUBDIRS = @TESTSUBDIR_TRUE@$(DIRLTDL) testsuite gcj include
-@TESTSUBDIR_FALSE@SUBDIRS = @TESTSUBDIR_FALSE@$(DIRLTDL) gcj include
-@USE_LIBDIR_TRUE@toolexeclibdir = @USE_LIBDIR_TRUE@$(libdir)$(MULTISUBDIR)
-@USE_LIBDIR_FALSE@toolexeclibdir = @USE_LIBDIR_FALSE@$(toolexecdir)/lib$(MULTISUBDIR)
-@USE_LIBDIR_FALSE@toolexecdir = @USE_LIBDIR_FALSE@$(exec_prefix)/$(target_alias)
-@XLIB_AWT_TRUE@cond_x_ltlibrary = @XLIB_AWT_TRUE@libgcjx.la
-@XLIB_AWT_FALSE@cond_x_ltlibrary = 
+@TESTSUBDIR_TRUE@SUBDIRS = \
+@TESTSUBDIR_TRUE@$(DIRLTDL) testsuite gcj include
+@TESTSUBDIR_FALSE@SUBDIRS = \
+@TESTSUBDIR_FALSE@$(DIRLTDL) gcj include
+@USE_LIBDIR_TRUE@toolexeclibdir = \
+@USE_LIBDIR_TRUE@$(libdir)$(MULTISUBDIR)
+@USE_LIBDIR_FALSE@toolexeclibdir = \
+@USE_LIBDIR_FALSE@$(toolexecdir)/lib$(MULTISUBDIR)
+@USE_LIBDIR_FALSE@toolexecdir = \
+@USE_LIBDIR_FALSE@$(exec_prefix)/$(target_alias)
+@XLIB_AWT_TRUE@cond_x_ltlibrary = \
+@XLIB_AWT_TRUE@libgcjx.la
+@XLIB_AWT_FALSE@cond_x_ltlibrary = \
 
 toolexeclib_LTLIBRARIES = libgcj.la $(cond_x_ltlibrary)
 toolexeclib_DATA = libgcj.spec
 data_DATA = libgcj.jar
 
-@NATIVE_TRUE@bin_PROGRAMS = @NATIVE_TRUE@jv-convert gij rmic rmiregistry
+@NATIVE_TRUE@bin_PROGRAMS = \
+@NATIVE_TRUE@jv-convert gij rmic rmiregistry
 
 bin_SCRIPTS = addr2name.awk
-@CANADIAN_TRUE@@NULL_TARGET_TRUE@ZIP = @CANADIAN_TRUE@@NULL_TARGET_TRUE@$(MULTIBUILDTOP)../$(COMPPATH)/fastjar/jar$(EXEEXT)
-@CANADIAN_TRUE@@NULL_TARGET_FALSE@ZIP = @CANADIAN_TRUE@@NULL_TARGET_FALSE@jar
-@CANADIAN_FALSE@ZIP = @CANADIAN_FALSE@$(MULTIBUILDTOP)../$(COMPPATH)/fastjar/jar$(EXEEXT)
-@CANADIAN_TRUE@GCJH = @CANADIAN_TRUE@gcjh
-@CANADIAN_FALSE@GCJH = @CANADIAN_FALSE@$(MULTIBUILDTOP)../$(COMPPATH)/gcc/gcjh$(EXEEXT)
+@CANADIAN_TRUE@@NULL_TARGET_TRUE@ZIP = \
+@CANADIAN_TRUE@@NULL_TARGET_TRUE@$(MULTIBUILDTOP)../$(COMPPATH)/fastjar/jar$(EXEEXT)
+@CANADIAN_TRUE@@NULL_TARGET_FALSE@ZIP = \
+@CANADIAN_TRUE@@NULL_TARGET_FALSE@jar
+@CANADIAN_FALSE@ZIP = \
+@CANADIAN_FALSE@$(MULTIBUILDTOP)../$(COMPPATH)/fastjar/jar$(EXEEXT)
+@CANADIAN_TRUE@GCJH = \
+@CANADIAN_TRUE@gcjh
+@CANADIAN_FALSE@GCJH = \
+@CANADIAN_FALSE@$(MULTIBUILDTOP)../$(COMPPATH)/gcc/gcjh$(EXEEXT)
 
 GCJ_WITH_FLAGS = $(GCJ) --encoding=UTF-8
 
@@ -162,8 +174,10 @@ AM_CXXFLAGS = -fno-rtti -fnon-call-exceptions \
 	@LIBGCJ_CXXFLAGS@ @X_CFLAGS@ $(WARNINGS) -D_GNU_SOURCE \
 	-DPREFIX="\"$(prefix)\""
 
-@USING_GCC_TRUE@AM_CFLAGS = @USING_GCC_TRUE@@LIBGCJ_CFLAGS@ $(WARNINGS)
-@USING_GCC_FALSE@AM_CFLAGS = @USING_GCC_FALSE@@LIBGCJ_CFLAGS@
+@USING_GCC_TRUE@AM_CFLAGS = \
+@USING_GCC_TRUE@@LIBGCJ_CFLAGS@ $(WARNINGS)
+@USING_GCC_FALSE@AM_CFLAGS = \
+@USING_GCC_FALSE@@LIBGCJ_CFLAGS@
 
 JCFLAGS = -g
 JC1FLAGS = @LIBGCJ_JAVAFLAGS@ $(GCJFLAGS)
@@ -232,7 +246,8 @@ extra_headers = java/lang/Object.h java/lang/Class.h
 
 NM = nm
 
-@NATIVE_TRUE@@MAINTAINER_MODE_TRUE@noinst_PROGRAMS = @NATIVE_TRUE@@MAINTAINER_MODE_TRUE@gen-from-JIS
+@NATIVE_TRUE@@MAINTAINER_MODE_TRUE@noinst_PROGRAMS = \
+@NATIVE_TRUE@@MAINTAINER_MODE_TRUE@gen-from-JIS
 
 CONVERT_DIR = gnu/gcj/convert
 
@@ -863,6 +878,7 @@ gnu/gcj/protocol/http/Handler.java \
 gnu/gcj/protocol/jar/Connection.java \
 gnu/gcj/protocol/jar/Handler.java \
 gnu/gcj/runtime/FileDeleter.java \
+gnu/gcj/runtime/FinalizerThread.java \
 gnu/gcj/runtime/FirstThread.java \
 gnu/gcj/runtime/SharedLibLoader.java \
 gnu/gcj/runtime/VMClassLoader.java \
@@ -1220,6 +1236,7 @@ gnu/gcj/convert/natOutput_SJIS.cc \
 gnu/gcj/io/natSimpleSHSStream.cc \
 gnu/gcj/io/shs.cc \
 gnu/gcj/protocol/core/natCoreInputStream.cc \
+gnu/gcj/runtime/natFinalizerThread.cc \
 gnu/gcj/runtime/natFirstThread.cc \
 gnu/gcj/runtime/natSharedLibLoader.cc \
 java/io/natFile.cc \
@@ -1385,13 +1402,14 @@ gnu/gcj/convert/natIconv.lo gnu/gcj/convert/natInput_EUCJIS.lo \
 gnu/gcj/convert/natInput_SJIS.lo gnu/gcj/convert/natOutput_EUCJIS.lo \
 gnu/gcj/convert/natOutput_SJIS.lo gnu/gcj/io/natSimpleSHSStream.lo \
 gnu/gcj/io/shs.lo gnu/gcj/protocol/core/natCoreInputStream.lo \
-gnu/gcj/runtime/natFirstThread.lo gnu/gcj/runtime/natSharedLibLoader.lo \
-java/io/natFile.lo java/io/natFileDescriptor.lo \
-java/io/natObjectInputStream.lo java/io/natObjectOutputStream.lo \
-java/lang/natCharacter.lo java/lang/natClass.lo \
-java/lang/natClassLoader.lo java/lang/natConcreteProcess.lo \
-java/lang/natDouble.lo java/lang/natFloat.lo java/lang/natMath.lo \
-java/lang/natObject.lo java/lang/natRuntime.lo java/lang/natString.lo \
+gnu/gcj/runtime/natFinalizerThread.lo gnu/gcj/runtime/natFirstThread.lo \
+gnu/gcj/runtime/natSharedLibLoader.lo java/io/natFile.lo \
+java/io/natFileDescriptor.lo java/io/natObjectInputStream.lo \
+java/io/natObjectOutputStream.lo java/lang/natCharacter.lo \
+java/lang/natClass.lo java/lang/natClassLoader.lo \
+java/lang/natConcreteProcess.lo java/lang/natDouble.lo \
+java/lang/natFloat.lo java/lang/natMath.lo java/lang/natObject.lo \
+java/lang/natRuntime.lo java/lang/natString.lo \
 java/lang/natStringBuffer.lo java/lang/natSystem.lo \
 java/lang/natThread.lo java/lang/natThrowable.lo \
 java/lang/ref/natReference.lo java/lang/reflect/natArray.lo \
@@ -1500,9 +1518,12 @@ DEP_FILES =  .deps/$(srcdir)/$(CONVERT_DIR)/gen-from-JIS.P \
 .deps/gnu/gcj/protocol/http/Handler.P \
 .deps/gnu/gcj/protocol/jar/Connection.P \
 .deps/gnu/gcj/protocol/jar/Handler.P \
-.deps/gnu/gcj/runtime/FileDeleter.P .deps/gnu/gcj/runtime/FirstThread.P \
+.deps/gnu/gcj/runtime/FileDeleter.P \
+.deps/gnu/gcj/runtime/FinalizerThread.P \
+.deps/gnu/gcj/runtime/FirstThread.P \
 .deps/gnu/gcj/runtime/SharedLibLoader.P \
 .deps/gnu/gcj/runtime/VMClassLoader.P \
+.deps/gnu/gcj/runtime/natFinalizerThread.P \
 .deps/gnu/gcj/runtime/natFirstThread.P \
 .deps/gnu/gcj/runtime/natSharedLibLoader.P .deps/gnu/gcj/xlib/Clip.P \
 .deps/gnu/gcj/xlib/Colormap.P .deps/gnu/gcj/xlib/Display.P \
@@ -2485,7 +2506,7 @@ distdir: $(DISTFILES)
 	@for file in $(DISTFILES); do \
 	  d=$(srcdir); \
 	  if test -d $$d/$$file; then \
-	    cp -pr $$d/$$file $(distdir)/$$file; \
+	    cp -pr $$/$$file $(distdir)/$$file; \
 	  else \
 	    test -f $(distdir)/$$file \
 	    || ln $$d/$$file $(distdir)/$$file 2> /dev/null \
diff --git a/libjava/boehm.cc b/libjava/boehm.cc
index 19b58bae908..e3dfe89f1e1 100644
--- a/libjava/boehm.cc
+++ b/libjava/boehm.cc
@@ -544,6 +544,13 @@ _Jv_AllocTraceOne (jsize size /* includes vtable slot */)
 #endif /* JV_HASH_SYNCHRONIZATION */
 
 void
+_Jv_GCInitializeFinalizers (void (*notifier) (void))
+{
+  GC_finalize_on_demand = 1;
+  GC_finalizer_notifier = notifier;
+}
+
+void
 _Jv_GCRegisterDisappearingLink (jobject *objp)
 {
   GC_general_register_disappearing_link ((GC_PTR *) objp, (GC_PTR) *objp);
diff --git a/libjava/gnu/gcj/runtime/FinalizerThread.java b/libjava/gnu/gcj/runtime/FinalizerThread.java
new file mode 100644
index 00000000000..e333d7a41c7
--- /dev/null
+++ b/libjava/gnu/gcj/runtime/FinalizerThread.java
@@ -0,0 +1,73 @@
+// FinalizerThread.java -- Thread in which finalizers are run.
+
+/* Copyright (C) 2001  Free Software Foundation
+
+   This file is part of libgcj.
+
+This software is copyrighted work licensed under the terms of the
+Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
+details.  */
+
+package gnu.gcj.runtime;
+
+/**
+ * @author Tom Tromey <tromey@redhat.com>
+ * @date October 3, 2001
+ */
+public final class FinalizerThread extends Thread
+{
+  // Finalizers must be run in a thread with no Java-visible locks
+  // held.  This qualifies because we don't make the lock visible.
+  private static final Object lock = new Object ();
+
+  // This is true if the finalizer thread started successfully.  It
+  // might be false if, for instance, there are no threads on the
+  // current platform.  In this situation we run finalizers in the
+  // caller's thread.
+  private static boolean thread_started = false;
+
+  public FinalizerThread ()
+  {
+    super ("LibgcjInternalFinalizerThread");
+    setDaemon (true);
+  }
+
+  // This is called by the runtime when a finalizer is ready to be
+  // run.  It simply wakes up the finalizer thread.
+  public static void finalizerReady ()
+  {
+    synchronized (lock)
+      {
+	if (! thread_started)
+	  runFinalizers ();
+	else
+	  lock.notify ();
+      }
+  }
+
+  // Actually run the finalizers.
+  private static native void runFinalizers ();
+
+  public void run ()
+  {
+    // Wait on a lock.  Whenever we wake up, try to invoke the
+    // finalizers.
+    synchronized (lock)
+      {
+	thread_started = true;
+	while (true)
+	  {
+	    try
+	      {
+		lock.wait ();
+	      }
+	    catch (InterruptedException _)
+	      {
+		// Just ignore it.  It doesn't hurt to run finalizers
+		// when none are pending.
+	      }
+	    runFinalizers ();
+	  }
+      }
+  }
+}
diff --git a/libjava/gnu/gcj/runtime/FirstThread.java b/libjava/gnu/gcj/runtime/FirstThread.java
index c52ab42c0ef..fbc7a5bee2b 100644
--- a/libjava/gnu/gcj/runtime/FirstThread.java
+++ b/libjava/gnu/gcj/runtime/FirstThread.java
@@ -1,6 +1,6 @@
 // FirstThread.java - Implementation of very first thread.
 
-/* Copyright (C) 1998, 1999, 2000  Free Software Foundation
+/* Copyright (C) 1998, 1999, 2000, 2001  Free Software Foundation
 
    This file is part of libgcj.
 
@@ -33,12 +33,12 @@ final class FirstThread extends Thread
     this.args = args;
     this.is_jar = is_jar;
   }
-  
+
   public void run()
   {
     if (is_jar)
       klass_name = getMain(klass_name);
-    
+
     if (klass == null)
       {
         try
@@ -50,7 +50,7 @@ final class FirstThread extends Thread
 	    throw new NoClassDefFoundError(klass_name);
 	  }
       }
-    
+
     call_main();
   }
 
diff --git a/libjava/gnu/gcj/runtime/natFinalizerThread.cc b/libjava/gnu/gcj/runtime/natFinalizerThread.cc
new file mode 100644
index 00000000000..d296bc40551
--- /dev/null
+++ b/libjava/gnu/gcj/runtime/natFinalizerThread.cc
@@ -0,0 +1,22 @@
+// natFinalizerThread.cc - Implementation of FinalizerThread native methods.
+
+/* Copyright (C) 2001  Free Software Foundation
+
+   This file is part of libgcj.
+
+This software is copyrighted work licensed under the terms of the
+Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
+details.  */
+
+#include <config.h>
+
+#include <gcj/cni.h>
+#include <jvm.h>
+
+#include <gnu/gcj/runtime/FinalizerThread.h>
+
+void
+gnu::gcj::runtime::FinalizerThread::runFinalizers ()
+{
+  _Jv_RunFinalizers ();
+}
diff --git a/libjava/include/jvm.h b/libjava/include/jvm.h
index 259d669c650..b4fceac4482 100644
--- a/libjava/include/jvm.h
+++ b/libjava/include/jvm.h
@@ -157,6 +157,9 @@ void * _Jv_BuildGCDescr(jclass);
    memory.  */
 void *_Jv_MallocUnchecked (jsize size) __attribute__((__malloc__));
 
+/* Initialize finalizers.  The argument is a function to be called
+   when a finalizer is ready to be run.  */
+void _Jv_GCInitializeFinalizers (void (*notifier) (void));
 /* Run finalizers for objects ready to be finalized..  */
 void _Jv_RunFinalizers (void);
 /* Run all finalizers.  Should be called only before exit.  */
diff --git a/libjava/java/lang/natRuntime.cc b/libjava/java/lang/natRuntime.cc
index cdd44a48dd1..0551ba620a6 100644
--- a/libjava/java/lang/natRuntime.cc
+++ b/libjava/java/lang/natRuntime.cc
@@ -18,6 +18,7 @@ details.  */
 #include <java/lang/UnknownError.h>
 #include <java/lang/UnsatisfiedLinkError.h>
 #include <gnu/gcj/runtime/FileDeleter.h>
+#include <gnu/gcj/runtime/FinalizerThread.h>
 
 #include <jni.h>
 
@@ -208,7 +209,7 @@ java::lang::Runtime::init (void)
 void
 java::lang::Runtime::runFinalization (void)
 {
-  _Jv_RunFinalizers ();
+  gnu::gcj::runtime::FinalizerThread::finalizerReady ();
 }
 
 jlong
diff --git a/libjava/no-threads.cc b/libjava/no-threads.cc
index dc982430629..4153dcd04de 100644
--- a/libjava/no-threads.cc
+++ b/libjava/no-threads.cc
@@ -1,6 +1,6 @@
 // no-thread.cc - Implementation of `no threads' threads.
 
-/* Copyright (C) 1998, 1999  Free Software Foundation
+/* Copyright (C) 1998, 1999, 2001  Free Software Foundation
 
    This file is part of libgcj.
 
@@ -13,22 +13,21 @@ details.  */
 #include <gcj/cni.h>
 #include <jvm.h>
 #include <java/lang/Thread.h>
+#include <java/lang/InternalError.h>
 
 java::lang::Thread *_Jv_OnlyThread = NULL;
 
 _Jv_Thread_t *
-_Jv_ThreadInitData (java::lang::Thread * thread)
+_Jv_ThreadInitData (java::lang::Thread *thread)
 {
-  // Don't use JvAssert, since we want this to fail even when compiled
-  // without assertions.
-  if (_Jv_OnlyThread)
-    JvFail ("only thread already running");
-  _Jv_OnlyThread = thread;
+  // It is ok to create a new Thread object, as long as it isn't started.
+  if (_Jv_OnlyThread == NULL)
+    _Jv_OnlyThread = thread;
   return NULL;
 }
 
 void
 _Jv_ThreadStart (java::lang::Thread *, _Jv_Thread_t *, _Jv_ThreadStartFunc *)
 {
-  JvFail ("Thread.start called but threads not available");
+  throw new java::lang::InternalError (JvNewStringLatin1 ("Thread.start called but threads not available"));
 }
diff --git a/libjava/nogc.cc b/libjava/nogc.cc
index 65cc8c30e22..82bf1192f35 100644
--- a/libjava/nogc.cc
+++ b/libjava/nogc.cc
@@ -92,6 +92,11 @@ _Jv_RunAllFinalizers (void)
 }
 
 void
+_Jv_GCInitializeFinalizers (void (*) (void))
+{
+}
+
+void
 _Jv_RunGC (void)
 {
 }
diff --git a/libjava/prims.cc b/libjava/prims.cc
index 9b4ac240df9..7205e1f6bfc 100644
--- a/libjava/prims.cc
+++ b/libjava/prims.cc
@@ -53,7 +53,6 @@ details.  */
 #include <java/lang/String.h>
 #include <java/lang/Thread.h>
 #include <java/lang/ThreadGroup.h>
-#include <gnu/gcj/runtime/FirstThread.h>
 #include <java/lang/ArrayIndexOutOfBoundsException.h>
 #include <java/lang/ArithmeticException.h>
 #include <java/lang/ClassFormatError.h>
@@ -64,7 +63,10 @@ details.  */
 #include <java/lang/reflect/Modifier.h>
 #include <java/io/PrintStream.h>
 #include <java/lang/UnsatisfiedLinkError.h>
+#include <java/lang/VirtualMachineError.h>
 #include <gnu/gcj/runtime/VMClassLoader.h>
+#include <gnu/gcj/runtime/FinalizerThread.h>
+#include <gnu/gcj/runtime/FirstThread.h>
 
 #ifdef USE_LTDL
 #include <ltdl.h>
@@ -894,6 +896,21 @@ _Jv_CreateJavaVM (void* /*vm_args*/)
 
   _Jv_JNI_Init ();
 
+  _Jv_GCInitializeFinalizers (&::gnu::gcj::runtime::FinalizerThread::finalizerReady);
+
+  // Start the GC finalizer thread.  A VirtualMachineError can be
+  // thrown by the runtime if, say, threads aren't available.  In this
+  // case finalizers simply won't run.
+  try
+    {
+      using namespace gnu::gcj::runtime;
+      FinalizerThread *ft = new FinalizerThread ();
+      ft->start ();
+    }
+  catch (java::lang::VirtualMachineError *ignore)
+    {
+    }
+
   return 0;
 }