6 files changed, 87 insertions, 18 deletions
diff --git a/libjava/gnu/gcj/xlib/Clip.java b/libjava/gnu/gcj/xlib/Clip.java
index 28bb02a..311dfa6 100644
--- a/libjava/gnu/gcj/xlib/Clip.java
+++ b/libjava/gnu/gcj/xlib/Clip.java
@@ -29,7 +29,12 @@ final class Clip
 
   private native void init(Rectangle[] rects);
 
-  public native void finalize();
+  public void finalize()
+  {
+    dispose ();
+  }
+  
+  public native void dispose();
 
   RawData xrects;
 }
diff --git a/libjava/gnu/gcj/xlib/Drawable.java b/libjava/gnu/gcj/xlib/Drawable.java
index 5652792..551aca8 100644
--- a/libjava/gnu/gcj/xlib/Drawable.java
+++ b/libjava/gnu/gcj/xlib/Drawable.java
@@ -16,6 +16,9 @@ import java.awt.Rectangle;
  */
 public class Drawable extends XID
 {
+  private GC[] gcCache = new GC[10];
+  private int gcCachedCount = 0;
+
   public Drawable(Display display, int xid)
   {
     super(display, xid);
@@ -78,5 +81,36 @@ public class Drawable extends XID
   
   private static final String MSG_XGETSUBIMAGE_FAILED =
     "XGetSubImage() failed.";
-    
+
+  protected void finalize() throws Throwable
+  {
+    // Dispose all the cached GCs, to reduce X server resource usage
+    for (int i=0; i<gcCachedCount; i++)
+      gcCache[i].disposeImpl ();
+    gcCachedCount = 0;
+    super.finalize();
+  }
+
+  /** Put a GC in the cache for this drawable, so it can be retrieved later.
+   * @param gc The GC to put
+   */
+  void putGCInCache (GC gc)
+  {
+    if (gcCachedCount >= gcCache.length)
+    {
+      // List full - extend it to double its present size
+      GC[] oldList = gcCache;
+      gcCache = new GC[oldList.length*2];
+      System.arraycopy (oldList,0,gcCache,0,oldList.length);
+    }
+    gcCache[gcCachedCount++] = gc;
+  }
+
+  /** Get a GC from the cache, if available
+   * @return A GC from the cache, or null if the cache is empty
+   */
+  GC getGCFromCache ()
+  {
+    return (gcCachedCount>0) ? gcCache[--gcCachedCount] : null;
+  }
 }
diff --git a/libjava/gnu/gcj/xlib/GC.java b/libjava/gnu/gcj/xlib/GC.java
index 1806c2a..2c4d8a8 100644
--- a/libjava/gnu/gcj/xlib/GC.java
+++ b/libjava/gnu/gcj/xlib/GC.java
@@ -23,17 +23,25 @@ import java.awt.Rectangle;
  */
 public class GC implements Cloneable
 {
-  
-  public GC(Drawable target)
+  /** Protected constructor, because GC.create(target) should be used instead.
+   */
+  protected GC(Drawable target)
   {
     this.target = target;
     initStructure(null);
   }
 
+  /** Try to get a suitable GC from the drawable's cache.
+   * If there isn't one, create one.
+   */
   public Object clone()
   {
-    GC gcClone = (GC) super.clone();
-    gcClone.structure = null;
+    GC gcClone = target.getGCFromCache ();
+    if (gcClone==null)
+    {
+      gcClone = (GC) super.clone();
+      gcClone.structure = null;
+    }
     gcClone.initStructure(this);
     gcClone.updateClip();
     return gcClone;
@@ -45,15 +53,31 @@ public class GC implements Cloneable
   {
     return (GC) clone();
   }
+  
+  /** Create a GC, or if one is already cached for target, return that.
+   * @param target The Drawable for which a GC is needed
+   * @return The new or retrieved GC
+   */
+  static public GC create (Drawable target)
+  {
+    GC returnValue = target.getGCFromCache ();
+    if (returnValue == null)
+      returnValue = new GC (target);
+    return returnValue;
+  }
 
   public void finalize()
   {
     disposeImpl();
   }
 
+  /** Save this GC in the drawable's cache.
+   *  The "real" dispose (disposeImpl) is called when the
+   *  drawable is finialized, to free X server resources.
+   */
   public void dispose()
   {
-    disposeImpl();
+    target.putGCInCache (this);
   }
 
   public synchronized native void disposeImpl();
diff --git a/libjava/gnu/gcj/xlib/Pixmap.java b/libjava/gnu/gcj/xlib/Pixmap.java
index a514d95..7ba5a62 100644
--- a/libjava/gnu/gcj/xlib/Pixmap.java
+++ b/libjava/gnu/gcj/xlib/Pixmap.java
@@ -25,7 +25,7 @@ public class Pixmap extends Drawable
     /* FIXME: don't create a new GC all the time.  This might actually
     not be as bad as initially believed.  The GC cache of Xlib makes
     this operation less costly. */
-    GC gc = new GC(this);
+    GC gc = GC.create (this);
     
     gc.putImage(image, 0, 0, 0, 0, image.getWidth(), image.getHeight());
   }
diff --git a/libjava/gnu/gcj/xlib/natClip.cc b/libjava/gnu/gcj/xlib/natClip.cc
index 51426c8..a1f626d 100644
--- a/libjava/gnu/gcj/xlib/natClip.cc
+++ b/libjava/gnu/gcj/xlib/natClip.cc
@@ -46,7 +46,11 @@ void gnu::gcj::xlib::Clip::init(AWTRectArray* rectangles)
   xrects = reinterpret_cast<gnu::gcj::RawData*>(xrectvector);
 }
 
-void gnu::gcj::xlib::Clip::finalize()
+void gnu::gcj::xlib::Clip::dispose()
 {
-  delete xrects; xrects = 0;
+  if (xrects)
+  {
+    delete xrects; 
+    xrects = 0;
+  }
 }
diff --git a/libjava/gnu/gcj/xlib/natGC.cc b/libjava/gnu/gcj/xlib/natGC.cc
index 11f4b28..16b0bc5 100644
--- a/libjava/gnu/gcj/xlib/natGC.cc
+++ b/libjava/gnu/gcj/xlib/natGC.cc
@@ -34,12 +34,16 @@ void gnu::gcj::xlib::GC::initStructure(GC* copyFrom)
 {
   Display* display = target->getDisplay();
   ::Display* dpy = (::Display*) (display->display);
-  ::Drawable drawableXID = target->getXID();
-    
-  ::GC gc = XCreateGC(dpy, drawableXID, 0, 0);
-  
-  if (gc == 0) 
-    throw new XException(JvNewStringLatin1("GC creation failed"));
+  ::GC gc = (::GC) structure;
+  if (gc == 0)
+  {
+    // If we haven't already created a GC, create one now
+    ::Drawable drawableXID = target->getXID();
+    gc = XCreateGC(dpy, drawableXID, 0, 0);
+    structure = reinterpret_cast<gnu::gcj::RawData*>(gc);
+    if (gc == 0) 
+      throw new XException(JvNewStringLatin1("GC creation failed"));
+  }
 
   if (copyFrom != 0)
     {
@@ -47,8 +51,6 @@ void gnu::gcj::xlib::GC::initStructure(GC* copyFrom)
       XCopyGC(dpy, fromGC, ~0, gc);
       // no fast fail
     }
-
-  structure = reinterpret_cast<gnu::gcj::RawData*>(gc);
 }
 
 void gnu::gcj::xlib::GC::disposeImpl()