Make error message handler in xpcall per-thread instead of per-globals.

README.html

@@ -910,6 +910,7 @@ Files are no longer hosted at LuaForge.
 <li>Implement formatting with os.date(), and table argument for os.time().</li>
 <li>Refactor APIs related to compiling and loading scripts.</li>
 <li>Let errors thrown in debug hooks bubble up to the running coroutine.</li>
+<li>Make error function in xpcall per-thread instead of per-globals.</li>
 
 </ul></td></tr>
 </table></td></tr></table>

src/core/org/luaj/vm2/Globals.java

@@ -136,9 +136,6 @@ public class Globals extends LuaTable {
 	/** The DebugLib instance loaded into this Globals, or null if debugging is not enabled */
 	public DebugLib debuglib;
 
-	/** The current error handler for this Globals */
-	public LuaValue errorfunc;
-
 	/** Interface for module that converts a Prototype into a LuaFunction with an environment. */
 	public interface Loader {
 		/** Convert the prototype into a LuaFunction with the supplied environment. */

src/core/org/luaj/vm2/LuaClosure.java

@@ -519,16 +519,18 @@ public class LuaClosure extends LuaFunction {
 	 *  @param msg the message to use in error hook processing. 
 	 * */
 	String errorHook(String msg) {
-		if (globals == null || globals.errorfunc == null)
-			return msg;
-		LuaValue errfunc = globals.errorfunc;
-		globals.errorfunc = null;
+		if (globals == null ) return msg;
+		final LuaThread running = globals.running;
+		if (running == null) return msg;
+		final LuaValue errfunc = running.errorfunc;
+		if (errfunc == null) return msg;
+		running.errorfunc = null;
 		try {
 			return errfunc.call( LuaValue.valueOf(msg) ).tojstring();
 		} catch ( Throwable t ) {
 			return "error in error handling";
 		} finally {
-			globals.errorfunc = errfunc;
+			running.errorfunc = errfunc;
 		}
 	}
 
@@ -536,8 +538,6 @@ public class LuaClosure extends LuaFunction {
 		le.fileline = (p.source != null? p.source.tojstring(): "?") + ":" 
 			+ (p.lineinfo != null && pc >= 0 && pc < p.lineinfo.length? String.valueOf(p.lineinfo[pc]): "?");
 		le.traceback = errorHook(le.getMessage());
-		if (globals != null && globals.debuglib != null)
-			le.traceback = le.traceback + "\n" + globals.debuglib.traceback(le.level);
 	}
 	
 	private UpValue findupval(LuaValue[] stack, short idx, UpValue[] openups) {
@@ -548,7 +548,7 @@ public class LuaClosure extends LuaFunction {
 		for (int i = 0; i < n; ++i)
 			if (openups[i] == null)
 				return openups[i] = new UpValue(stack, idx);
-		this.error("No space for upvalue");
+		error("No space for upvalue");
 		return null;
 	}
 

src/core/org/luaj/vm2/LuaThread.java

@@ -93,8 +93,12 @@ public class LuaThread extends LuaValue {
 
 	public final Globals globals;
 
-	// Hook function control state used by debug lib.
+	/** Hook function control state used by debug lib. */
 	public LuaValue hookfunc;
+
+	/** Error message handler for this thread, if any.  */
+	public LuaValue errorfunc;
+
 	public boolean hookline;
 	public boolean hookcall;
 	public boolean hookrtrn;

src/core/org/luaj/vm2/lib/BaseLib.java

@@ -29,6 +29,7 @@ import org.luaj.vm2.Lua;
 import org.luaj.vm2.LuaError;
 import org.luaj.vm2.LuaString;
 import org.luaj.vm2.LuaTable;
+import org.luaj.vm2.LuaThread;
 import org.luaj.vm2.LuaValue;
 import org.luaj.vm2.Varargs;
 
@@ -213,7 +214,13 @@ public class BaseLib extends TwoArgFunction implements ResourceFinder {
 			if (globals != null && globals.debuglib != null)
 				globals.debuglib.onCall(this);
 			try {
-				return pcall(func,args.subargs(2),null);
+				return varargsOf(TRUE, func.invoke(args.subargs(2)));
+			} catch ( LuaError le ) {
+				final String m = le.getMessage();
+				return varargsOf(FALSE, m!=null? valueOf(m): NIL);
+			} catch ( Exception e ) {
+				final String m = e.getMessage();
+				return varargsOf(FALSE, valueOf(m!=null? m: e.toString()));
 			} finally {
 				if (globals != null && globals.debuglib != null)
 					globals.debuglib.onReturn();
@@ -353,14 +360,27 @@ public class BaseLib extends TwoArgFunction implements ResourceFinder {
 	// "xpcall", // (f, err) -> result1, ...				
 	final class xpcall extends VarArgFunction {
 		public Varargs invoke(Varargs args) {
+			final LuaThread t = globals.running;
+			final LuaValue preverror = t.errorfunc;
+			t.errorfunc = args.checkvalue(2);
+			try {
 				if (globals != null && globals.debuglib != null)
 					globals.debuglib.onCall(this);
 				try {
-				return pcall(args.arg1(),args.subargs(3),args.checkvalue(2));
+					return varargsOf(TRUE, args.arg1().invoke(args.subargs(3)));
+				} catch ( LuaError le ) {
+					final String m = le.getMessage();
+					return varargsOf(FALSE, m!=null? valueOf(m): NIL);
+				} catch ( Exception e ) {
+					final String m = e.getMessage();
+					return varargsOf(FALSE, valueOf(m!=null? m: e.toString()));
 				} finally {
 					if (globals != null && globals.debuglib != null)
 						globals.debuglib.onReturn();
 				}
+			} finally {
+				t.errorfunc = preverror;
+			}
 		}
 	}
 	
@@ -397,24 +417,6 @@ public class BaseLib extends TwoArgFunction implements ResourceFinder {
 		}
 	}
 	
-	public Varargs pcall(LuaValue func, Varargs args, LuaValue errorfunc) {
-		try {
-			LuaValue olderr = globals.errorfunc;
-			globals.errorfunc = errorfunc;
-			try {
-				return varargsOf(LuaValue.TRUE, func.invoke(args));
-			} finally {
-				globals.errorfunc = olderr;
-			}
-		} catch ( LuaError le ) {
-			String m = le.getMessage();
-			return varargsOf(FALSE, m!=null? valueOf(m): NIL);
-		} catch ( Exception e ) {
-			String m = e.getMessage();
-			return varargsOf(FALSE, valueOf(m!=null? m: e.toString()));
-		}
-	}
-	
 	/** 
 	 * Load from a named file, returning the chunk or nil,error of can't load
 	 * @param env