Add support to call erlang from java using erjang.RPC.call(m,f,a). To…

… do this, we added a bif called rpc:call_from_java/4, and a special pseudo term mbox representing the caller's mbox which is where to send the result, one of: {ok,Value} or {error,CatchValue}.

src/main/java/erjang/RPC.java

@@ -0,0 +1,42 @@
+package erjang;
+
+import erjang.m.erlang.ErlBif;
+import erjang.m.erlang.ErlProc;
+import erjang.m.rpc.MBox;
+
+public class RPC {
+
+	static EAtom am_$gen_call = EAtom.intern("$gen_call");
+	static EAtom am_rex = EAtom.intern("rex");
+	static EAtom am_undefined = EAtom.intern("undefined");
+	static EAtom am_user = EAtom.intern("user");
+	static EAtom am_call = EAtom.intern("call");
+	static EAtom am_rpc = EAtom.intern("rpc");
+	static EAtom am_call_from_java = EAtom.intern("call_from_java");
+
+
+
+	public static EObject call(EAtom mod, EAtom fun, ESeq args) {
+
+		MBox mbox = new MBox();
+		EProc proc = new EProc(null, am_rpc, am_call_from_java, EList.make(mod, fun, args, mbox));
+		ERT.run(proc);
+		proc.joinb();
+
+		return mbox.get_b();
+	}
+
+
+	public static EObject call(EAtom mod, EAtom fun, ESeq args, long timeout) {
+
+		MBox mbox = new MBox();
+
+		EProc proc = new EProc(null, am_rpc, am_call_from_java, 
+							   EList.make(mod, fun, args, mbox));
+		ERT.run(proc);
+
+		return mbox.get_b(timeout);
+	}
+
+
+}

src/main/java/erjang/m/rpc/MBox.java

@@ -0,0 +1,27 @@
+package erjang.m.rpc;
+
+import kilim.Mailbox;
+import kilim.Pausable;
+import erjang.EObject;
+import erjang.EPseudoTerm;
+
+public class MBox extends EPseudoTerm {
+
+	Mailbox<EObject> mbox;
+
+	public MBox() {
+		this.mbox = new Mailbox<EObject>();
+	}
+
+	public void put(EObject value) throws Pausable {
+		mbox.put(value);
+	}
+
+	public EObject get_b() {
+		return mbox.getb();
+	}
+
+	public EObject get_b(long timeout) {
+		return mbox.getb(timeout);
+	}
+}

src/main/java/erjang/m/rpc/Native.java

@@ -0,0 +1,37 @@
+package erjang.m.rpc;
+
+import kilim.Pausable;
+import erjang.BIF;
+import erjang.ENative;
+import erjang.EObject;
+import erjang.EProc;
+import erjang.ERT;
+import erjang.ETuple;
+import erjang.ErlangException;
+import erjang.m.erlang.ErlBif;
+
+public class Native extends ENative {
+
+	@BIF
+	static public EObject call_from_java(EProc self, EObject m, EObject f, EObject args, 
+										 EObject mbox) throws Pausable
+
+	{
+		if (mbox instanceof MBox) {
+			MBox embox = (MBox) mbox;
+
+			try {
+				EObject res = ErlBif.apply(self, m, f, args);
+				embox.put(ETuple.make(ERT.am_ok, res));				
+				return res;
+			} catch (ErlangException e) {
+				embox.put(ETuple.make(ERT.am_error, e.getCatchValue()));	
+				return ERT.am_undefined;
+			}
+
+		} else {
+			throw ERT.badarg();
+		}
+	}
+
+}