Ur/Web: lib/js/urweb.js comparison

comparison lib/js/urweb.js @ 728:2197f0e24a9f

Avoid thread death via message receive

author	Adam Chlipala <adamc@hcoop.net>
date	Thu, 16 Apr 2009 13:00:40 -0400
parents	6fc633d990e7
children	7c6b6c3c7b79

comparison

equal deleted inserted replaced

-:ba4c230b7231
+:2197f0e24a9f
 var cl = newClosure(tr.closure);
 cls.v = cons(cl, cls.v);
 return "cr(" + cl + ")";
 } else
 return tr;
+}
+function flattenLocal(s) {
+var cls = {v : null};
+var r = flatten(cls, s);
+for (cl = cls.v; cl != null; cl = cl.next)
+freeClosure(cl.data);
+return r;
 }
 // Dynamic tree management
 }
 function er(s) {
 for (var ls = errorHandlers; ls; ls = ls.next)
 ls.data(s)(null);
-throw s;
+throw {uw_error: s};
+}
+var failHandlers = null;
+function onFail(f) {
+failHandlers = cons(f, failHandlers);
+}
+function doExn(v) {
+if (v == null || v.uw_error == null) {
+var s = (v == null ? "null" : v.toString());
+for (var ls = failHandlers; ls; ls = ls.next)
+ls.data(s)(null);
+}
 }
 // Remote calls
 xhr.send(null);
 }
 function rc(uri, parse, k) {
-var cls = {v : null};
+uri = flattenLocal(uri);
-uri = flatten(cls, uri);
-for (cl = cls.v; cl != null; cl = cl.next)
-freeClosure(cl.data);
 var xhr = getXHR();
 xhr.onreadystatechange = function() {
 if (xhr.readyState == 4) {
 var isok = false;
 var listener = dequeue(ch.listeners);
 if (listener == null) {
 enqueue(ch.msgs, msg);
 } else {
-listener(msg);
+try {
+listener(msg);
+} catch (v) {
+doExn(v);
+}
 }
 }
 connect();
 }
 var msg = dequeue(ch.msgs);
 if (msg == null) {
 enqueue(ch.listeners, function(msg) { k(parse(msg))(null); });
 } else {
-k(parse(msg))(null);
+try {
+k(parse(msg))(null);
+} catch (v) {
+doExn(v);
+}
 }
 }
 // App-specific code