HTTP Server: Fix random deadlocks when serving multiple concurrent requests (writing json)

400_xowa/src/gplx/xowa/addons/servers/https/utils/Xoa_util_svc.java

@@ -28,6 +28,7 @@ public class Xoa_util_svc {
 	public void Page_get(Json_nde args) {
 		// get args
 		String page_get_cbk = args.Get_as_str("page_get_cbk");
+		byte[] protocol = args.Get_as_bry("protocol");
 		byte[] wiki_bry = args.Get_as_bry("wiki");
 		byte[] page_bry = args.Get_as_bry("page");
 		String vega_cbk_guid = args.Get_as_str("vega_cbk_guid");
@@ -43,12 +44,18 @@ public class Xoa_util_svc {
 		// get page
 		Xoa_ttl ttl = wiki.Ttl_parse(page_bry);
 		Xow_page_cache_itm page_itm = wiki.Cache_mgr().Page_cache().Get_or_load_as_itm_2(ttl);
+		byte[] page_text = page_itm == null ? null : page_itm.Wtxt__direct();
+		if (page_text == null) {
+			Gfo_usr_dlg_.Instance.Warn_many("", "", "Xoa_utl_svc:page not found: wiki=~{0} page=~{1}", wiki_bry, page_bry);
+		}
+
 		Xog_cbk_trg cbk_trg = Xog_cbk_trg.New_by_guid(page_guid);
 		cbk_mgr.Send_json(cbk_trg, page_get_cbk, gplx.core.gfobjs.Gfobj_nde.New()
+			.Add_bry("protocol", protocol)
 			.Add_bry("wiki", wiki_bry)
 			.Add_bry("page", page_bry)
 			.Add_str("vega_cbk_guid", vega_cbk_guid)
-			.Add_bry("page_text", page_itm.Wtxt__direct())
+			.Add_bry("page_text", page_text)
 			);
 	}
 }

400_xowa/src/gplx/xowa/guis/cbks/swts/Gfobj_wtr__json__browser.java

@@ -15,7 +15,8 @@ Apache License: https://github.com/gnosygnu/xowa/blob/master/LICENSE-APACHE2.txt
 */
 package gplx.xowa.guis.cbks.swts; import gplx.*; import gplx.xowa.*; import gplx.xowa.guis.*; import gplx.xowa.guis.cbks.*;
 import gplx.core.gfobjs.*;
-public class Gfobj_wtr__json__browser extends Gfobj_wtr__json {		private final    Bry_bfr bfr;
+public class Gfobj_wtr__json__browser extends Gfobj_wtr__json {		private final    Object thread_lock = new Object();
+	private final    Bry_bfr bfr;
 	public Gfobj_wtr__json__browser() {
 		this.Opt_ws_(Bool_.N).Opt_backslash_2x_(Bool_.Y);
 		this.bfr = this.Bfr();
@@ -23,12 +24,14 @@ public class Gfobj_wtr__json__browser extends Gfobj_wtr__json {		private final
 	public String Write_as_func__swt(String func_name, Gfobj_grp root) {return Write_as_func(Bool_.Y, func_name, root);}
 	public String Write_as_func__drd(String func_name, Gfobj_grp root) {return Write_as_func(Bool_.N, func_name, root);}
 	private String Write_as_func(boolean write_return, String func_name, Gfobj_grp root) {
-		if (write_return) bfr.Add(Bry__func_bgn);	// NOTE: Android WebView fails if return is passed; EX: "return 'true'" works on SWT.Browser, but not WebView
-		bfr.Add_str_u8(func_name);
-		bfr.Add(Bry__args_bgn);
-		this.Write(root);
-		bfr.Add(Bry__args_end);
-		return this.To_str();
+		synchronized (thread_lock) { // LOCK:needed else random http_server issues; DATE:2018-03-13
+			if (write_return) bfr.Add(Bry__func_bgn);	// NOTE: Android WebView fails if return is passed; EX: "return 'true'" works on SWT.Browser, but not WebView
+			bfr.Add_str_u8(func_name);
+			bfr.Add(Bry__args_bgn);
+			this.Write(root);
+			bfr.Add(Bry__args_end);
+			return this.To_str();
+		}
 	}
 	private static final    byte[]
 	  Bry__func_bgn	= Bry_.new_a7("return ")

400_xowa/src/gplx/xowa/htmls/heads/Xoh_head_itm__graph.java

@@ -65,7 +65,7 @@ public class Xoh_head_itm__graph extends Xoh_head_itm__base {
 			tags.Add(Xopg_tag_itm.New_js_file(xtn_dir.GenSubFil_nest("lib", "d3.layout.cloud.js")));
 			tags.Add(Xopg_tag_itm.New_js_file(xtn_dir.GenSubFil_nest("lib", "vega2", "vega.js")));
 			tags.Add(Xopg_tag_itm.New_js_file(xtn_dir.GenSubFil_nest("lib", "graph2.compiled.js")));
-			// tags.Add(Xopg_tag_itm.New_js_file(xtn_dir.GenSubFil_nest("modules", "graph2.js")));
+			tags.Add(Xopg_tag_itm.New_js_file(xtn_dir.GenSubFil_nest("modules", "graph2.js")));
 		}
 		else {
 			tags.Add(Xopg_tag_itm.New_js_file(xtn_dir.GenSubFil_nest("lib", "vega1", "vega.js")));