Merge pull request livecode#3500 from peter-b/js/unwaitify

peter-b · peter-b · commit a3560159178b · 2016-01-26T09:41:44.000Z
[Bug 16619][emscripten] Disable "wait" in HTML5 engine
diff --git a/docs/guides/HTML5 Deployment.md b/docs/guides/HTML5 Deployment.md
@@ -30,8 +30,13 @@ Several important features are not yet supported:
 
 * some `ask` and `answer` message boxes
 * networking
+* JavaScript in LiveCode Builder extensions
 
-The HTML5 engine is unlikely ever to support externals (including revdb).
+Two important unsupported features are unlikely to be added in the near future:
+
+* operations that need to pause the script while something happens
+  (e.g. `wait 10`)
+* externals (including revdb)
 
 # How to deploy an app to HTML5
 
diff --git a/docs/notes/bugfix-16076.md b/docs/notes/bugfix-16076.md
diff --git a/docs/notes/bugfix-16619.md b/docs/notes/bugfix-16619.md
@@ -0,0 +1,10 @@
+# No "wait" syntax in HTML5 standalones
+
+In LiveCode 8.0.0-dp-11, changes were made to the HTML5 standalone
+engine to enable the use of `wait` (and related syntax; see
+[bug 16076](http://quality.livecode.com/show_bug.cgi?id/16076).  These
+changes made the HTML5 engine run unacceptably slowly, and have now
+been removed.
+
+Instead of using `wait` in stacks for HTML5 deployment, the use of the
+`send <message> in <time>` syntax is recommended.
diff --git a/engine/src/em-dc-mainloop.cpp b/engine/src/em-dc-mainloop.cpp
@@ -118,6 +118,9 @@ X_init(int argc,
 	/* ---------- Set up global variables */
 	X_clear_globals();
 
+	/* No blocking during initialization */
+	++MCwaitdepth;
+
 	MCswapbytes = MCEmscriptenIsLittleEndian();
 	MCtruemcstring = MCtruestring;
 	MCfalsemcstring = MCfalsestring;
@@ -132,33 +135,33 @@ X_init(int argc,
 
 	if (!MCFontInitialize())
 	{
-		return false;
+		goto error_cleanup;
 	}
 
 	if (!MCLogicalFontTableInitialize())
 	{
-		return false;
+		goto error_cleanup;
 	}
 
 	/* ---------- More globals */
 
 	/* executable file name */
 	if (!MCsystem->PathFromNative(argv[0], MCcmd))
 	{
-		return false;
+		goto error_cleanup;
 	}
 
 	/* Locales */
 	if (!MCLocaleCreateWithName(MCSTR("en_US"), kMCBasicLocale))
 	{
-		return false;
+		goto error_cleanup;
 	}
 
 	kMCSystemLocale = MCS_getsystemlocale();
 
 	if (nil == kMCSystemLocale)
 	{
-		return false;
+		goto error_cleanup;
 	}
 
 	/* ---------- argv[] global variables */
@@ -178,11 +181,21 @@ X_init(int argc,
 	 * available in the VFS before calling X_open(). */
 	if (!MCEmscriptenStandaloneUnpack())
 	{
-		return false;
+		goto error_cleanup;
 	}
 
 	/* ---------- Continue booting... */
-	return X_open(argc, argv, envp);
+	if (!X_open(argc, argv, envp))
+	{
+		goto error_cleanup;
+	}
+
+	--MCwaitdepth;
+	return true;
+
+ error_cleanup:
+	--MCwaitdepth;
+	return false;
 }
 
 /* ================================================================
diff --git a/engine/src/em-dc.cpp b/engine/src/em-dc.cpp
@@ -170,12 +170,19 @@ MCScreenDC::GetCurrentStack()
  * Event loop
  * ================================================================ */
 
-/* Returns true if quit is requested. */
+/* Returns true if quit is requested, or from any inner main loop. */
 Boolean
 MCScreenDC::wait(real64_t p_duration,
                  Boolean p_allow_dispatch,
                  Boolean p_accept_any_event)
 {
+	/* Don't permit inner main loops.  They cause amusing "-12" assertion
+	 * failures from Emterpreter. */
+	if (0 < int(MCwaitdepth))
+	{
+		return true;
+	}
+
 	p_duration = MCMax(p_duration, 0.0);
 
 	/* We allow p_duration to be infinite, but only if
diff --git a/engine/src/em-whitelist.json b/engine/src/em-whitelist.json
@@ -6,51 +6,9 @@
     "^__Z20send_startup_messageb",
     "^__Z13platform_mainiPPcS0_$",
     "^__Z21X_main_loop_iterationv$",
+    "^__ZN10MCScreenDC4waitEdhh$",
 
     "^_MCEventQueueDispatch$",
     "^__ZL25MCEventQueueDispatchEventP7MCEvent$",
-    "^_MCEmscriptenAsyncYield$",
-
-    "MCWidgetExec",
-    "MCWidgetOn",
-
-    "AddRunloopAction",
-    "DoRunloopActions",
-
-    "(exec|eval)_ctxt",
-    "4wait",
-    "26message_with_valueref_args",
-    "addmessage",
-    "7message",
-    "6handle",
-    "13handlepending",
-    "10handleself",
-    "11exechandler",
-    "[0-9]+close",
-    "3del",
-    "help",
-    "[0-9]+(k|m)(focus|down|up)",
-    "mdrag",
-    "paste",
-    "doubledown",
-    "layerchanged",
-    "resizeparent",
-    "sync_mfocus",
-    "toolchanged",
-    "wdoubledown",
-    "wmdragenter",
-    "wmdragleave",
-    "wmfocus_stack",
-
-    "MCExecContext[0-9]+(TryTo)?[Ee]val",
-    "MCEngineEvalValue",
-    "MCEngine\\w*Wait",
-    "MCEngineExecDispatch",
-    "MCEngineExecDo",
-    "MCEngineExecSend",
-
-    "MC[SU]_\\w*url(?!(en|de)code)",
-
-    "__ZN9MCHandler4exec",
-    "MCKeywordsExec"
+    "^_MCEmscriptenAsyncYield$"
 ]
diff --git a/engine/src/globals.cpp b/engine/src/globals.cpp
@@ -241,7 +241,7 @@ uint2 MCnsockets;
 MCStack **MCusing;
 uint2 MCnusing;
 uint2 MCiconicstacks;
-uint2 MCwaitdepth;
+MCSemaphore MCwaitdepth;
 uint4 MCrecursionlimit = 400000; // actual max is about 480K on OSX
 
 MCClipboard* MCclipboard;
@@ -634,7 +634,7 @@ void X_clear_globals(void)
 	MCusing = nil;
 	MCnusing = 0;
 	MCiconicstacks = 0;
-	MCwaitdepth = 0;
+	MCwaitdepth = MCSemaphore("wait-depth");
 	MCrecursionlimit = 400000;
 	MCclipboard = NULL;
 	MCselection = NULL;
diff --git a/engine/src/globals.h b/engine/src/globals.h
@@ -163,7 +163,7 @@ extern uint2 MCnsockets;
 extern MCStack **MCusing;
 extern uint2 MCnusing;
 extern uint2 MCiconicstacks;
-extern uint2 MCwaitdepth;
+extern MCSemaphore MCwaitdepth;
 extern uint4 MCrecursionlimit;
 
 
diff --git a/engine/src/mcsemaphore.h b/engine/src/mcsemaphore.h
@@ -64,6 +64,12 @@ class MCSemaphore
 		return IsLocked();
 	}
 
+	/* Automatic extraction of the wait depth */
+	operator int() const
+	{
+		return m_counter;
+	}
+
 	/* ---------- Locking ops */
 	void Lock()
 	{
diff --git a/tests/_emscripten/__boot.livecodescript b/tests/_emscripten/__boot.livecodescript
@@ -16,7 +16,7 @@ on startup
 	TestLoadLibrary "_inputlib"
 
 	-- Run tests
-	local tTestFiles, tTestFile, tStackName, tCommand, tSetupResult
+	local tTestFiles, tTestFile, tStackName, tCommand, tSetupResult, tError
 
 	put TesterGetTestFileNames("/boot/standalone") into tTestFiles
 
@@ -45,7 +45,12 @@ on startup
 			end if
 
 			-- Run tests
-			dispatch tCommand to tStackName
+			try
+				dispatch tCommand to tStackName
+			catch tError
+				TestDiagnostic tError
+				TestAssert empty, false
+			end try
 
 			-- Send teardown command
 			dispatch "TestTearDown" to tStackName

Original file line number	Diff line number	Diff line change
`@@ -118,6 +118,9 @@ X_init(int argc,`
`118`	`118`	`/* ---------- Set up global variables */`
`119`	`119`	`X_clear_globals();`
`120`	`120`
	`121`	`+ /* No blocking during initialization */`
	`122`	`+ ++MCwaitdepth;`
	`123`	`+`
`121`	`124`	`MCswapbytes = MCEmscriptenIsLittleEndian();`
`122`	`125`	`MCtruemcstring = MCtruestring;`
`123`	`126`	`MCfalsemcstring = MCfalsestring;`
`@@ -132,33 +135,33 @@ X_init(int argc,`
`132`	`135`
`133`	`136`	`if (!MCFontInitialize())`
`134`	`137`	`{`
`135`		`- return false;`
	`138`	`+ goto error_cleanup;`
`136`	`139`	`}`
`137`	`140`
`138`	`141`	`if (!MCLogicalFontTableInitialize())`
`139`	`142`	`{`
`140`		`- return false;`
	`143`	`+ goto error_cleanup;`
`141`	`144`	`}`
`142`	`145`
`143`	`146`	`/* ---------- More globals */`
`144`	`147`
`145`	`148`	`/* executable file name */`
`146`	`149`	`if (!MCsystem->PathFromNative(argv[0], MCcmd))`
`147`	`150`	`{`
`148`		`- return false;`
	`151`	`+ goto error_cleanup;`
`149`	`152`	`}`
`150`	`153`
`151`	`154`	`/* Locales */`
`152`	`155`	`if (!MCLocaleCreateWithName(MCSTR("en_US"), kMCBasicLocale))`
`153`	`156`	`{`
`154`		`- return false;`
	`157`	`+ goto error_cleanup;`
`155`	`158`	`}`
`156`	`159`
`157`	`160`	`kMCSystemLocale = MCS_getsystemlocale();`
`158`	`161`
`159`	`162`	`if (nil == kMCSystemLocale)`
`160`	`163`	`{`
`161`		`- return false;`
	`164`	`+ goto error_cleanup;`
`162`	`165`	`}`
`163`	`166`
`164`	`167`	`/* ---------- argv[] global variables */`
`@@ -178,11 +181,21 @@ X_init(int argc,`
`178`	`181`	`* available in the VFS before calling X_open(). */`
`179`	`182`	`if (!MCEmscriptenStandaloneUnpack())`
`180`	`183`	`{`
`181`		`- return false;`
	`184`	`+ goto error_cleanup;`
`182`	`185`	`}`
`183`	`186`
`184`	`187`	`/* ---------- Continue booting... */`
`185`		`- return X_open(argc, argv, envp);`
	`188`	`+ if (!X_open(argc, argv, envp))`
	`189`	`+ {`
	`190`	`+ goto error_cleanup;`
	`191`	`+ }`
	`192`	`+`
	`193`	`+ --MCwaitdepth;`
	`194`	`+ return true;`
	`195`	`+`
	`196`	`+ error_cleanup:`
	`197`	`+ --MCwaitdepth;`
	`198`	`+ return false;`
`186`	`199`	`}`
`187`	`200`
`188`	`201`	`/* ================================================================`
Original file line number	Diff line number	Diff line change
`@@ -64,6 +64,12 @@ class MCSemaphore`
`64`	`64`	`return IsLocked();`
`65`	`65`	`}`
`66`	`66`
	`67`	`+ /* Automatic extraction of the wait depth */`
	`68`	`+ operator int() const`
	`69`	`+ {`
	`70`	`+ return m_counter;`
	`71`	`+ }`
	`72`	`+`
`67`	`73`	`/* ---------- Locking ops */`
`68`	`74`	`void Lock()`
`69`	`75`	`{`