From 323781fe5fe16612591dfdfbec7482e3787c7110 Mon Sep 17 00:00:00 2001
From: Sergey Fedorov <barracuda@macos-powerpc.org>
Date: Tue, 9 Jul 2024 02:37:36 +0800
Subject: [PATCH] java_md_macosx: fix broken ObjC code

---
 jdk/src/macosx/bin/java_md_macosx.c | 56 +++++++++++++++++++----------
 1 file changed, 38 insertions(+), 18 deletions(-)

diff --git jdk/src/macosx/bin/java_md_macosx.c jdk/src/macosx/bin/java_md_macosx.c
index 854d848f81..89210cb708 100644
--- jdk/src/macosx/bin/java_md_macosx.c
+++ jdk/src/macosx/bin/java_md_macosx.c
@@ -1026,6 +1026,32 @@ SetXStartOnFirstThreadArg()
     setenv(envVar, "1", 1);
 }
 
+/* This class is made for performSelectorOnMainThread when java main
+ * should be launched on main thread.
+ * We cannot use dispatch_sync here, because it blocks the main dispatch queue
+ * which is used inside Cocoa
+ */
+@interface JavaLaunchHelper : NSObject {
+    int _returnValue;
+}
+- (void) launchJava:(NSValue*)argsValue;
+- (int) getReturnValue;
+@end
+
+@implementation JavaLaunchHelper
+
+- (void) launchJava:(NSValue*)argsValue
+{
+    _returnValue = JavaMain([argsValue pointerValue]);
+}
+
+- (int) getReturnValue
+{
+    return _returnValue;
+}
+
+@end
+
 // MacOSX we may continue in the same thread
 int
 JVMInit(InvocationFunctions* ifn, jlong threadStackSize,
@@ -1035,26 +1061,20 @@ JVMInit(InvocationFunctions* ifn, jlong threadStackSize,
         JLI_TraceLauncher("In same thread\n");
         // need to block this thread against the main thread
         // so signals get caught correctly
-        __block int rslt = 0;
+        JavaMainArgs args;
+        args.argc = argc;
+        args.argv = argv;
+        args.mode = mode;
+        args.what = what;
+        args.ifn  = *ifn;
+        int rslt;
         NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
         {
-            NSBlockOperation *op = [NSBlockOperation blockOperationWithBlock: ^{
-                JavaMainArgs args;
-                args.argc = argc;
-                args.argv = argv;
-                args.mode = mode;
-                args.what = what;
-                args.ifn  = *ifn;
-                rslt = JavaMain(&args);
-            }];
-
-            /*
-             * We cannot use dispatch_sync here, because it blocks the main dispatch queue.
-             * Using the main NSRunLoop allows the dispatch queue to run properly once
-             * SWT (or whatever toolkit this is needed for) kicks off it's own NSRunLoop
-             * and starts running.
-             */
-            [op performSelectorOnMainThread:@selector(start) withObject:nil waitUntilDone:YES];
+            JavaLaunchHelper* launcher = [[[JavaLaunchHelper alloc] init] autorelease];
+            [launcher performSelectorOnMainThread:@selector(launchJava:)
+                                       withObject:[NSValue valueWithPointer:(void*)&args]
+                                    waitUntilDone:YES];
+            rslt = [launcher getReturnValue];
         }
         [pool drain];
         return rslt;