From fc69d6b227310b170a9690e0b2658d36a8e2ca6c Mon Sep 17 00:00:00 2001
From: Patrick Luby <plubius@neooffice.org>
Date: Sat, 14 Oct 2023 21:13:26 -0400
Subject: [PATCH] tdf#101376 don't detach thread if it is the main thread on
 macOS

On macOS, many AWT classes do their work on the main thread
deep in native methods in the java.awt.* classes. The problem
is that Oracle's and OpenJDK's JVMs don't bracket their
"perform on main thread" native calls with "attach/detach
current thread" calls to the JVM.

Change-Id: I0859dc9e20f34bd0b43bb321898507764fd530fb
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/157985
Tested-by: Jenkins
Reviewed-by: Patrick Luby <plubius@neooffice.org>
---
 stoc/Library_javavm.mk        |  6 ++++++
 stoc/source/javavm/javavm.cxx | 15 +++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/stoc/Library_javavm.mk b/stoc/Library_javavm.mk
index e096565769f9..adcb49691ce1 100644
--- a/stoc/Library_javavm.mk
+++ b/stoc/Library_javavm.mk
@@ -31,4 +31,10 @@ $(eval $(call gb_Library_add_exception_objects,javavm,\
     stoc/source/javavm/jvmargs \
 ))
 
+ifeq ($(OS),MACOSX)
+$(eval $(call gb_Library_use_system_darwin_frameworks,javavm,\
+    CoreFoundation \
+))
+endif
+
 # vim:set noet sw=4 ts=4:
diff --git a/stoc/source/javavm/javavm.cxx b/stoc/source/javavm/javavm.cxx
index 091bb7779eeb..fa5883ae3fa7 100644
--- a/stoc/source/javavm/javavm.cxx
+++ b/stoc/source/javavm/javavm.cxx
@@ -79,6 +79,12 @@
 #define TIMEZONE "MET"
 #endif
 
+#ifdef MACOSX
+#include <premac.h>
+#include <CoreFoundation/CoreFoundation.h>
+#include <postmac.h>
+#endif
+
 /* Within this implementation of the com.sun.star.java.JavaVirtualMachine
  * service and com.sun.star.java.theJavaVirtualMachine singleton, the method
  * com.sun.star.java.XJavaVM.getJavaVM relies on the following:
@@ -459,6 +465,15 @@ public:
     explicit DetachCurrentThread(JavaVM * jvm): m_jvm(jvm) {}
 
     ~DetachCurrentThread() {
+#ifdef MACOSX
+        // tdf#101376 don't detach thread if it is the main thread on macOS
+        // On macOS, many AWT classes do their work on the main thread
+        // deep in native methods in the java.awt.* classes. The problem
+        // is that Oracle's and OpenJDK's JVMs don't bracket their
+        // "perform on main thread" native calls with "attach/detach
+        // current thread" calls to the JVM.
+        if (CFRunLoopGetCurrent() != CFRunLoopGetMain())
+#endif
         if (m_jvm->DetachCurrentThread() != 0) {
             OSL_ASSERT(false);
         }