--- a/Admin/components/README.md Fri Mar 21 10:45:56 2025 +0000
+++ b/Admin/components/README.md Fri Mar 21 10:48:48 2025 +0000
@@ -47,6 +47,7 @@
- macOS 15 Sequoia (untested)
* `x86_64-windows`
+ - Windows Server 2019 (minimum for Java ZGC)
- **Windows Server 2022** (`se0.proof.cit.tum.de`)
- **Windows 10**
- Windows 11
--- a/NEWS Fri Mar 21 10:45:56 2025 +0000
+++ b/NEWS Fri Mar 21 10:48:48 2025 +0000
@@ -112,6 +112,11 @@
*** System ***
+* The Z Garbage Collector (ZGC) of Java 21 is now used by default (see
+also https://wiki.openjdk.org/display/zgc). This should work uniformly
+on all platforms, but requires a reasonably new version of Windows
+(Windows 10 or Windows Server 2019).
+
* SSH connections allow both bash and zsh as remote shell. This is
particularly important for macOS, where zsh is the default user shell.
--- a/etc/settings Fri Mar 21 10:45:56 2025 +0000
+++ b/etc/settings Fri Mar 21 10:48:48 2025 +0000
@@ -12,7 +12,7 @@
### Isabelle/Scala
###
-ISABELLE_JAVA_SYSTEM_OPTIONS="-server -Dfile.encoding=UTF-8 -Disabelle.threads=0"
+ISABELLE_JAVA_SYSTEM_OPTIONS="-server -Dfile.encoding=UTF-8 -Disabelle.threads=0 -XX:+UseZGC -XX:+ZGenerational"
ISABELLE_TOOL_JAVA_OPTIONS="-Djava.awt.headless=true -Xms512m -Xmx4g -Xss16m"
--- a/src/Pure/ROOT.ML Fri Mar 21 10:45:56 2025 +0000
+++ b/src/Pure/ROOT.ML Fri Mar 21 10:48:48 2025 +0000
@@ -1,6 +1,6 @@
(* Title: Pure/ROOT.ML
Author: Makarius
- UUID: 26c42c05-587c-41c1-882d-903627102706
+ UUID: 619a7a37-9241-410f-82a1-be35d8c9e937
Main entry point for the Isabelle/Pure bootstrap process.
--- a/src/Pure/ROOT.scala Fri Mar 21 10:45:56 2025 +0000
+++ b/src/Pure/ROOT.scala Fri Mar 21 10:48:48 2025 +0000
@@ -1,6 +1,6 @@
/* Title: Pure/ROOT.scala
Author: Makarius
- UUID: 26c42c05-587c-41c1-882d-903627102706
+ UUID: 619a7a37-9241-410f-82a1-be35d8c9e937
Root of isabelle package.
*/