[Backport] 8305895: Fix G1 root region scanning crash of original 830…

…5895 backport Summary: Fix G1 root region scanning crash of 8305895 backport Testing : CI pipeline Reviewers: yulei, ddh Issue: #755
dragonwell-project · Dec 27, 2023 · 1070e67 · 1070e67
1 parent 35874c1
commit 1070e67
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Showing 3 changed files with 16 additions and 0 deletions.
diff --git a/src/hotspot/share/gc/g1/g1CollectedHeap.hpp b/src/hotspot/share/gc/g1/g1CollectedHeap.hpp
@@ -1403,6 +1403,8 @@ class G1CollectedHeap : public CollectedHeap {
   G1HeapSummary create_g1_heap_summary();
   G1EvacSummary create_g1_evac_summary(G1EvacStats* stats);
 
+  inline bool root_region_scanning();
+
   // Printing
 private:
   void print_heap_regions() const;

diff --git a/src/hotspot/share/gc/g1/g1CollectedHeap.inline.hpp b/src/hotspot/share/gc/g1/g1CollectedHeap.inline.hpp
@@ -289,4 +289,8 @@ inline void G1CollectedHeap::set_humongous_is_live(oop obj) {
   }
 }
 
+inline bool G1CollectedHeap::root_region_scanning() {
+  return _cm->root_regions()->scan_in_progress();
+}
+
 #endif // SHARE_VM_GC_G1_G1COLLECTEDHEAP_INLINE_HPP
diff --git a/src/hotspot/share/runtime/safepoint.cpp b/src/hotspot/share/runtime/safepoint.cpp
@@ -69,6 +69,9 @@
 #ifdef COMPILER1
 #include "c1/c1_globals.hpp"
 #endif
+#if INCLUDE_G1GC
+#include "gc/g1/g1CollectedHeap.inline.hpp"
+#endif // INCLUDE_G1GC
 
 template <typename E>
 static void set_current_safepoint_id(E* event, int adjustment = 0) {
@@ -732,6 +735,13 @@ void SafepointSynchronize::do_cleanup_tasks() {
 
   TraceTime timer("safepoint cleanup tasks", TRACETIME_LOG(Info, safepoint, cleanup));
 
+#if INCLUDE_G1GC
+  if (UseCompactObjectHeaders && UseG1GC && G1CollectedHeap::heap()->root_region_scanning()) {
+    log_info(safepoint)("Safepoint cancels cleanup due to G1 root region scanning.");
+    return;
+  }
+#endif // INCLUDE_G1GC
+
   // Prepare for monitor deflation.
   DeflateMonitorCounters deflate_counters;
   ObjectSynchronizer::prepare_deflate_idle_monitors(&deflate_counters);