src/share/vm/gc/shared/gcId.cpp

@@ -45,10 +45,22 @@
 
 const uint GCId::current_raw() {
   return currentNamedthread()->gc_id();
 }
 
+size_t GCId::print_prefix(char* buf, size_t len) {
+  if (Thread::current()->is_Named_thread()) {
+    uint gc_id = current_raw();
+    if (gc_id != undefined()) {
+      int ret = jio_snprintf(buf, len, "GC(%u) ", gc_id);
+      assert(ret > 0, "Failed to print prefix. Log buffer too small?");
+      return (size_t)ret;
+    }
+  }
+  return 0;
+}
+
 GCIdMark::GCIdMark() : _gc_id(GCId::create()) {
   currentNamedthread()->set_gc_id(_gc_id);
 }
 
 GCIdMark::GCIdMark(uint gc_id) : _gc_id(gc_id) {