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

*** 24,33 ****
--- 24,34 ----
  
  #include "precompiled.hpp"
  #include "gc/shared/gcId.hpp"
  #include "runtime/safepoint.hpp"
  #include "runtime/thread.inline.hpp"
+ #include "runtime/threadLocalStorage.hpp"
  
  uint GCId::_next_id = 0;
  
  NamedThread* currentNamedthread() {
    assert(Thread::current()->is_Named_thread(), "This thread must be NamedThread");
*** 45,54 ****
--- 46,68 ----
  
  const uint GCId::current_raw() {
    return currentNamedthread()->gc_id();
  }
  
+ size_t GCId::print_prefix(char* buf, size_t len) {
+   Thread* thread = ThreadLocalStorage::thread();
+   if (thread != NULL && thread->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) {