src/hotspot/share/runtime/sweeper.cpp

rev 51807 : imported patch nmethod-marking.patch
rev 51808 : 8132849: Increased stop time in cleanup phase because of single-threaded walk of thread stacks in NMethodSweeper::mark_active_nmethods()
rev 51809 : [mq]: JDK-8132849-01.patch

*** 245,254 ****
--- 245,263 ----
      }
    }
  }
  
  CodeBlobClosure* NMethodSweeper::prepare_mark_active_nmethods() {
+ #ifdef ASSERT
+   if (ThreadLocalHandshakes) {
+     assert(Thread::current()->is_Code_cache_sweeper_thread(), "must be executed under CodeCache_lock and in sweeper thread");
+     assert_lock_strong(CodeCache_lock);
+   } else {
+     assert(SafepointSynchronize::is_at_safepoint(), "must be executed at a safepoint");
+   }
+ #endif
+ 
    // If we do not want to reclaim not-entrant or zombie methods there is no need
    // to scan stacks
    if (!MethodFlushing) {
      return NULL;
    }
*** 293,303 ****
    */
  void NMethodSweeper::do_stack_scanning() {
    assert(!CodeCache_lock->owned_by_self(), "just checking");
    if (wait_for_stack_scanning()) {
      if (ThreadLocalHandshakes) {
!       CodeBlobClosure* code_cl = prepare_mark_active_nmethods();
        if (code_cl != NULL) {
          ThreadToCodeBlobClosure tcl(code_cl);
          Handshake::execute(&tcl);
        }
      } else {
--- 302,316 ----
    */
  void NMethodSweeper::do_stack_scanning() {
    assert(!CodeCache_lock->owned_by_self(), "just checking");
    if (wait_for_stack_scanning()) {
      if (ThreadLocalHandshakes) {
!       CodeBlobClosure* code_cl;
!       {
!         MutexLockerEx ccl(CodeCache_lock, Mutex::_no_safepoint_check_flag);
!         code_cl = prepare_mark_active_nmethods();
!       }
        if (code_cl != NULL) {
          ThreadToCodeBlobClosure tcl(code_cl);
          Handshake::execute(&tcl);
        }
      } else {