src/share/vm/runtime/sweeper.cpp

rev 13233 : 8180932: Parallelize safepoint cleanup
Summary: Provide infrastructure to do safepoint cleanup tasks using parallel worker threads
Reviewed-by: dholmes, rehn, dcubed, thartmann

*** 1,7 ****
  /*
!  * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
--- 1,7 ----
  /*
!  * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
*** 110,120 ****
  }
  
  void NMethodSweeper::record_sweep(CompiledMethod* nm, int line) {
    if (_records != NULL) {
      _records[_sweep_index].traversal = _traversals;
!     _records[_sweep_index].traversal_mark = nm->is_nmethod() ? ((nmethod*)nm)->_stack_traversal_mark : 0;
      _records[_sweep_index].compile_id = nm->compile_id();
      _records[_sweep_index].kind = nm->compile_kind();
      _records[_sweep_index].state = nm->get_state();
      _records[_sweep_index].vep = nm->verified_entry_point();
      _records[_sweep_index].uep = nm->entry_point();
--- 110,120 ----
  }
  
  void NMethodSweeper::record_sweep(CompiledMethod* nm, int line) {
    if (_records != NULL) {
      _records[_sweep_index].traversal = _traversals;
!     _records[_sweep_index].traversal_mark = nm->is_nmethod() ? ((nmethod*)nm)->stack_traversal_mark() : 0;
      _records[_sweep_index].compile_id = nm->compile_id();
      _records[_sweep_index].kind = nm->compile_kind();
      _records[_sweep_index].state = nm->get_state();
      _records[_sweep_index].vep = nm->verified_entry_point();
      _records[_sweep_index].uep = nm->entry_point();
*** 197,211 ****
    * Scans the stacks of all Java threads and marks activations of not-entrant methods.
    * No need to synchronize access, since 'mark_active_nmethods' is always executed at a
    * safepoint.
    */
  void NMethodSweeper::mark_active_nmethods() {
    assert(SafepointSynchronize::is_at_safepoint(), "must be executed at a safepoint");
    // If we do not want to reclaim not-entrant or zombie methods there is no need
    // to scan stacks
    if (!MethodFlushing) {
!     return;
    }
  
    // Increase time so that we can estimate when to invoke the sweeper again.
    _time_counter++;
  
--- 197,218 ----
    * Scans the stacks of all Java threads and marks activations of not-entrant methods.
    * No need to synchronize access, since 'mark_active_nmethods' is always executed at a
    * safepoint.
    */
  void NMethodSweeper::mark_active_nmethods() {
+   CodeBlobClosure* cl = prepare_mark_active_nmethods();
+   if (cl != NULL) {
+     Threads::nmethods_do(cl);
+   }
+ }
+ 
+ CodeBlobClosure* NMethodSweeper::prepare_mark_active_nmethods() {
    assert(SafepointSynchronize::is_at_safepoint(), "must be executed at a safepoint");
    // If we do not want to reclaim not-entrant or zombie methods there is no need
    // to scan stacks
    if (!MethodFlushing) {
!     return NULL;
    }
  
    // Increase time so that we can estimate when to invoke the sweeper again.
    _time_counter++;
  
*** 229,246 ****
      _total_time_this_sweep = Tickspan();
  
      if (PrintMethodFlushing) {
        tty->print_cr("### Sweep: stack traversal %ld", _traversals);
      }
!     Threads::nmethods_do(&mark_activation_closure);
  
    } else {
      // Only set hotness counter
!     Threads::nmethods_do(&set_hotness_closure);
    }
  
-   OrderAccess::storestore();
  }
  
  /**
    * This function triggers a VM operation that does stack scanning of active
    * methods. Stack scanning is mandatory for the sweeper to make progress.
--- 236,252 ----
      _total_time_this_sweep = Tickspan();
  
      if (PrintMethodFlushing) {
        tty->print_cr("### Sweep: stack traversal %ld", _traversals);
      }
!     return &mark_activation_closure;
  
    } else {
      // Only set hotness counter
!     return &set_hotness_closure;
    }
  
  }
  
  /**
    * This function triggers a VM operation that does stack scanning of active
    * methods. Stack scanning is mandatory for the sweeper to make progress.