rev 11508 : 8157240: GC task trace logging is incomprehensible
Reviewed-by: tschatzl
rev 11509 : imported patch code_review2

   1 /*
   2  * Copyright (c) 2016 Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_GC_SHARED_WORKERMANAGER_HPP
  26 #define SHARE_VM_GC_SHARED_WORKERMANAGER_HPP
  27 
  28 #include "gc/shared/adaptiveSizePolicy.hpp"
  29 
  30 class WorkerManager : public AllStatic {
  31  public:
  32   // Create additional workers as needed.
  33   //   active_workers - number of workers being requested for an upcoming
  34   // parallel task.
  35   //   total_workers - total number of workers.  This is the maximum
  36   // number possible.
  37   //   created_workers - number of workers already created.  This maybe
  38   // less than, equal to, or greater than active workers.  If greater than
  39   // or equal to active_workers, nothing is done.
  40   //   worker_type - type of thread.
  41   //   initializing - true if this is called to get the initial number of
  42   // GC workers.
  43   // If initializing is true, do a vm exit if the workers cannot be created.
  44   // The initializing = true case is for JVM start up and failing to
  45   // create all the worker at start should considered a problem so exit.
  46   // If initializing = false, there are already some number of worker
  47   // threads and a failure would not be optimal but should not be fatal.
  48   template <class WorkerType>
  49   static uint add_workers (WorkerType* holder,
  50                            uint active_workers,
  51                            uint total_workers,
  52                            uint created_workers,
  53                            os::ThreadType worker_type,
  54                            bool initializing) {
  55     uint start = created_workers;
  56     uint end = MIN2(active_workers, total_workers);
  57     for (uint worker_id = start; worker_id < end; worker_id += 1) {
  58       WorkerThread* new_worker = holder->install_worker(worker_id);
  59       assert(new_worker != NULL, "Failed to allocate GangWorker");
  60       if (new_worker == NULL || !os::create_thread(new_worker, worker_type)) {
  61         if (initializing) {
  62           vm_exit_out_of_memory(0, OOM_MALLOC_ERROR,
  63                   "Cannot create worker GC thread. Out of system resources.");
  64         }
  65       }
  66       created_workers++;
  67       os::start_thread(new_worker);
  68     }
  69 




  70     return created_workers;
  71   }
  72 
  73   // Log (at trace level) a change in the number of created workers.
  74   template <class WorkerType>
  75   static void log_worker_creation(WorkerType* holder,
  76                                   uint previous_created_workers,
  77                                   uint active_workers,
  78                                   uint created_workers,
  79                                   bool initializing) {
  80     if (previous_created_workers < created_workers) {
  81       const char* initializing_msg =  initializing ? "Adding initial" : "Creating additional";
  82       log_trace(gc, task)("%s %s(s) previously created workers %u active workers %u total created workers %u",
  83                           initializing_msg, holder->group_name(), previous_created_workers, active_workers, created_workers);
  84     }
  85   }
  86 };
  87 #endif // SHARE_VM_GC_SHARED_WORKERMANAGER_HPP
--- EOF ---