1 /*
   2  * Copyright (c) 2002, 2015, 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
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  23  */
  24 
  25 #ifndef SHARE_VM_GC_SHARED_GCCAUSE_HPP
  26 #define SHARE_VM_GC_SHARED_GCCAUSE_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 
  30 //
  31 // This class exposes implementation details of the various
  32 // collector(s), and we need to be very careful with it. If
  33 // use of this class grows, we should split it into public
  34 // and implementation-private "causes".
  35 //
  36 // The definitions in the SA code should be kept in sync
  37 // with the definitions here.
  38 //
  39 
  40 class GCCause : public AllStatic {
  41  public:
  42   enum Cause {
  43     /* public */
  44     _java_lang_system_gc,
  45     _full_gc_alot,
  46     _scavenge_alot,
  47     _allocation_profiler,
  48     _jvmti_force_gc,
  49     _gc_locker,
  50     _heap_inspection,
  51     _heap_dump,
  52     _wb_young_gc,
  53     _wb_conc_mark,
  54     _wb_full_gc,
  55 
  56     /* implementation independent, but reserved for GC use */
  57     _no_gc,
  58     _no_cause_specified,
  59     _allocation_failure,
  60 
  61     /* implementation specific */
  62 
  63     _tenured_generation_full,
  64     _metadata_GC_threshold,
  65     _metadata_GC_clear_soft_refs,
  66 
  67     _cms_generation_full,
  68     _cms_initial_mark,
  69     _cms_final_remark,
  70     _cms_concurrent_mark,
  71 
  72     _old_generation_expanded_on_last_scavenge,
  73     _old_generation_too_full_to_scavenge,
  74     _adaptive_size_policy,
  75 
  76     _g1_inc_collection_pause,
  77     _g1_humongous_allocation,
  78     _g1_periodic_collection,
  79 
  80     _dcmd_gc_run,
  81 
  82     _z_timer,
  83     _z_warmup,
  84     _z_allocation_rate,
  85     _z_allocation_stall,
  86     _z_proactive,
  87 
  88     _last_gc_cause
  89   };
  90 
  91   inline static bool is_user_requested_gc(GCCause::Cause cause) {
  92     return (cause == GCCause::_java_lang_system_gc ||
  93             cause == GCCause::_dcmd_gc_run);
  94   }
  95 
  96   inline static bool is_serviceability_requested_gc(GCCause::Cause
  97                                                              cause) {
  98     return (cause == GCCause::_jvmti_force_gc ||
  99             cause == GCCause::_heap_inspection ||
 100             cause == GCCause::_heap_dump);
 101   }
 102 
 103   // Causes for collection of the tenured gernation
 104   inline static bool is_tenured_allocation_failure_gc(GCCause::Cause cause) {
 105     assert(cause != GCCause::_old_generation_too_full_to_scavenge &&
 106            cause != GCCause::_old_generation_expanded_on_last_scavenge,
 107            "This GCCause may be correct but is not expected yet: %s",
 108            to_string(cause));
 109     // _tenured_generation_full or _cms_generation_full for full tenured generations
 110     // _adaptive_size_policy for a full collection after a young GC
 111     // _allocation_failure is the generic cause a collection which could result
 112     // in the collection of the tenured generation if there is not enough space
 113     // in the tenured generation to support a young GC.
 114     return (cause == GCCause::_tenured_generation_full ||
 115             cause == GCCause::_cms_generation_full ||
 116             cause == GCCause::_adaptive_size_policy ||
 117             cause == GCCause::_allocation_failure);
 118   }
 119 
 120   // Causes for collection of the young generation
 121   inline static bool is_allocation_failure_gc(GCCause::Cause cause) {
 122     // _allocation_failure is the generic cause a collection for allocation failure
 123     // _adaptive_size_policy is for a collecton done before a full GC
 124     return (cause == GCCause::_allocation_failure ||
 125             cause == GCCause::_adaptive_size_policy);
 126   }
 127 
 128   // Return a string describing the GCCause.
 129   static const char* to_string(GCCause::Cause cause);
 130 };
 131 
 132 #endif // SHARE_VM_GC_SHARED_GCCAUSE_HPP