1 /*
  2  * Copyright (c) 2023, 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_OOPS_INSTANCEKLASSFLAGS_HPP
 26 #define SHARE_OOPS_INSTANCEKLASSFLAGS_HPP
 27 
 28 #include "runtime/atomic.hpp"
 29 
 30 class ClassLoaderData;
 31 
 32 // The InstanceKlassFlags class contains the parse-time and writeable flags associated with
 33 // an InstanceKlass, and their associated accessors.
 34 // _flags are parse-time and constant in the InstanceKlass after that.  _status are set at runtime and
 35 // require atomic access.
 36 // These flags are JVM internal and not part of the AccessFlags classfile specification.
 37 
 38 class InstanceKlassFlags {
 39   friend class VMStructs;
 40   friend class JVMCIVMStructs;
 41 
 42 #define IK_FLAGS_DO(flag)  \
 43     flag(rewritten                          , 1 << 0) /* methods rewritten. */ \
 44     flag(has_nonstatic_fields               , 1 << 1) /* for sizing with UseCompressedOops */ \
 45     flag(should_verify_class                , 1 << 2) /* allow caching of preverification */ \
 46     flag(is_contended                       , 1 << 3) /* marked with contended annotation */ \
 47     flag(has_nonstatic_concrete_methods     , 1 << 4) /* class/superclass/implemented interfaces has non-static, concrete methods */ \
 48     flag(declares_nonstatic_concrete_methods, 1 << 5) /* directly declares non-static, concrete methods */ \
 49     flag(shared_loading_failed              , 1 << 6) /* class has been loaded from shared archive */ \
 50     flag(is_shared_boot_class               , 1 << 7) /* defining class loader is boot class loader */ \
 51     flag(is_shared_platform_class           , 1 << 8) /* defining class loader is platform class loader */ \
 52     flag(is_shared_app_class                , 1 << 9) /* defining class loader is app class loader */ \
 53     flag(has_contended_annotations          , 1 << 10) /* has @Contended annotation */ \
 54     flag(has_localvariable_table            , 1 << 11) /* has localvariable information */ \
 55     flag(has_miranda_methods                , 1 << 12) /* True if this class has miranda methods in it's vtable */ \
 56     flag(has_vanilla_constructor            , 1 << 13) /* True if klass has a vanilla default constructor */ \
 57     flag(has_final_method                   , 1 << 14) /* True if klass has final method */ \
 58     /* end of list */
 59 
 60 #define IK_FLAGS_ENUM_NAME(name, value)    _misc_##name = value,
 61   enum {
 62     IK_FLAGS_DO(IK_FLAGS_ENUM_NAME)
 63   };
 64 #undef IK_FLAGS_ENUM_NAME
 65 
 66 #define IK_STATUS_DO(status)  \
 67     status(is_being_redefined                , 1 << 0) /* True if the klass is being redefined */ \
 68     status(has_resolved_methods              , 1 << 1) /* True if the klass has resolved MethodHandle methods */ \
 69     status(has_been_redefined                , 1 << 2) /* class has been redefined */ \
 70     status(is_scratch_class                  , 1 << 3) /* class is the redefined scratch class */ \
 71     status(is_marked_dependent               , 1 << 4) /* class is the redefined scratch class */ \
 72     /* end of list */
 73 
 74 #define IK_STATUS_ENUM_NAME(name, value)    _misc_##name = value,
 75   enum {
 76     IK_STATUS_DO(IK_STATUS_ENUM_NAME)
 77   };
 78 #undef IK_STATUS_ENUM_NAME
 79 
 80   u2 shared_loader_type_bits() const {
 81     return _misc_is_shared_boot_class|_misc_is_shared_platform_class|_misc_is_shared_app_class;
 82   }
 83 
 84   // These flags are write-once before the class is published and then read-only so don't require atomic updates.
 85   u2 _flags;
 86 
 87   // These flags are written during execution so require atomic stores
 88   u1 _status;
 89 
 90  public:
 91 
 92   InstanceKlassFlags() : _flags(0), _status(0) {}
 93 
 94   // Create getters and setters for the flag values.
 95 #define IK_FLAGS_GET_SET(name, ignore)          \
 96   bool name() const { return (_flags & _misc_##name) != 0; } \
 97   void set_##name(bool b) {         \
 98     assert_is_safe(name());         \
 99     if (b) _flags |= _misc_##name; \
100   }
101   IK_FLAGS_DO(IK_FLAGS_GET_SET)
102 #undef IK_FLAGS_GET_SET
103 
104   bool is_shared_unregistered_class() const {
105     return (_flags & shared_loader_type_bits()) == 0;
106   }
107 
108   void set_shared_class_loader_type(s2 loader_type);
109 
110   void assign_class_loader_type(const ClassLoaderData* cld);
111   void assert_is_safe(bool set) NOT_DEBUG_RETURN;
112 
113   // Create getters and setters for the status values.
114 #define IK_STATUS_GET_SET(name, ignore)          \
115   bool name() const { return (_status & _misc_##name) != 0; } \
116   void set_##name(bool b) {         \
117     if (b) { \
118       atomic_set_bits(_misc_##name); \
119     } else { \
120       atomic_clear_bits(_misc_##name); \
121     } \
122   }
123   IK_STATUS_DO(IK_STATUS_GET_SET)
124 #undef IK_STATUS_GET_SET
125 
126   void atomic_set_bits(u1 bits)   { Atomic::fetch_then_or(&_status, bits); }
127   void atomic_clear_bits(u1 bits) { Atomic::fetch_then_and(&_status, (u1)(~bits)); }
128   void print_on(outputStream* st) const;
129 };
130 
131 #endif // SHARE_OOPS_INSTANCEKLASSFLAGS_HPP