1 /*
  2  * Copyright (c) 2022, 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_RUNTIME_CONTINUATIONENTRY_HPP
 26 #define SHARE_VM_RUNTIME_CONTINUATIONENTRY_HPP
 27 
 28 #include "oops/oop.hpp"
 29 #include "oops/oopsHierarchy.hpp"
 30 #include "runtime/continuation.hpp"
 31 #include "utilities/sizes.hpp"
 32 
 33 #include CPU_HEADER(continuationEntry)
 34 
 35 class CompiledMethod;
 36 class JavaThread;
 37 class OopMap;
 38 class RegisterMap;
 39 
 40 // Metadata stored in the continuation entry frame
 41 class ContinuationEntry {
 42   ContinuationEntryPD _pd;
 43 #ifdef ASSERT
 44 private:
 45   static const int COOKIE_VALUE = 0x1234;
 46   int cookie;
 47 
 48 public:
 49   static int cookie_value() { return COOKIE_VALUE; }
 50   static ByteSize cookie_offset() { return byte_offset_of(ContinuationEntry, cookie); }
 51 
 52   void verify_cookie() {
 53     assert(cookie == COOKIE_VALUE, "Bad cookie: %#x, expected: %#x", cookie, COOKIE_VALUE);
 54   }
 55 #endif
 56 
 57 public:
 58   static int _return_pc_offset; // friend gen_continuation_enter
 59   static void set_enter_code(CompiledMethod* cm, int interpreted_entry_offset);
 60   static bool is_interpreted_call(address call_address);
 61 
 62 private:
 63   static address _return_pc;
 64   static CompiledMethod* _enter_special;
 65   static int _interpreted_entry_offset;
 66 
 67 private:
 68   ContinuationEntry* _parent;
 69   oopDesc* _cont;
 70   oopDesc* _chunk;
 71   int _flags;
 72   // Size in words of the stack arguments of the bottom frame on stack if compiled 0 otherwise.
 73   // The caller (if there is one) is the still frozen top frame in the StackChunk.
 74   int _argsize;
 75   intptr_t* _parent_cont_fastpath;
 76 #ifdef _LP64
 77   int64_t   _parent_held_monitor_count;
 78 #else
 79   int32_t   _parent_held_monitor_count;
 80 #endif
 81   uint _pin_count;
 82 
 83 public:
 84   static ByteSize parent_offset()   { return byte_offset_of(ContinuationEntry, _parent); }
 85   static ByteSize cont_offset()     { return byte_offset_of(ContinuationEntry, _cont); }
 86   static ByteSize chunk_offset()    { return byte_offset_of(ContinuationEntry, _chunk); }
 87   static ByteSize flags_offset()    { return byte_offset_of(ContinuationEntry, _flags); }
 88   static ByteSize argsize_offset()  { return byte_offset_of(ContinuationEntry, _argsize); }
 89   static ByteSize pin_count_offset(){ return byte_offset_of(ContinuationEntry, _pin_count); }
 90   static ByteSize parent_cont_fastpath_offset()      { return byte_offset_of(ContinuationEntry, _parent_cont_fastpath); }
 91   static ByteSize parent_held_monitor_count_offset() { return byte_offset_of(ContinuationEntry, _parent_held_monitor_count); }
 92 
 93 public:
 94   static size_t size() { return align_up((int)sizeof(ContinuationEntry), 2*wordSize); }
 95 
 96   ContinuationEntry* parent() const { return _parent; }
 97   int64_t parent_held_monitor_count() const { return (int64_t)_parent_held_monitor_count; }
 98 
 99   static address entry_pc() { return _return_pc; }
100   intptr_t* entry_sp() const { return (intptr_t*)this; }
101   intptr_t* entry_fp() const;
102 
103   static address compiled_entry();
104   static address interpreted_entry();
105 
106   int argsize() const { return _argsize; }
107   void set_argsize(int value) { _argsize = value; }
108 
109   bool is_pinned() { return _pin_count > 0; }
110   bool pin() {
111     if (_pin_count == UINT_MAX) return false;
112     _pin_count++;
113     return true;
114   }
115   bool unpin() {
116     if (_pin_count == 0) return false;
117     _pin_count--;
118     return true;
119   }
120 
121   intptr_t* parent_cont_fastpath() const { return _parent_cont_fastpath; }
122   void set_parent_cont_fastpath(intptr_t* x) { _parent_cont_fastpath = x; }
123 
124   static ContinuationEntry* from_frame(const frame& f);
125   frame to_frame() const;
126   void update_register_map(RegisterMap* map) const;
127   void flush_stack_processing(JavaThread* thread) const;
128 
129   inline intptr_t* bottom_sender_sp() const;
130   inline oop cont_oop(const JavaThread* thread) const;
131   inline oop scope(const JavaThread* thread) const;
132   inline static oop cont_oop_or_null(const ContinuationEntry* ce, const JavaThread* thread);
133 
134   oop* cont_addr() { return (oop*)&_cont; }
135   oop* chunk_addr() { return (oop*)&_chunk; }
136 
137   bool is_virtual_thread() const { return _flags != 0; }
138 
139 #ifndef PRODUCT
140   void describe(FrameValues& values, int frame_no) const;
141 #endif
142 
143 #ifdef ASSERT
144   static bool assert_entry_frame_laid_out(JavaThread* thread);
145 #endif
146 };
147 
148 #endif // SHARE_VM_RUNTIME_CONTINUATIONENTRY_HPP