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 int _thaw_call_pc_offset;
 60   static address _thaw_call_pc;
 61   static void set_enter_code(CompiledMethod* cm, int interpreted_entry_offset);
 62   static bool is_interpreted_call(address call_address);
 63 
 64 private:
 65   static address _return_pc;
 66   static CompiledMethod* _enter_special;
 67   static int _interpreted_entry_offset;
 68 
 69 private:
 70   ContinuationEntry* _parent;
 71   oopDesc* _cont;
 72   oopDesc* _chunk;
 73   int _flags;
 74   // Size in words of the stack arguments of the bottom frame on stack if compiled 0 otherwise.
 75   // The caller (if there is one) is the still frozen top frame in the StackChunk.
 76   int _argsize;
 77   intptr_t* _parent_cont_fastpath;
 78 #ifdef _LP64
 79   int64_t   _parent_held_monitor_count;
 80 #else
 81   int32_t   _parent_held_monitor_count;
 82 #endif
 83   uint _pin_count;
 84 
 85 public:
 86   static ByteSize parent_offset()   { return byte_offset_of(ContinuationEntry, _parent); }
 87   static ByteSize cont_offset()     { return byte_offset_of(ContinuationEntry, _cont); }
 88   static ByteSize chunk_offset()    { return byte_offset_of(ContinuationEntry, _chunk); }
 89   static ByteSize flags_offset()    { return byte_offset_of(ContinuationEntry, _flags); }
 90   static ByteSize argsize_offset()  { return byte_offset_of(ContinuationEntry, _argsize); }
 91   static ByteSize pin_count_offset(){ return byte_offset_of(ContinuationEntry, _pin_count); }
 92   static ByteSize parent_cont_fastpath_offset()      { return byte_offset_of(ContinuationEntry, _parent_cont_fastpath); }
 93   static ByteSize parent_held_monitor_count_offset() { return byte_offset_of(ContinuationEntry, _parent_held_monitor_count); }
 94 
 95 public:
 96   static size_t size() { return align_up((int)sizeof(ContinuationEntry), 2*wordSize); }
 97 
 98   ContinuationEntry* parent() const { return _parent; }
 99   int64_t parent_held_monitor_count() const { return (int64_t)_parent_held_monitor_count; }
100 
101   static address entry_pc() { return _return_pc; }
102   intptr_t* entry_sp() const { return (intptr_t*)this; }
103   intptr_t* entry_fp() const;
104 
105   static address compiled_entry();
106   static address interpreted_entry();
107 
108   int argsize() const { return _argsize; }
109   void set_argsize(int value) { _argsize = value; }
110 
111   bool is_pinned() { return _pin_count > 0; }
112   bool pin() {
113     if (_pin_count == UINT_MAX) return false;
114     _pin_count++;
115     return true;
116   }
117   bool unpin() {
118     if (_pin_count == 0) return false;
119     _pin_count--;
120     return true;
121   }
122 
123   intptr_t* parent_cont_fastpath() const { return _parent_cont_fastpath; }
124   void set_parent_cont_fastpath(intptr_t* x) { _parent_cont_fastpath = x; }
125 
126   static ContinuationEntry* from_frame(const frame& f);
127   frame to_frame() const;
128   void update_register_map(RegisterMap* map) const;
129   void flush_stack_processing(JavaThread* thread) const;
130 
131   inline intptr_t* bottom_sender_sp() const;
132   inline oop cont_oop(const JavaThread* thread) const;
133   inline oop scope(const JavaThread* thread) const;
134   inline static oop cont_oop_or_null(const ContinuationEntry* ce, const JavaThread* thread);
135 
136   oop* cont_addr() { return (oop*)&_cont; }
137   oop* chunk_addr() { return (oop*)&_chunk; }
138 
139   bool is_virtual_thread() const { return _flags != 0; }
140 
141 #ifndef PRODUCT
142   void describe(FrameValues& values, int frame_no) const;
143 #endif
144 
145 #ifdef ASSERT
146   static bool assert_entry_frame_laid_out(JavaThread* thread);
147 #endif
148 };
149 
150 #endif // SHARE_VM_RUNTIME_CONTINUATIONENTRY_HPP