1 /* 2 * Copyright (c) 2002, 2018, 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_JAVAFRAMEANCHOR_HPP 26 #define SHARE_VM_RUNTIME_JAVAFRAMEANCHOR_HPP 27 28 #include "runtime/orderAccess.inline.hpp" 29 #include "utilities/globalDefinitions.hpp" 30 #include "utilities/macros.hpp" 31 32 // 33 // An object for encapsulating the machine/os dependent part of a JavaThread frame state 34 // 35 class JavaThread; 36 37 class JavaFrameAnchor { 38 // Too many friends... 39 friend class CallNativeDirectNode; 40 friend class OptoRuntime; 41 friend class Runtime1; 42 friend class StubAssembler; 43 friend class CallRuntimeDirectNode; 44 friend class MacroAssembler; 45 friend class LIR_Assembler; 46 friend class GraphKit; 47 friend class StubGenerator; 48 friend class JavaThread; 49 friend class frame; 50 friend class VMStructs; 51 friend class JVMCIVMStructs; 52 friend class BytecodeInterpreter; 53 friend class JavaCallWrapper; 54 55 private: 56 // 57 // Whenever _last_Java_sp != NULL other anchor fields MUST be valid! 58 // The stack may not be walkable [check with walkable() ] but the values must be valid. 59 // The profiler apparently depends on this. 60 // 61 intptr_t* volatile _last_Java_sp; 62 63 // Whenever we call from Java to native we can not be assured that the return 64 // address that composes the last_Java_frame will be in an accessible location 65 // so calls from Java to native store that pc (or one good enough to locate 66 // the oopmap) in the frame anchor. Since the frames that call from Java to 67 // native are never deoptimized we never need to patch the pc and so this 68 // is acceptable. 69 volatile address _last_Java_pc; 70 71 // tells whether the last Java frame is set 72 // It is important that when last_Java_sp != NULL that the rest of the frame 73 // anchor (including platform specific) all be valid. 74 75 bool has_last_Java_frame() const { return _last_Java_sp != NULL; } 76 // This is very dangerous unless sp == NULL 77 // Invalidate the anchor so that has_last_frame is false 78 // and no one should look at the other fields. 79 void zap(void) { _last_Java_sp = NULL; } 80 81 #include CPU_HEADER(javaFrameAnchor) 82 83 public: 84 JavaFrameAnchor() { clear(); } 85 JavaFrameAnchor(JavaFrameAnchor *src) { copy(src); } 86 87 void set_last_Java_pc(address pc) { _last_Java_pc = pc; } 88 89 // Assembly stub generation helpers 90 91 static ByteSize last_Java_sp_offset() { return byte_offset_of(JavaFrameAnchor, _last_Java_sp); } 92 static ByteSize last_Java_pc_offset() { return byte_offset_of(JavaFrameAnchor, _last_Java_pc); } 93 94 }; 95 96 #endif // SHARE_VM_RUNTIME_JAVAFRAMEANCHOR_HPP