registerMap.hpp revision 6760:22b98ab2a69f 
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24
25#ifndef SHARE_VM_RUNTIME_REGISTERMAP_HPP
26#define SHARE_VM_RUNTIME_REGISTERMAP_HPP
27
28#include "code/vmreg.hpp"
29#include "utilities/globalDefinitions.hpp"
30
31class JavaThread;
32
33//
34// RegisterMap
35//
36// A companion structure used for stack traversal. The RegisterMap contains
37// misc. information needed in order to do correct stack traversal of stack
38// frames.  Hence, it must always be passed in as an argument to
39// frame::sender(RegisterMap*).
40//
41// In particular,
42//   1) It provides access to the thread for which the stack belongs.  The
43//      thread object is needed in order to get sender of a deoptimized frame.
44//
45//   2) It is used to pass information from a callee frame to its caller
46//      frame about how the frame should be traversed.  This is used to let
47//      the caller frame take care of calling oops-do of out-going
48//      arguments, when the callee frame is not instantiated yet.  This
49//      happens, e.g., when a compiled frame calls into
50//      resolve_virtual_call.  (Hence, it is critical that the same
51//      RegisterMap object is used for the entire stack walk.  Normally,
52//      this is hidden by using the StackFrameStream.)  This is used when
53//      doing follow_oops and oops_do.
54//
55//   3) The RegisterMap keeps track of the values of callee-saved registers
56//      from frame to frame (hence, the name).  For some stack traversal the
57//      values of the callee-saved registers does not matter, e.g., if you
58//      only need the static properties such as frame type, pc, and such.
59//      Updating of the RegisterMap can be turned off by instantiating the
60//      register map as: RegisterMap map(thread, false);
61
62class RegisterMap : public StackObj {
63 public:
64    typedef julong LocationValidType;
65  enum {
66    reg_count = ConcreteRegisterImpl::number_of_registers,
67    location_valid_type_size = sizeof(LocationValidType)*8,
68    location_valid_size = (reg_count+location_valid_type_size-1)/location_valid_type_size
69  };
70 private:
71  intptr_t*    _location[reg_count];    // Location of registers (intptr_t* looks better than address in the debugger)
72  LocationValidType _location_valid[location_valid_size];
73  bool        _include_argument_oops;   // Should include argument_oop marked locations for compiler
74  JavaThread* _thread;                  // Reference to current thread
75  bool        _update_map;              // Tells if the register map need to be
76                                        // updated when traversing the stack
77
78#ifdef ASSERT
79  void check_location_valid();
80#else
81  void check_location_valid() {}
82#endif
83
84 public:
85  debug_only(intptr_t* _update_for_id;) // Assert that RegisterMap is not updated twice for same frame
86  RegisterMap(JavaThread *thread, bool update_map = true);
87  RegisterMap(const RegisterMap* map);
88
89  address location(VMReg reg) const {
90    int index = reg->value() / location_valid_type_size;
91    assert(0 <= reg->value() && reg->value() < reg_count, "range check");
92    assert(0 <= index && index < location_valid_size, "range check");
93    if (_location_valid[index] & ((LocationValidType)1 << (reg->value() % location_valid_type_size))) {
94      return (address) _location[reg->value()];
95    } else {
96      return pd_location(reg);
97    }
98  }
99
100  void set_location(VMReg reg, address loc) {
101    int index = reg->value() / location_valid_type_size;
102    assert(0 <= reg->value() && reg->value() < reg_count, "range check");
103    assert(0 <= index && index < location_valid_size, "range check");
104    assert(_update_map, "updating map that does not need updating");
105    _location[reg->value()] = (intptr_t*) loc;
106    _location_valid[index] |= ((LocationValidType)1 << (reg->value() % location_valid_type_size));
107    check_location_valid();
108  }
109
110  // Called by an entry frame.
111  void clear();
112
113  bool include_argument_oops() const      { return _include_argument_oops; }
114  void set_include_argument_oops(bool f)  { _include_argument_oops = f; }
115
116  JavaThread *thread() const { return _thread; }
117  bool update_map()    const { return _update_map; }
118
119  void print_on(outputStream* st) const;
120  void print() const;
121
122  // the following contains the definition of pd_xxx methods
123#ifdef TARGET_ARCH_x86
124# include "registerMap_x86.hpp"
125#endif
126#ifdef TARGET_ARCH_sparc
127# include "registerMap_sparc.hpp"
128#endif
129#ifdef TARGET_ARCH_zero
130# include "registerMap_zero.hpp"
131#endif
132#ifdef TARGET_ARCH_arm
133# include "registerMap_arm.hpp"
134#endif
135#ifdef TARGET_ARCH_ppc
136# include "registerMap_ppc.hpp"
137#endif
138
139};
140
141#endif // SHARE_VM_RUNTIME_REGISTERMAP_HPP
142