src/share/vm/runtime/deoptimization.hpp

Fri, 06 May 2011 19:34:55 -0700

author
never
date
Fri, 06 May 2011 19:34:55 -0700
changeset 2896
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parent 2877
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child 2901
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Merge

     1 /*
     2  * Copyright (c) 1997, 2011, 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  */
    25 #ifndef SHARE_VM_RUNTIME_DEOPTIMIZATION_HPP
    26 #define SHARE_VM_RUNTIME_DEOPTIMIZATION_HPP
    28 #include "memory/allocation.hpp"
    29 #include "runtime/frame.inline.hpp"
    31 class ProfileData;
    32 class vframeArray;
    33 class MonitorValue;
    34 class ObjectValue;
    36 class Deoptimization : AllStatic {
    37  public:
    38   // What condition caused the deoptimization?
    39   enum DeoptReason {
    40     Reason_many = -1,             // indicates presence of several reasons
    41     Reason_none = 0,              // indicates absence of a relevant deopt.
    42     // Next 7 reasons are recorded per bytecode in DataLayout::trap_bits
    43     Reason_null_check,            // saw unexpected null or zero divisor (@bci)
    44     Reason_null_assert,           // saw unexpected non-null or non-zero (@bci)
    45     Reason_range_check,           // saw unexpected array index (@bci)
    46     Reason_class_check,           // saw unexpected object class (@bci)
    47     Reason_array_check,           // saw unexpected array class (aastore @bci)
    48     Reason_intrinsic,             // saw unexpected operand to intrinsic (@bci)
    49     Reason_bimorphic,             // saw unexpected object class in bimorphic inlining (@bci)
    51     Reason_unloaded,              // unloaded class or constant pool entry
    52     Reason_uninitialized,         // bad class state (uninitialized)
    53     Reason_unreached,             // code is not reached, compiler
    54     Reason_unhandled,             // arbitrary compiler limitation
    55     Reason_constraint,            // arbitrary runtime constraint violated
    56     Reason_div0_check,            // a null_check due to division by zero
    57     Reason_age,                   // nmethod too old; tier threshold reached
    58     Reason_predicate,             // compiler generated predicate failed
    59     Reason_loop_limit_check,      // compiler generated loop limits check failed
    60     Reason_LIMIT,
    61     // Note:  Keep this enum in sync. with _trap_reason_name.
    62     Reason_RECORDED_LIMIT = Reason_bimorphic  // some are not recorded per bc
    63     // Note:  Reason_RECORDED_LIMIT should be < 8 to fit into 3 bits of
    64     // DataLayout::trap_bits.  This dependency is enforced indirectly
    65     // via asserts, to avoid excessive direct header-to-header dependencies.
    66     // See Deoptimization::trap_state_reason and class DataLayout.
    67   };
    69   // What action must be taken by the runtime?
    70   enum DeoptAction {
    71     Action_none,                  // just interpret, do not invalidate nmethod
    72     Action_maybe_recompile,       // recompile the nmethod; need not invalidate
    73     Action_reinterpret,           // invalidate the nmethod, reset IC, maybe recompile
    74     Action_make_not_entrant,      // invalidate the nmethod, recompile (probably)
    75     Action_make_not_compilable,   // invalidate the nmethod and do not compile
    76     Action_LIMIT
    77     // Note:  Keep this enum in sync. with _trap_action_name.
    78   };
    80   enum {
    81     _action_bits = 3,
    82     _reason_bits = 5,
    83     _action_shift = 0,
    84     _reason_shift = _action_shift+_action_bits,
    85     BC_CASE_LIMIT = PRODUCT_ONLY(1) NOT_PRODUCT(4) // for _deoptimization_hist
    86   };
    88   enum UnpackType {
    89     Unpack_deopt                = 0, // normal deoptimization, use pc computed in unpack_vframe_on_stack
    90     Unpack_exception            = 1, // exception is pending
    91     Unpack_uncommon_trap        = 2, // redo last byte code (C2 only)
    92     Unpack_reexecute            = 3  // reexecute bytecode (C1 only)
    93   };
    95   // Checks all compiled methods. Invalid methods are deleted and
    96   // corresponding activations are deoptimized.
    97   static int deoptimize_dependents();
    99   // Deoptimizes a frame lazily. nmethod gets patched deopt happens on return to the frame
   100   static void deoptimize(JavaThread* thread, frame fr, RegisterMap *reg_map);
   102   private:
   103   // Does the actual work for deoptimizing a single frame
   104   static void deoptimize_single_frame(JavaThread* thread, frame fr);
   106   // Helper function to revoke biases of all monitors in frame if UseBiasedLocking
   107   // is enabled
   108   static void revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map);
   109   // Helper function to revoke biases of all monitors in frames
   110   // executing in a particular CodeBlob if UseBiasedLocking is enabled
   111   static void revoke_biases_of_monitors(CodeBlob* cb);
   113 #ifdef COMPILER2
   114   // Support for restoring non-escaping objects
   115   static bool realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS);
   116   static void reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type);
   117   static void reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj);
   118   static void reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects);
   119   static void relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread);
   120   NOT_PRODUCT(static void print_objects(GrowableArray<ScopeValue*>* objects);)
   121 #endif // COMPILER2
   123   public:
   124   static vframeArray* create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk);
   126   // Interface used for unpacking deoptimized frames
   128   // UnrollBlock is returned by fetch_unroll_info() to the deoptimization handler (blob).
   129   // This is only a CheapObj to ease debugging after a deopt failure
   130   class UnrollBlock : public CHeapObj {
   131    private:
   132     int       _size_of_deoptimized_frame; // Size, in bytes, of current deoptimized frame
   133     int       _caller_adjustment;         // Adjustment, in bytes, to caller's SP by initial interpreted frame
   134     int       _number_of_frames;          // Number frames to unroll
   135     int       _total_frame_sizes;         // Total of number*sizes frames
   136     intptr_t* _frame_sizes;               // Array of frame sizes, in bytes, for unrolling the stack
   137     address*  _frame_pcs;                 // Array of frame pc's, in bytes, for unrolling the stack
   138     intptr_t* _register_block;            // Block for storing callee-saved registers.
   139     BasicType _return_type;               // Tells if we have to restore double or long return value
   140     intptr_t  _initial_fp;                // FP of the sender frame
   141     // The following fields are used as temps during the unpacking phase
   142     // (which is tight on registers, especially on x86). They really ought
   143     // to be PD variables but that involves moving this class into its own
   144     // file to use the pd include mechanism. Maybe in a later cleanup ...
   145     intptr_t  _counter_temp;              // SHOULD BE PD VARIABLE (x86 frame count temp)
   146     intptr_t  _unpack_kind;               // SHOULD BE PD VARIABLE (x86 unpack kind)
   147     intptr_t  _sender_sp_temp;            // SHOULD BE PD VARIABLE (x86 sender_sp)
   148    public:
   149     // Constructor
   150     UnrollBlock(int  size_of_deoptimized_frame,
   151                 int  caller_adjustment,
   152                 int  number_of_frames,
   153                 intptr_t* frame_sizes,
   154                 address* frames_pcs,
   155                 BasicType return_type);
   156     ~UnrollBlock();
   158     // Returns where a register is located.
   159     intptr_t* value_addr_at(int register_number) const;
   161     // Accessors
   162     intptr_t* frame_sizes()  const { return _frame_sizes; }
   163     int number_of_frames()  const { return _number_of_frames; }
   164     address*  frame_pcs()   const { return _frame_pcs ; }
   166     // Returns the total size of frames
   167     int size_of_frames() const;
   169     void set_initial_fp(intptr_t fp) { _initial_fp = fp; }
   171     // Accessors used by the code generator for the unpack stub.
   172     static int size_of_deoptimized_frame_offset_in_bytes() { return offset_of(UnrollBlock, _size_of_deoptimized_frame); }
   173     static int caller_adjustment_offset_in_bytes()         { return offset_of(UnrollBlock, _caller_adjustment);         }
   174     static int number_of_frames_offset_in_bytes()          { return offset_of(UnrollBlock, _number_of_frames);          }
   175     static int frame_sizes_offset_in_bytes()               { return offset_of(UnrollBlock, _frame_sizes);               }
   176     static int total_frame_sizes_offset_in_bytes()         { return offset_of(UnrollBlock, _total_frame_sizes);         }
   177     static int frame_pcs_offset_in_bytes()                 { return offset_of(UnrollBlock, _frame_pcs);                 }
   178     static int register_block_offset_in_bytes()            { return offset_of(UnrollBlock, _register_block);            }
   179     static int return_type_offset_in_bytes()               { return offset_of(UnrollBlock, _return_type);               }
   180     static int counter_temp_offset_in_bytes()              { return offset_of(UnrollBlock, _counter_temp);              }
   181     static int initial_fp_offset_in_bytes()                { return offset_of(UnrollBlock, _initial_fp);                }
   182     static int unpack_kind_offset_in_bytes()               { return offset_of(UnrollBlock, _unpack_kind);               }
   183     static int sender_sp_temp_offset_in_bytes()            { return offset_of(UnrollBlock, _sender_sp_temp);            }
   185     BasicType return_type() const { return _return_type; }
   186     void print();
   187   };
   189   //** Returns an UnrollBlock continuing information
   190   // how to make room for the resulting interpreter frames.
   191   // Called by assembly stub after execution has returned to
   192   // deoptimized frame.
   193   // @argument thread.     Thread where stub_frame resides.
   194   // @see OptoRuntime::deoptimization_fetch_unroll_info_C
   195   static UnrollBlock* fetch_unroll_info(JavaThread* thread);
   197   //** Unpacks vframeArray onto execution stack
   198   // Called by assembly stub after execution has returned to
   199   // deoptimized frame and after the stack unrolling.
   200   // @argument thread.     Thread where stub_frame resides.
   201   // @argument exec_mode.  Determines how execution should be continuted in top frame.
   202   //                       0 means continue after current byte code
   203   //                       1 means exception has happened, handle exception
   204   //                       2 means reexecute current bytecode (for uncommon traps).
   205   // @see OptoRuntime::deoptimization_unpack_frames_C
   206   // Return BasicType of call return type, if any
   207   static BasicType unpack_frames(JavaThread* thread, int exec_mode);
   209   // Cleans up deoptimization bits on thread after unpacking or in the
   210   // case of an exception.
   211   static void cleanup_deopt_info(JavaThread  *thread,
   212                                  vframeArray * array);
   214   // Restores callee saved values from deoptimized frame into oldest interpreter frame
   215   // so caller of the deoptimized frame will get back the values it expects.
   216   static void unwind_callee_save_values(frame* f, vframeArray* vframe_array);
   218   //** Performs an uncommon trap for compiled code.
   219   // The top most compiler frame is converted into interpreter frames
   220   static UnrollBlock* uncommon_trap(JavaThread* thread, jint unloaded_class_index);
   221   // Helper routine that enters the VM and may block
   222   static void uncommon_trap_inner(JavaThread* thread, jint unloaded_class_index);
   224   //** Deoptimizes the frame identified by id.
   225   // Only called from VMDeoptimizeFrame
   226   // @argument thread.     Thread where stub_frame resides.
   227   // @argument id.         id of frame that should be deoptimized.
   228   static void deoptimize_frame_internal(JavaThread* thread, intptr_t* id);
   230   // If thread is not the current thread then execute
   231   // VM_DeoptimizeFrame otherwise deoptimize directly.
   232   static void deoptimize_frame(JavaThread* thread, intptr_t* id);
   234   // Statistics
   235   static void gather_statistics(DeoptReason reason, DeoptAction action,
   236                                 Bytecodes::Code bc = Bytecodes::_illegal);
   237   static void print_statistics();
   239   // How much room to adjust the last frame's SP by, to make space for
   240   // the callee's interpreter frame (which expects locals to be next to
   241   // incoming arguments)
   242   static int last_frame_adjust(int callee_parameters, int callee_locals);
   244   // trap_request codes
   245   static DeoptReason trap_request_reason(int trap_request) {
   246     if (trap_request < 0)
   247       return (DeoptReason)
   248         ((~(trap_request) >> _reason_shift) & right_n_bits(_reason_bits));
   249     else
   250       // standard reason for unloaded CP entry
   251       return Reason_unloaded;
   252   }
   253   static DeoptAction trap_request_action(int trap_request) {
   254     if (trap_request < 0)
   255       return (DeoptAction)
   256         ((~(trap_request) >> _action_shift) & right_n_bits(_action_bits));
   257     else
   258       // standard action for unloaded CP entry
   259       return _unloaded_action;
   260   }
   261   static int trap_request_index(int trap_request) {
   262     if (trap_request < 0)
   263       return -1;
   264     else
   265       return trap_request;
   266   }
   267   static int make_trap_request(DeoptReason reason, DeoptAction action,
   268                                int index = -1) {
   269     assert((1 << _reason_bits) >= Reason_LIMIT, "enough bits");
   270     assert((1 << _action_bits) >= Action_LIMIT, "enough bits");
   271     int trap_request;
   272     if (index != -1)
   273       trap_request = index;
   274     else
   275       trap_request = (~(((reason) << _reason_shift)
   276                         + ((action) << _action_shift)));
   277     assert(reason == trap_request_reason(trap_request), "valid reason");
   278     assert(action == trap_request_action(trap_request), "valid action");
   279     assert(index  == trap_request_index(trap_request),  "valid index");
   280     return trap_request;
   281   }
   283   // The trap_state stored in a MDO is decoded here.
   284   // It records two items of information.
   285   //  reason:  If a deoptimization happened here, what its reason was,
   286   //           or if there were multiple deopts with differing reasons.
   287   //  recompiled: If a deoptimization here triggered a recompilation.
   288   // Note that not all reasons are recorded per-bci.
   289   static DeoptReason trap_state_reason(int trap_state);
   290   static int  trap_state_has_reason(int trap_state, int reason);
   291   static int  trap_state_add_reason(int trap_state, int reason);
   292   static bool trap_state_is_recompiled(int trap_state);
   293   static int  trap_state_set_recompiled(int trap_state, bool z);
   294   static const char* format_trap_state(char* buf, size_t buflen,
   295                                        int trap_state);
   297   static bool reason_is_recorded_per_bytecode(DeoptReason reason) {
   298     return reason > Reason_none && reason <= Reason_RECORDED_LIMIT;
   299   }
   301   static DeoptReason reason_recorded_per_bytecode_if_any(DeoptReason reason) {
   302     if (reason_is_recorded_per_bytecode(reason))
   303       return reason;
   304     else if (reason == Reason_div0_check) // null check due to divide-by-zero?
   305       return Reason_null_check;           // recorded per BCI as a null check
   306     else
   307       return Reason_none;
   308   }
   310   static const char* trap_reason_name(int reason);
   311   static const char* trap_action_name(int action);
   312   // Format like reason='foo' action='bar' index='123'.
   313   // This is suitable both for XML and for tty output.
   314   static const char* format_trap_request(char* buf, size_t buflen,
   315                                          int trap_request);
   317   static jint total_deoptimization_count();
   318   static jint deoptimization_count(DeoptReason reason);
   320   // JVMTI PopFrame support
   322   // Preserves incoming arguments to the popped frame when it is
   323   // returning to a deoptimized caller
   324   static void popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address);
   326  private:
   327   static methodDataOop get_method_data(JavaThread* thread, methodHandle m, bool create_if_missing);
   328   // Update the mdo's count and per-BCI reason bits, returning previous state:
   329   static ProfileData* query_update_method_data(methodDataHandle trap_mdo,
   330                                                int trap_bci,
   331                                                DeoptReason reason,
   332                                                //outputs:
   333                                                uint& ret_this_trap_count,
   334                                                bool& ret_maybe_prior_trap,
   335                                                bool& ret_maybe_prior_recompile);
   336   // class loading support for uncommon trap
   337   static void load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS);
   338   static void load_class_by_index(constantPoolHandle constant_pool, int index);
   340   static UnrollBlock* fetch_unroll_info_helper(JavaThread* thread);
   342   static DeoptAction _unloaded_action; // == Action_reinterpret;
   343   static const char* _trap_reason_name[Reason_LIMIT];
   344   static const char* _trap_action_name[Action_LIMIT];
   346   static juint _deoptimization_hist[Reason_LIMIT][1+Action_LIMIT][BC_CASE_LIMIT];
   347   // Note:  Histogram array size is 1-2 Kb.
   349  public:
   350   static void update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason);
   351 };
   353 class DeoptimizationMarker : StackObj {  // for profiling
   354   static bool _is_active;
   355 public:
   356   DeoptimizationMarker()  { _is_active = true; }
   357   ~DeoptimizationMarker() { _is_active = false; }
   358   static bool is_active() { return _is_active; }
   359 };
   361 #endif // SHARE_VM_RUNTIME_DEOPTIMIZATION_HPP

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