hotspot/src/share/vm/runtime/deoptimization.hpp
changeset 1 489c9b5090e2
child 256 70fdc3927a4e
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/runtime/deoptimization.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,348 @@
+/*
+ * Copyright 1997-2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+class ProfileData;
+class vframeArray;
+class MonitorValue;
+class ObjectValue;
+
+class Deoptimization : AllStatic {
+ public:
+  // What condition caused the deoptimization?
+  enum DeoptReason {
+    Reason_many = -1,             // indicates presence of several reasons
+    Reason_none = 0,              // indicates absence of a relevant deopt.
+    Reason_null_check,            // saw unexpected null or zero divisor (@bci)
+    Reason_null_assert,           // saw unexpected non-null or non-zero (@bci)
+    Reason_range_check,           // saw unexpected array index (@bci)
+    Reason_class_check,           // saw unexpected object class (@bci)
+    Reason_array_check,           // saw unexpected array class (aastore @bci)
+    Reason_intrinsic,             // saw unexpected operand to intrinsic (@bci)
+    Reason_unloaded,              // unloaded class or constant pool entry
+    Reason_uninitialized,         // bad class state (uninitialized)
+    Reason_unreached,             // code is not reached, compiler
+    Reason_unhandled,             // arbitrary compiler limitation
+    Reason_constraint,            // arbitrary runtime constraint violated
+    Reason_div0_check,            // a null_check due to division by zero
+    Reason_age,                   // nmethod too old; tier threshold reached
+    Reason_LIMIT,
+    // Note:  Keep this enum in sync. with _trap_reason_name.
+    Reason_RECORDED_LIMIT = Reason_unloaded   // some are not recorded per bc
+    // Note:  Reason_RECORDED_LIMIT should be < 8 to fit into 3 bits of
+    // DataLayout::trap_bits.  This dependency is enforced indirectly
+    // via asserts, to avoid excessive direct header-to-header dependencies.
+    // See Deoptimization::trap_state_reason and class DataLayout.
+  };
+
+  // What action must be taken by the runtime?
+  enum DeoptAction {
+    Action_none,                  // just interpret, do not invalidate nmethod
+    Action_maybe_recompile,       // recompile the nmethod; need not invalidate
+    Action_reinterpret,           // invalidate the nmethod, reset IC, maybe recompile
+    Action_make_not_entrant,      // invalidate the nmethod, recompile (probably)
+    Action_make_not_compilable,   // invalidate the nmethod and do not compile
+    Action_LIMIT
+    // Note:  Keep this enum in sync. with _trap_action_name.
+  };
+
+  enum {
+    _action_bits = 3,
+    _reason_bits = 4,
+    _action_shift = 0,
+    _reason_shift = _action_shift+_action_bits,
+    BC_CASE_LIMIT = PRODUCT_ONLY(1) NOT_PRODUCT(4) // for _deoptimization_hist
+  };
+
+  enum UnpackType {
+    Unpack_deopt                = 0, // normal deoptimization, use pc computed in unpack_vframe_on_stack
+    Unpack_exception            = 1, // exception is pending
+    Unpack_uncommon_trap        = 2, // redo last byte code (C2 only)
+    Unpack_reexecute            = 3  // reexecute bytecode (C1 only)
+  };
+
+  // Checks all compiled methods. Invalid methods are deleted and
+  // corresponding activations are deoptimized.
+  static int deoptimize_dependents();
+
+  // Deoptimizes a frame lazily. nmethod gets patched deopt happens on return to the frame
+  static void deoptimize(JavaThread* thread, frame fr, RegisterMap *reg_map);
+
+  private:
+  // Does the actual work for deoptimizing a single frame
+  static void deoptimize_single_frame(JavaThread* thread, frame fr);
+
+  // Helper function to revoke biases of all monitors in frame if UseBiasedLocking
+  // is enabled
+  static void revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map);
+  // Helper function to revoke biases of all monitors in frames
+  // executing in a particular CodeBlob if UseBiasedLocking is enabled
+  static void revoke_biases_of_monitors(CodeBlob* cb);
+
+#ifdef COMPILER2
+  // Support for restoring non-escaping objects
+  static bool realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS);
+  static void reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type);
+  static void reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj);
+  static void reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects);
+  static void relock_objects(frame* fr, RegisterMap* reg_map, GrowableArray<MonitorValue*>* monitors);
+  NOT_PRODUCT(static void print_objects(GrowableArray<ScopeValue*>* objects);)
+#endif // COMPILER2
+
+  public:
+  static vframeArray* create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk);
+
+  // Interface used for unpacking deoptimized frames
+
+  // UnrollBlock is returned by fetch_unroll_info() to the deoptimization handler (blob).
+  // This is only a CheapObj to ease debugging after a deopt failure
+  class UnrollBlock : public CHeapObj {
+   private:
+    int       _size_of_deoptimized_frame; // Size, in bytes, of current deoptimized frame
+    int       _caller_adjustment;         // Adjustment, in bytes, to caller's SP by initial interpreted frame
+    int       _number_of_frames;          // Number frames to unroll
+    int       _total_frame_sizes;         // Total of number*sizes frames
+    intptr_t* _frame_sizes;               // Array of frame sizes, in bytes, for unrolling the stack
+    address*  _frame_pcs;                 // Array of frame pc's, in bytes, for unrolling the stack
+    intptr_t* _register_block;            // Block for storing callee-saved registers.
+    BasicType _return_type;               // Tells if we have to restore double or long return value
+    // The following fields are used as temps during the unpacking phase
+    // (which is tight on registers, especially on x86). They really ought
+    // to be PD variables but that involves moving this class into its own
+    // file to use the pd include mechanism. Maybe in a later cleanup ...
+    intptr_t  _counter_temp;              // SHOULD BE PD VARIABLE (x86 frame count temp)
+    intptr_t  _initial_fp;                // SHOULD BE PD VARIABLE (x86/c2 initial ebp)
+    intptr_t  _unpack_kind;               // SHOULD BE PD VARIABLE (x86 unpack kind)
+    intptr_t  _sender_sp_temp;            // SHOULD BE PD VARIABLE (x86 sender_sp)
+   public:
+    // Constructor
+    UnrollBlock(int  size_of_deoptimized_frame,
+                int  caller_adjustment,
+                int  number_of_frames,
+                intptr_t* frame_sizes,
+                address* frames_pcs,
+                BasicType return_type);
+    ~UnrollBlock();
+
+    // Returns where a register is located.
+    intptr_t* value_addr_at(int register_number) const;
+
+    // Accessors
+    intptr_t* frame_sizes()  const { return _frame_sizes; }
+    int number_of_frames()  const { return _number_of_frames; }
+    address*  frame_pcs()   const { return _frame_pcs ; }
+
+    // Returns the total size of frames
+    int size_of_frames() const;
+
+    // Accessors used by the code generator for the unpack stub.
+    static int size_of_deoptimized_frame_offset_in_bytes() { return offset_of(UnrollBlock, _size_of_deoptimized_frame); }
+    static int caller_adjustment_offset_in_bytes()         { return offset_of(UnrollBlock, _caller_adjustment);         }
+    static int number_of_frames_offset_in_bytes()          { return offset_of(UnrollBlock, _number_of_frames);          }
+    static int frame_sizes_offset_in_bytes()               { return offset_of(UnrollBlock, _frame_sizes);               }
+    static int total_frame_sizes_offset_in_bytes()         { return offset_of(UnrollBlock, _total_frame_sizes);         }
+    static int frame_pcs_offset_in_bytes()                 { return offset_of(UnrollBlock, _frame_pcs);                 }
+    static int register_block_offset_in_bytes()            { return offset_of(UnrollBlock, _register_block);            }
+    static int return_type_offset_in_bytes()               { return offset_of(UnrollBlock, _return_type);               }
+    static int counter_temp_offset_in_bytes()              { return offset_of(UnrollBlock, _counter_temp);              }
+    static int initial_fp_offset_in_bytes()                { return offset_of(UnrollBlock, _initial_fp);                }
+    static int unpack_kind_offset_in_bytes()               { return offset_of(UnrollBlock, _unpack_kind);               }
+    static int sender_sp_temp_offset_in_bytes()            { return offset_of(UnrollBlock, _sender_sp_temp);            }
+
+    BasicType return_type() const { return _return_type; }
+    void print();
+  };
+
+  //** Returns an UnrollBlock continuing information
+  // how to make room for the resulting interpreter frames.
+  // Called by assembly stub after execution has returned to
+  // deoptimized frame.
+  // @argument thread.     Thread where stub_frame resides.
+  // @see OptoRuntime::deoptimization_fetch_unroll_info_C
+  static UnrollBlock* fetch_unroll_info(JavaThread* thread);
+
+  //** Unpacks vframeArray onto execution stack
+  // Called by assembly stub after execution has returned to
+  // deoptimized frame and after the stack unrolling.
+  // @argument thread.     Thread where stub_frame resides.
+  // @argument exec_mode.  Determines how execution should be continuted in top frame.
+  //                       0 means continue after current byte code
+  //                       1 means exception has happened, handle exception
+  //                       2 means reexecute current bytecode (for uncommon traps).
+  // @see OptoRuntime::deoptimization_unpack_frames_C
+  // Return BasicType of call return type, if any
+  static BasicType unpack_frames(JavaThread* thread, int exec_mode);
+
+  // Cleans up deoptimization bits on thread after unpacking or in the
+  // case of an exception.
+  static void cleanup_deopt_info(JavaThread  *thread,
+                                 vframeArray * array);
+
+  // Restores callee saved values from deoptimized frame into oldest interpreter frame
+  // so caller of the deoptimized frame will get back the values it expects.
+  static void unwind_callee_save_values(frame* f, vframeArray* vframe_array);
+
+  //** Performs an uncommon trap for compiled code.
+  // The top most compiler frame is converted into interpreter frames
+  static UnrollBlock* uncommon_trap(JavaThread* thread, jint unloaded_class_index);
+  // Helper routine that enters the VM and may block
+  static void uncommon_trap_inner(JavaThread* thread, jint unloaded_class_index);
+
+  //** Deoptimizes the frame identified by id.
+  // Only called from VMDeoptimizeFrame
+  // @argument thread.     Thread where stub_frame resides.
+  // @argument id.         id of frame that should be deoptimized.
+  static void deoptimize_frame(JavaThread* thread, intptr_t* id);
+
+  // Statistics
+  static void gather_statistics(DeoptReason reason, DeoptAction action,
+                                Bytecodes::Code bc = Bytecodes::_illegal);
+  static void print_statistics();
+
+  // How much room to adjust the last frame's SP by, to make space for
+  // the callee's interpreter frame (which expects locals to be next to
+  // incoming arguments)
+  static int last_frame_adjust(int callee_parameters, int callee_locals);
+
+  // trap_request codes
+  static DeoptReason trap_request_reason(int trap_request) {
+    if (trap_request < 0)
+      return (DeoptReason)
+        ((~(trap_request) >> _reason_shift) & right_n_bits(_reason_bits));
+    else
+      // standard reason for unloaded CP entry
+      return Reason_unloaded;
+  }
+  static DeoptAction trap_request_action(int trap_request) {
+    if (trap_request < 0)
+      return (DeoptAction)
+        ((~(trap_request) >> _action_shift) & right_n_bits(_action_bits));
+    else
+      // standard action for unloaded CP entry
+      return _unloaded_action;
+  }
+  static int trap_request_index(int trap_request) {
+    if (trap_request < 0)
+      return -1;
+    else
+      return trap_request;
+  }
+  static int make_trap_request(DeoptReason reason, DeoptAction action,
+                               int index = -1) {
+    assert((1 << _reason_bits) >= Reason_LIMIT, "enough bits");
+    assert((1 << _action_bits) >= Action_LIMIT, "enough bits");
+    int trap_request;
+    if (index != -1)
+      trap_request = index;
+    else
+      trap_request = (~(((reason) << _reason_shift)
+                        + ((action) << _action_shift)));
+    assert(reason == trap_request_reason(trap_request), "valid reason");
+    assert(action == trap_request_action(trap_request), "valid action");
+    assert(index  == trap_request_index(trap_request),  "valid index");
+    return trap_request;
+  }
+
+  // The trap_state stored in a MDO is decoded here.
+  // It records two items of information.
+  //  reason:  If a deoptimization happened here, what its reason was,
+  //           or if there were multiple deopts with differing reasons.
+  //  recompiled: If a deoptimization here triggered a recompilation.
+  // Note that not all reasons are recorded per-bci.
+  static DeoptReason trap_state_reason(int trap_state);
+  static int  trap_state_has_reason(int trap_state, int reason);
+  static int  trap_state_add_reason(int trap_state, int reason);
+  static bool trap_state_is_recompiled(int trap_state);
+  static int  trap_state_set_recompiled(int trap_state, bool z);
+  static const char* format_trap_state(char* buf, size_t buflen,
+                                       int trap_state);
+
+  static bool reason_is_recorded_per_bytecode(DeoptReason reason) {
+    return reason > Reason_none && reason < Reason_RECORDED_LIMIT;
+  }
+
+  static DeoptReason reason_recorded_per_bytecode_if_any(DeoptReason reason) {
+    if (reason_is_recorded_per_bytecode(reason))
+      return reason;
+    else if (reason == Reason_div0_check) // null check due to divide-by-zero?
+      return Reason_null_check;           // recorded per BCI as a null check
+    else
+      return Reason_none;
+  }
+
+  static const char* trap_reason_name(int reason);
+  static const char* trap_action_name(int action);
+  // Format like reason='foo' action='bar' index='123'.
+  // This is suitable both for XML and for tty output.
+  static const char* format_trap_request(char* buf, size_t buflen,
+                                         int trap_request);
+
+  static jint total_deoptimization_count();
+  static jint deoptimization_count(DeoptReason reason);
+
+  // JVMTI PopFrame support
+
+  // Preserves incoming arguments to the popped frame when it is
+  // returning to a deoptimized caller
+  static void popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address);
+
+ private:
+  enum {
+    _no_count = -1
+  };
+
+  static void reset_invocation_counter(ScopeDesc* trap_scope, jint count = _no_count);
+
+  static methodDataOop get_method_data(JavaThread* thread, methodHandle m, bool create_if_missing);
+  // Update the mdo's count and per-BCI reason bits, returning previous state:
+  static ProfileData* query_update_method_data(methodDataHandle trap_mdo,
+                                               int trap_bci,
+                                               DeoptReason reason,
+                                               //outputs:
+                                               uint& ret_this_trap_count,
+                                               bool& ret_maybe_prior_trap,
+                                               bool& ret_maybe_prior_recompile);
+  // class loading support for uncommon trap
+  static void load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS);
+  static void load_class_by_index(constantPoolHandle constant_pool, int index);
+
+  static UnrollBlock* fetch_unroll_info_helper(JavaThread* thread);
+
+  static DeoptAction _unloaded_action; // == Action_reinterpret;
+  static const char* _trap_reason_name[Reason_LIMIT];
+  static const char* _trap_action_name[Action_LIMIT];
+
+  static juint _deoptimization_hist[Reason_LIMIT][1+Action_LIMIT][BC_CASE_LIMIT];
+  // Note:  Histogram array size is 1-2 Kb.
+
+ public:
+  static void update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason);
+};
+
+class DeoptimizationMarker : StackObj {  // for profiling
+  static bool _is_active;
+public:
+  DeoptimizationMarker()  { _is_active = true; }
+  ~DeoptimizationMarker() { _is_active = false; }
+  static bool is_active() { return _is_active; }
+};