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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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #ifndef SHARE_VM_RUNTIME_DEOPTIMIZATION_HPP #define SHARE_VM_RUNTIME_DEOPTIMIZATION_HPP #include "memory/allocation.hpp" #include "runtime/frame.inline.hpp" class ProfileData; class vframeArray; class MonitorValue; class ObjectValue; class Deoptimization : AllStatic { friend class VMStructs; 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. // Next 7 reasons are recorded per bytecode in DataLayout::trap_bits 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_bimorphic, // saw unexpected object class in bimorphic inlining (@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_predicate, // compiler generated predicate failed Reason_loop_limit_check, // compiler generated loop limits check failed Reason_speculate_class_check, // saw unexpected object class from type speculation Reason_rtm_state_change, // rtm state change detected Reason_unstable_if, // a branch predicted always false was taken Reason_LIMIT, // Note: Keep this enum in sync. with _trap_reason_name. Reason_RECORDED_LIMIT = Reason_bimorphic // 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 = 5, _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* 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* objects); static void relock_objects(GrowableArray* monitors, JavaThread* thread); NOT_PRODUCT(static void print_objects(GrowableArray* objects);) #endif // COMPILER2 public: static vframeArray* create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray* 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 intptr_t _initial_info; // Platform dependent data for the sender frame (was FP on x86) int _caller_actual_parameters; // The number of actual arguments at the // interpreted caller of the deoptimized frame // 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 _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 caller_actual_parameters, 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; void set_initial_info(intptr_t info) { _initial_info = info; } int caller_actual_parameters() const { return _caller_actual_parameters; } // 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_info_offset_in_bytes() { return offset_of(UnrollBlock, _initial_info); } 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_internal(JavaThread* thread, intptr_t* id); // If thread is not the current thread then execute // VM_DeoptimizeFrame otherwise deoptimize directly. 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 if (reason == Reason_speculate_class_check) return Reason_class_check; else if (reason == Reason_unstable_if) return Reason_intrinsic; else return Reason_none; } static bool reason_is_speculate(int reason) { if (reason == Reason_speculate_class_check) { return true; } return false; } static uint per_method_trap_limit(int reason) { return reason_is_speculate(reason) ? (uint)PerMethodSpecTrapLimit : (uint)PerMethodTrapLimit; } 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: static MethodData* 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(MethodData* trap_mdo, int trap_bci, DeoptReason reason, Method* compiled_method, //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(MethodData* 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; } }; #endif // SHARE_VM_RUNTIME_DEOPTIMIZATION_HPP