Mon, 23 Jun 2008 14:11:12 -0700
6708714: Optimize long LShift on 32-bits x86
Summary: For small (1-3 bits) left long shifts in 32-bits VM use sets of add+addc instructions instead of shld+shl on new AMD cpus.
Reviewed-by: never
Contributed-by: shrinivas.joshi@amd.com
duke@435 | 1 | /* |
duke@435 | 2 | * Copyright 1997-2007 Sun Microsystems, Inc. All Rights Reserved. |
duke@435 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
duke@435 | 4 | * |
duke@435 | 5 | * This code is free software; you can redistribute it and/or modify it |
duke@435 | 6 | * under the terms of the GNU General Public License version 2 only, as |
duke@435 | 7 | * published by the Free Software Foundation. |
duke@435 | 8 | * |
duke@435 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
duke@435 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
duke@435 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
duke@435 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
duke@435 | 13 | * accompanied this code). |
duke@435 | 14 | * |
duke@435 | 15 | * You should have received a copy of the GNU General Public License version |
duke@435 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
duke@435 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
duke@435 | 18 | * |
duke@435 | 19 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
duke@435 | 20 | * CA 95054 USA or visit www.sun.com if you need additional information or |
duke@435 | 21 | * have any questions. |
duke@435 | 22 | * |
duke@435 | 23 | */ |
duke@435 | 24 | |
duke@435 | 25 | class ProfileData; |
duke@435 | 26 | class vframeArray; |
duke@435 | 27 | class MonitorValue; |
duke@435 | 28 | class ObjectValue; |
duke@435 | 29 | |
duke@435 | 30 | class Deoptimization : AllStatic { |
duke@435 | 31 | public: |
duke@435 | 32 | // What condition caused the deoptimization? |
duke@435 | 33 | enum DeoptReason { |
duke@435 | 34 | Reason_many = -1, // indicates presence of several reasons |
duke@435 | 35 | Reason_none = 0, // indicates absence of a relevant deopt. |
duke@435 | 36 | Reason_null_check, // saw unexpected null or zero divisor (@bci) |
duke@435 | 37 | Reason_null_assert, // saw unexpected non-null or non-zero (@bci) |
duke@435 | 38 | Reason_range_check, // saw unexpected array index (@bci) |
duke@435 | 39 | Reason_class_check, // saw unexpected object class (@bci) |
duke@435 | 40 | Reason_array_check, // saw unexpected array class (aastore @bci) |
duke@435 | 41 | Reason_intrinsic, // saw unexpected operand to intrinsic (@bci) |
duke@435 | 42 | Reason_unloaded, // unloaded class or constant pool entry |
duke@435 | 43 | Reason_uninitialized, // bad class state (uninitialized) |
duke@435 | 44 | Reason_unreached, // code is not reached, compiler |
duke@435 | 45 | Reason_unhandled, // arbitrary compiler limitation |
duke@435 | 46 | Reason_constraint, // arbitrary runtime constraint violated |
duke@435 | 47 | Reason_div0_check, // a null_check due to division by zero |
duke@435 | 48 | Reason_age, // nmethod too old; tier threshold reached |
duke@435 | 49 | Reason_LIMIT, |
duke@435 | 50 | // Note: Keep this enum in sync. with _trap_reason_name. |
duke@435 | 51 | Reason_RECORDED_LIMIT = Reason_unloaded // some are not recorded per bc |
duke@435 | 52 | // Note: Reason_RECORDED_LIMIT should be < 8 to fit into 3 bits of |
duke@435 | 53 | // DataLayout::trap_bits. This dependency is enforced indirectly |
duke@435 | 54 | // via asserts, to avoid excessive direct header-to-header dependencies. |
duke@435 | 55 | // See Deoptimization::trap_state_reason and class DataLayout. |
duke@435 | 56 | }; |
duke@435 | 57 | |
duke@435 | 58 | // What action must be taken by the runtime? |
duke@435 | 59 | enum DeoptAction { |
duke@435 | 60 | Action_none, // just interpret, do not invalidate nmethod |
duke@435 | 61 | Action_maybe_recompile, // recompile the nmethod; need not invalidate |
duke@435 | 62 | Action_reinterpret, // invalidate the nmethod, reset IC, maybe recompile |
duke@435 | 63 | Action_make_not_entrant, // invalidate the nmethod, recompile (probably) |
duke@435 | 64 | Action_make_not_compilable, // invalidate the nmethod and do not compile |
duke@435 | 65 | Action_LIMIT |
duke@435 | 66 | // Note: Keep this enum in sync. with _trap_action_name. |
duke@435 | 67 | }; |
duke@435 | 68 | |
duke@435 | 69 | enum { |
duke@435 | 70 | _action_bits = 3, |
duke@435 | 71 | _reason_bits = 4, |
duke@435 | 72 | _action_shift = 0, |
duke@435 | 73 | _reason_shift = _action_shift+_action_bits, |
duke@435 | 74 | BC_CASE_LIMIT = PRODUCT_ONLY(1) NOT_PRODUCT(4) // for _deoptimization_hist |
duke@435 | 75 | }; |
duke@435 | 76 | |
duke@435 | 77 | enum UnpackType { |
duke@435 | 78 | Unpack_deopt = 0, // normal deoptimization, use pc computed in unpack_vframe_on_stack |
duke@435 | 79 | Unpack_exception = 1, // exception is pending |
duke@435 | 80 | Unpack_uncommon_trap = 2, // redo last byte code (C2 only) |
duke@435 | 81 | Unpack_reexecute = 3 // reexecute bytecode (C1 only) |
duke@435 | 82 | }; |
duke@435 | 83 | |
duke@435 | 84 | // Checks all compiled methods. Invalid methods are deleted and |
duke@435 | 85 | // corresponding activations are deoptimized. |
duke@435 | 86 | static int deoptimize_dependents(); |
duke@435 | 87 | |
duke@435 | 88 | // Deoptimizes a frame lazily. nmethod gets patched deopt happens on return to the frame |
duke@435 | 89 | static void deoptimize(JavaThread* thread, frame fr, RegisterMap *reg_map); |
duke@435 | 90 | |
duke@435 | 91 | private: |
duke@435 | 92 | // Does the actual work for deoptimizing a single frame |
duke@435 | 93 | static void deoptimize_single_frame(JavaThread* thread, frame fr); |
duke@435 | 94 | |
duke@435 | 95 | // Helper function to revoke biases of all monitors in frame if UseBiasedLocking |
duke@435 | 96 | // is enabled |
duke@435 | 97 | static void revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map); |
duke@435 | 98 | // Helper function to revoke biases of all monitors in frames |
duke@435 | 99 | // executing in a particular CodeBlob if UseBiasedLocking is enabled |
duke@435 | 100 | static void revoke_biases_of_monitors(CodeBlob* cb); |
duke@435 | 101 | |
duke@435 | 102 | #ifdef COMPILER2 |
duke@435 | 103 | // Support for restoring non-escaping objects |
duke@435 | 104 | static bool realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS); |
duke@435 | 105 | static void reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type); |
duke@435 | 106 | static void reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj); |
duke@435 | 107 | static void reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects); |
kvn@518 | 108 | static void relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread); |
duke@435 | 109 | NOT_PRODUCT(static void print_objects(GrowableArray<ScopeValue*>* objects);) |
duke@435 | 110 | #endif // COMPILER2 |
duke@435 | 111 | |
duke@435 | 112 | public: |
duke@435 | 113 | static vframeArray* create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk); |
duke@435 | 114 | |
duke@435 | 115 | // Interface used for unpacking deoptimized frames |
duke@435 | 116 | |
duke@435 | 117 | // UnrollBlock is returned by fetch_unroll_info() to the deoptimization handler (blob). |
duke@435 | 118 | // This is only a CheapObj to ease debugging after a deopt failure |
duke@435 | 119 | class UnrollBlock : public CHeapObj { |
duke@435 | 120 | private: |
duke@435 | 121 | int _size_of_deoptimized_frame; // Size, in bytes, of current deoptimized frame |
duke@435 | 122 | int _caller_adjustment; // Adjustment, in bytes, to caller's SP by initial interpreted frame |
duke@435 | 123 | int _number_of_frames; // Number frames to unroll |
duke@435 | 124 | int _total_frame_sizes; // Total of number*sizes frames |
duke@435 | 125 | intptr_t* _frame_sizes; // Array of frame sizes, in bytes, for unrolling the stack |
duke@435 | 126 | address* _frame_pcs; // Array of frame pc's, in bytes, for unrolling the stack |
duke@435 | 127 | intptr_t* _register_block; // Block for storing callee-saved registers. |
duke@435 | 128 | BasicType _return_type; // Tells if we have to restore double or long return value |
duke@435 | 129 | // The following fields are used as temps during the unpacking phase |
duke@435 | 130 | // (which is tight on registers, especially on x86). They really ought |
duke@435 | 131 | // to be PD variables but that involves moving this class into its own |
duke@435 | 132 | // file to use the pd include mechanism. Maybe in a later cleanup ... |
duke@435 | 133 | intptr_t _counter_temp; // SHOULD BE PD VARIABLE (x86 frame count temp) |
duke@435 | 134 | intptr_t _initial_fp; // SHOULD BE PD VARIABLE (x86/c2 initial ebp) |
duke@435 | 135 | intptr_t _unpack_kind; // SHOULD BE PD VARIABLE (x86 unpack kind) |
duke@435 | 136 | intptr_t _sender_sp_temp; // SHOULD BE PD VARIABLE (x86 sender_sp) |
duke@435 | 137 | public: |
duke@435 | 138 | // Constructor |
duke@435 | 139 | UnrollBlock(int size_of_deoptimized_frame, |
duke@435 | 140 | int caller_adjustment, |
duke@435 | 141 | int number_of_frames, |
duke@435 | 142 | intptr_t* frame_sizes, |
duke@435 | 143 | address* frames_pcs, |
duke@435 | 144 | BasicType return_type); |
duke@435 | 145 | ~UnrollBlock(); |
duke@435 | 146 | |
duke@435 | 147 | // Returns where a register is located. |
duke@435 | 148 | intptr_t* value_addr_at(int register_number) const; |
duke@435 | 149 | |
duke@435 | 150 | // Accessors |
duke@435 | 151 | intptr_t* frame_sizes() const { return _frame_sizes; } |
duke@435 | 152 | int number_of_frames() const { return _number_of_frames; } |
duke@435 | 153 | address* frame_pcs() const { return _frame_pcs ; } |
duke@435 | 154 | |
duke@435 | 155 | // Returns the total size of frames |
duke@435 | 156 | int size_of_frames() const; |
duke@435 | 157 | |
duke@435 | 158 | // Accessors used by the code generator for the unpack stub. |
duke@435 | 159 | static int size_of_deoptimized_frame_offset_in_bytes() { return offset_of(UnrollBlock, _size_of_deoptimized_frame); } |
duke@435 | 160 | static int caller_adjustment_offset_in_bytes() { return offset_of(UnrollBlock, _caller_adjustment); } |
duke@435 | 161 | static int number_of_frames_offset_in_bytes() { return offset_of(UnrollBlock, _number_of_frames); } |
duke@435 | 162 | static int frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _frame_sizes); } |
duke@435 | 163 | static int total_frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _total_frame_sizes); } |
duke@435 | 164 | static int frame_pcs_offset_in_bytes() { return offset_of(UnrollBlock, _frame_pcs); } |
duke@435 | 165 | static int register_block_offset_in_bytes() { return offset_of(UnrollBlock, _register_block); } |
duke@435 | 166 | static int return_type_offset_in_bytes() { return offset_of(UnrollBlock, _return_type); } |
duke@435 | 167 | static int counter_temp_offset_in_bytes() { return offset_of(UnrollBlock, _counter_temp); } |
duke@435 | 168 | static int initial_fp_offset_in_bytes() { return offset_of(UnrollBlock, _initial_fp); } |
duke@435 | 169 | static int unpack_kind_offset_in_bytes() { return offset_of(UnrollBlock, _unpack_kind); } |
duke@435 | 170 | static int sender_sp_temp_offset_in_bytes() { return offset_of(UnrollBlock, _sender_sp_temp); } |
duke@435 | 171 | |
duke@435 | 172 | BasicType return_type() const { return _return_type; } |
duke@435 | 173 | void print(); |
duke@435 | 174 | }; |
duke@435 | 175 | |
duke@435 | 176 | //** Returns an UnrollBlock continuing information |
duke@435 | 177 | // how to make room for the resulting interpreter frames. |
duke@435 | 178 | // Called by assembly stub after execution has returned to |
duke@435 | 179 | // deoptimized frame. |
duke@435 | 180 | // @argument thread. Thread where stub_frame resides. |
duke@435 | 181 | // @see OptoRuntime::deoptimization_fetch_unroll_info_C |
duke@435 | 182 | static UnrollBlock* fetch_unroll_info(JavaThread* thread); |
duke@435 | 183 | |
duke@435 | 184 | //** Unpacks vframeArray onto execution stack |
duke@435 | 185 | // Called by assembly stub after execution has returned to |
duke@435 | 186 | // deoptimized frame and after the stack unrolling. |
duke@435 | 187 | // @argument thread. Thread where stub_frame resides. |
duke@435 | 188 | // @argument exec_mode. Determines how execution should be continuted in top frame. |
duke@435 | 189 | // 0 means continue after current byte code |
duke@435 | 190 | // 1 means exception has happened, handle exception |
duke@435 | 191 | // 2 means reexecute current bytecode (for uncommon traps). |
duke@435 | 192 | // @see OptoRuntime::deoptimization_unpack_frames_C |
duke@435 | 193 | // Return BasicType of call return type, if any |
duke@435 | 194 | static BasicType unpack_frames(JavaThread* thread, int exec_mode); |
duke@435 | 195 | |
duke@435 | 196 | // Cleans up deoptimization bits on thread after unpacking or in the |
duke@435 | 197 | // case of an exception. |
duke@435 | 198 | static void cleanup_deopt_info(JavaThread *thread, |
duke@435 | 199 | vframeArray * array); |
duke@435 | 200 | |
duke@435 | 201 | // Restores callee saved values from deoptimized frame into oldest interpreter frame |
duke@435 | 202 | // so caller of the deoptimized frame will get back the values it expects. |
duke@435 | 203 | static void unwind_callee_save_values(frame* f, vframeArray* vframe_array); |
duke@435 | 204 | |
duke@435 | 205 | //** Performs an uncommon trap for compiled code. |
duke@435 | 206 | // The top most compiler frame is converted into interpreter frames |
duke@435 | 207 | static UnrollBlock* uncommon_trap(JavaThread* thread, jint unloaded_class_index); |
duke@435 | 208 | // Helper routine that enters the VM and may block |
duke@435 | 209 | static void uncommon_trap_inner(JavaThread* thread, jint unloaded_class_index); |
duke@435 | 210 | |
duke@435 | 211 | //** Deoptimizes the frame identified by id. |
duke@435 | 212 | // Only called from VMDeoptimizeFrame |
duke@435 | 213 | // @argument thread. Thread where stub_frame resides. |
duke@435 | 214 | // @argument id. id of frame that should be deoptimized. |
duke@435 | 215 | static void deoptimize_frame(JavaThread* thread, intptr_t* id); |
duke@435 | 216 | |
duke@435 | 217 | // Statistics |
duke@435 | 218 | static void gather_statistics(DeoptReason reason, DeoptAction action, |
duke@435 | 219 | Bytecodes::Code bc = Bytecodes::_illegal); |
duke@435 | 220 | static void print_statistics(); |
duke@435 | 221 | |
duke@435 | 222 | // How much room to adjust the last frame's SP by, to make space for |
duke@435 | 223 | // the callee's interpreter frame (which expects locals to be next to |
duke@435 | 224 | // incoming arguments) |
duke@435 | 225 | static int last_frame_adjust(int callee_parameters, int callee_locals); |
duke@435 | 226 | |
duke@435 | 227 | // trap_request codes |
duke@435 | 228 | static DeoptReason trap_request_reason(int trap_request) { |
duke@435 | 229 | if (trap_request < 0) |
duke@435 | 230 | return (DeoptReason) |
duke@435 | 231 | ((~(trap_request) >> _reason_shift) & right_n_bits(_reason_bits)); |
duke@435 | 232 | else |
duke@435 | 233 | // standard reason for unloaded CP entry |
duke@435 | 234 | return Reason_unloaded; |
duke@435 | 235 | } |
duke@435 | 236 | static DeoptAction trap_request_action(int trap_request) { |
duke@435 | 237 | if (trap_request < 0) |
duke@435 | 238 | return (DeoptAction) |
duke@435 | 239 | ((~(trap_request) >> _action_shift) & right_n_bits(_action_bits)); |
duke@435 | 240 | else |
duke@435 | 241 | // standard action for unloaded CP entry |
duke@435 | 242 | return _unloaded_action; |
duke@435 | 243 | } |
duke@435 | 244 | static int trap_request_index(int trap_request) { |
duke@435 | 245 | if (trap_request < 0) |
duke@435 | 246 | return -1; |
duke@435 | 247 | else |
duke@435 | 248 | return trap_request; |
duke@435 | 249 | } |
duke@435 | 250 | static int make_trap_request(DeoptReason reason, DeoptAction action, |
duke@435 | 251 | int index = -1) { |
duke@435 | 252 | assert((1 << _reason_bits) >= Reason_LIMIT, "enough bits"); |
duke@435 | 253 | assert((1 << _action_bits) >= Action_LIMIT, "enough bits"); |
duke@435 | 254 | int trap_request; |
duke@435 | 255 | if (index != -1) |
duke@435 | 256 | trap_request = index; |
duke@435 | 257 | else |
duke@435 | 258 | trap_request = (~(((reason) << _reason_shift) |
duke@435 | 259 | + ((action) << _action_shift))); |
duke@435 | 260 | assert(reason == trap_request_reason(trap_request), "valid reason"); |
duke@435 | 261 | assert(action == trap_request_action(trap_request), "valid action"); |
duke@435 | 262 | assert(index == trap_request_index(trap_request), "valid index"); |
duke@435 | 263 | return trap_request; |
duke@435 | 264 | } |
duke@435 | 265 | |
duke@435 | 266 | // The trap_state stored in a MDO is decoded here. |
duke@435 | 267 | // It records two items of information. |
duke@435 | 268 | // reason: If a deoptimization happened here, what its reason was, |
duke@435 | 269 | // or if there were multiple deopts with differing reasons. |
duke@435 | 270 | // recompiled: If a deoptimization here triggered a recompilation. |
duke@435 | 271 | // Note that not all reasons are recorded per-bci. |
duke@435 | 272 | static DeoptReason trap_state_reason(int trap_state); |
duke@435 | 273 | static int trap_state_has_reason(int trap_state, int reason); |
duke@435 | 274 | static int trap_state_add_reason(int trap_state, int reason); |
duke@435 | 275 | static bool trap_state_is_recompiled(int trap_state); |
duke@435 | 276 | static int trap_state_set_recompiled(int trap_state, bool z); |
duke@435 | 277 | static const char* format_trap_state(char* buf, size_t buflen, |
duke@435 | 278 | int trap_state); |
duke@435 | 279 | |
duke@435 | 280 | static bool reason_is_recorded_per_bytecode(DeoptReason reason) { |
duke@435 | 281 | return reason > Reason_none && reason < Reason_RECORDED_LIMIT; |
duke@435 | 282 | } |
duke@435 | 283 | |
duke@435 | 284 | static DeoptReason reason_recorded_per_bytecode_if_any(DeoptReason reason) { |
duke@435 | 285 | if (reason_is_recorded_per_bytecode(reason)) |
duke@435 | 286 | return reason; |
duke@435 | 287 | else if (reason == Reason_div0_check) // null check due to divide-by-zero? |
duke@435 | 288 | return Reason_null_check; // recorded per BCI as a null check |
duke@435 | 289 | else |
duke@435 | 290 | return Reason_none; |
duke@435 | 291 | } |
duke@435 | 292 | |
duke@435 | 293 | static const char* trap_reason_name(int reason); |
duke@435 | 294 | static const char* trap_action_name(int action); |
duke@435 | 295 | // Format like reason='foo' action='bar' index='123'. |
duke@435 | 296 | // This is suitable both for XML and for tty output. |
duke@435 | 297 | static const char* format_trap_request(char* buf, size_t buflen, |
duke@435 | 298 | int trap_request); |
duke@435 | 299 | |
duke@435 | 300 | static jint total_deoptimization_count(); |
duke@435 | 301 | static jint deoptimization_count(DeoptReason reason); |
duke@435 | 302 | |
duke@435 | 303 | // JVMTI PopFrame support |
duke@435 | 304 | |
duke@435 | 305 | // Preserves incoming arguments to the popped frame when it is |
duke@435 | 306 | // returning to a deoptimized caller |
duke@435 | 307 | static void popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address); |
duke@435 | 308 | |
duke@435 | 309 | private: |
duke@435 | 310 | enum { |
duke@435 | 311 | _no_count = -1 |
duke@435 | 312 | }; |
duke@435 | 313 | |
duke@435 | 314 | static void reset_invocation_counter(ScopeDesc* trap_scope, jint count = _no_count); |
duke@435 | 315 | |
duke@435 | 316 | static methodDataOop get_method_data(JavaThread* thread, methodHandle m, bool create_if_missing); |
duke@435 | 317 | // Update the mdo's count and per-BCI reason bits, returning previous state: |
duke@435 | 318 | static ProfileData* query_update_method_data(methodDataHandle trap_mdo, |
duke@435 | 319 | int trap_bci, |
duke@435 | 320 | DeoptReason reason, |
duke@435 | 321 | //outputs: |
duke@435 | 322 | uint& ret_this_trap_count, |
duke@435 | 323 | bool& ret_maybe_prior_trap, |
duke@435 | 324 | bool& ret_maybe_prior_recompile); |
duke@435 | 325 | // class loading support for uncommon trap |
duke@435 | 326 | static void load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS); |
duke@435 | 327 | static void load_class_by_index(constantPoolHandle constant_pool, int index); |
duke@435 | 328 | |
duke@435 | 329 | static UnrollBlock* fetch_unroll_info_helper(JavaThread* thread); |
duke@435 | 330 | |
duke@435 | 331 | static DeoptAction _unloaded_action; // == Action_reinterpret; |
duke@435 | 332 | static const char* _trap_reason_name[Reason_LIMIT]; |
duke@435 | 333 | static const char* _trap_action_name[Action_LIMIT]; |
duke@435 | 334 | |
duke@435 | 335 | static juint _deoptimization_hist[Reason_LIMIT][1+Action_LIMIT][BC_CASE_LIMIT]; |
duke@435 | 336 | // Note: Histogram array size is 1-2 Kb. |
duke@435 | 337 | |
duke@435 | 338 | public: |
duke@435 | 339 | static void update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason); |
duke@435 | 340 | }; |
duke@435 | 341 | |
duke@435 | 342 | class DeoptimizationMarker : StackObj { // for profiling |
duke@435 | 343 | static bool _is_active; |
duke@435 | 344 | public: |
duke@435 | 345 | DeoptimizationMarker() { _is_active = true; } |
duke@435 | 346 | ~DeoptimizationMarker() { _is_active = false; } |
duke@435 | 347 | static bool is_active() { return _is_active; } |
duke@435 | 348 | }; |