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 */ 24 25 #ifndef SHARE_VM_RUNTIME_DEOPTIMIZATION_HPP 26 #define SHARE_VM_RUNTIME_DEOPTIMIZATION_HPP 27 28 #include "memory/allocation.hpp" 29 #include "runtime/frame.inline.hpp" 30 31 class ProfileData; 32 class vframeArray; 33 class MonitorValue; 34 class ObjectValue; 35 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) 50 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 }; 68 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 }; 79 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 }; 87 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 }; 94 95 // Checks all compiled methods. Invalid methods are deleted and 96 // corresponding activations are deoptimized. 97 static int deoptimize_dependents(); 98 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); 101 102 private: 103 // Does the actual work for deoptimizing a single frame 104 static void deoptimize_single_frame(JavaThread* thread, frame fr); 105 106 // 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); 112 113 #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 122 123 public: 124 static vframeArray* create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk); 125 126 // Interface used for unpacking deoptimized frames 127 128 // 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 int _caller_actual_parameters; // The number of actual arguments at the 142 // interpreted caller of the deoptimized frame 143 144 // The following fields are used as temps during the unpacking phase 145 // (which is tight on registers, especially on x86). They really ought 146 // to be PD variables but that involves moving this class into its own 147 // file to use the pd include mechanism. Maybe in a later cleanup ... 148 intptr_t _counter_temp; // SHOULD BE PD VARIABLE (x86 frame count temp) 149 intptr_t _unpack_kind; // SHOULD BE PD VARIABLE (x86 unpack kind) 150 intptr_t _sender_sp_temp; // SHOULD BE PD VARIABLE (x86 sender_sp) 151 public: 152 // Constructor 153 UnrollBlock(int size_of_deoptimized_frame, 154 int caller_adjustment, 155 int caller_actual_parameters, 156 int number_of_frames, 157 intptr_t* frame_sizes, 158 address* frames_pcs, 159 BasicType return_type); 160 ~UnrollBlock(); 161 162 // Returns where a register is located. 163 intptr_t* value_addr_at(int register_number) const; 164 165 // Accessors 166 intptr_t* frame_sizes() const { return _frame_sizes; } 167 int number_of_frames() const { return _number_of_frames; } 168 address* frame_pcs() const { return _frame_pcs ; } 169 170 // Returns the total size of frames 171 int size_of_frames() const; 172 173 void set_initial_fp(intptr_t fp) { _initial_fp = fp; } 174 175 int caller_actual_parameters() const { return _caller_actual_parameters; } 176 177 // Accessors used by the code generator for the unpack stub. 178 static int size_of_deoptimized_frame_offset_in_bytes() { return offset_of(UnrollBlock, _size_of_deoptimized_frame); } 179 static int caller_adjustment_offset_in_bytes() { return offset_of(UnrollBlock, _caller_adjustment); } 180 static int number_of_frames_offset_in_bytes() { return offset_of(UnrollBlock, _number_of_frames); } 181 static int frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _frame_sizes); } 182 static int total_frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _total_frame_sizes); } 183 static int frame_pcs_offset_in_bytes() { return offset_of(UnrollBlock, _frame_pcs); } 184 static int register_block_offset_in_bytes() { return offset_of(UnrollBlock, _register_block); } 185 static int return_type_offset_in_bytes() { return offset_of(UnrollBlock, _return_type); } 186 static int counter_temp_offset_in_bytes() { return offset_of(UnrollBlock, _counter_temp); } 187 static int initial_fp_offset_in_bytes() { return offset_of(UnrollBlock, _initial_fp); } 188 static int unpack_kind_offset_in_bytes() { return offset_of(UnrollBlock, _unpack_kind); } 189 static int sender_sp_temp_offset_in_bytes() { return offset_of(UnrollBlock, _sender_sp_temp); } 190 191 BasicType return_type() const { return _return_type; } 192 void print(); 193 }; 194 195 //** Returns an UnrollBlock continuing information 196 // how to make room for the resulting interpreter frames. 197 // Called by assembly stub after execution has returned to 198 // deoptimized frame. 199 // @argument thread. Thread where stub_frame resides. 200 // @see OptoRuntime::deoptimization_fetch_unroll_info_C 201 static UnrollBlock* fetch_unroll_info(JavaThread* thread); 202 203 //** Unpacks vframeArray onto execution stack 204 // Called by assembly stub after execution has returned to 205 // deoptimized frame and after the stack unrolling. 206 // @argument thread. Thread where stub_frame resides. 207 // @argument exec_mode. Determines how execution should be continuted in top frame. 208 // 0 means continue after current byte code 209 // 1 means exception has happened, handle exception 210 // 2 means reexecute current bytecode (for uncommon traps). 211 // @see OptoRuntime::deoptimization_unpack_frames_C 212 // Return BasicType of call return type, if any 213 static BasicType unpack_frames(JavaThread* thread, int exec_mode); 214 215 // Cleans up deoptimization bits on thread after unpacking or in the 216 // case of an exception. 217 static void cleanup_deopt_info(JavaThread *thread, 218 vframeArray * array); 219 220 // Restores callee saved values from deoptimized frame into oldest interpreter frame 221 // so caller of the deoptimized frame will get back the values it expects. 222 static void unwind_callee_save_values(frame* f, vframeArray* vframe_array); 223 224 //** Performs an uncommon trap for compiled code. 225 // The top most compiler frame is converted into interpreter frames 226 static UnrollBlock* uncommon_trap(JavaThread* thread, jint unloaded_class_index); 227 // Helper routine that enters the VM and may block 228 static void uncommon_trap_inner(JavaThread* thread, jint unloaded_class_index); 229 230 //** Deoptimizes the frame identified by id. 231 // Only called from VMDeoptimizeFrame 232 // @argument thread. Thread where stub_frame resides. 233 // @argument id. id of frame that should be deoptimized. 234 static void deoptimize_frame_internal(JavaThread* thread, intptr_t* id); 235 236 // If thread is not the current thread then execute 237 // VM_DeoptimizeFrame otherwise deoptimize directly. 238 static void deoptimize_frame(JavaThread* thread, intptr_t* id); 239 240 // Statistics 241 static void gather_statistics(DeoptReason reason, DeoptAction action, 242 Bytecodes::Code bc = Bytecodes::_illegal); 243 static void print_statistics(); 244 245 // How much room to adjust the last frame's SP by, to make space for 246 // the callee's interpreter frame (which expects locals to be next to 247 // incoming arguments) 248 static int last_frame_adjust(int callee_parameters, int callee_locals); 249 250 // trap_request codes 251 static DeoptReason trap_request_reason(int trap_request) { 252 if (trap_request < 0) 253 return (DeoptReason) 254 ((~(trap_request) >> _reason_shift) & right_n_bits(_reason_bits)); 255 else 256 // standard reason for unloaded CP entry 257 return Reason_unloaded; 258 } 259 static DeoptAction trap_request_action(int trap_request) { 260 if (trap_request < 0) 261 return (DeoptAction) 262 ((~(trap_request) >> _action_shift) & right_n_bits(_action_bits)); 263 else 264 // standard action for unloaded CP entry 265 return _unloaded_action; 266 } 267 static int trap_request_index(int trap_request) { 268 if (trap_request < 0) 269 return -1; 270 else 271 return trap_request; 272 } 273 static int make_trap_request(DeoptReason reason, DeoptAction action, 274 int index = -1) { 275 assert((1 << _reason_bits) >= Reason_LIMIT, "enough bits"); 276 assert((1 << _action_bits) >= Action_LIMIT, "enough bits"); 277 int trap_request; 278 if (index != -1) 279 trap_request = index; 280 else 281 trap_request = (~(((reason) << _reason_shift) 282 + ((action) << _action_shift))); 283 assert(reason == trap_request_reason(trap_request), "valid reason"); 284 assert(action == trap_request_action(trap_request), "valid action"); 285 assert(index == trap_request_index(trap_request), "valid index"); 286 return trap_request; 287 } 288 289 // The trap_state stored in a MDO is decoded here. 290 // It records two items of information. 291 // reason: If a deoptimization happened here, what its reason was, 292 // or if there were multiple deopts with differing reasons. 293 // recompiled: If a deoptimization here triggered a recompilation. 294 // Note that not all reasons are recorded per-bci. 295 static DeoptReason trap_state_reason(int trap_state); 296 static int trap_state_has_reason(int trap_state, int reason); 297 static int trap_state_add_reason(int trap_state, int reason); 298 static bool trap_state_is_recompiled(int trap_state); 299 static int trap_state_set_recompiled(int trap_state, bool z); 300 static const char* format_trap_state(char* buf, size_t buflen, 301 int trap_state); 302 303 static bool reason_is_recorded_per_bytecode(DeoptReason reason) { 304 return reason > Reason_none && reason <= Reason_RECORDED_LIMIT; 305 } 306 307 static DeoptReason reason_recorded_per_bytecode_if_any(DeoptReason reason) { 308 if (reason_is_recorded_per_bytecode(reason)) 309 return reason; 310 else if (reason == Reason_div0_check) // null check due to divide-by-zero? 311 return Reason_null_check; // recorded per BCI as a null check 312 else 313 return Reason_none; 314 } 315 316 static const char* trap_reason_name(int reason); 317 static const char* trap_action_name(int action); 318 // Format like reason='foo' action='bar' index='123'. 319 // This is suitable both for XML and for tty output. 320 static const char* format_trap_request(char* buf, size_t buflen, 321 int trap_request); 322 323 static jint total_deoptimization_count(); 324 static jint deoptimization_count(DeoptReason reason); 325 326 // JVMTI PopFrame support 327 328 // Preserves incoming arguments to the popped frame when it is 329 // returning to a deoptimized caller 330 static void popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address); 331 332 private: 333 static methodDataOop get_method_data(JavaThread* thread, methodHandle m, bool create_if_missing); 334 // Update the mdo's count and per-BCI reason bits, returning previous state: 335 static ProfileData* query_update_method_data(methodDataHandle trap_mdo, 336 int trap_bci, 337 DeoptReason reason, 338 //outputs: 339 uint& ret_this_trap_count, 340 bool& ret_maybe_prior_trap, 341 bool& ret_maybe_prior_recompile); 342 // class loading support for uncommon trap 343 static void load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS); 344 static void load_class_by_index(constantPoolHandle constant_pool, int index); 345 346 static UnrollBlock* fetch_unroll_info_helper(JavaThread* thread); 347 348 static DeoptAction _unloaded_action; // == Action_reinterpret; 349 static const char* _trap_reason_name[Reason_LIMIT]; 350 static const char* _trap_action_name[Action_LIMIT]; 351 352 static juint _deoptimization_hist[Reason_LIMIT][1+Action_LIMIT][BC_CASE_LIMIT]; 353 // Note: Histogram array size is 1-2 Kb. 354 355 public: 356 static void update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason); 357 }; 358 359 class DeoptimizationMarker : StackObj { // for profiling 360 static bool _is_active; 361 public: 362 DeoptimizationMarker() { _is_active = true; } 363 ~DeoptimizationMarker() { _is_active = false; } 364 static bool is_active() { return _is_active; } 365 }; 366 367 #endif // SHARE_VM_RUNTIME_DEOPTIMIZATION_HPP