1 /* 2 * Copyright (c) 1997, 2012, 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 friend class VMStructs; 38 39 public: 40 // What condition caused the deoptimization? 41 enum DeoptReason { 42 Reason_many = -1, // indicates presence of several reasons 43 Reason_none = 0, // indicates absence of a relevant deopt. 44 // Next 7 reasons are recorded per bytecode in DataLayout::trap_bits 45 Reason_null_check, // saw unexpected null or zero divisor (@bci) 46 Reason_null_assert, // saw unexpected non-null or non-zero (@bci) 47 Reason_range_check, // saw unexpected array index (@bci) 48 Reason_class_check, // saw unexpected object class (@bci) 49 Reason_array_check, // saw unexpected array class (aastore @bci) 50 Reason_intrinsic, // saw unexpected operand to intrinsic (@bci) 51 Reason_bimorphic, // saw unexpected object class in bimorphic inlining (@bci) 52 53 Reason_unloaded, // unloaded class or constant pool entry 54 Reason_uninitialized, // bad class state (uninitialized) 55 Reason_unreached, // code is not reached, compiler 56 Reason_unhandled, // arbitrary compiler limitation 57 Reason_constraint, // arbitrary runtime constraint violated 58 Reason_div0_check, // a null_check due to division by zero 59 Reason_age, // nmethod too old; tier threshold reached 60 Reason_predicate, // compiler generated predicate failed 61 Reason_loop_limit_check, // compiler generated loop limits check failed 62 Reason_LIMIT, 63 // Note: Keep this enum in sync. with _trap_reason_name. 64 Reason_RECORDED_LIMIT = Reason_bimorphic // some are not recorded per bc 65 // Note: Reason_RECORDED_LIMIT should be < 8 to fit into 3 bits of 66 // DataLayout::trap_bits. This dependency is enforced indirectly 67 // via asserts, to avoid excessive direct header-to-header dependencies. 68 // See Deoptimization::trap_state_reason and class DataLayout. 69 }; 70 71 // What action must be taken by the runtime? 72 enum DeoptAction { 73 Action_none, // just interpret, do not invalidate nmethod 74 Action_maybe_recompile, // recompile the nmethod; need not invalidate 75 Action_reinterpret, // invalidate the nmethod, reset IC, maybe recompile 76 Action_make_not_entrant, // invalidate the nmethod, recompile (probably) 77 Action_make_not_compilable, // invalidate the nmethod and do not compile 78 Action_LIMIT 79 // Note: Keep this enum in sync. with _trap_action_name. 80 }; 81 82 enum { 83 _action_bits = 3, 84 _reason_bits = 5, 85 _action_shift = 0, 86 _reason_shift = _action_shift+_action_bits, 87 BC_CASE_LIMIT = PRODUCT_ONLY(1) NOT_PRODUCT(4) // for _deoptimization_hist 88 }; 89 90 enum UnpackType { 91 Unpack_deopt = 0, // normal deoptimization, use pc computed in unpack_vframe_on_stack 92 Unpack_exception = 1, // exception is pending 93 Unpack_uncommon_trap = 2, // redo last byte code (C2 only) 94 Unpack_reexecute = 3 // reexecute bytecode (C1 only) 95 }; 96 97 // Checks all compiled methods. Invalid methods are deleted and 98 // corresponding activations are deoptimized. 99 static int deoptimize_dependents(); 100 101 // Deoptimizes a frame lazily. nmethod gets patched deopt happens on return to the frame 102 static void deoptimize(JavaThread* thread, frame fr, RegisterMap *reg_map); 103 104 private: 105 // Does the actual work for deoptimizing a single frame 106 static void deoptimize_single_frame(JavaThread* thread, frame fr); 107 108 // Helper function to revoke biases of all monitors in frame if UseBiasedLocking 109 // is enabled 110 static void revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map); 111 // Helper function to revoke biases of all monitors in frames 112 // executing in a particular CodeBlob if UseBiasedLocking is enabled 113 static void revoke_biases_of_monitors(CodeBlob* cb); 114 115 #ifdef COMPILER2 116 // Support for restoring non-escaping objects 117 static bool realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS); 118 static void reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type); 119 static void reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj); 120 static void reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects); 121 static void relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread); 122 NOT_PRODUCT(static void print_objects(GrowableArray<ScopeValue*>* objects);) 123 #endif // COMPILER2 124 125 public: 126 static vframeArray* create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk); 127 128 // Interface used for unpacking deoptimized frames 129 130 // UnrollBlock is returned by fetch_unroll_info() to the deoptimization handler (blob). 131 // This is only a CheapObj to ease debugging after a deopt failure 132 class UnrollBlock : public CHeapObj<mtCompiler> { 133 private: 134 int _size_of_deoptimized_frame; // Size, in bytes, of current deoptimized frame 135 int _caller_adjustment; // Adjustment, in bytes, to caller's SP by initial interpreted frame 136 int _number_of_frames; // Number frames to unroll 137 int _total_frame_sizes; // Total of number*sizes frames 138 intptr_t* _frame_sizes; // Array of frame sizes, in bytes, for unrolling the stack 139 address* _frame_pcs; // Array of frame pc's, in bytes, for unrolling the stack 140 intptr_t* _register_block; // Block for storing callee-saved registers. 141 BasicType _return_type; // Tells if we have to restore double or long return value 142 intptr_t _initial_info; // Platform dependent data for the sender frame (was FP on x86) 143 int _caller_actual_parameters; // The number of actual arguments at the 144 // interpreted caller of the deoptimized frame 145 146 // The following fields are used as temps during the unpacking phase 147 // (which is tight on registers, especially on x86). They really ought 148 // to be PD variables but that involves moving this class into its own 149 // file to use the pd include mechanism. Maybe in a later cleanup ... 150 intptr_t _counter_temp; // SHOULD BE PD VARIABLE (x86 frame count temp) 151 intptr_t _unpack_kind; // SHOULD BE PD VARIABLE (x86 unpack kind) 152 intptr_t _sender_sp_temp; // SHOULD BE PD VARIABLE (x86 sender_sp) 153 public: 154 // Constructor 155 UnrollBlock(int size_of_deoptimized_frame, 156 int caller_adjustment, 157 int caller_actual_parameters, 158 int number_of_frames, 159 intptr_t* frame_sizes, 160 address* frames_pcs, 161 BasicType return_type); 162 ~UnrollBlock(); 163 164 // Returns where a register is located. 165 intptr_t* value_addr_at(int register_number) const; 166 167 // Accessors 168 intptr_t* frame_sizes() const { return _frame_sizes; } 169 int number_of_frames() const { return _number_of_frames; } 170 address* frame_pcs() const { return _frame_pcs ; } 171 172 // Returns the total size of frames 173 int size_of_frames() const; 174 175 void set_initial_info(intptr_t info) { _initial_info = info; } 176 177 int caller_actual_parameters() const { return _caller_actual_parameters; } 178 179 // Accessors used by the code generator for the unpack stub. 180 static int size_of_deoptimized_frame_offset_in_bytes() { return offset_of(UnrollBlock, _size_of_deoptimized_frame); } 181 static int caller_adjustment_offset_in_bytes() { return offset_of(UnrollBlock, _caller_adjustment); } 182 static int number_of_frames_offset_in_bytes() { return offset_of(UnrollBlock, _number_of_frames); } 183 static int frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _frame_sizes); } 184 static int total_frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _total_frame_sizes); } 185 static int frame_pcs_offset_in_bytes() { return offset_of(UnrollBlock, _frame_pcs); } 186 static int register_block_offset_in_bytes() { return offset_of(UnrollBlock, _register_block); } 187 static int return_type_offset_in_bytes() { return offset_of(UnrollBlock, _return_type); } 188 static int counter_temp_offset_in_bytes() { return offset_of(UnrollBlock, _counter_temp); } 189 static int initial_info_offset_in_bytes() { return offset_of(UnrollBlock, _initial_info); } 190 static int unpack_kind_offset_in_bytes() { return offset_of(UnrollBlock, _unpack_kind); } 191 static int sender_sp_temp_offset_in_bytes() { return offset_of(UnrollBlock, _sender_sp_temp); } 192 193 BasicType return_type() const { return _return_type; } 194 void print(); 195 }; 196 197 //** Returns an UnrollBlock continuing information 198 // how to make room for the resulting interpreter frames. 199 // Called by assembly stub after execution has returned to 200 // deoptimized frame. 201 // @argument thread. Thread where stub_frame resides. 202 // @see OptoRuntime::deoptimization_fetch_unroll_info_C 203 static UnrollBlock* fetch_unroll_info(JavaThread* thread); 204 205 //** Unpacks vframeArray onto execution stack 206 // Called by assembly stub after execution has returned to 207 // deoptimized frame and after the stack unrolling. 208 // @argument thread. Thread where stub_frame resides. 209 // @argument exec_mode. Determines how execution should be continuted in top frame. 210 // 0 means continue after current byte code 211 // 1 means exception has happened, handle exception 212 // 2 means reexecute current bytecode (for uncommon traps). 213 // @see OptoRuntime::deoptimization_unpack_frames_C 214 // Return BasicType of call return type, if any 215 static BasicType unpack_frames(JavaThread* thread, int exec_mode); 216 217 // Cleans up deoptimization bits on thread after unpacking or in the 218 // case of an exception. 219 static void cleanup_deopt_info(JavaThread *thread, 220 vframeArray * array); 221 222 // Restores callee saved values from deoptimized frame into oldest interpreter frame 223 // so caller of the deoptimized frame will get back the values it expects. 224 static void unwind_callee_save_values(frame* f, vframeArray* vframe_array); 225 226 //** Performs an uncommon trap for compiled code. 227 // The top most compiler frame is converted into interpreter frames 228 static UnrollBlock* uncommon_trap(JavaThread* thread, jint unloaded_class_index); 229 // Helper routine that enters the VM and may block 230 static void uncommon_trap_inner(JavaThread* thread, jint unloaded_class_index); 231 232 //** Deoptimizes the frame identified by id. 233 // Only called from VMDeoptimizeFrame 234 // @argument thread. Thread where stub_frame resides. 235 // @argument id. id of frame that should be deoptimized. 236 static void deoptimize_frame_internal(JavaThread* thread, intptr_t* id); 237 238 // If thread is not the current thread then execute 239 // VM_DeoptimizeFrame otherwise deoptimize directly. 240 static void deoptimize_frame(JavaThread* thread, intptr_t* id); 241 242 // Statistics 243 static void gather_statistics(DeoptReason reason, DeoptAction action, 244 Bytecodes::Code bc = Bytecodes::_illegal); 245 static void print_statistics(); 246 247 // How much room to adjust the last frame's SP by, to make space for 248 // the callee's interpreter frame (which expects locals to be next to 249 // incoming arguments) 250 static int last_frame_adjust(int callee_parameters, int callee_locals); 251 252 // trap_request codes 253 static DeoptReason trap_request_reason(int trap_request) { 254 if (trap_request < 0) 255 return (DeoptReason) 256 ((~(trap_request) >> _reason_shift) & right_n_bits(_reason_bits)); 257 else 258 // standard reason for unloaded CP entry 259 return Reason_unloaded; 260 } 261 static DeoptAction trap_request_action(int trap_request) { 262 if (trap_request < 0) 263 return (DeoptAction) 264 ((~(trap_request) >> _action_shift) & right_n_bits(_action_bits)); 265 else 266 // standard action for unloaded CP entry 267 return _unloaded_action; 268 } 269 static int trap_request_index(int trap_request) { 270 if (trap_request < 0) 271 return -1; 272 else 273 return trap_request; 274 } 275 static int make_trap_request(DeoptReason reason, DeoptAction action, 276 int index = -1) { 277 assert((1 << _reason_bits) >= Reason_LIMIT, "enough bits"); 278 assert((1 << _action_bits) >= Action_LIMIT, "enough bits"); 279 int trap_request; 280 if (index != -1) 281 trap_request = index; 282 else 283 trap_request = (~(((reason) << _reason_shift) 284 + ((action) << _action_shift))); 285 assert(reason == trap_request_reason(trap_request), "valid reason"); 286 assert(action == trap_request_action(trap_request), "valid action"); 287 assert(index == trap_request_index(trap_request), "valid index"); 288 return trap_request; 289 } 290 291 // The trap_state stored in a MDO is decoded here. 292 // It records two items of information. 293 // reason: If a deoptimization happened here, what its reason was, 294 // or if there were multiple deopts with differing reasons. 295 // recompiled: If a deoptimization here triggered a recompilation. 296 // Note that not all reasons are recorded per-bci. 297 static DeoptReason trap_state_reason(int trap_state); 298 static int trap_state_has_reason(int trap_state, int reason); 299 static int trap_state_add_reason(int trap_state, int reason); 300 static bool trap_state_is_recompiled(int trap_state); 301 static int trap_state_set_recompiled(int trap_state, bool z); 302 static const char* format_trap_state(char* buf, size_t buflen, 303 int trap_state); 304 305 static bool reason_is_recorded_per_bytecode(DeoptReason reason) { 306 return reason > Reason_none && reason <= Reason_RECORDED_LIMIT; 307 } 308 309 static DeoptReason reason_recorded_per_bytecode_if_any(DeoptReason reason) { 310 if (reason_is_recorded_per_bytecode(reason)) 311 return reason; 312 else if (reason == Reason_div0_check) // null check due to divide-by-zero? 313 return Reason_null_check; // recorded per BCI as a null check 314 else 315 return Reason_none; 316 } 317 318 static const char* trap_reason_name(int reason); 319 static const char* trap_action_name(int action); 320 // Format like reason='foo' action='bar' index='123'. 321 // This is suitable both for XML and for tty output. 322 static const char* format_trap_request(char* buf, size_t buflen, 323 int trap_request); 324 325 static jint total_deoptimization_count(); 326 static jint deoptimization_count(DeoptReason reason); 327 328 // JVMTI PopFrame support 329 330 // Preserves incoming arguments to the popped frame when it is 331 // returning to a deoptimized caller 332 static void popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address); 333 334 private: 335 static MethodData* get_method_data(JavaThread* thread, methodHandle m, bool create_if_missing); 336 // Update the mdo's count and per-BCI reason bits, returning previous state: 337 static ProfileData* query_update_method_data(MethodData* trap_mdo, 338 int trap_bci, 339 DeoptReason reason, 340 //outputs: 341 uint& ret_this_trap_count, 342 bool& ret_maybe_prior_trap, 343 bool& ret_maybe_prior_recompile); 344 // class loading support for uncommon trap 345 static void load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS); 346 static void load_class_by_index(constantPoolHandle constant_pool, int index); 347 348 static UnrollBlock* fetch_unroll_info_helper(JavaThread* thread); 349 350 static DeoptAction _unloaded_action; // == Action_reinterpret; 351 static const char* _trap_reason_name[Reason_LIMIT]; 352 static const char* _trap_action_name[Action_LIMIT]; 353 354 static juint _deoptimization_hist[Reason_LIMIT][1+Action_LIMIT][BC_CASE_LIMIT]; 355 // Note: Histogram array size is 1-2 Kb. 356 357 public: 358 static void update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason); 359 }; 360 361 class DeoptimizationMarker : StackObj { // for profiling 362 static bool _is_active; 363 public: 364 DeoptimizationMarker() { _is_active = true; } 365 ~DeoptimizationMarker() { _is_active = false; } 366 static bool is_active() { return _is_active; } 367 }; 368 369 #endif // SHARE_VM_RUNTIME_DEOPTIMIZATION_HPP