1 /* 2 * Copyright (c) 1997, 2010, 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_LIMIT, 60 // Note: Keep this enum in sync. with _trap_reason_name. 61 Reason_RECORDED_LIMIT = Reason_bimorphic // some are not recorded per bc 62 // Note: Reason_RECORDED_LIMIT should be < 8 to fit into 3 bits of 63 // DataLayout::trap_bits. This dependency is enforced indirectly 64 // via asserts, to avoid excessive direct header-to-header dependencies. 65 // See Deoptimization::trap_state_reason and class DataLayout. 66 }; 67 68 // What action must be taken by the runtime? 69 enum DeoptAction { 70 Action_none, // just interpret, do not invalidate nmethod 71 Action_maybe_recompile, // recompile the nmethod; need not invalidate 72 Action_reinterpret, // invalidate the nmethod, reset IC, maybe recompile 73 Action_make_not_entrant, // invalidate the nmethod, recompile (probably) 74 Action_make_not_compilable, // invalidate the nmethod and do not compile 75 Action_LIMIT 76 // Note: Keep this enum in sync. with _trap_action_name. 77 }; 78 79 enum { 80 _action_bits = 3, 81 _reason_bits = 4, 82 _action_shift = 0, 83 _reason_shift = _action_shift+_action_bits, 84 BC_CASE_LIMIT = PRODUCT_ONLY(1) NOT_PRODUCT(4) // for _deoptimization_hist 85 }; 86 87 enum UnpackType { 88 Unpack_deopt = 0, // normal deoptimization, use pc computed in unpack_vframe_on_stack 89 Unpack_exception = 1, // exception is pending 90 Unpack_uncommon_trap = 2, // redo last byte code (C2 only) 91 Unpack_reexecute = 3 // reexecute bytecode (C1 only) 92 }; 93 94 // Checks all compiled methods. Invalid methods are deleted and 95 // corresponding activations are deoptimized. 96 static int deoptimize_dependents(); 97 98 // Deoptimizes a frame lazily. nmethod gets patched deopt happens on return to the frame 99 static void deoptimize(JavaThread* thread, frame fr, RegisterMap *reg_map); 100 101 private: 102 // Does the actual work for deoptimizing a single frame 103 static void deoptimize_single_frame(JavaThread* thread, frame fr); 104 105 // Helper function to revoke biases of all monitors in frame if UseBiasedLocking 106 // is enabled 107 static void revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map); 108 // Helper function to revoke biases of all monitors in frames 109 // executing in a particular CodeBlob if UseBiasedLocking is enabled 110 static void revoke_biases_of_monitors(CodeBlob* cb); 111 112 #ifdef COMPILER2 113 // Support for restoring non-escaping objects 114 static bool realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS); 115 static void reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type); 116 static void reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj); 117 static void reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects); 118 static void relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread); 119 NOT_PRODUCT(static void print_objects(GrowableArray<ScopeValue*>* objects);) 120 #endif // COMPILER2 121 122 public: 123 static vframeArray* create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk); 124 125 // Interface used for unpacking deoptimized frames 126 127 // UnrollBlock is returned by fetch_unroll_info() to the deoptimization handler (blob). 128 // This is only a CheapObj to ease debugging after a deopt failure 129 class UnrollBlock : public CHeapObj { 130 private: 131 int _size_of_deoptimized_frame; // Size, in bytes, of current deoptimized frame 132 int _caller_adjustment; // Adjustment, in bytes, to caller's SP by initial interpreted frame 133 int _number_of_frames; // Number frames to unroll 134 int _total_frame_sizes; // Total of number*sizes frames 135 intptr_t* _frame_sizes; // Array of frame sizes, in bytes, for unrolling the stack 136 address* _frame_pcs; // Array of frame pc's, in bytes, for unrolling the stack 137 intptr_t* _register_block; // Block for storing callee-saved registers. 138 BasicType _return_type; // Tells if we have to restore double or long return value 139 // The following fields are used as temps during the unpacking phase 140 // (which is tight on registers, especially on x86). They really ought 141 // to be PD variables but that involves moving this class into its own 142 // file to use the pd include mechanism. Maybe in a later cleanup ... 143 intptr_t _counter_temp; // SHOULD BE PD VARIABLE (x86 frame count temp) 144 intptr_t _initial_fp; // no longer PD (beneficial to other ports) 145 intptr_t _unpack_kind; // SHOULD BE PD VARIABLE (x86 unpack kind) 146 intptr_t _sender_sp_temp; // SHOULD BE PD VARIABLE (x86 sender_sp) 147 public: 148 // Constructor 149 UnrollBlock(int size_of_deoptimized_frame, 150 int caller_adjustment, 151 int number_of_frames, 152 intptr_t* frame_sizes, 153 address* frames_pcs, 154 BasicType return_type); 155 ~UnrollBlock(); 156 157 // Returns where a register is located. 158 intptr_t* value_addr_at(int register_number) const; 159 160 // Accessors 161 intptr_t* frame_sizes() const { return _frame_sizes; } 162 int number_of_frames() const { return _number_of_frames; } 163 address* frame_pcs() const { return _frame_pcs ; } 164 165 // Returns the total size of frames 166 int size_of_frames() const; 167 168 void set_initial_fp(intptr_t fp) { _initial_fp = fp; } 169 170 // Accessors used by the code generator for the unpack stub. 171 static int size_of_deoptimized_frame_offset_in_bytes() { return offset_of(UnrollBlock, _size_of_deoptimized_frame); } 172 static int caller_adjustment_offset_in_bytes() { return offset_of(UnrollBlock, _caller_adjustment); } 173 static int number_of_frames_offset_in_bytes() { return offset_of(UnrollBlock, _number_of_frames); } 174 static int frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _frame_sizes); } 175 static int total_frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _total_frame_sizes); } 176 static int frame_pcs_offset_in_bytes() { return offset_of(UnrollBlock, _frame_pcs); } 177 static int register_block_offset_in_bytes() { return offset_of(UnrollBlock, _register_block); } 178 static int return_type_offset_in_bytes() { return offset_of(UnrollBlock, _return_type); } 179 static int counter_temp_offset_in_bytes() { return offset_of(UnrollBlock, _counter_temp); } 180 static int initial_fp_offset_in_bytes() { return offset_of(UnrollBlock, _initial_fp); } 181 static int unpack_kind_offset_in_bytes() { return offset_of(UnrollBlock, _unpack_kind); } 182 static int sender_sp_temp_offset_in_bytes() { return offset_of(UnrollBlock, _sender_sp_temp); } 183 184 BasicType return_type() const { return _return_type; } 185 void print(); 186 }; 187 188 //** Returns an UnrollBlock continuing information 189 // how to make room for the resulting interpreter frames. 190 // Called by assembly stub after execution has returned to 191 // deoptimized frame. 192 // @argument thread. Thread where stub_frame resides. 193 // @see OptoRuntime::deoptimization_fetch_unroll_info_C 194 static UnrollBlock* fetch_unroll_info(JavaThread* thread); 195 196 //** Unpacks vframeArray onto execution stack 197 // Called by assembly stub after execution has returned to 198 // deoptimized frame and after the stack unrolling. 199 // @argument thread. Thread where stub_frame resides. 200 // @argument exec_mode. Determines how execution should be continuted in top frame. 201 // 0 means continue after current byte code 202 // 1 means exception has happened, handle exception 203 // 2 means reexecute current bytecode (for uncommon traps). 204 // @see OptoRuntime::deoptimization_unpack_frames_C 205 // Return BasicType of call return type, if any 206 static BasicType unpack_frames(JavaThread* thread, int exec_mode); 207 208 // Cleans up deoptimization bits on thread after unpacking or in the 209 // case of an exception. 210 static void cleanup_deopt_info(JavaThread *thread, 211 vframeArray * array); 212 213 // Restores callee saved values from deoptimized frame into oldest interpreter frame 214 // so caller of the deoptimized frame will get back the values it expects. 215 static void unwind_callee_save_values(frame* f, vframeArray* vframe_array); 216 217 //** Performs an uncommon trap for compiled code. 218 // The top most compiler frame is converted into interpreter frames 219 static UnrollBlock* uncommon_trap(JavaThread* thread, jint unloaded_class_index); 220 // Helper routine that enters the VM and may block 221 static void uncommon_trap_inner(JavaThread* thread, jint unloaded_class_index); 222 223 //** Deoptimizes the frame identified by id. 224 // Only called from VMDeoptimizeFrame 225 // @argument thread. Thread where stub_frame resides. 226 // @argument id. id of frame that should be deoptimized. 227 static void deoptimize_frame_internal(JavaThread* thread, intptr_t* id); 228 229 // If thread is not the current thread then execute 230 // VM_DeoptimizeFrame otherwise deoptimize directly. 231 static void deoptimize_frame(JavaThread* thread, intptr_t* id); 232 233 // Statistics 234 static void gather_statistics(DeoptReason reason, DeoptAction action, 235 Bytecodes::Code bc = Bytecodes::_illegal); 236 static void print_statistics(); 237 238 // How much room to adjust the last frame's SP by, to make space for 239 // the callee's interpreter frame (which expects locals to be next to 240 // incoming arguments) 241 static int last_frame_adjust(int callee_parameters, int callee_locals); 242 243 // trap_request codes 244 static DeoptReason trap_request_reason(int trap_request) { 245 if (trap_request < 0) 246 return (DeoptReason) 247 ((~(trap_request) >> _reason_shift) & right_n_bits(_reason_bits)); 248 else 249 // standard reason for unloaded CP entry 250 return Reason_unloaded; 251 } 252 static DeoptAction trap_request_action(int trap_request) { 253 if (trap_request < 0) 254 return (DeoptAction) 255 ((~(trap_request) >> _action_shift) & right_n_bits(_action_bits)); 256 else 257 // standard action for unloaded CP entry 258 return _unloaded_action; 259 } 260 static int trap_request_index(int trap_request) { 261 if (trap_request < 0) 262 return -1; 263 else 264 return trap_request; 265 } 266 static int make_trap_request(DeoptReason reason, DeoptAction action, 267 int index = -1) { 268 assert((1 << _reason_bits) >= Reason_LIMIT, "enough bits"); 269 assert((1 << _action_bits) >= Action_LIMIT, "enough bits"); 270 int trap_request; 271 if (index != -1) 272 trap_request = index; 273 else 274 trap_request = (~(((reason) << _reason_shift) 275 + ((action) << _action_shift))); 276 assert(reason == trap_request_reason(trap_request), "valid reason"); 277 assert(action == trap_request_action(trap_request), "valid action"); 278 assert(index == trap_request_index(trap_request), "valid index"); 279 return trap_request; 280 } 281 282 // The trap_state stored in a MDO is decoded here. 283 // It records two items of information. 284 // reason: If a deoptimization happened here, what its reason was, 285 // or if there were multiple deopts with differing reasons. 286 // recompiled: If a deoptimization here triggered a recompilation. 287 // Note that not all reasons are recorded per-bci. 288 static DeoptReason trap_state_reason(int trap_state); 289 static int trap_state_has_reason(int trap_state, int reason); 290 static int trap_state_add_reason(int trap_state, int reason); 291 static bool trap_state_is_recompiled(int trap_state); 292 static int trap_state_set_recompiled(int trap_state, bool z); 293 static const char* format_trap_state(char* buf, size_t buflen, 294 int trap_state); 295 296 static bool reason_is_recorded_per_bytecode(DeoptReason reason) { 297 return reason > Reason_none && reason <= Reason_RECORDED_LIMIT; 298 } 299 300 static DeoptReason reason_recorded_per_bytecode_if_any(DeoptReason reason) { 301 if (reason_is_recorded_per_bytecode(reason)) 302 return reason; 303 else if (reason == Reason_div0_check) // null check due to divide-by-zero? 304 return Reason_null_check; // recorded per BCI as a null check 305 else 306 return Reason_none; 307 } 308 309 static const char* trap_reason_name(int reason); 310 static const char* trap_action_name(int action); 311 // Format like reason='foo' action='bar' index='123'. 312 // This is suitable both for XML and for tty output. 313 static const char* format_trap_request(char* buf, size_t buflen, 314 int trap_request); 315 316 static jint total_deoptimization_count(); 317 static jint deoptimization_count(DeoptReason reason); 318 319 // JVMTI PopFrame support 320 321 // Preserves incoming arguments to the popped frame when it is 322 // returning to a deoptimized caller 323 static void popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address); 324 325 private: 326 static methodDataOop get_method_data(JavaThread* thread, methodHandle m, bool create_if_missing); 327 // Update the mdo's count and per-BCI reason bits, returning previous state: 328 static ProfileData* query_update_method_data(methodDataHandle trap_mdo, 329 int trap_bci, 330 DeoptReason reason, 331 //outputs: 332 uint& ret_this_trap_count, 333 bool& ret_maybe_prior_trap, 334 bool& ret_maybe_prior_recompile); 335 // class loading support for uncommon trap 336 static void load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS); 337 static void load_class_by_index(constantPoolHandle constant_pool, int index); 338 339 static UnrollBlock* fetch_unroll_info_helper(JavaThread* thread); 340 341 static DeoptAction _unloaded_action; // == Action_reinterpret; 342 static const char* _trap_reason_name[Reason_LIMIT]; 343 static const char* _trap_action_name[Action_LIMIT]; 344 345 static juint _deoptimization_hist[Reason_LIMIT][1+Action_LIMIT][BC_CASE_LIMIT]; 346 // Note: Histogram array size is 1-2 Kb. 347 348 public: 349 static void update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason); 350 }; 351 352 class DeoptimizationMarker : StackObj { // for profiling 353 static bool _is_active; 354 public: 355 DeoptimizationMarker() { _is_active = true; } 356 ~DeoptimizationMarker() { _is_active = false; } 357 static bool is_active() { return _is_active; } 358 }; 359 360 #endif // SHARE_VM_RUNTIME_DEOPTIMIZATION_HPP