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