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24
25 #ifndef SHARE_RUNTIME_DEOPTIMIZATION_HPP
26 #define SHARE_RUNTIME_DEOPTIMIZATION_HPP
27
28 #include "interpreter/bytecodes.hpp"
29 #include "memory/allocation.hpp"
30 #include "runtime/frame.hpp"
31
32 class ProfileData;
33 class vframeArray;
34 class MonitorInfo;
35 class MonitorValue;
36 class ObjectValue;
37 class AutoBoxObjectValue;
38 class ScopeValue;
39 class compiledVFrame;
40
41 template<class E> class GrowableArray;
42
43 class DeoptimizationScope {
44 private:
45 // What gen we have done the deopt handshake for.
46 static uint64_t _committed_deopt_gen;
47 // What gen to mark a method with, hence larger than _committed_deopt_gen.
48 static uint64_t _active_deopt_gen;
49 // Indicate an in-progress deopt handshake.
50 static bool _committing_in_progress;
51
52 // The required gen we need to execute/wait for
53 uint64_t _required_gen;
54 DEBUG_ONLY(bool _deopted;)
55
56 public:
57 DeoptimizationScope();
58 ~DeoptimizationScope();
59 // Mark a method, if already marked as dependent.
60 void mark(nmethod* nm, bool inc_recompile_counts = true);
61 // Record this as a dependent method.
62 void dependent(nmethod* nm);
63
64 // Execute the deoptimization.
65 // Make the nmethods not entrant, stackwalks and patch return pcs and sets post call nops.
66 void deoptimize_marked();
67 };
68
69 class Deoptimization : AllStatic {
70 friend class VMStructs;
71 friend class EscapeBarrier;
72
73 public:
74 // What condition caused the deoptimization?
75 // Note: Keep this enum in sync. with Deoptimization::_trap_reason_name.
76 enum DeoptReason {
77 Reason_many = -1, // indicates presence of several reasons
78 Reason_none = 0, // indicates absence of a relevant deopt.
79 // Next 8 reasons are recorded per bytecode in DataLayout::trap_bits.
80 Reason_null_check, // saw unexpected null or zero divisor (@bci)
81 Reason_null_assert, // saw unexpected non-null or non-zero (@bci)
82 Reason_range_check, // saw unexpected array index (@bci)
83 Reason_class_check, // saw unexpected object class (@bci)
84 Reason_array_check, // saw unexpected array class (aastore @bci)
85 Reason_intrinsic, // saw unexpected operand to intrinsic (@bci)
86 Reason_bimorphic, // saw unexpected object class in bimorphic inlining (@bci)
87
88 Reason_profile_predicate, // compiler generated predicate moved from frequent branch in a loop failed
89 Reason_auto_vectorization_check, // compiler generated (speculative) auto vectorization checks failed
90
91 // recorded per method
92 Reason_unloaded, // unloaded class or constant pool entry
93 Reason_uninitialized, // bad class state (uninitialized)
94 Reason_initialized, // class has been fully initialized
95 Reason_unreached, // code is not reached, compiler
96 Reason_unhandled, // arbitrary compiler limitation
97 Reason_constraint, // arbitrary runtime constraint violated
98 Reason_div0_check, // a null_check due to division by zero
99 Reason_age, // nmethod too old; tier threshold reached
100 Reason_predicate, // compiler generated predicate failed
101 Reason_loop_limit_check, // compiler generated loop limits check failed
102 Reason_speculate_class_check, // saw unexpected object class from type speculation
103 Reason_speculate_null_check, // saw unexpected null from type speculation
104 Reason_speculate_null_assert, // saw unexpected null from type speculation
105 Reason_unstable_if, // a branch predicted always false was taken
106 Reason_unstable_fused_if, // fused two ifs that had each one untaken branch. One is now taken.
107 Reason_receiver_constraint, // receiver subtype check failed
108 Reason_not_compiled_exception_handler, // missing compiled exception handler
109 Reason_short_running_long_loop, // profile reports loop runs for small number of iterations
110
111 // Used to define MethodData::_trap_hist_limit where Reason_tenured isn't included
112 Reason_TRAP_HISTORY_LENGTH,
113
114 // Reason_tenured is counted separately, add normal counted Reasons above.
115 Reason_tenured = Reason_TRAP_HISTORY_LENGTH, // age of the code has reached the limit
116 Reason_LIMIT,
117
118 // Note: Reason_RECORDED_LIMIT should fit into 31 bits of
119 // DataLayout::trap_bits. This dependency is enforced indirectly
120 // via asserts, to avoid excessive direct header-to-header dependencies.
121 // See Deoptimization::trap_state_reason and class DataLayout.
122 Reason_RECORDED_LIMIT = Reason_profile_predicate, // some are not recorded per bc
123 };
124
125 // What action must be taken by the runtime?
126 // Note: Keep this enum in sync. with Deoptimization::_trap_action_name.
127 enum DeoptAction {
128 Action_none, // just interpret, do not invalidate nmethod
129 Action_maybe_recompile, // recompile the nmethod; need not invalidate
130 Action_reinterpret, // invalidate the nmethod, reset IC, maybe recompile
131 Action_make_not_entrant, // invalidate the nmethod, recompile (probably)
132 Action_make_not_compilable, // invalidate the nmethod and do not compile
133 Action_LIMIT
134 };
135
136 enum {
137 _action_bits = 3,
138 _reason_bits = 5,
139 _action_shift = 0,
140 _reason_shift = _action_shift+_action_bits,
141 BC_CASE_LIMIT = PRODUCT_ONLY(1) NOT_PRODUCT(4) // for _deoptimization_hist
142 };
143
144 enum UnpackType {
145 Unpack_deopt = 0, // normal deoptimization, use pc computed in unpack_vframe_on_stack
146 Unpack_exception = 1, // exception is pending
147 Unpack_uncommon_trap = 2, // redo last byte code (C2 only)
148 Unpack_reexecute = 3, // reexecute bytecode (C1 only)
149 Unpack_none = 4, // not deoptimizing the frame, just reallocating/relocking for JVMTI
150 Unpack_LIMIT = 5
151 };
152
153 // Make all nmethods that are marked_for_deoptimization not_entrant and deoptimize any live
154 // activations using those nmethods. Scan of the code cache is done to
155 // find all marked nmethods and they are made not_entrant.
156 static void deoptimize_all_marked();
157
158 public:
159 // Deoptimizes a frame lazily. Deopt happens on return to the frame.
160 static void deoptimize(JavaThread* thread, frame fr, DeoptReason reason = Reason_constraint);
161
162 static address deoptimize_for_missing_exception_handler(nmethod* nm, bool make_not_entrant);
163
164 private:
165 // Does the actual work for deoptimizing a single frame
166 static void deoptimize_single_frame(JavaThread* thread, frame fr, DeoptReason reason);
167
168 #ifdef COMPILER2
169 // Deoptimize objects, that is reallocate and relock them, just before they
170 // escape through JVMTI. The given vframes cover one physical frame.
171 static bool deoptimize_objects_internal(JavaThread* thread, GrowableArray<compiledVFrame*>* chunk,
172 bool& realloc_failures);
173
174 public:
175
176 // Support for restoring non-escaping objects
177 static bool realloc_objects(JavaThread* thread, frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, TRAPS);
178 static bool realloc_inline_type_result(InlineKlass* vk, const RegisterMap& map, GrowableArray<Handle>& return_oops, TRAPS);
179 static void reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type);
180 static void reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj);
181 static void reassign_flat_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, flatArrayOop obj, FlatArrayKlass* vak, TRAPS);
182 static void reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, bool realloc_failures, TRAPS);
183 static bool relock_objects(JavaThread* thread, GrowableArray<MonitorInfo*>* monitors,
184 JavaThread* deoptee_thread, frame& fr, int exec_mode, bool realloc_failures);
185 static void pop_frames_failed_reallocs(JavaThread* thread, vframeArray* array);
186 #endif // COMPILER2
187
188 public:
189 static vframeArray* create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures);
190
191 // Interface used for unpacking deoptimized frames
192
193 // UnrollBlock is returned by fetch_unroll_info() to the deoptimization handler (blob).
194 // This is only a CheapObj to ease debugging after a deopt failure
195 class UnrollBlock : public CHeapObj<mtCompiler> {
196 friend class VMStructs;
197 private:
198 int _size_of_deoptimized_frame; // Size, in bytes, of current deoptimized frame
199 int _caller_adjustment; // Adjustment, in bytes, to caller's SP by initial interpreted frame
200 int _number_of_frames; // Number frames to unroll
201 int _total_frame_sizes; // Total of number*sizes frames
202 intptr_t* _frame_sizes; // Array of frame sizes, in bytes, for unrolling the stack
203 address* _frame_pcs; // Array of frame pc's, in bytes, for unrolling the stack
204 intptr_t* _register_block; // Block for storing callee-saved registers.
205 BasicType _return_type; // Tells if we have to restore double or long return value
206 intptr_t _initial_info; // Platform dependent data for the sender frame (was FP on x86)
207 int _caller_actual_parameters; // The number of actual arguments at the
208 // interpreted caller of the deoptimized frame
209 int _unpack_kind; // exec_mode that can be changed during fetch_unroll_info
210
211 // The following fields are used as temps during the unpacking phase
212 // (which is tight on registers, especially on x86). They really ought
213 // to be PD variables but that involves moving this class into its own
214 // file to use the pd include mechanism. Maybe in a later cleanup ...
215 intptr_t _counter_temp; // SHOULD BE PD VARIABLE (x86 frame count temp)
216 intptr_t _sender_sp_temp; // SHOULD BE PD VARIABLE (x86 sender_sp)
217 public:
218 // Constructor
219 UnrollBlock(int size_of_deoptimized_frame,
220 int caller_adjustment,
221 int caller_actual_parameters,
222 int number_of_frames,
223 intptr_t* frame_sizes,
224 address* frames_pcs,
225 BasicType return_type,
226 int unpack_kind);
227 ~UnrollBlock();
228
229 // Accessors
230 intptr_t* frame_sizes() const { return _frame_sizes; }
231 int number_of_frames() const { return _number_of_frames; }
232
233 // Returns the total size of frames
234 int size_of_frames() const;
235
236 void set_initial_info(intptr_t info) { _initial_info = info; }
237
238 int caller_actual_parameters() const { return _caller_actual_parameters; }
239
240 // Accessors used by the code generator for the unpack stub.
241 static ByteSize size_of_deoptimized_frame_offset() { return byte_offset_of(UnrollBlock, _size_of_deoptimized_frame); }
242 static ByteSize caller_adjustment_offset() { return byte_offset_of(UnrollBlock, _caller_adjustment); }
243 static ByteSize number_of_frames_offset() { return byte_offset_of(UnrollBlock, _number_of_frames); }
244 static ByteSize frame_sizes_offset() { return byte_offset_of(UnrollBlock, _frame_sizes); }
245 static ByteSize total_frame_sizes_offset() { return byte_offset_of(UnrollBlock, _total_frame_sizes); }
246 static ByteSize frame_pcs_offset() { return byte_offset_of(UnrollBlock, _frame_pcs); }
247 static ByteSize counter_temp_offset() { return byte_offset_of(UnrollBlock, _counter_temp); }
248 static ByteSize initial_info_offset() { return byte_offset_of(UnrollBlock, _initial_info); }
249 static ByteSize unpack_kind_offset() { return byte_offset_of(UnrollBlock, _unpack_kind); }
250 static ByteSize sender_sp_temp_offset() { return byte_offset_of(UnrollBlock, _sender_sp_temp); }
251
252 BasicType return_type() const { return _return_type; }
253 void print();
254 };
255
256 //** Returns an UnrollBlock continuing information
257 // how to make room for the resulting interpreter frames.
258 // Called by assembly stub after execution has returned to
259 // deoptimized frame.
260 // @argument thread. Thread where stub_frame resides.
261 // @see OptoRuntime::deoptimization_fetch_unroll_info_C
262 static UnrollBlock* fetch_unroll_info(JavaThread* current, int exec_mode);
263
264 //** Unpacks vframeArray onto execution stack
265 // Called by assembly stub after execution has returned to
266 // deoptimized frame and after the stack unrolling.
267 // @argument thread. Thread where stub_frame resides.
268 // @argument exec_mode. Determines how execution should be continued in top frame.
269 // 0 means continue after current byte code
270 // 1 means exception has happened, handle exception
271 // 2 means reexecute current bytecode (for uncommon traps).
272 // @see OptoRuntime::deoptimization_unpack_frames_C
273 // Return BasicType of call return type, if any
274 static BasicType unpack_frames(JavaThread* thread, int exec_mode);
275
276 // Cleans up deoptimization bits on thread after unpacking or in the
277 // case of an exception.
278 static void cleanup_deopt_info(JavaThread *thread,
279 vframeArray * array);
280
281 // Restores callee saved values from deoptimized frame into oldest interpreter frame
282 // so caller of the deoptimized frame will get back the values it expects.
283 static void unwind_callee_save_values(frame* f, vframeArray* vframe_array);
284
285 //** Performs an uncommon trap for compiled code.
286 // The top most compiler frame is converted into interpreter frames
287 static UnrollBlock* uncommon_trap(JavaThread* current, jint unloaded_class_index, jint exec_mode);
288 // Helper routine that enters the VM and may block
289 static void uncommon_trap_inner(JavaThread* current, jint unloaded_class_index);
290
291 //** Deoptimizes the frame identified by id.
292 // Only called from VMDeoptimizeFrame
293 // @argument thread. Thread where stub_frame resides.
294 // @argument id. id of frame that should be deoptimized.
295 static void deoptimize_frame_internal(JavaThread* thread, intptr_t* id, DeoptReason reason);
296
297 // if thread is not the current thread then execute
298 // VM_DeoptimizeFrame otherwise deoptimize directly.
299 static void deoptimize_frame(JavaThread* thread, intptr_t* id, DeoptReason reason);
300 static void deoptimize_frame(JavaThread* thread, intptr_t* id);
301
302 // Statistics
303 static void gather_statistics(DeoptReason reason, DeoptAction action,
304 Bytecodes::Code bc = Bytecodes::_illegal);
305 static void print_statistics();
306
307 // How much room to adjust the last frame's SP by, to make space for
308 // the callee's interpreter frame (which expects locals to be next to
309 // incoming arguments)
310 static int last_frame_adjust(int callee_parameters, int callee_locals);
311
312 // trap_request codes
313 static DeoptReason trap_request_reason(int trap_request) {
314 if (trap_request < 0)
315 return (DeoptReason)
316 ((~(trap_request) >> _reason_shift) & right_n_bits(_reason_bits));
317 else
318 // standard reason for unloaded CP entry
319 return Reason_unloaded;
320 }
321 static DeoptAction trap_request_action(int trap_request) {
322 if (trap_request < 0)
323 return (DeoptAction)
324 ((~(trap_request) >> _action_shift) & right_n_bits(_action_bits));
325 else
326 // standard action for unloaded CP entry
327 return _unloaded_action;
328 }
329 static int trap_request_index(int trap_request) {
330 if (trap_request < 0)
331 return -1;
332 else
333 return trap_request;
334 }
335 static int make_trap_request(DeoptReason reason, DeoptAction action,
336 int index = -1) {
337 assert((1 << _reason_bits) >= Reason_LIMIT, "enough bits");
338 assert((1 << _action_bits) >= Action_LIMIT, "enough bits");
339 int trap_request;
340 if (index != -1)
341 trap_request = index;
342 else
343 trap_request = (~(((reason) << _reason_shift)
344 + ((action) << _action_shift)));
345 assert(reason == trap_request_reason(trap_request), "valid reason");
346 assert(action == trap_request_action(trap_request), "valid action");
347 assert(index == trap_request_index(trap_request), "valid index");
348 return trap_request;
349 }
350
351 // The trap_state stored in a MDO is decoded here.
352 // It records two items of information.
353 // reason: If a deoptimization happened here, what its reason was,
354 // or if there were multiple deopts with differing reasons.
355 // recompiled: If a deoptimization here triggered a recompilation.
356 // Note that not all reasons are recorded per-bci.
357 static DeoptReason trap_state_reason(int trap_state);
358 static int trap_state_has_reason(int trap_state, int reason);
359 static int trap_state_add_reason(int trap_state, int reason);
360 static bool trap_state_is_recompiled(int trap_state);
361 static int trap_state_set_recompiled(int trap_state, bool z);
362 static const char* format_trap_state(char* buf, size_t buflen,
363 int trap_state);
364
365 static bool reason_is_recorded_per_bytecode(DeoptReason reason) {
366 return reason > Reason_none && reason <= Reason_RECORDED_LIMIT;
367 }
368
369 static DeoptReason reason_recorded_per_bytecode_if_any(DeoptReason reason) {
370 if (reason_is_recorded_per_bytecode(reason))
371 return reason;
372 else if (reason == Reason_div0_check) // null check due to divide-by-zero?
373 return Reason_null_check; // recorded per BCI as a null check
374 else if (reason == Reason_speculate_class_check)
375 return Reason_class_check;
376 else if (reason == Reason_speculate_null_check)
377 return Reason_null_check;
378 else if (reason == Reason_speculate_null_assert)
379 return Reason_null_assert;
380 else if (reason == Reason_unstable_if)
381 return Reason_intrinsic;
382 else if (reason == Reason_unstable_fused_if)
383 return Reason_range_check;
384 else
385 return Reason_none;
386 }
387
388 static bool reason_is_speculate(int reason) {
389 if (reason == Reason_speculate_class_check ||
390 reason == Reason_speculate_null_check ||
391 reason == Reason_speculate_null_assert) {
392 return true;
393 }
394 return false;
395 }
396
397 static DeoptReason reason_null_check(bool speculative) {
398 return speculative ? Deoptimization::Reason_speculate_null_check : Deoptimization::Reason_null_check;
399 }
400
401 static DeoptReason reason_class_check(bool speculative) {
402 return speculative ? Deoptimization::Reason_speculate_class_check : Deoptimization::Reason_class_check;
403 }
404
405 static DeoptReason reason_null_assert(bool speculative) {
406 return speculative ? Deoptimization::Reason_speculate_null_assert : Deoptimization::Reason_null_assert;
407 }
408
409 static uint per_method_trap_limit(int reason) {
410 return reason_is_speculate(reason) ? (uint)PerMethodSpecTrapLimit : (uint)PerMethodTrapLimit;
411 }
412
413 static const char* trap_reason_name(int reason);
414 static const char* trap_action_name(int action);
415 // Format like reason='foo' action='bar' index='123'.
416 // This is suitable both for XML and for tty output.
417 static const char* format_trap_request(char* buf, size_t buflen,
418 int trap_request);
419
420 static jint total_deoptimization_count();
421 static jint deoptimization_count(const char* reason_str, const char* action_str);
422
423 // JVMTI PopFrame support
424
425 // Preserves incoming arguments to the popped frame when it is
426 // returning to a deoptimized caller
427 static void popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address);
428
429 static MethodData* get_method_data(JavaThread* thread, const methodHandle& m, bool create_if_missing);
430 private:
431 // Update the mdo's count and per-BCI reason bits, returning previous state:
432 static ProfileData* query_update_method_data(MethodData* trap_mdo,
433 int trap_bci,
434 DeoptReason reason,
435 Method* compiled_method,
436 //outputs:
437 uint& ret_this_trap_count,
438 bool& ret_maybe_prior_trap,
439 bool& ret_maybe_prior_recompile);
440 // class loading support for uncommon trap
441 static void load_class_by_index(const constantPoolHandle& constant_pool, int index, TRAPS);
442
443 static UnrollBlock* fetch_unroll_info_helper(JavaThread* current, int exec_mode);
444
445 static DeoptAction _unloaded_action; // == Action_reinterpret;
446 static const char* _trap_reason_name[];
447 static const char* _trap_action_name[];
448
449 static juint _deoptimization_hist[Reason_LIMIT][1+Action_LIMIT][BC_CASE_LIMIT];
450 // Note: Histogram array size is 1-2 Kb.
451
452 public:
453 static void update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason);
454 };
455
456 #endif // SHARE_RUNTIME_DEOPTIMIZATION_HPP