1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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_speculate_class_check, // saw unexpected object class from type speculation
63 Reason_speculate_null_check, // saw unexpected null from type speculation
64 Reason_rtm_state_change, // rtm state change detected
65 Reason_unstable_if, // a branch predicted always false was taken
66
67 // Reason_tenured is counted separately, add normal counted Reasons above.
68 // Related to MethodData::_trap_hist_limit where Reason_tenured isn't included
69 Reason_tenured, // age of the code has reached the limit
70 Reason_LIMIT,
71 // Note: Keep this enum in sync. with _trap_reason_name.
72 Reason_RECORDED_LIMIT = Reason_bimorphic // some are not recorded per bc
73 // Note: Reason_RECORDED_LIMIT should be < 8 to fit into 3 bits of
74 // DataLayout::trap_bits. This dependency is enforced indirectly
75 // via asserts, to avoid excessive direct header-to-header dependencies.
76 // See Deoptimization::trap_state_reason and class DataLayout.
77 };
78
79 // What action must be taken by the runtime?
80 enum DeoptAction {
81 Action_none, // just interpret, do not invalidate nmethod
82 Action_maybe_recompile, // recompile the nmethod; need not invalidate
83 Action_reinterpret, // invalidate the nmethod, reset IC, maybe recompile
84 Action_make_not_entrant, // invalidate the nmethod, recompile (probably)
85 Action_make_not_compilable, // invalidate the nmethod and do not compile
86 Action_LIMIT
87 // Note: Keep this enum in sync. with _trap_action_name.
88 };
89
90 enum {
91 _action_bits = 3,
92 _reason_bits = 5,
93 _action_shift = 0,
94 _reason_shift = _action_shift+_action_bits,
95 BC_CASE_LIMIT = PRODUCT_ONLY(1) NOT_PRODUCT(4) // for _deoptimization_hist
96 };
97
98 enum UnpackType {
99 Unpack_deopt = 0, // normal deoptimization, use pc computed in unpack_vframe_on_stack
100 Unpack_exception = 1, // exception is pending
101 Unpack_uncommon_trap = 2, // redo last byte code (C2 only)
102 Unpack_reexecute = 3 // reexecute bytecode (C1 only)
103 };
104
105 // Checks all compiled methods. Invalid methods are deleted and
106 // corresponding activations are deoptimized.
107 static int deoptimize_dependents();
108
109 // Deoptimizes a frame lazily. nmethod gets patched deopt happens on return to the frame
110 static void deoptimize(JavaThread* thread, frame fr, RegisterMap *reg_map);
111
112 private:
113 // Does the actual work for deoptimizing a single frame
114 static void deoptimize_single_frame(JavaThread* thread, frame fr);
115
116 // Helper function to revoke biases of all monitors in frame if UseBiasedLocking
117 // is enabled
118 static void revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map);
119 // Helper function to revoke biases of all monitors in frames
120 // executing in a particular CodeBlob if UseBiasedLocking is enabled
121 static void revoke_biases_of_monitors(CodeBlob* cb);
122
123 #ifdef COMPILER2
124 // Support for restoring non-escaping objects
125 static bool realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS);
126 static void reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type);
127 static void reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj);
128 static void reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, bool realloc_failures);
129 static void relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread, bool realloc_failures);
130 static void pop_frames_failed_reallocs(JavaThread* thread, vframeArray* array);
131 NOT_PRODUCT(static void print_objects(GrowableArray<ScopeValue*>* objects, bool realloc_failures);)
132 #endif // COMPILER2
133
134 public:
135 static vframeArray* create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures);
136
137 // Interface used for unpacking deoptimized frames
138
139 // UnrollBlock is returned by fetch_unroll_info() to the deoptimization handler (blob).
140 // This is only a CheapObj to ease debugging after a deopt failure
141 class UnrollBlock : public CHeapObj<mtCompiler> {
142 private:
143 int _size_of_deoptimized_frame; // Size, in bytes, of current deoptimized frame
144 int _caller_adjustment; // Adjustment, in bytes, to caller's SP by initial interpreted frame
145 int _number_of_frames; // Number frames to unroll
146 int _total_frame_sizes; // Total of number*sizes frames
147 intptr_t* _frame_sizes; // Array of frame sizes, in bytes, for unrolling the stack
148 address* _frame_pcs; // Array of frame pc's, in bytes, for unrolling the stack
149 intptr_t* _register_block; // Block for storing callee-saved registers.
150 BasicType _return_type; // Tells if we have to restore double or long return value
151 intptr_t _initial_info; // Platform dependent data for the sender frame (was FP on x86)
152 int _caller_actual_parameters; // The number of actual arguments at the
153 // interpreted caller of the deoptimized frame
154
155 // The following fields are used as temps during the unpacking phase
156 // (which is tight on registers, especially on x86). They really ought
157 // to be PD variables but that involves moving this class into its own
158 // file to use the pd include mechanism. Maybe in a later cleanup ...
159 intptr_t _counter_temp; // SHOULD BE PD VARIABLE (x86 frame count temp)
160 intptr_t _unpack_kind; // SHOULD BE PD VARIABLE (x86 unpack kind)
161 intptr_t _sender_sp_temp; // SHOULD BE PD VARIABLE (x86 sender_sp)
162 public:
163 // Constructor
164 UnrollBlock(int size_of_deoptimized_frame,
165 int caller_adjustment,
166 int caller_actual_parameters,
167 int number_of_frames,
168 intptr_t* frame_sizes,
169 address* frames_pcs,
170 BasicType return_type);
171 ~UnrollBlock();
172
173 // Returns where a register is located.
174 intptr_t* value_addr_at(int register_number) const;
175
176 // Accessors
177 intptr_t* frame_sizes() const { return _frame_sizes; }
178 int number_of_frames() const { return _number_of_frames; }
179 address* frame_pcs() const { return _frame_pcs ; }
180
181 // Returns the total size of frames
182 int size_of_frames() const;
183
184 void set_initial_info(intptr_t info) { _initial_info = info; }
185
186 int caller_actual_parameters() const { return _caller_actual_parameters; }
187
188 // Accessors used by the code generator for the unpack stub.
189 static int size_of_deoptimized_frame_offset_in_bytes() { return offset_of(UnrollBlock, _size_of_deoptimized_frame); }
190 static int caller_adjustment_offset_in_bytes() { return offset_of(UnrollBlock, _caller_adjustment); }
191 static int number_of_frames_offset_in_bytes() { return offset_of(UnrollBlock, _number_of_frames); }
192 static int frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _frame_sizes); }
193 static int total_frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _total_frame_sizes); }
194 static int frame_pcs_offset_in_bytes() { return offset_of(UnrollBlock, _frame_pcs); }
195 static int register_block_offset_in_bytes() { return offset_of(UnrollBlock, _register_block); }
196 static int return_type_offset_in_bytes() { return offset_of(UnrollBlock, _return_type); }
197 static int counter_temp_offset_in_bytes() { return offset_of(UnrollBlock, _counter_temp); }
198 static int initial_info_offset_in_bytes() { return offset_of(UnrollBlock, _initial_info); }
199 static int unpack_kind_offset_in_bytes() { return offset_of(UnrollBlock, _unpack_kind); }
200 static int sender_sp_temp_offset_in_bytes() { return offset_of(UnrollBlock, _sender_sp_temp); }
201
202 BasicType return_type() const { return _return_type; }
203 void print();
204 };
205
206 //** Returns an UnrollBlock continuing information
207 // how to make room for the resulting interpreter frames.
208 // Called by assembly stub after execution has returned to
209 // deoptimized frame.
210 // @argument thread. Thread where stub_frame resides.
211 // @see OptoRuntime::deoptimization_fetch_unroll_info_C
212 static UnrollBlock* fetch_unroll_info(JavaThread* thread);
213
214 //** Unpacks vframeArray onto execution stack
215 // Called by assembly stub after execution has returned to
216 // deoptimized frame and after the stack unrolling.
217 // @argument thread. Thread where stub_frame resides.
218 // @argument exec_mode. Determines how execution should be continued in top frame.
219 // 0 means continue after current byte code
220 // 1 means exception has happened, handle exception
221 // 2 means reexecute current bytecode (for uncommon traps).
222 // @see OptoRuntime::deoptimization_unpack_frames_C
223 // Return BasicType of call return type, if any
224 static BasicType unpack_frames(JavaThread* thread, int exec_mode);
225
226 // Cleans up deoptimization bits on thread after unpacking or in the
227 // case of an exception.
228 static void cleanup_deopt_info(JavaThread *thread,
229 vframeArray * array);
230
231 // Restores callee saved values from deoptimized frame into oldest interpreter frame
232 // so caller of the deoptimized frame will get back the values it expects.
233 static void unwind_callee_save_values(frame* f, vframeArray* vframe_array);
234
235 //** Performs an uncommon trap for compiled code.
236 // The top most compiler frame is converted into interpreter frames
237 static UnrollBlock* uncommon_trap(JavaThread* thread, jint unloaded_class_index);
238 // Helper routine that enters the VM and may block
239 static void uncommon_trap_inner(JavaThread* thread, jint unloaded_class_index);
240
241 //** Deoptimizes the frame identified by id.
242 // Only called from VMDeoptimizeFrame
243 // @argument thread. Thread where stub_frame resides.
244 // @argument id. id of frame that should be deoptimized.
245 static void deoptimize_frame_internal(JavaThread* thread, intptr_t* id);
246
247 // If thread is not the current thread then execute
248 // VM_DeoptimizeFrame otherwise deoptimize directly.
249 static void deoptimize_frame(JavaThread* thread, intptr_t* id);
250
251 // Statistics
252 static void gather_statistics(DeoptReason reason, DeoptAction action,
253 Bytecodes::Code bc = Bytecodes::_illegal);
254 static void print_statistics();
255
256 // How much room to adjust the last frame's SP by, to make space for
257 // the callee's interpreter frame (which expects locals to be next to
258 // incoming arguments)
259 static int last_frame_adjust(int callee_parameters, int callee_locals);
260
261 // trap_request codes
262 static DeoptReason trap_request_reason(int trap_request) {
263 if (trap_request < 0)
264 return (DeoptReason)
265 ((~(trap_request) >> _reason_shift) & right_n_bits(_reason_bits));
266 else
267 // standard reason for unloaded CP entry
268 return Reason_unloaded;
269 }
270 static DeoptAction trap_request_action(int trap_request) {
271 if (trap_request < 0)
272 return (DeoptAction)
273 ((~(trap_request) >> _action_shift) & right_n_bits(_action_bits));
274 else
275 // standard action for unloaded CP entry
276 return _unloaded_action;
277 }
278 static int trap_request_index(int trap_request) {
279 if (trap_request < 0)
280 return -1;
281 else
282 return trap_request;
283 }
284 static int make_trap_request(DeoptReason reason, DeoptAction action,
285 int index = -1) {
286 assert((1 << _reason_bits) >= Reason_LIMIT, "enough bits");
287 assert((1 << _action_bits) >= Action_LIMIT, "enough bits");
288 int trap_request;
289 if (index != -1)
290 trap_request = index;
291 else
292 trap_request = (~(((reason) << _reason_shift)
293 + ((action) << _action_shift)));
294 assert(reason == trap_request_reason(trap_request), "valid reason");
295 assert(action == trap_request_action(trap_request), "valid action");
296 assert(index == trap_request_index(trap_request), "valid index");
297 return trap_request;
298 }
299
300 // The trap_state stored in a MDO is decoded here.
301 // It records two items of information.
302 // reason: If a deoptimization happened here, what its reason was,
303 // or if there were multiple deopts with differing reasons.
304 // recompiled: If a deoptimization here triggered a recompilation.
305 // Note that not all reasons are recorded per-bci.
306 static DeoptReason trap_state_reason(int trap_state);
307 static int trap_state_has_reason(int trap_state, int reason);
308 static int trap_state_add_reason(int trap_state, int reason);
309 static bool trap_state_is_recompiled(int trap_state);
310 static int trap_state_set_recompiled(int trap_state, bool z);
311 static const char* format_trap_state(char* buf, size_t buflen,
312 int trap_state);
313
314 static bool reason_is_recorded_per_bytecode(DeoptReason reason) {
315 return reason > Reason_none && reason <= Reason_RECORDED_LIMIT;
316 }
317
318 static DeoptReason reason_recorded_per_bytecode_if_any(DeoptReason reason) {
319 if (reason_is_recorded_per_bytecode(reason))
320 return reason;
321 else if (reason == Reason_div0_check) // null check due to divide-by-zero?
322 return Reason_null_check; // recorded per BCI as a null check
323 else if (reason == Reason_speculate_class_check)
324 return Reason_class_check;
325 else if (reason == Reason_speculate_null_check)
326 return Reason_null_check;
327 else if (reason == Reason_unstable_if)
328 return Reason_intrinsic;
329 else
330 return Reason_none;
331 }
332
333 static bool reason_is_speculate(int reason) {
334 if (reason == Reason_speculate_class_check || reason == Reason_speculate_null_check) {
335 return true;
336 }
337 return false;
338 }
339
340 static DeoptReason reason_null_check(bool speculative) {
341 return speculative ? Deoptimization::Reason_speculate_null_check : Deoptimization::Reason_null_check;
342 }
343
344 static DeoptReason reason_class_check(bool speculative) {
345 return speculative ? Deoptimization::Reason_speculate_class_check : Deoptimization::Reason_class_check;
346 }
347
348 static uint per_method_trap_limit(int reason) {
349 return reason_is_speculate(reason) ? (uint)PerMethodSpecTrapLimit : (uint)PerMethodTrapLimit;
350 }
351
352 static const char* trap_reason_name(int reason);
353 static const char* trap_action_name(int action);
354 // Format like reason='foo' action='bar' index='123'.
355 // This is suitable both for XML and for tty output.
356 static const char* format_trap_request(char* buf, size_t buflen,
357 int trap_request);
358
359 static jint total_deoptimization_count();
360 static jint deoptimization_count(DeoptReason reason);
361
362 // JVMTI PopFrame support
363
364 // Preserves incoming arguments to the popped frame when it is
365 // returning to a deoptimized caller
366 static void popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address);
367
368 static MethodData* get_method_data(JavaThread* thread, methodHandle m, bool create_if_missing);
369 private:
370 // Update the mdo's count and per-BCI reason bits, returning previous state:
371 static ProfileData* query_update_method_data(MethodData* trap_mdo,
372 int trap_bci,
373 DeoptReason reason,
374 Method* compiled_method,
375 //outputs:
376 uint& ret_this_trap_count,
377 bool& ret_maybe_prior_trap,
378 bool& ret_maybe_prior_recompile);
379 // class loading support for uncommon trap
380 static void load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS);
381 static void load_class_by_index(constantPoolHandle constant_pool, int index);
382
383 static UnrollBlock* fetch_unroll_info_helper(JavaThread* thread);
384
385 static DeoptAction _unloaded_action; // == Action_reinterpret;
386 static const char* _trap_reason_name[];
387 static const char* _trap_action_name[];
388
389 static juint _deoptimization_hist[Reason_LIMIT][1+Action_LIMIT][BC_CASE_LIMIT];
390 // Note: Histogram array size is 1-2 Kb.
391
392 public:
393 static void update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason);
394 };
395
396 class DeoptimizationMarker : StackObj { // for profiling
397 static bool _is_active;
398 public:
399 DeoptimizationMarker() { _is_active = true; }
400 ~DeoptimizationMarker() { _is_active = false; }
401 static bool is_active() { return _is_active; }
402 };
403
404 #endif // SHARE_VM_RUNTIME_DEOPTIMIZATION_HPP