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