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 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; // SHOULD BE PD VARIABLE (x86/c2 initial ebp)
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 // Accessors used by the code generator for the unpack stub.
169 static int size_of_deoptimized_frame_offset_in_bytes() { return offset_of(UnrollBlock, _size_of_deoptimized_frame); }
170 static int caller_adjustment_offset_in_bytes() { return offset_of(UnrollBlock, _caller_adjustment); }
171 static int number_of_frames_offset_in_bytes() { return offset_of(UnrollBlock, _number_of_frames); }
172 static int frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _frame_sizes); }
173 static int total_frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _total_frame_sizes); }
174 static int frame_pcs_offset_in_bytes() { return offset_of(UnrollBlock, _frame_pcs); }
175 static int register_block_offset_in_bytes() { return offset_of(UnrollBlock, _register_block); }
176 static int return_type_offset_in_bytes() { return offset_of(UnrollBlock, _return_type); }
177 static int counter_temp_offset_in_bytes() { return offset_of(UnrollBlock, _counter_temp); }
178 static int initial_fp_offset_in_bytes() { return offset_of(UnrollBlock, _initial_fp); }
179 static int unpack_kind_offset_in_bytes() { return offset_of(UnrollBlock, _unpack_kind); }
180 static int sender_sp_temp_offset_in_bytes() { return offset_of(UnrollBlock, _sender_sp_temp); }
181
182 BasicType return_type() const { return _return_type; }
183 void print();
184 };
185
186 //** Returns an UnrollBlock continuing information
187 // how to make room for the resulting interpreter frames.
188 // Called by assembly stub after execution has returned to
189 // deoptimized frame.
190 // @argument thread. Thread where stub_frame resides.
191 // @see OptoRuntime::deoptimization_fetch_unroll_info_C
192 static UnrollBlock* fetch_unroll_info(JavaThread* thread);
193
194 //** Unpacks vframeArray onto execution stack
195 // Called by assembly stub after execution has returned to
196 // deoptimized frame and after the stack unrolling.
197 // @argument thread. Thread where stub_frame resides.
198 // @argument exec_mode. Determines how execution should be continuted in top frame.
199 // 0 means continue after current byte code
200 // 1 means exception has happened, handle exception
201 // 2 means reexecute current bytecode (for uncommon traps).
202 // @see OptoRuntime::deoptimization_unpack_frames_C
203 // Return BasicType of call return type, if any
204 static BasicType unpack_frames(JavaThread* thread, int exec_mode);
205
206 // Cleans up deoptimization bits on thread after unpacking or in the
207 // case of an exception.
208 static void cleanup_deopt_info(JavaThread *thread,
209 vframeArray * array);
210
211 // Restores callee saved values from deoptimized frame into oldest interpreter frame
212 // so caller of the deoptimized frame will get back the values it expects.
213 static void unwind_callee_save_values(frame* f, vframeArray* vframe_array);
214
215 //** Performs an uncommon trap for compiled code.
216 // The top most compiler frame is converted into interpreter frames
217 static UnrollBlock* uncommon_trap(JavaThread* thread, jint unloaded_class_index);
218 // Helper routine that enters the VM and may block
219 static void uncommon_trap_inner(JavaThread* thread, jint unloaded_class_index);
220
221 //** Deoptimizes the frame identified by id.
222 // Only called from VMDeoptimizeFrame
223 // @argument thread. Thread where stub_frame resides.
224 // @argument id. id of frame that should be deoptimized.
225 static void deoptimize_frame_internal(JavaThread* thread, intptr_t* id);
226
227 // If thread is not the current thread then execute
228 // VM_DeoptimizeFrame otherwise deoptimize directly.
229 static void deoptimize_frame(JavaThread* thread, intptr_t* id);
230
231 // Statistics
232 static void gather_statistics(DeoptReason reason, DeoptAction action,
233 Bytecodes::Code bc = Bytecodes::_illegal);
234 static void print_statistics();
235
236 // How much room to adjust the last frame's SP by, to make space for
237 // the callee's interpreter frame (which expects locals to be next to
238 // incoming arguments)
239 static int last_frame_adjust(int callee_parameters, int callee_locals);
240
241 // trap_request codes
242 static DeoptReason trap_request_reason(int trap_request) {
243 if (trap_request < 0)
244 return (DeoptReason)
245 ((~(trap_request) >> _reason_shift) & right_n_bits(_reason_bits));
246 else
247 // standard reason for unloaded CP entry
248 return Reason_unloaded;
249 }
250 static DeoptAction trap_request_action(int trap_request) {
251 if (trap_request < 0)
252 return (DeoptAction)
253 ((~(trap_request) >> _action_shift) & right_n_bits(_action_bits));
254 else
255 // standard action for unloaded CP entry
256 return _unloaded_action;
257 }
258 static int trap_request_index(int trap_request) {
259 if (trap_request < 0)
260 return -1;
261 else
262 return trap_request;
263 }
264 static int make_trap_request(DeoptReason reason, DeoptAction action,
265 int index = -1) {
266 assert((1 << _reason_bits) >= Reason_LIMIT, "enough bits");
267 assert((1 << _action_bits) >= Action_LIMIT, "enough bits");
268 int trap_request;
269 if (index != -1)
270 trap_request = index;
271 else
272 trap_request = (~(((reason) << _reason_shift)
273 + ((action) << _action_shift)));
274 assert(reason == trap_request_reason(trap_request), "valid reason");
275 assert(action == trap_request_action(trap_request), "valid action");
276 assert(index == trap_request_index(trap_request), "valid index");
277 return trap_request;
278 }
279
280 // The trap_state stored in a MDO is decoded here.
281 // It records two items of information.
282 // reason: If a deoptimization happened here, what its reason was,
283 // or if there were multiple deopts with differing reasons.
284 // recompiled: If a deoptimization here triggered a recompilation.
285 // Note that not all reasons are recorded per-bci.
286 static DeoptReason trap_state_reason(int trap_state);
287 static int trap_state_has_reason(int trap_state, int reason);
288 static int trap_state_add_reason(int trap_state, int reason);
289 static bool trap_state_is_recompiled(int trap_state);
290 static int trap_state_set_recompiled(int trap_state, bool z);
291 static const char* format_trap_state(char* buf, size_t buflen,
292 int trap_state);
293
294 static bool reason_is_recorded_per_bytecode(DeoptReason reason) {
295 return reason > Reason_none && reason <= Reason_RECORDED_LIMIT;
296 }
297
298 static DeoptReason reason_recorded_per_bytecode_if_any(DeoptReason reason) {
299 if (reason_is_recorded_per_bytecode(reason))
300 return reason;
301 else if (reason == Reason_div0_check) // null check due to divide-by-zero?
302 return Reason_null_check; // recorded per BCI as a null check
303 else
304 return Reason_none;
305 }
306
307 static const char* trap_reason_name(int reason);
308 static const char* trap_action_name(int action);
309 // Format like reason='foo' action='bar' index='123'.
310 // This is suitable both for XML and for tty output.
311 static const char* format_trap_request(char* buf, size_t buflen,
312 int trap_request);
313
314 static jint total_deoptimization_count();
315 static jint deoptimization_count(DeoptReason reason);
316
317 // JVMTI PopFrame support
318
319 // Preserves incoming arguments to the popped frame when it is
320 // returning to a deoptimized caller
321 static void popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address);
322
323 private:
324 static methodDataOop get_method_data(JavaThread* thread, methodHandle m, bool create_if_missing);
325 // Update the mdo's count and per-BCI reason bits, returning previous state:
326 static ProfileData* query_update_method_data(methodDataHandle trap_mdo,
327 int trap_bci,
328 DeoptReason reason,
329 //outputs:
330 uint& ret_this_trap_count,
331 bool& ret_maybe_prior_trap,
332 bool& ret_maybe_prior_recompile);
333 // class loading support for uncommon trap
334 static void load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS);
335 static void load_class_by_index(constantPoolHandle constant_pool, int index);
336
337 static UnrollBlock* fetch_unroll_info_helper(JavaThread* thread);
338
339 static DeoptAction _unloaded_action; // == Action_reinterpret;
340 static const char* _trap_reason_name[Reason_LIMIT];
341 static const char* _trap_action_name[Action_LIMIT];
342
343 static juint _deoptimization_hist[Reason_LIMIT][1+Action_LIMIT][BC_CASE_LIMIT];
344 // Note: Histogram array size is 1-2 Kb.
345
346 public:
347 static void update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason);
348 };
349
350 class DeoptimizationMarker : StackObj { // for profiling
351 static bool _is_active;
352 public:
353 DeoptimizationMarker() { _is_active = true; }
354 ~DeoptimizationMarker() { _is_active = false; }
355 static bool is_active() { return _is_active; }
356 };
357
358 #endif // SHARE_VM_RUNTIME_DEOPTIMIZATION_HPP