Fri, 31 Oct 2014 12:16:20 +0100
8062169: Multiple OSR compilations issued for same bci
Summary: Fixed 'SimpleThresholdPolicy::event' to always perform OSR if an OSR nmethod is available.
Reviewed-by: kvn, iveresov
1 /*
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25 #ifndef SHARE_VM_RUNTIME_DEOPTIMIZATION_HPP
26 #define SHARE_VM_RUNTIME_DEOPTIMIZATION_HPP
28 #include "memory/allocation.hpp"
29 #include "runtime/frame.inline.hpp"
31 class ProfileData;
32 class vframeArray;
33 class MonitorValue;
34 class ObjectValue;
36 class Deoptimization : AllStatic {
37 friend class VMStructs;
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)
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_rtm_state_change, // rtm state change detected
64 Reason_unstable_if, // a branch predicted always false was taken
65 Reason_LIMIT,
66 // Note: Keep this enum in sync. with _trap_reason_name.
67 Reason_RECORDED_LIMIT = Reason_bimorphic // some are not recorded per bc
68 // Note: Reason_RECORDED_LIMIT should be < 8 to fit into 3 bits of
69 // DataLayout::trap_bits. This dependency is enforced indirectly
70 // via asserts, to avoid excessive direct header-to-header dependencies.
71 // See Deoptimization::trap_state_reason and class DataLayout.
72 };
74 // What action must be taken by the runtime?
75 enum DeoptAction {
76 Action_none, // just interpret, do not invalidate nmethod
77 Action_maybe_recompile, // recompile the nmethod; need not invalidate
78 Action_reinterpret, // invalidate the nmethod, reset IC, maybe recompile
79 Action_make_not_entrant, // invalidate the nmethod, recompile (probably)
80 Action_make_not_compilable, // invalidate the nmethod and do not compile
81 Action_LIMIT
82 // Note: Keep this enum in sync. with _trap_action_name.
83 };
85 enum {
86 _action_bits = 3,
87 _reason_bits = 5,
88 _action_shift = 0,
89 _reason_shift = _action_shift+_action_bits,
90 BC_CASE_LIMIT = PRODUCT_ONLY(1) NOT_PRODUCT(4) // for _deoptimization_hist
91 };
93 enum UnpackType {
94 Unpack_deopt = 0, // normal deoptimization, use pc computed in unpack_vframe_on_stack
95 Unpack_exception = 1, // exception is pending
96 Unpack_uncommon_trap = 2, // redo last byte code (C2 only)
97 Unpack_reexecute = 3 // reexecute bytecode (C1 only)
98 };
100 // Checks all compiled methods. Invalid methods are deleted and
101 // corresponding activations are deoptimized.
102 static int deoptimize_dependents();
104 // Deoptimizes a frame lazily. nmethod gets patched deopt happens on return to the frame
105 static void deoptimize(JavaThread* thread, frame fr, RegisterMap *reg_map);
107 private:
108 // Does the actual work for deoptimizing a single frame
109 static void deoptimize_single_frame(JavaThread* thread, frame fr);
111 // Helper function to revoke biases of all monitors in frame if UseBiasedLocking
112 // is enabled
113 static void revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map);
114 // Helper function to revoke biases of all monitors in frames
115 // executing in a particular CodeBlob if UseBiasedLocking is enabled
116 static void revoke_biases_of_monitors(CodeBlob* cb);
118 #ifdef COMPILER2
119 // Support for restoring non-escaping objects
120 static bool realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS);
121 static void reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type);
122 static void reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj);
123 static void reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects);
124 static void relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread);
125 NOT_PRODUCT(static void print_objects(GrowableArray<ScopeValue*>* objects);)
126 #endif // COMPILER2
128 public:
129 static vframeArray* create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk);
131 // Interface used for unpacking deoptimized frames
133 // UnrollBlock is returned by fetch_unroll_info() to the deoptimization handler (blob).
134 // This is only a CheapObj to ease debugging after a deopt failure
135 class UnrollBlock : public CHeapObj<mtCompiler> {
136 private:
137 int _size_of_deoptimized_frame; // Size, in bytes, of current deoptimized frame
138 int _caller_adjustment; // Adjustment, in bytes, to caller's SP by initial interpreted frame
139 int _number_of_frames; // Number frames to unroll
140 int _total_frame_sizes; // Total of number*sizes frames
141 intptr_t* _frame_sizes; // Array of frame sizes, in bytes, for unrolling the stack
142 address* _frame_pcs; // Array of frame pc's, in bytes, for unrolling the stack
143 intptr_t* _register_block; // Block for storing callee-saved registers.
144 BasicType _return_type; // Tells if we have to restore double or long return value
145 intptr_t _initial_info; // Platform dependent data for the sender frame (was FP on x86)
146 int _caller_actual_parameters; // The number of actual arguments at the
147 // interpreted caller of the deoptimized frame
149 // The following fields are used as temps during the unpacking phase
150 // (which is tight on registers, especially on x86). They really ought
151 // to be PD variables but that involves moving this class into its own
152 // file to use the pd include mechanism. Maybe in a later cleanup ...
153 intptr_t _counter_temp; // SHOULD BE PD VARIABLE (x86 frame count temp)
154 intptr_t _unpack_kind; // SHOULD BE PD VARIABLE (x86 unpack kind)
155 intptr_t _sender_sp_temp; // SHOULD BE PD VARIABLE (x86 sender_sp)
156 public:
157 // Constructor
158 UnrollBlock(int size_of_deoptimized_frame,
159 int caller_adjustment,
160 int caller_actual_parameters,
161 int number_of_frames,
162 intptr_t* frame_sizes,
163 address* frames_pcs,
164 BasicType return_type);
165 ~UnrollBlock();
167 // Returns where a register is located.
168 intptr_t* value_addr_at(int register_number) const;
170 // Accessors
171 intptr_t* frame_sizes() const { return _frame_sizes; }
172 int number_of_frames() const { return _number_of_frames; }
173 address* frame_pcs() const { return _frame_pcs ; }
175 // Returns the total size of frames
176 int size_of_frames() const;
178 void set_initial_info(intptr_t info) { _initial_info = info; }
180 int caller_actual_parameters() const { return _caller_actual_parameters; }
182 // Accessors used by the code generator for the unpack stub.
183 static int size_of_deoptimized_frame_offset_in_bytes() { return offset_of(UnrollBlock, _size_of_deoptimized_frame); }
184 static int caller_adjustment_offset_in_bytes() { return offset_of(UnrollBlock, _caller_adjustment); }
185 static int number_of_frames_offset_in_bytes() { return offset_of(UnrollBlock, _number_of_frames); }
186 static int frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _frame_sizes); }
187 static int total_frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _total_frame_sizes); }
188 static int frame_pcs_offset_in_bytes() { return offset_of(UnrollBlock, _frame_pcs); }
189 static int register_block_offset_in_bytes() { return offset_of(UnrollBlock, _register_block); }
190 static int return_type_offset_in_bytes() { return offset_of(UnrollBlock, _return_type); }
191 static int counter_temp_offset_in_bytes() { return offset_of(UnrollBlock, _counter_temp); }
192 static int initial_info_offset_in_bytes() { return offset_of(UnrollBlock, _initial_info); }
193 static int unpack_kind_offset_in_bytes() { return offset_of(UnrollBlock, _unpack_kind); }
194 static int sender_sp_temp_offset_in_bytes() { return offset_of(UnrollBlock, _sender_sp_temp); }
196 BasicType return_type() const { return _return_type; }
197 void print();
198 };
200 //** Returns an UnrollBlock continuing information
201 // how to make room for the resulting interpreter frames.
202 // Called by assembly stub after execution has returned to
203 // deoptimized frame.
204 // @argument thread. Thread where stub_frame resides.
205 // @see OptoRuntime::deoptimization_fetch_unroll_info_C
206 static UnrollBlock* fetch_unroll_info(JavaThread* thread);
208 //** Unpacks vframeArray onto execution stack
209 // Called by assembly stub after execution has returned to
210 // deoptimized frame and after the stack unrolling.
211 // @argument thread. Thread where stub_frame resides.
212 // @argument exec_mode. Determines how execution should be continuted in top frame.
213 // 0 means continue after current byte code
214 // 1 means exception has happened, handle exception
215 // 2 means reexecute current bytecode (for uncommon traps).
216 // @see OptoRuntime::deoptimization_unpack_frames_C
217 // Return BasicType of call return type, if any
218 static BasicType unpack_frames(JavaThread* thread, int exec_mode);
220 // Cleans up deoptimization bits on thread after unpacking or in the
221 // case of an exception.
222 static void cleanup_deopt_info(JavaThread *thread,
223 vframeArray * array);
225 // Restores callee saved values from deoptimized frame into oldest interpreter frame
226 // so caller of the deoptimized frame will get back the values it expects.
227 static void unwind_callee_save_values(frame* f, vframeArray* vframe_array);
229 //** Performs an uncommon trap for compiled code.
230 // The top most compiler frame is converted into interpreter frames
231 static UnrollBlock* uncommon_trap(JavaThread* thread, jint unloaded_class_index);
232 // Helper routine that enters the VM and may block
233 static void uncommon_trap_inner(JavaThread* thread, jint unloaded_class_index);
235 //** Deoptimizes the frame identified by id.
236 // Only called from VMDeoptimizeFrame
237 // @argument thread. Thread where stub_frame resides.
238 // @argument id. id of frame that should be deoptimized.
239 static void deoptimize_frame_internal(JavaThread* thread, intptr_t* id);
241 // If thread is not the current thread then execute
242 // VM_DeoptimizeFrame otherwise deoptimize directly.
243 static void deoptimize_frame(JavaThread* thread, intptr_t* id);
245 // Statistics
246 static void gather_statistics(DeoptReason reason, DeoptAction action,
247 Bytecodes::Code bc = Bytecodes::_illegal);
248 static void print_statistics();
250 // How much room to adjust the last frame's SP by, to make space for
251 // the callee's interpreter frame (which expects locals to be next to
252 // incoming arguments)
253 static int last_frame_adjust(int callee_parameters, int callee_locals);
255 // trap_request codes
256 static DeoptReason trap_request_reason(int trap_request) {
257 if (trap_request < 0)
258 return (DeoptReason)
259 ((~(trap_request) >> _reason_shift) & right_n_bits(_reason_bits));
260 else
261 // standard reason for unloaded CP entry
262 return Reason_unloaded;
263 }
264 static DeoptAction trap_request_action(int trap_request) {
265 if (trap_request < 0)
266 return (DeoptAction)
267 ((~(trap_request) >> _action_shift) & right_n_bits(_action_bits));
268 else
269 // standard action for unloaded CP entry
270 return _unloaded_action;
271 }
272 static int trap_request_index(int trap_request) {
273 if (trap_request < 0)
274 return -1;
275 else
276 return trap_request;
277 }
278 static int make_trap_request(DeoptReason reason, DeoptAction action,
279 int index = -1) {
280 assert((1 << _reason_bits) >= Reason_LIMIT, "enough bits");
281 assert((1 << _action_bits) >= Action_LIMIT, "enough bits");
282 int trap_request;
283 if (index != -1)
284 trap_request = index;
285 else
286 trap_request = (~(((reason) << _reason_shift)
287 + ((action) << _action_shift)));
288 assert(reason == trap_request_reason(trap_request), "valid reason");
289 assert(action == trap_request_action(trap_request), "valid action");
290 assert(index == trap_request_index(trap_request), "valid index");
291 return trap_request;
292 }
294 // The trap_state stored in a MDO is decoded here.
295 // It records two items of information.
296 // reason: If a deoptimization happened here, what its reason was,
297 // or if there were multiple deopts with differing reasons.
298 // recompiled: If a deoptimization here triggered a recompilation.
299 // Note that not all reasons are recorded per-bci.
300 static DeoptReason trap_state_reason(int trap_state);
301 static int trap_state_has_reason(int trap_state, int reason);
302 static int trap_state_add_reason(int trap_state, int reason);
303 static bool trap_state_is_recompiled(int trap_state);
304 static int trap_state_set_recompiled(int trap_state, bool z);
305 static const char* format_trap_state(char* buf, size_t buflen,
306 int trap_state);
308 static bool reason_is_recorded_per_bytecode(DeoptReason reason) {
309 return reason > Reason_none && reason <= Reason_RECORDED_LIMIT;
310 }
312 static DeoptReason reason_recorded_per_bytecode_if_any(DeoptReason reason) {
313 if (reason_is_recorded_per_bytecode(reason))
314 return reason;
315 else if (reason == Reason_div0_check) // null check due to divide-by-zero?
316 return Reason_null_check; // recorded per BCI as a null check
317 else if (reason == Reason_speculate_class_check)
318 return Reason_class_check;
319 else if (reason == Reason_unstable_if)
320 return Reason_intrinsic;
321 else
322 return Reason_none;
323 }
325 static bool reason_is_speculate(int reason) {
326 if (reason == Reason_speculate_class_check) {
327 return true;
328 }
329 return false;
330 }
332 static uint per_method_trap_limit(int reason) {
333 return reason_is_speculate(reason) ? (uint)PerMethodSpecTrapLimit : (uint)PerMethodTrapLimit;
334 }
336 static const char* trap_reason_name(int reason);
337 static const char* trap_action_name(int action);
338 // Format like reason='foo' action='bar' index='123'.
339 // This is suitable both for XML and for tty output.
340 static const char* format_trap_request(char* buf, size_t buflen,
341 int trap_request);
343 static jint total_deoptimization_count();
344 static jint deoptimization_count(DeoptReason reason);
346 // JVMTI PopFrame support
348 // Preserves incoming arguments to the popped frame when it is
349 // returning to a deoptimized caller
350 static void popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address);
352 private:
353 static MethodData* get_method_data(JavaThread* thread, methodHandle m, bool create_if_missing);
354 // Update the mdo's count and per-BCI reason bits, returning previous state:
355 static ProfileData* query_update_method_data(MethodData* trap_mdo,
356 int trap_bci,
357 DeoptReason reason,
358 Method* compiled_method,
359 //outputs:
360 uint& ret_this_trap_count,
361 bool& ret_maybe_prior_trap,
362 bool& ret_maybe_prior_recompile);
363 // class loading support for uncommon trap
364 static void load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS);
365 static void load_class_by_index(constantPoolHandle constant_pool, int index);
367 static UnrollBlock* fetch_unroll_info_helper(JavaThread* thread);
369 static DeoptAction _unloaded_action; // == Action_reinterpret;
370 static const char* _trap_reason_name[Reason_LIMIT];
371 static const char* _trap_action_name[Action_LIMIT];
373 static juint _deoptimization_hist[Reason_LIMIT][1+Action_LIMIT][BC_CASE_LIMIT];
374 // Note: Histogram array size is 1-2 Kb.
376 public:
377 static void update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason);
378 };
380 class DeoptimizationMarker : StackObj { // for profiling
381 static bool _is_active;
382 public:
383 DeoptimizationMarker() { _is_active = true; }
384 ~DeoptimizationMarker() { _is_active = false; }
385 static bool is_active() { return _is_active; }
386 };
388 #endif // SHARE_VM_RUNTIME_DEOPTIMIZATION_HPP