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src/hotspot/share/compiler/compilationPolicy.hpp

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 29 #include "compiler/compileBroker.hpp"
 30 #include "oops/methodData.hpp"
 31 #include "oops/trainingData.hpp"
 32 #include "utilities/globalDefinitions.hpp"
 33 
 34 namespace CompilationPolicyUtils {
 35 template<typename T>
 36 class Queue {
 37   class QueueNode : public CHeapObj<mtCompiler> {
 38     T* _value;
 39     QueueNode* _next;
 40   public:
 41     QueueNode(T* value, QueueNode* next) : _value(value), _next(next) { }
 42     T* value() const { return _value; }
 43     void set_next(QueueNode* next) { _next = next; }
 44     QueueNode* next() const { return _next; }
 45   };
 46 
 47   QueueNode* _head;
 48   QueueNode* _tail;

 49 
 50   void push_unlocked(T* value) {
 51     QueueNode* n = new QueueNode(value, nullptr);
 52     if (_tail != nullptr) {
 53       _tail->set_next(n);
 54     }
 55     _tail = n;
 56     if (_head == nullptr) {
 57       _head = _tail;
 58     }
 59   }
 60   T* pop_unlocked() {
 61     QueueNode* n = _head;
 62     if (_head != nullptr) {
 63       _head = _head->next();
 64     }
 65     if (_head == nullptr) {
 66       _tail = _head;
 67     }
 68     T* value = nullptr;
 69     if (n != nullptr) {
 70       value = n->value();
 71       delete n;
 72     }
 73     return value;
 74   }
 75 public:
 76   Queue() : _head(nullptr), _tail(nullptr) { }
 77   void push(T* value, Monitor* lock, JavaThread* current) {
 78     MonitorLocker locker(current, lock);
 79     push_unlocked(value);
 80     locker.notify_all();
 81   }
 82 
 83   bool is_empty_unlocked() const { return _head == nullptr; }

 84 
 85   T* pop(Monitor* lock, JavaThread* current) {
 86     MonitorLocker locker(current, lock);
 87     while (is_empty_unlocked() && !CompileBroker::is_compilation_disabled_forever()) {
 88       locker.wait();
 89     }
 90     T* value = pop_unlocked();
 91     return value;
 92   }
 93 
 94   T* try_pop(Monitor* lock, JavaThread* current) {
 95     MonitorLocker locker(current, lock);
 96     T* value = pop_unlocked();
 97     return value;
 98   }
 99   void print_on(outputStream* st);
100 };
101 } // namespace CompilationPolicyUtils
102 
103 class CompileTask;

225  *
226  * - TieredStopAtLevel, is used mostly for testing. It allows to bypass the policy logic and stick
227  *   to a given level. For example it's useful to set TieredStopAtLevel = 1 in order to compile everything
228  *   with pure c1.
229  *
230  * - Tier0ProfilingStartPercentage allows the interpreter to start profiling when the inequalities in the
231  *   0->3 predicate are already exceeded by the given percentage but the level 3 version of the
232  *   method is still not ready. We can even go directly from level 0 to 4 if c1 doesn't produce a compiled
233  *   version in time. This reduces the overall transition to level 4 and decreases the startup time.
234  *   Note that this behavior is also guarded by the Tier3Delay mechanism: when the c2 queue is too long
235  *   these is not reason to start profiling prematurely.
236  *
237  * - TieredRateUpdateMinTime and TieredRateUpdateMaxTime are parameters of the rate computation.
238  *   Basically, the rate is not computed more frequently than TieredRateUpdateMinTime and is considered
239  *   to be zero if no events occurred in TieredRateUpdateMaxTime.
240  */
241 
242 class CompilationPolicy : AllStatic {
243   friend class CallPredicate;
244   friend class LoopPredicate;

245 
246   typedef CompilationPolicyUtils::Queue<InstanceKlass> TrainingReplayQueue;
247 
248   static int64_t _start_time;
249   static int _c1_count, _c2_count;
250   static double _increase_threshold_at_ratio;
251   static TrainingReplayQueue _training_replay_queue;
252 
253   // Set carry flags in the counters (in Method* and MDO).
254   inline static void handle_counter_overflow(const methodHandle& method);
255 #ifdef ASSERT
256   // Verify that a level is consistent with the compilation mode
257   static bool verify_level(CompLevel level);
258 #endif
259   // Clamp the request level according to various constraints.
260   inline static CompLevel limit_level(CompLevel level);
261   // Common transition function. Given a predicate determines if a method should transition to another level.
262   template<typename Predicate>
263   static CompLevel common(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD, bool disable_feedback = false);
264 
265   template<typename Predicate>
266   static CompLevel transition_from_none(const methodHandle& method, CompLevel cur_level, bool disable_feedback);
267   template<typename Predicate>
268   static CompLevel transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, bool disable_feedback);
269   template<typename Predicate>

280   // Transition functions.
281   // call_event determines if a method should be compiled at a different
282   // level with a regular invocation entry.
283   static CompLevel call_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD);
284   // loop_event checks if a method should be OSR compiled at a different
285   // level.
286   static CompLevel loop_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD);
287   static void print_counters_on(outputStream* st, const char* prefix, Method* m);
288   static void print_training_data_on(outputStream* st, const char* prefix, Method* method, CompLevel cur_level);
289   // Has a method been long around?
290   // We don't remove old methods from the compile queue even if they have
291   // very low activity (see select_task()).
292   inline static bool is_old(const methodHandle& method);
293   // Was a given method inactive for a given number of milliseconds.
294   // If it is, we would remove it from the queue (see select_task()).
295   inline static bool is_stale(int64_t t, int64_t timeout, const methodHandle& method);
296   // Compute the weight of the method for the compilation scheduling
297   inline static double weight(Method* method);
298   // Apply heuristics and return true if x should be compiled before y
299   inline static bool compare_methods(Method* x, Method* y);

300   // Compute event rate for a given method. The rate is the number of event (invocations + backedges)
301   // per millisecond.
302   inline static void update_rate(int64_t t, const methodHandle& method);
303   // Compute threshold scaling coefficient
304   inline static double threshold_scale(CompLevel level, int feedback_k);
305   // If a method is old enough and is still in the interpreter we would want to
306   // start profiling without waiting for the compiled method to arrive. This function
307   // determines whether we should do that.
308   inline static bool should_create_mdo(const methodHandle& method, CompLevel cur_level);
309   // Create MDO if necessary.
310   static void create_mdo(const methodHandle& mh, JavaThread* THREAD);
311   // Is method profiled enough?
312   static bool is_method_profiled(const methodHandle& method);
313 
314   static void set_c1_count(int x) { _c1_count = x;    }
315   static void set_c2_count(int x) { _c2_count = x;    }

316 
317   enum EventType { CALL, LOOP, COMPILE, FORCE_COMPILE, FORCE_RECOMPILE, REMOVE_FROM_QUEUE, UPDATE_IN_QUEUE, REPROFILE, MAKE_NOT_ENTRANT };
318   static void print_event_on(outputStream *st, EventType type, Method* m, Method* im, int bci, CompLevel level);
319   static void print_event(EventType type, Method* m, Method* im, int bci, CompLevel level);
320   // Check if the method can be compiled, change level if necessary
321   static void compile(const methodHandle& mh, int bci, CompLevel level, TRAPS);
322   // Simple methods are as good being compiled with C1 as C2.
323   // This function tells if it's such a function.
324   inline static bool is_trivial(const methodHandle& method);
325   // Force method to be compiled at CompLevel_simple?
326   inline static bool force_comp_at_level_simple(const methodHandle& method);
327 
328   // Get a compilation level for a given method.
329   static CompLevel comp_level(Method* method);
330   static void method_invocation_event(const methodHandle& method, const methodHandle& inlinee,
331                                       CompLevel level, nmethod* nm, TRAPS);
332   static void method_back_branch_event(const methodHandle& method, const methodHandle& inlinee,
333                                       int bci, CompLevel level, nmethod* nm, TRAPS);
334 
335   static void set_increase_threshold_at_ratio() { _increase_threshold_at_ratio = 100 / (100 - (double)IncreaseFirstTierCompileThresholdAt); }
336   static void set_start_time(int64_t t) { _start_time = t;    }
337   static int64_t start_time()           { return _start_time; }
338 
339   // m must be compiled before executing it
340   static bool must_be_compiled(const methodHandle& m, int comp_level = CompLevel_any);
341   static void maybe_compile_early(const methodHandle& m, TRAPS);
342   static void replay_training_at_init_impl(InstanceKlass* klass, JavaThread* current);
343  public:
344   static int min_invocations() { return Tier4MinInvocationThreshold; }
345   static int c1_count() { return _c1_count; }
346   static int c2_count() { return _c2_count; }

347   static int compiler_count(CompLevel comp_level);
348   // If m must_be_compiled then request a compilation from the CompileBroker.
349   // This supports the -Xcomp option.
350   static void compile_if_required(const methodHandle& m, TRAPS);
351 
352   static void replay_training_at_init(InstanceKlass* klass, JavaThread* current);
353   static void replay_training_at_init_loop(JavaThread* current);
354 
355   // m is allowed to be compiled
356   static bool can_be_compiled(const methodHandle& m, int comp_level = CompLevel_any);
357   // m is allowed to be osr compiled
358   static bool can_be_osr_compiled(const methodHandle& m, int comp_level = CompLevel_any);
359   static bool is_compilation_enabled();
360 
361   static CompileTask* select_task_helper(CompileQueue* compile_queue);
362   // Return initial compile level to use with Xcomp (depends on compilation mode).
363   static void reprofile(ScopeDesc* trap_scope, bool is_osr);
364   static nmethod* event(const methodHandle& method, const methodHandle& inlinee,
365                         int branch_bci, int bci, CompLevel comp_level, nmethod* nm, TRAPS);
366   // Select task is called by CompileBroker. We should return a task or nullptr.
367   static CompileTask* select_task(CompileQueue* compile_queue, JavaThread* THREAD);
368   // Tell the runtime if we think a given method is adequately profiled.
369   static bool is_mature(MethodData* mdo);
370   // Initialize: set compiler thread count
371   static void initialize();
372   static bool should_not_inline(ciEnv* env, ciMethod* callee);
373 
374   // Return desired initial compilation level for Xcomp
375   static CompLevel initial_compile_level(const methodHandle& method);
376   // Return highest level possible
377   static CompLevel highest_compile_level();
378   static void dump();




379 };
380 
381 #endif // SHARE_COMPILER_COMPILATIONPOLICY_HPP

 29 #include "compiler/compileBroker.hpp"
 30 #include "oops/methodData.hpp"
 31 #include "oops/trainingData.hpp"
 32 #include "utilities/globalDefinitions.hpp"
 33 
 34 namespace CompilationPolicyUtils {
 35 template<typename T>
 36 class Queue {
 37   class QueueNode : public CHeapObj<mtCompiler> {
 38     T* _value;
 39     QueueNode* _next;
 40   public:
 41     QueueNode(T* value, QueueNode* next) : _value(value), _next(next) { }
 42     T* value() const { return _value; }
 43     void set_next(QueueNode* next) { _next = next; }
 44     QueueNode* next() const { return _next; }
 45   };
 46 
 47   QueueNode* _head;
 48   QueueNode* _tail;
 49   int _processing;
 50 
 51   void push_unlocked(T* value) {
 52     QueueNode* n = new QueueNode(value, nullptr);
 53     if (_tail != nullptr) {
 54       _tail->set_next(n);
 55     }
 56     _tail = n;
 57     if (_head == nullptr) {
 58       _head = _tail;
 59     }
 60   }
 61   T* pop_unlocked() {
 62     QueueNode* n = _head;
 63     if (_head != nullptr) {
 64       _head = _head->next();
 65     }
 66     if (_head == nullptr) {
 67       _tail = _head;
 68     }
 69     T* value = nullptr;
 70     if (n != nullptr) {
 71       value = n->value();
 72       delete n;
 73     }
 74     return value;
 75   }
 76 public:
 77   Queue() : _head(nullptr), _tail(nullptr) { }
 78   void push(T* value, Monitor* lock, JavaThread* current) {
 79     MonitorLocker locker(current, lock);
 80     push_unlocked(value);
 81     locker.notify_all();
 82   }
 83 
 84   bool is_empty_unlocked() const { return _head == nullptr; }
 85   bool is_processing_unlocked() const { return _processing > 0; }
 86 
 87   T* pop(Monitor* lock, JavaThread* current) {
 88     MonitorLocker locker(current, lock);
 89     while (is_empty_unlocked() && !CompileBroker::is_compilation_disabled_forever()) {
 90       locker.wait();
 91     }
 92     T* value = pop_unlocked();
 93     return value;
 94   }
 95 
 96   T* try_pop(Monitor* lock, JavaThread* current) {
 97     MonitorLocker locker(current, lock);
 98     T* value = pop_unlocked();
 99     return value;
100   }
101   void print_on(outputStream* st);
102 };
103 } // namespace CompilationPolicyUtils
104 
105 class CompileTask;

227  *
228  * - TieredStopAtLevel, is used mostly for testing. It allows to bypass the policy logic and stick
229  *   to a given level. For example it's useful to set TieredStopAtLevel = 1 in order to compile everything
230  *   with pure c1.
231  *
232  * - Tier0ProfilingStartPercentage allows the interpreter to start profiling when the inequalities in the
233  *   0->3 predicate are already exceeded by the given percentage but the level 3 version of the
234  *   method is still not ready. We can even go directly from level 0 to 4 if c1 doesn't produce a compiled
235  *   version in time. This reduces the overall transition to level 4 and decreases the startup time.
236  *   Note that this behavior is also guarded by the Tier3Delay mechanism: when the c2 queue is too long
237  *   these is not reason to start profiling prematurely.
238  *
239  * - TieredRateUpdateMinTime and TieredRateUpdateMaxTime are parameters of the rate computation.
240  *   Basically, the rate is not computed more frequently than TieredRateUpdateMinTime and is considered
241  *   to be zero if no events occurred in TieredRateUpdateMaxTime.
242  */
243 
244 class CompilationPolicy : AllStatic {
245   friend class CallPredicate;
246   friend class LoopPredicate;
247   friend class RecompilationPolicy;
248 
249   typedef CompilationPolicyUtils::Queue<InstanceKlass> TrainingReplayQueue;
250 
251   static int64_t _start_time;
252   static int _c1_count, _c2_count, _ac_count;
253   static double _increase_threshold_at_ratio;
254   static TrainingReplayQueue _training_replay_queue;
255 
256   // Set carry flags in the counters (in Method* and MDO).
257   inline static void handle_counter_overflow(const methodHandle& method);
258 #ifdef ASSERT
259   // Verify that a level is consistent with the compilation mode
260   static bool verify_level(CompLevel level);
261 #endif
262   // Clamp the request level according to various constraints.
263   inline static CompLevel limit_level(CompLevel level);
264   // Common transition function. Given a predicate determines if a method should transition to another level.
265   template<typename Predicate>
266   static CompLevel common(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD, bool disable_feedback = false);
267 
268   template<typename Predicate>
269   static CompLevel transition_from_none(const methodHandle& method, CompLevel cur_level, bool disable_feedback);
270   template<typename Predicate>
271   static CompLevel transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, bool disable_feedback);
272   template<typename Predicate>

283   // Transition functions.
284   // call_event determines if a method should be compiled at a different
285   // level with a regular invocation entry.
286   static CompLevel call_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD);
287   // loop_event checks if a method should be OSR compiled at a different
288   // level.
289   static CompLevel loop_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD);
290   static void print_counters_on(outputStream* st, const char* prefix, Method* m);
291   static void print_training_data_on(outputStream* st, const char* prefix, Method* method, CompLevel cur_level);
292   // Has a method been long around?
293   // We don't remove old methods from the compile queue even if they have
294   // very low activity (see select_task()).
295   inline static bool is_old(const methodHandle& method);
296   // Was a given method inactive for a given number of milliseconds.
297   // If it is, we would remove it from the queue (see select_task()).
298   inline static bool is_stale(int64_t t, int64_t timeout, const methodHandle& method);
299   // Compute the weight of the method for the compilation scheduling
300   inline static double weight(Method* method);
301   // Apply heuristics and return true if x should be compiled before y
302   inline static bool compare_methods(Method* x, Method* y);
303   inline static bool compare_tasks(CompileTask* x, CompileTask* y);
304   // Compute event rate for a given method. The rate is the number of event (invocations + backedges)
305   // per millisecond.
306   inline static void update_rate(int64_t t, const methodHandle& method);
307   // Compute threshold scaling coefficient
308   inline static double threshold_scale(CompLevel level, int feedback_k);
309   // If a method is old enough and is still in the interpreter we would want to
310   // start profiling without waiting for the compiled method to arrive. This function
311   // determines whether we should do that.
312   inline static bool should_create_mdo(const methodHandle& method, CompLevel cur_level);
313   // Create MDO if necessary.
314   static void create_mdo(const methodHandle& mh, JavaThread* THREAD);
315   // Is method profiled enough?
316   static bool is_method_profiled(const methodHandle& method);
317 
318   static void set_c1_count(int x) { _c1_count = x;    }
319   static void set_c2_count(int x) { _c2_count = x;    }
320   static void set_ac_count(int x) { _ac_count = x;    }
321 
322   enum EventType { CALL, LOOP, COMPILE, FORCE_COMPILE, FORCE_RECOMPILE, REMOVE_FROM_QUEUE, UPDATE_IN_QUEUE, REPROFILE, MAKE_NOT_ENTRANT };
323   static void print_event_on(outputStream *st, EventType type, Method* m, Method* im, int bci, CompLevel level);
324   static void print_event(EventType type, Method* m, Method* im, int bci, CompLevel level);
325   // Check if the method can be compiled, change level if necessary
326   static void compile(const methodHandle& mh, int bci, CompLevel level, TRAPS);
327   // Simple methods are as good being compiled with C1 as C2.
328   // This function tells if it's such a function.
329   inline static bool is_trivial(const methodHandle& method);
330   // Force method to be compiled at CompLevel_simple?
331   inline static bool force_comp_at_level_simple(const methodHandle& method);
332 
333   // Get a compilation level for a given method.
334   static CompLevel comp_level(Method* method);
335   static void method_invocation_event(const methodHandle& method, const methodHandle& inlinee,
336                                       CompLevel level, nmethod* nm, TRAPS);
337   static void method_back_branch_event(const methodHandle& method, const methodHandle& inlinee,
338                                       int bci, CompLevel level, nmethod* nm, TRAPS);
339 
340   static void set_increase_threshold_at_ratio() { _increase_threshold_at_ratio = 100 / (100 - (double)IncreaseFirstTierCompileThresholdAt); }
341   static void set_start_time(int64_t t) { _start_time = t;    }
342   static int64_t start_time()           { return _start_time; }
343 
344   // m must be compiled before executing it
345   static bool must_be_compiled(const methodHandle& m, int comp_level = CompLevel_any);
346   static void maybe_compile_early(const methodHandle& m, TRAPS);
347   static void replay_training_at_init_impl(InstanceKlass* klass, JavaThread* current);
348  public:
349   static int min_invocations() { return Tier4MinInvocationThreshold; }
350   static int c1_count() { return _c1_count; }
351   static int c2_count() { return _c2_count; }
352   static int ac_count() { return _ac_count; }
353   static int compiler_count(CompLevel comp_level);
354   // If m must_be_compiled then request a compilation from the CompileBroker.
355   // This supports the -Xcomp option.
356   static void compile_if_required(const methodHandle& m, TRAPS);
357 
358   static void replay_training_at_init(InstanceKlass* klass, JavaThread* current);
359   static void replay_training_at_init_loop(JavaThread* current);
360 
361   // m is allowed to be compiled
362   static bool can_be_compiled(const methodHandle& m, int comp_level = CompLevel_any);
363   // m is allowed to be osr compiled
364   static bool can_be_osr_compiled(const methodHandle& m, int comp_level = CompLevel_any);
365   static bool is_compilation_enabled();
366 
367   static CompileTask* select_task_helper(CompileQueue* compile_queue);
368   // Return initial compile level to use with Xcomp (depends on compilation mode).
369   static void reprofile(ScopeDesc* trap_scope, bool is_osr);
370   static nmethod* event(const methodHandle& method, const methodHandle& inlinee,
371                         int branch_bci, int bci, CompLevel comp_level, nmethod* nm, TRAPS);
372   // Select task is called by CompileBroker. We should return a task or nullptr.
373   static CompileTask* select_task(CompileQueue* compile_queue, JavaThread* THREAD);
374   // Tell the runtime if we think a given method is adequately profiled.
375   static bool is_mature(MethodData* mdo);
376   // Initialize: set compiler thread count
377   static void initialize();
378   static bool should_not_inline(ciEnv* env, ciMethod* callee);
379 
380   // Return desired initial compilation level for Xcomp
381   static CompLevel initial_compile_level(const methodHandle& method);
382   // Return highest level possible
383   static CompLevel highest_compile_level();
384   static void dump();
385 
386   static void sample_load_average();
387   static bool have_recompilation_work();
388   static bool recompilation_step(int step, TRAPS);
389 };
390 
391 #endif // SHARE_COMPILER_COMPILATIONPOLICY_HPP
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