1 /*
2 * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
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23 */
24
25 #ifndef SHARE_VM_MEMORY_REFERENCEPROCESSOR_HPP
26 #define SHARE_VM_MEMORY_REFERENCEPROCESSOR_HPP
27
28 #include "gc_implementation/shared/gcTrace.hpp"
29 #include "memory/referencePolicy.hpp"
30 #include "memory/referenceProcessorStats.hpp"
31 #include "memory/referenceType.hpp"
32 #include "oops/instanceRefKlass.hpp"
33
34 class GCTimer;
35
36 // ReferenceProcessor class encapsulates the per-"collector" processing
37 // of java.lang.Reference objects for GC. The interface is useful for supporting
38 // a generational abstraction, in particular when there are multiple
39 // generations that are being independently collected -- possibly
40 // concurrently and/or incrementally. Note, however, that the
41 // ReferenceProcessor class abstracts away from a generational setting
42 // by using only a heap interval (called "span" below), thus allowing
43 // its use in a straightforward manner in a general, non-generational
44 // setting.
45 //
46 // The basic idea is that each ReferenceProcessor object concerns
47 // itself with ("weak") reference processing in a specific "span"
48 // of the heap of interest to a specific collector. Currently,
49 // the span is a convex interval of the heap, but, efficiency
50 // apart, there seems to be no reason it couldn't be extended
51 // (with appropriate modifications) to any "non-convex interval".
52
53 // forward references
54 class ReferencePolicy;
55 class AbstractRefProcTaskExecutor;
56
57 // List of discovered references.
58 class DiscoveredList {
59 public:
60 DiscoveredList() : _len(0), _compressed_head(0), _oop_head(NULL) { }
61 oop head() const {
62 return UseCompressedOops ? oopDesc::decode_heap_oop(_compressed_head) :
63 _oop_head;
64 }
65 HeapWord* adr_head() {
66 return UseCompressedOops ? (HeapWord*)&_compressed_head :
67 (HeapWord*)&_oop_head;
68 }
69 void set_head(oop o) {
70 if (UseCompressedOops) {
71 // Must compress the head ptr.
72 _compressed_head = oopDesc::encode_heap_oop(o);
73 } else {
74 _oop_head = o;
75 }
76 }
77 bool is_empty() const { return head() == NULL; }
78 size_t length() { return _len; }
79 void set_length(size_t len) { _len = len; }
80 void inc_length(size_t inc) { _len += inc; assert(_len > 0, "Error"); }
81 void dec_length(size_t dec) { _len -= dec; }
82 private:
83 // Set value depending on UseCompressedOops. This could be a template class
84 // but then we have to fix all the instantiations and declarations that use this class.
85 oop _oop_head;
86 narrowOop _compressed_head;
87 size_t _len;
88 };
89
90 // Iterator for the list of discovered references.
91 class DiscoveredListIterator {
92 private:
93 DiscoveredList& _refs_list;
94 HeapWord* _prev_next;
95 oop _prev;
96 oop _ref;
97 HeapWord* _discovered_addr;
98 oop _next;
99 HeapWord* _referent_addr;
100 oop _referent;
101 OopClosure* _keep_alive;
102 BoolObjectClosure* _is_alive;
103
104 DEBUG_ONLY(
105 oop _first_seen; // cyclic linked list check
106 )
107
108 NOT_PRODUCT(
109 size_t _processed;
110 size_t _removed;
111 )
112
113 public:
114 inline DiscoveredListIterator(DiscoveredList& refs_list,
115 OopClosure* keep_alive,
116 BoolObjectClosure* is_alive):
117 _refs_list(refs_list),
118 _prev_next(refs_list.adr_head()),
119 _prev(NULL),
120 _ref(refs_list.head()),
121 #ifdef ASSERT
122 _first_seen(refs_list.head()),
123 #endif
124 #ifndef PRODUCT
125 _processed(0),
126 _removed(0),
127 #endif
128 _next(NULL),
129 _keep_alive(keep_alive),
130 _is_alive(is_alive)
131 { }
132
133 // End Of List.
134 inline bool has_next() const { return _ref != NULL; }
135
136 // Get oop to the Reference object.
137 inline oop obj() const { return _ref; }
138
139 // Get oop to the referent object.
140 inline oop referent() const { return _referent; }
141
142 // Returns true if referent is alive.
143 inline bool is_referent_alive() const {
144 return _is_alive->do_object_b(_referent);
145 }
146
147 // Loads data for the current reference.
148 // The "allow_null_referent" argument tells us to allow for the possibility
149 // of a NULL referent in the discovered Reference object. This typically
150 // happens in the case of concurrent collectors that may have done the
151 // discovery concurrently, or interleaved, with mutator execution.
152 void load_ptrs(DEBUG_ONLY(bool allow_null_referent));
153
154 // Move to the next discovered reference.
155 inline void next() {
156 _prev_next = _discovered_addr;
157 _prev = _ref;
158 move_to_next();
159 }
160
161 // Remove the current reference from the list
162 void remove();
163
164 // Make the Reference object active again.
165 void make_active();
166
167 // Make the referent alive.
168 inline void make_referent_alive() {
169 if (UseCompressedOops) {
170 _keep_alive->do_oop((narrowOop*)_referent_addr);
171 } else {
172 _keep_alive->do_oop((oop*)_referent_addr);
173 }
174 }
175
176 // Update the discovered field.
177 inline void update_discovered() {
178 // First _prev_next ref actually points into DiscoveredList (gross).
179 if (UseCompressedOops) {
180 if (!oopDesc::is_null(*(narrowOop*)_prev_next)) {
181 _keep_alive->do_oop((narrowOop*)_prev_next);
182 }
183 } else {
184 if (!oopDesc::is_null(*(oop*)_prev_next)) {
185 _keep_alive->do_oop((oop*)_prev_next);
186 }
187 }
188 }
189
190 // NULL out referent pointer.
191 void clear_referent();
192
193 // Statistics
194 NOT_PRODUCT(
195 inline size_t processed() const { return _processed; }
196 inline size_t removed() const { return _removed; }
197 )
198
199 inline void move_to_next() {
200 if (_ref == _next) {
201 // End of the list.
202 _ref = NULL;
203 } else {
204 _ref = _next;
205 }
206 assert(_ref != _first_seen, "cyclic ref_list found");
207 NOT_PRODUCT(_processed++);
208 }
209 };
210
211 class ReferenceProcessor : public CHeapObj<mtGC> {
212
213 public:
214 size_t total_count(DiscoveredList lists[]);
215
216 protected:
217 // Compatibility with pre-4965777 JDK's
218 static bool _pending_list_uses_discovered_field;
219
220 // The SoftReference master timestamp clock
221 static jlong _soft_ref_timestamp_clock;
222
223 MemRegion _span; // (right-open) interval of heap
224 // subject to wkref discovery
225
226 bool _discovering_refs; // true when discovery enabled
227 bool _discovery_is_atomic; // if discovery is atomic wrt
228 // other collectors in configuration
229 bool _discovery_is_mt; // true if reference discovery is MT.
230
231 bool _enqueuing_is_done; // true if all weak references enqueued
232 bool _processing_is_mt; // true during phases when
233 // reference processing is MT.
234 uint _next_id; // round-robin mod _num_q counter in
235 // support of work distribution
236
237 // For collectors that do not keep GC liveness information
238 // in the object header, this field holds a closure that
239 // helps the reference processor determine the reachability
240 // of an oop. It is currently initialized to NULL for all
241 // collectors except for CMS and G1.
242 BoolObjectClosure* _is_alive_non_header;
243
244 // Soft ref clearing policies
245 // . the default policy
246 static ReferencePolicy* _default_soft_ref_policy;
247 // . the "clear all" policy
248 static ReferencePolicy* _always_clear_soft_ref_policy;
249 // . the current policy below is either one of the above
250 ReferencePolicy* _current_soft_ref_policy;
251
252 // The discovered ref lists themselves
253
254 // The active MT'ness degree of the queues below
255 uint _num_q;
256 // The maximum MT'ness degree of the queues below
257 uint _max_num_q;
258
259 // Master array of discovered oops
260 DiscoveredList* _discovered_refs;
261
262 // Arrays of lists of oops, one per thread (pointers into master array above)
263 DiscoveredList* _discoveredSoftRefs;
264 DiscoveredList* _discoveredWeakRefs;
265 DiscoveredList* _discoveredFinalRefs;
266 DiscoveredList* _discoveredPhantomRefs;
267 DiscoveredList* _discoveredCleanerRefs;
268
269 public:
270 static int number_of_subclasses_of_ref() { return (REF_CLEANER - REF_OTHER); }
271
272 uint num_q() { return _num_q; }
273 uint max_num_q() { return _max_num_q; }
274 void set_active_mt_degree(uint v) { _num_q = v; }
275
276 DiscoveredList* discovered_refs() { return _discovered_refs; }
277
278 ReferencePolicy* setup_policy(bool always_clear) {
279 _current_soft_ref_policy = always_clear ?
280 _always_clear_soft_ref_policy : _default_soft_ref_policy;
281 _current_soft_ref_policy->setup(); // snapshot the policy threshold
282 return _current_soft_ref_policy;
283 }
284
285 // Process references with a certain reachability level.
286 size_t process_discovered_reflist(DiscoveredList refs_lists[],
287 ReferencePolicy* policy,
288 bool clear_referent,
289 BoolObjectClosure* is_alive,
290 OopClosure* keep_alive,
291 VoidClosure* complete_gc,
292 AbstractRefProcTaskExecutor* task_executor);
293
294 void process_phaseJNI(BoolObjectClosure* is_alive,
295 OopClosure* keep_alive,
296 VoidClosure* complete_gc);
297
298 // Work methods used by the method process_discovered_reflist
299 // Phase1: keep alive all those referents that are otherwise
300 // dead but which must be kept alive by policy (and their closure).
301 void process_phase1(DiscoveredList& refs_list,
302 ReferencePolicy* policy,
303 BoolObjectClosure* is_alive,
304 OopClosure* keep_alive,
305 VoidClosure* complete_gc);
306 // Phase2: remove all those references whose referents are
307 // reachable.
308 inline void process_phase2(DiscoveredList& refs_list,
309 BoolObjectClosure* is_alive,
310 OopClosure* keep_alive,
311 VoidClosure* complete_gc) {
312 if (discovery_is_atomic()) {
313 // complete_gc is ignored in this case for this phase
314 pp2_work(refs_list, is_alive, keep_alive);
315 } else {
316 assert(complete_gc != NULL, "Error");
317 pp2_work_concurrent_discovery(refs_list, is_alive,
318 keep_alive, complete_gc);
319 }
320 }
321 // Work methods in support of process_phase2
322 void pp2_work(DiscoveredList& refs_list,
323 BoolObjectClosure* is_alive,
324 OopClosure* keep_alive);
325 void pp2_work_concurrent_discovery(
326 DiscoveredList& refs_list,
327 BoolObjectClosure* is_alive,
328 OopClosure* keep_alive,
329 VoidClosure* complete_gc);
330 // Phase3: process the referents by either clearing them
331 // or keeping them alive (and their closure)
332 void process_phase3(DiscoveredList& refs_list,
333 bool clear_referent,
334 BoolObjectClosure* is_alive,
335 OopClosure* keep_alive,
336 VoidClosure* complete_gc);
337
338 // Enqueue references with a certain reachability level
339 void enqueue_discovered_reflist(DiscoveredList& refs_list, HeapWord* pending_list_addr);
340
341 // "Preclean" all the discovered reference lists
342 // by removing references with strongly reachable referents.
343 // The first argument is a predicate on an oop that indicates
344 // its (strong) reachability and the second is a closure that
345 // may be used to incrementalize or abort the precleaning process.
346 // The caller is responsible for taking care of potential
347 // interference with concurrent operations on these lists
348 // (or predicates involved) by other threads. Currently
349 // only used by the CMS collector.
350 void preclean_discovered_references(BoolObjectClosure* is_alive,
351 OopClosure* keep_alive,
352 VoidClosure* complete_gc,
353 YieldClosure* yield,
354 GCTimer* gc_timer,
355 GCId gc_id);
356
357 // Delete entries in the discovered lists that have
358 // either a null referent or are not active. Such
359 // Reference objects can result from the clearing
360 // or enqueueing of Reference objects concurrent
361 // with their discovery by a (concurrent) collector.
362 // For a definition of "active" see java.lang.ref.Reference;
363 // Refs are born active, become inactive when enqueued,
364 // and never become active again. The state of being
365 // active is encoded as follows: A Ref is active
366 // if and only if its "next" field is NULL.
367 void clean_up_discovered_references();
368 void clean_up_discovered_reflist(DiscoveredList& refs_list);
369
370 // Returns the name of the discovered reference list
371 // occupying the i / _num_q slot.
372 const char* list_name(uint i);
373
374 void enqueue_discovered_reflists(HeapWord* pending_list_addr, AbstractRefProcTaskExecutor* task_executor);
375
376 protected:
377 // "Preclean" the given discovered reference list
378 // by removing references with strongly reachable referents.
379 // Currently used in support of CMS only.
380 void preclean_discovered_reflist(DiscoveredList& refs_list,
381 BoolObjectClosure* is_alive,
382 OopClosure* keep_alive,
383 VoidClosure* complete_gc,
384 YieldClosure* yield);
385
386 // round-robin mod _num_q (not: _not_ mode _max_num_q)
387 uint next_id() {
388 uint id = _next_id;
389 if (++_next_id == _num_q) {
390 _next_id = 0;
391 }
392 return id;
393 }
394 DiscoveredList* get_discovered_list(ReferenceType rt);
395 inline void add_to_discovered_list_mt(DiscoveredList& refs_list, oop obj,
396 HeapWord* discovered_addr);
397 void verify_ok_to_handle_reflists() PRODUCT_RETURN;
398
399 void clear_discovered_references(DiscoveredList& refs_list);
400 void abandon_partial_discovered_list(DiscoveredList& refs_list);
401
402 // Calculate the number of jni handles.
403 unsigned int count_jni_refs();
404
405 // Balances reference queues.
406 void balance_queues(DiscoveredList ref_lists[]);
407
408 // Update (advance) the soft ref master clock field.
409 void update_soft_ref_master_clock();
410
411 public:
412 // Default parameters give you a vanilla reference processor.
413 ReferenceProcessor(MemRegion span,
414 bool mt_processing = false, uint mt_processing_degree = 1,
415 bool mt_discovery = false, uint mt_discovery_degree = 1,
416 bool atomic_discovery = true,
417 BoolObjectClosure* is_alive_non_header = NULL);
418
419 // RefDiscoveryPolicy values
420 enum DiscoveryPolicy {
421 ReferenceBasedDiscovery = 0,
422 ReferentBasedDiscovery = 1,
423 DiscoveryPolicyMin = ReferenceBasedDiscovery,
424 DiscoveryPolicyMax = ReferentBasedDiscovery
425 };
426
427 static void init_statics();
428
429 public:
430 // get and set "is_alive_non_header" field
431 BoolObjectClosure* is_alive_non_header() {
432 return _is_alive_non_header;
433 }
434 void set_is_alive_non_header(BoolObjectClosure* is_alive_non_header) {
435 _is_alive_non_header = is_alive_non_header;
436 }
437
438 // get and set span
439 MemRegion span() { return _span; }
440 void set_span(MemRegion span) { _span = span; }
441
442 // start and stop weak ref discovery
443 void enable_discovery(bool verify_disabled, bool check_no_refs);
444 void disable_discovery() { _discovering_refs = false; }
445 bool discovery_enabled() { return _discovering_refs; }
446
447 // whether discovery is atomic wrt other collectors
448 bool discovery_is_atomic() const { return _discovery_is_atomic; }
449 void set_atomic_discovery(bool atomic) { _discovery_is_atomic = atomic; }
450
451 // whether the JDK in which we are embedded is a pre-4965777 JDK,
452 // and thus whether or not it uses the discovered field to chain
453 // the entries in the pending list.
454 static bool pending_list_uses_discovered_field() {
455 return _pending_list_uses_discovered_field;
456 }
457
458 // whether discovery is done by multiple threads same-old-timeously
459 bool discovery_is_mt() const { return _discovery_is_mt; }
460 void set_mt_discovery(bool mt) { _discovery_is_mt = mt; }
461
462 // Whether we are in a phase when _processing_ is MT.
463 bool processing_is_mt() const { return _processing_is_mt; }
464 void set_mt_processing(bool mt) { _processing_is_mt = mt; }
465
466 // whether all enqueuing of weak references is complete
467 bool enqueuing_is_done() { return _enqueuing_is_done; }
468 void set_enqueuing_is_done(bool v) { _enqueuing_is_done = v; }
469
470 // iterate over oops
471 void weak_oops_do(OopClosure* f); // weak roots
472
473 // Balance each of the discovered lists.
474 void balance_all_queues();
475 void verify_list(DiscoveredList& ref_list);
476
477 // Discover a Reference object, using appropriate discovery criteria
478 bool discover_reference(oop obj, ReferenceType rt);
479
480 // Process references found during GC (called by the garbage collector)
481 ReferenceProcessorStats
482 process_discovered_references(BoolObjectClosure* is_alive,
483 OopClosure* keep_alive,
484 VoidClosure* complete_gc,
485 AbstractRefProcTaskExecutor* task_executor,
486 GCTimer *gc_timer,
487 GCId gc_id);
488
489 // Enqueue references at end of GC (called by the garbage collector)
490 bool enqueue_discovered_references(AbstractRefProcTaskExecutor* task_executor = NULL);
491
492 // If a discovery is in process that is being superceded, abandon it: all
493 // the discovered lists will be empty, and all the objects on them will
494 // have NULL discovered fields. Must be called only at a safepoint.
495 void abandon_partial_discovery();
496
497 // debugging
498 void verify_no_references_recorded() PRODUCT_RETURN;
499 void verify_referent(oop obj) PRODUCT_RETURN;
500
501 // clear the discovered lists (unlinking each entry).
502 void clear_discovered_references() PRODUCT_RETURN;
503 };
504
505 // A utility class to disable reference discovery in
506 // the scope which contains it, for given ReferenceProcessor.
507 class NoRefDiscovery: StackObj {
508 private:
509 ReferenceProcessor* _rp;
510 bool _was_discovering_refs;
511 public:
512 NoRefDiscovery(ReferenceProcessor* rp) : _rp(rp) {
513 _was_discovering_refs = _rp->discovery_enabled();
514 if (_was_discovering_refs) {
515 _rp->disable_discovery();
516 }
517 }
518
519 ~NoRefDiscovery() {
520 if (_was_discovering_refs) {
521 _rp->enable_discovery(true /*verify_disabled*/, false /*check_no_refs*/);
522 }
523 }
524 };
525
526
527 // A utility class to temporarily mutate the span of the
528 // given ReferenceProcessor in the scope that contains it.
529 class ReferenceProcessorSpanMutator: StackObj {
530 private:
531 ReferenceProcessor* _rp;
532 MemRegion _saved_span;
533
534 public:
535 ReferenceProcessorSpanMutator(ReferenceProcessor* rp,
536 MemRegion span):
537 _rp(rp) {
538 _saved_span = _rp->span();
539 _rp->set_span(span);
540 }
541
542 ~ReferenceProcessorSpanMutator() {
543 _rp->set_span(_saved_span);
544 }
545 };
546
547 // A utility class to temporarily change the MT'ness of
548 // reference discovery for the given ReferenceProcessor
549 // in the scope that contains it.
550 class ReferenceProcessorMTDiscoveryMutator: StackObj {
551 private:
552 ReferenceProcessor* _rp;
553 bool _saved_mt;
554
555 public:
556 ReferenceProcessorMTDiscoveryMutator(ReferenceProcessor* rp,
557 bool mt):
558 _rp(rp) {
559 _saved_mt = _rp->discovery_is_mt();
560 _rp->set_mt_discovery(mt);
561 }
562
563 ~ReferenceProcessorMTDiscoveryMutator() {
564 _rp->set_mt_discovery(_saved_mt);
565 }
566 };
567
568
569 // A utility class to temporarily change the disposition
570 // of the "is_alive_non_header" closure field of the
571 // given ReferenceProcessor in the scope that contains it.
572 class ReferenceProcessorIsAliveMutator: StackObj {
573 private:
574 ReferenceProcessor* _rp;
575 BoolObjectClosure* _saved_cl;
576
577 public:
578 ReferenceProcessorIsAliveMutator(ReferenceProcessor* rp,
579 BoolObjectClosure* cl):
580 _rp(rp) {
581 _saved_cl = _rp->is_alive_non_header();
582 _rp->set_is_alive_non_header(cl);
583 }
584
585 ~ReferenceProcessorIsAliveMutator() {
586 _rp->set_is_alive_non_header(_saved_cl);
587 }
588 };
589
590 // A utility class to temporarily change the disposition
591 // of the "discovery_is_atomic" field of the
592 // given ReferenceProcessor in the scope that contains it.
593 class ReferenceProcessorAtomicMutator: StackObj {
594 private:
595 ReferenceProcessor* _rp;
596 bool _saved_atomic_discovery;
597
598 public:
599 ReferenceProcessorAtomicMutator(ReferenceProcessor* rp,
600 bool atomic):
601 _rp(rp) {
602 _saved_atomic_discovery = _rp->discovery_is_atomic();
603 _rp->set_atomic_discovery(atomic);
604 }
605
606 ~ReferenceProcessorAtomicMutator() {
607 _rp->set_atomic_discovery(_saved_atomic_discovery);
608 }
609 };
610
611
612 // A utility class to temporarily change the MT processing
613 // disposition of the given ReferenceProcessor instance
614 // in the scope that contains it.
615 class ReferenceProcessorMTProcMutator: StackObj {
616 private:
617 ReferenceProcessor* _rp;
618 bool _saved_mt;
619
620 public:
621 ReferenceProcessorMTProcMutator(ReferenceProcessor* rp,
622 bool mt):
623 _rp(rp) {
624 _saved_mt = _rp->processing_is_mt();
625 _rp->set_mt_processing(mt);
626 }
627
628 ~ReferenceProcessorMTProcMutator() {
629 _rp->set_mt_processing(_saved_mt);
630 }
631 };
632
633
634 // This class is an interface used to implement task execution for the
635 // reference processing.
636 class AbstractRefProcTaskExecutor {
637 public:
638
639 // Abstract tasks to execute.
640 class ProcessTask;
641 class EnqueueTask;
642
643 // Executes a task using worker threads.
644 virtual void execute(ProcessTask& task) = 0;
645 virtual void execute(EnqueueTask& task) = 0;
646
647 // Switch to single threaded mode.
648 virtual void set_single_threaded_mode() { };
649 };
650
651 // Abstract reference processing task to execute.
652 class AbstractRefProcTaskExecutor::ProcessTask {
653 protected:
654 ProcessTask(ReferenceProcessor& ref_processor,
655 DiscoveredList refs_lists[],
656 bool marks_oops_alive)
657 : _ref_processor(ref_processor),
658 _refs_lists(refs_lists),
659 _marks_oops_alive(marks_oops_alive)
660 { }
661
662 public:
663 virtual void work(unsigned int work_id, BoolObjectClosure& is_alive,
664 OopClosure& keep_alive,
665 VoidClosure& complete_gc) = 0;
666
667 // Returns true if a task marks some oops as alive.
668 bool marks_oops_alive() const
669 { return _marks_oops_alive; }
670
671 bool is_empty() const {
672 return _ref_processor.total_count(_refs_lists) == 0;
673 }
674
675 protected:
676 ReferenceProcessor& _ref_processor;
677 DiscoveredList* _refs_lists;
678 const bool _marks_oops_alive;
679 };
680
681 // Abstract reference processing task to execute.
682 class AbstractRefProcTaskExecutor::EnqueueTask {
683 protected:
684 EnqueueTask(ReferenceProcessor& ref_processor,
685 DiscoveredList refs_lists[],
686 HeapWord* pending_list_addr,
687 int n_queues)
688 : _ref_processor(ref_processor),
689 _refs_lists(refs_lists),
690 _pending_list_addr(pending_list_addr),
691 _n_queues(n_queues)
692 { }
693
694 public:
695 virtual void work(unsigned int work_id) = 0;
696
697 protected:
698 ReferenceProcessor& _ref_processor;
699 DiscoveredList* _refs_lists;
700 HeapWord* _pending_list_addr;
701 int _n_queues;
702 };
703
704 #endif // SHARE_VM_MEMORY_REFERENCEPROCESSOR_HPP