src/share/vm/gc_implementation/parallelScavenge/psPromotionManager.inline.hpp

Tue, 20 Jun 2017 14:59:09 +0800

author
fujie
date
Tue, 20 Jun 2017 14:59:09 +0800
changeset 414
c5f826fdfc22
parent 413
6deac53aa96b
child 6876
710a3c8b516e
permissions
-rw-r--r--

Rewrite low level concurrency primitives for MIPS.

     1 /*
     2  * Copyright (c) 2002, 2014, 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.
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     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    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).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
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    23  */
    25 #ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPROMOTIONMANAGER_INLINE_HPP
    26 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPROMOTIONMANAGER_INLINE_HPP
    28 #include "gc_implementation/parallelScavenge/psOldGen.hpp"
    29 #include "gc_implementation/parallelScavenge/psPromotionManager.hpp"
    30 #include "gc_implementation/parallelScavenge/psScavenge.hpp"
    31 #include "oops/oop.psgc.inline.hpp"
    33 inline PSPromotionManager* PSPromotionManager::manager_array(int index) {
    34   assert(_manager_array != NULL, "access of NULL manager_array");
    35   assert(index >= 0 && index <= (int)ParallelGCThreads, "out of range manager_array access");
    36   return &_manager_array[index];
    37 }
    39 template <class T>
    40 inline void PSPromotionManager::claim_or_forward_internal_depth(T* p) {
    41   if (p != NULL) { // XXX: error if p != NULL here
    42     oop o = oopDesc::load_decode_heap_oop_not_null(p);
    43     if (o->is_forwarded()) {
    44       o = o->forwardee();
    45       // Card mark
    46       if (PSScavenge::is_obj_in_young(o)) {
    47         PSScavenge::card_table()->inline_write_ref_field_gc(p, o);
    48       }
    49       oopDesc::encode_store_heap_oop_not_null(p, o);
    50     } else {
    51       push_depth(p);
    52     }
    53   }
    54 }
    56 template <class T>
    57 inline void PSPromotionManager::claim_or_forward_depth(T* p) {
    58   assert(PSScavenge::should_scavenge(p, true), "revisiting object?");
    59   assert(Universe::heap()->kind() == CollectedHeap::ParallelScavengeHeap,
    60          "Sanity");
    61   assert(Universe::heap()->is_in(p), "pointer outside heap");
    63   claim_or_forward_internal_depth(p);
    64 }
    66 //
    67 // This method is pretty bulky. It would be nice to split it up
    68 // into smaller submethods, but we need to be careful not to hurt
    69 // performance.
    70 //
    71 template<bool promote_immediately>
    72 oop PSPromotionManager::copy_to_survivor_space(oop o) {
    73   assert(PSScavenge::should_scavenge(&o), "Sanity");
    75   oop new_obj = NULL;
    77 #ifdef MIPS64
    78   if (Use3A2000) OrderAccess::fence();
    79 #endif
    81   // NOTE! We must be very careful with any methods that access the mark
    82   // in o. There may be multiple threads racing on it, and it may be forwarded
    83   // at any time. Do not use oop methods for accessing the mark!
    84   markOop test_mark = o->mark();
    86 #ifdef MIPS64
    87   if (Use3A2000) OrderAccess::fence();
    88 #endif
    90   // The same test as "o->is_forwarded()"
    91   if (!test_mark->is_marked()) {
    92     bool new_obj_is_tenured = false;
    93     size_t new_obj_size = o->size();
    95     if (!promote_immediately) {
    96       // Find the objects age, MT safe.
    97       uint age = (test_mark->has_displaced_mark_helper() /* o->has_displaced_mark() */) ?
    98         test_mark->displaced_mark_helper()->age() : test_mark->age();
   100       // Try allocating obj in to-space (unless too old)
   101       if (age < PSScavenge::tenuring_threshold()) {
   102         new_obj = (oop) _young_lab.allocate(new_obj_size);
   103         if (new_obj == NULL && !_young_gen_is_full) {
   104           // Do we allocate directly, or flush and refill?
   105           if (new_obj_size > (YoungPLABSize / 2)) {
   106             // Allocate this object directly
   107             new_obj = (oop)young_space()->cas_allocate(new_obj_size);
   108           } else {
   109             // Flush and fill
   110             _young_lab.flush();
   112             HeapWord* lab_base = young_space()->cas_allocate(YoungPLABSize);
   113             if (lab_base != NULL) {
   114               _young_lab.initialize(MemRegion(lab_base, YoungPLABSize));
   115               // Try the young lab allocation again.
   116               new_obj = (oop) _young_lab.allocate(new_obj_size);
   117             } else {
   118               _young_gen_is_full = true;
   119             }
   120           }
   121         }
   123 #ifdef MIPS64
   124         if (Use3A2000) OrderAccess::fence();
   125 #endif
   126       }
   127     }
   129     // Otherwise try allocating obj tenured
   130     if (new_obj == NULL) {
   131 #ifndef PRODUCT
   132       if (Universe::heap()->promotion_should_fail()) {
   133         return oop_promotion_failed(o, test_mark);
   134       }
   135 #endif  // #ifndef PRODUCT
   137       new_obj = (oop) _old_lab.allocate(new_obj_size);
   138       new_obj_is_tenured = true;
   140       if (new_obj == NULL) {
   141         if (!_old_gen_is_full) {
   142           // Do we allocate directly, or flush and refill?
   143           if (new_obj_size > (OldPLABSize / 2)) {
   144             // Allocate this object directly
   145             new_obj = (oop)old_gen()->cas_allocate(new_obj_size);
   146           } else {
   147             // Flush and fill
   148             _old_lab.flush();
   150             HeapWord* lab_base = old_gen()->cas_allocate(OldPLABSize);
   151             if(lab_base != NULL) {
   152 #ifdef ASSERT
   153               // Delay the initialization of the promotion lab (plab).
   154               // This exposes uninitialized plabs to card table processing.
   155               if (GCWorkerDelayMillis > 0) {
   156                 os::sleep(Thread::current(), GCWorkerDelayMillis, false);
   157               }
   158 #endif
   159               _old_lab.initialize(MemRegion(lab_base, OldPLABSize));
   160               // Try the old lab allocation again.
   161               new_obj = (oop) _old_lab.allocate(new_obj_size);
   162             }
   163           }
   164         }
   166         // This is the promotion failed test, and code handling.
   167         // The code belongs here for two reasons. It is slightly
   168         // different than the code below, and cannot share the
   169         // CAS testing code. Keeping the code here also minimizes
   170         // the impact on the common case fast path code.
   172         if (new_obj == NULL) {
   173           _old_gen_is_full = true;
   174           return oop_promotion_failed(o, test_mark);
   175         }
   176       }
   177     }
   179     assert(new_obj != NULL, "allocation should have succeeded");
   181     // Copy obj
   182     Copy::aligned_disjoint_words((HeapWord*)o, (HeapWord*)new_obj, new_obj_size);
   183 #ifdef MIPS64
   184     if (Use3A2000) OrderAccess::fence();
   185 #endif
   187     // Now we have to CAS in the header.
   188     if (o->cas_forward_to(new_obj, test_mark)) {
   189       // We won any races, we "own" this object.
   190       assert(new_obj == o->forwardee(), "Sanity");
   192       // Increment age if obj still in new generation. Now that
   193       // we're dealing with a markOop that cannot change, it is
   194       // okay to use the non mt safe oop methods.
   195       if (!new_obj_is_tenured) {
   196         new_obj->incr_age();
   197         assert(young_space()->contains(new_obj), "Attempt to push non-promoted obj");
   198       }
   200       // Do the size comparison first with new_obj_size, which we
   201       // already have. Hopefully, only a few objects are larger than
   202       // _min_array_size_for_chunking, and most of them will be arrays.
   203       // So, the is->objArray() test would be very infrequent.
   204       if (new_obj_size > _min_array_size_for_chunking &&
   205           new_obj->is_objArray() &&
   206           PSChunkLargeArrays) {
   207         // we'll chunk it
   208         oop* const masked_o = mask_chunked_array_oop(o);
   209         push_depth(masked_o);
   210         TASKQUEUE_STATS_ONLY(++_arrays_chunked; ++_masked_pushes);
   211       } else {
   212         // we'll just push its contents
   213         new_obj->push_contents(this);
   214       }
   215     }  else {
   216       // We lost, someone else "owns" this object
   217       guarantee(o->is_forwarded(), "Object must be forwarded if the cas failed.");
   219       // Try to deallocate the space.  If it was directly allocated we cannot
   220       // deallocate it, so we have to test.  If the deallocation fails,
   221       // overwrite with a filler object.
   222       if (new_obj_is_tenured) {
   223         if (!_old_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
   224           CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
   225         }
   226       } else if (!_young_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
   227         CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
   228       }
   230       // don't update this before the unallocation!
   231       new_obj = o->forwardee();
   232     }
   234 #ifdef MIPS64
   235     if (Use3A2000) OrderAccess::fence();
   236 #endif
   237   } else {
   238     assert(o->is_forwarded(), "Sanity");
   239     new_obj = o->forwardee();
   240   }
   242 #ifndef PRODUCT
   243   // This code must come after the CAS test, or it will print incorrect
   244   // information.
   245   if (TraceScavenge) {
   246     gclog_or_tty->print_cr("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
   247        PSScavenge::should_scavenge(&new_obj) ? "copying" : "tenuring",
   248        new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), new_obj->size());
   249   }
   250 #endif
   252   return new_obj;
   253 }
   256 inline void PSPromotionManager::process_popped_location_depth(StarTask p) {
   257   if (is_oop_masked(p)) {
   258     assert(PSChunkLargeArrays, "invariant");
   259     oop const old = unmask_chunked_array_oop(p);
   260     process_array_chunk(old);
   261   } else {
   262     if (p.is_narrow()) {
   263       assert(UseCompressedOops, "Error");
   264       PSScavenge::copy_and_push_safe_barrier<narrowOop, /*promote_immediately=*/false>(this, p);
   265     } else {
   266       PSScavenge::copy_and_push_safe_barrier<oop, /*promote_immediately=*/false>(this, p);
   267     }
   268   }
   269 }
   271 #if TASKQUEUE_STATS
   272 void PSPromotionManager::record_steal(StarTask& p) {
   273   if (is_oop_masked(p)) {
   274     ++_masked_steals;
   275   }
   276 }
   277 #endif // TASKQUEUE_STATS
   279 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPROMOTIONMANAGER_INLINE_HPP

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