src/share/vm/gc_interface/collectedHeap.inline.hpp

Sun, 13 Apr 2008 17:43:42 -0400

author
coleenp
date
Sun, 13 Apr 2008 17:43:42 -0400
changeset 548
ba764ed4b6f2
parent 435
a61af66fc99e
child 602
feeb96a45707
child 777
37f87013dfd8
permissions
-rw-r--r--

6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
Summary: Compressed oops in instances, arrays, and headers. Code contributors are coleenp, phh, never, swamyv
Reviewed-by: jmasa, kamg, acorn, tbell, kvn, rasbold

     1 /*
     2  * Copyright 2001-2007 Sun Microsystems, Inc.  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  *
     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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 // Inline allocation implementations.
    27 void CollectedHeap::post_allocation_setup_common(KlassHandle klass,
    28                                                  HeapWord* obj,
    29                                                  size_t size) {
    30   post_allocation_setup_no_klass_install(klass, obj, size);
    31   post_allocation_install_obj_klass(klass, oop(obj), (int) size);
    32 }
    34 void CollectedHeap::post_allocation_setup_no_klass_install(KlassHandle klass,
    35                                                            HeapWord* objPtr,
    36                                                            size_t size) {
    38   oop obj = (oop)objPtr;
    40   assert(obj != NULL, "NULL object pointer");
    41   if (UseBiasedLocking && (klass() != NULL)) {
    42     obj->set_mark(klass->prototype_header());
    43   } else {
    44     // May be bootstrapping
    45     obj->set_mark(markOopDesc::prototype());
    46   }
    48   // support low memory notifications (no-op if not enabled)
    49   LowMemoryDetector::detect_low_memory_for_collected_pools();
    50 }
    52 void CollectedHeap::post_allocation_install_obj_klass(KlassHandle klass,
    53                                                    oop obj,
    54                                                    int size) {
    55   // These asserts are kind of complicated because of klassKlass
    56   // and the beginning of the world.
    57   assert(klass() != NULL || !Universe::is_fully_initialized(), "NULL klass");
    58   assert(klass() == NULL || klass()->is_klass(), "not a klass");
    59   assert(klass() == NULL || klass()->klass_part() != NULL, "not a klass");
    60   assert(obj != NULL, "NULL object pointer");
    61   obj->set_klass(klass());
    62   assert(!Universe::is_fully_initialized() || obj->blueprint() != NULL,
    63          "missing blueprint");
    64 }
    66 // Support for jvmti and dtrace
    67 inline void post_allocation_notify(KlassHandle klass, oop obj) {
    68   // support for JVMTI VMObjectAlloc event (no-op if not enabled)
    69   JvmtiExport::vm_object_alloc_event_collector(obj);
    71   if (DTraceAllocProbes) {
    72     // support for Dtrace object alloc event (no-op most of the time)
    73     if (klass() != NULL && klass()->klass_part()->name() != NULL) {
    74       SharedRuntime::dtrace_object_alloc(obj);
    75     }
    76   }
    77 }
    79 void CollectedHeap::post_allocation_setup_obj(KlassHandle klass,
    80                                               HeapWord* obj,
    81                                               size_t size) {
    82   post_allocation_setup_common(klass, obj, size);
    83   assert(Universe::is_bootstrapping() ||
    84          !((oop)obj)->blueprint()->oop_is_array(), "must not be an array");
    85   // notify jvmti and dtrace
    86   post_allocation_notify(klass, (oop)obj);
    87 }
    89 void CollectedHeap::post_allocation_setup_array(KlassHandle klass,
    90                                                 HeapWord* obj,
    91                                                 size_t size,
    92                                                 int length) {
    93   assert(length >= 0, "length should be non-negative");
    94   post_allocation_setup_common(klass, obj, size);
    95   // Must set length after installing klass as set_klass zeros the length
    96   // field in UseCompressedOops
    97   ((arrayOop)obj)->set_length(length);
    98   assert(((oop)obj)->blueprint()->oop_is_array(), "must be an array");
    99   // notify jvmti and dtrace (must be after length is set for dtrace)
   100   post_allocation_notify(klass, (oop)obj);
   101 }
   103 HeapWord* CollectedHeap::common_mem_allocate_noinit(size_t size, bool is_noref, TRAPS) {
   105   // Clear unhandled oops for memory allocation.  Memory allocation might
   106   // not take out a lock if from tlab, so clear here.
   107   CHECK_UNHANDLED_OOPS_ONLY(THREAD->clear_unhandled_oops();)
   109   if (HAS_PENDING_EXCEPTION) {
   110     NOT_PRODUCT(guarantee(false, "Should not allocate with exception pending"));
   111     return NULL;  // caller does a CHECK_0 too
   112   }
   114   // We may want to update this, is_noref objects might not be allocated in TLABs.
   115   HeapWord* result = NULL;
   116   if (UseTLAB) {
   117     result = CollectedHeap::allocate_from_tlab(THREAD, size);
   118     if (result != NULL) {
   119       assert(!HAS_PENDING_EXCEPTION,
   120              "Unexpected exception, will result in uninitialized storage");
   121       return result;
   122     }
   123   }
   124   bool gc_overhead_limit_was_exceeded;
   125   result = Universe::heap()->mem_allocate(size,
   126                                           is_noref,
   127                                           false,
   128                                           &gc_overhead_limit_was_exceeded);
   129   if (result != NULL) {
   130     NOT_PRODUCT(Universe::heap()->
   131       check_for_non_bad_heap_word_value(result, size));
   132     assert(!HAS_PENDING_EXCEPTION,
   133            "Unexpected exception, will result in uninitialized storage");
   134     return result;
   135   }
   138   if (!gc_overhead_limit_was_exceeded) {
   139     // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
   140     report_java_out_of_memory("Java heap space");
   142     if (JvmtiExport::should_post_resource_exhausted()) {
   143       JvmtiExport::post_resource_exhausted(
   144         JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR | JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP,
   145         "Java heap space");
   146     }
   148     THROW_OOP_0(Universe::out_of_memory_error_java_heap());
   149   } else {
   150     // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
   151     report_java_out_of_memory("GC overhead limit exceeded");
   153     if (JvmtiExport::should_post_resource_exhausted()) {
   154       JvmtiExport::post_resource_exhausted(
   155         JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR | JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP,
   156         "GC overhead limit exceeded");
   157     }
   159     THROW_OOP_0(Universe::out_of_memory_error_gc_overhead_limit());
   160   }
   161 }
   163 HeapWord* CollectedHeap::common_mem_allocate_init(size_t size, bool is_noref, TRAPS) {
   164   HeapWord* obj = common_mem_allocate_noinit(size, is_noref, CHECK_NULL);
   165   init_obj(obj, size);
   166   return obj;
   167 }
   169 // Need to investigate, do we really want to throw OOM exception here?
   170 HeapWord* CollectedHeap::common_permanent_mem_allocate_noinit(size_t size, TRAPS) {
   171   if (HAS_PENDING_EXCEPTION) {
   172     NOT_PRODUCT(guarantee(false, "Should not allocate with exception pending"));
   173     return NULL;  // caller does a CHECK_NULL too
   174   }
   176 #ifdef ASSERT
   177   if (CIFireOOMAt > 0 && THREAD->is_Compiler_thread() &&
   178       ++_fire_out_of_memory_count >= CIFireOOMAt) {
   179     // For testing of OOM handling in the CI throw an OOM and see how
   180     // it does.  Historically improper handling of these has resulted
   181     // in crashes which we really don't want to have in the CI.
   182     THROW_OOP_0(Universe::out_of_memory_error_perm_gen());
   183   }
   184 #endif
   186   HeapWord* result = Universe::heap()->permanent_mem_allocate(size);
   187   if (result != NULL) {
   188     NOT_PRODUCT(Universe::heap()->
   189       check_for_non_bad_heap_word_value(result, size));
   190     assert(!HAS_PENDING_EXCEPTION,
   191            "Unexpected exception, will result in uninitialized storage");
   192     return result;
   193   }
   194   // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
   195   report_java_out_of_memory("PermGen space");
   197   if (JvmtiExport::should_post_resource_exhausted()) {
   198     JvmtiExport::post_resource_exhausted(
   199         JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR,
   200         "PermGen space");
   201   }
   203   THROW_OOP_0(Universe::out_of_memory_error_perm_gen());
   204 }
   206 HeapWord* CollectedHeap::common_permanent_mem_allocate_init(size_t size, TRAPS) {
   207   HeapWord* obj = common_permanent_mem_allocate_noinit(size, CHECK_NULL);
   208   init_obj(obj, size);
   209   return obj;
   210 }
   212 HeapWord* CollectedHeap::allocate_from_tlab(Thread* thread, size_t size) {
   213   assert(UseTLAB, "should use UseTLAB");
   215   HeapWord* obj = thread->tlab().allocate(size);
   216   if (obj != NULL) {
   217     return obj;
   218   }
   219   // Otherwise...
   220   return allocate_from_tlab_slow(thread, size);
   221 }
   223 void CollectedHeap::init_obj(HeapWord* obj, size_t size) {
   224   assert(obj != NULL, "cannot initialize NULL object");
   225   const size_t hs = oopDesc::header_size();
   226   assert(size >= hs, "unexpected object size");
   227   Copy::fill_to_aligned_words(obj + hs, size - hs);
   228 }
   230 oop CollectedHeap::obj_allocate(KlassHandle klass, int size, TRAPS) {
   231   debug_only(check_for_valid_allocation_state());
   232   assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
   233   assert(size >= 0, "int won't convert to size_t");
   234   HeapWord* obj = common_mem_allocate_init(size, false, CHECK_NULL);
   235   post_allocation_setup_obj(klass, obj, size);
   236   NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
   237   return (oop)obj;
   238 }
   240 oop CollectedHeap::array_allocate(KlassHandle klass,
   241                                   int size,
   242                                   int length,
   243                                   TRAPS) {
   244   debug_only(check_for_valid_allocation_state());
   245   assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
   246   assert(size >= 0, "int won't convert to size_t");
   247   HeapWord* obj = common_mem_allocate_init(size, false, CHECK_NULL);
   248   post_allocation_setup_array(klass, obj, size, length);
   249   NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
   250   return (oop)obj;
   251 }
   253 oop CollectedHeap::large_typearray_allocate(KlassHandle klass,
   254                                             int size,
   255                                             int length,
   256                                             TRAPS) {
   257   debug_only(check_for_valid_allocation_state());
   258   assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
   259   assert(size >= 0, "int won't convert to size_t");
   260   HeapWord* obj = common_mem_allocate_init(size, true, CHECK_NULL);
   261   post_allocation_setup_array(klass, obj, size, length);
   262   NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
   263   return (oop)obj;
   264 }
   266 oop CollectedHeap::permanent_obj_allocate(KlassHandle klass, int size, TRAPS) {
   267   oop obj = permanent_obj_allocate_no_klass_install(klass, size, CHECK_NULL);
   268   post_allocation_install_obj_klass(klass, obj, size);
   269   NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value((HeapWord*) obj,
   270                                                               size));
   271   return obj;
   272 }
   274 oop CollectedHeap::permanent_obj_allocate_no_klass_install(KlassHandle klass,
   275                                                            int size,
   276                                                            TRAPS) {
   277   debug_only(check_for_valid_allocation_state());
   278   assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
   279   assert(size >= 0, "int won't convert to size_t");
   280   HeapWord* obj = common_permanent_mem_allocate_init(size, CHECK_NULL);
   281   post_allocation_setup_no_klass_install(klass, obj, size);
   282   NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
   283   return (oop)obj;
   284 }
   286 oop CollectedHeap::permanent_array_allocate(KlassHandle klass,
   287                                             int size,
   288                                             int length,
   289                                             TRAPS) {
   290   debug_only(check_for_valid_allocation_state());
   291   assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
   292   assert(size >= 0, "int won't convert to size_t");
   293   HeapWord* obj = common_permanent_mem_allocate_init(size, CHECK_NULL);
   294   post_allocation_setup_array(klass, obj, size, length);
   295   NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
   296   return (oop)obj;
   297 }
   299 // Returns "TRUE" if "p" is a method oop in the
   300 // current heap with high probability. NOTE: The main
   301 // current consumers of this interface are Forte::
   302 // and ThreadProfiler::. In these cases, the
   303 // interpreter frame from which "p" came, may be
   304 // under construction when sampled asynchronously, so
   305 // the clients want to check that it represents a
   306 // valid method before using it. Nonetheless since
   307 // the clients do not typically lock out GC, the
   308 // predicate is_valid_method() is not stable, so
   309 // it is possible that by the time "p" is used, it
   310 // is no longer valid.
   311 inline bool CollectedHeap::is_valid_method(oop p) const {
   312   return
   313     p != NULL &&
   315     // Check whether it is aligned at a HeapWord boundary.
   316     Space::is_aligned(p) &&
   318     // Check whether "method" is in the allocated part of the
   319     // permanent generation -- this needs to be checked before
   320     // p->klass() below to avoid a SEGV (but see below
   321     // for a potential window of vulnerability).
   322     is_permanent((void*)p) &&
   324     // See if GC is active; however, there is still an
   325     // apparently unavoidable window after this call
   326     // and before the client of this interface uses "p".
   327     // If the client chooses not to lock out GC, then
   328     // it's a risk the client must accept.
   329     !is_gc_active() &&
   331     // Check that p is a methodOop.
   332     p->klass() == Universe::methodKlassObj();
   333 }
   336 #ifndef PRODUCT
   338 inline bool
   339 CollectedHeap::promotion_should_fail(volatile size_t* count) {
   340   // Access to count is not atomic; the value does not have to be exact.
   341   if (PromotionFailureALot) {
   342     const size_t gc_num = total_collections();
   343     const size_t elapsed_gcs = gc_num - _promotion_failure_alot_gc_number;
   344     if (elapsed_gcs >= PromotionFailureALotInterval) {
   345       // Test for unsigned arithmetic wrap-around.
   346       if (++*count >= PromotionFailureALotCount) {
   347         *count = 0;
   348         return true;
   349       }
   350     }
   351   }
   352   return false;
   353 }
   355 inline bool CollectedHeap::promotion_should_fail() {
   356   return promotion_should_fail(&_promotion_failure_alot_count);
   357 }
   359 inline void CollectedHeap::reset_promotion_should_fail(volatile size_t* count) {
   360   if (PromotionFailureALot) {
   361     _promotion_failure_alot_gc_number = total_collections();
   362     *count = 0;
   363   }
   364 }
   366 inline void CollectedHeap::reset_promotion_should_fail() {
   367   reset_promotion_should_fail(&_promotion_failure_alot_count);
   368 }
   369 #endif  // #ifndef PRODUCT

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