1 /*
   2  * Copyright (c) 2001, 2012, 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  *
   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
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_GC_INTERFACE_COLLECTEDHEAP_INLINE_HPP
  26 #define SHARE_VM_GC_INTERFACE_COLLECTEDHEAP_INLINE_HPP
  27 
  28 #include "gc_interface/collectedHeap.hpp"
  29 #include "memory/threadLocalAllocBuffer.inline.hpp"
  30 #include "memory/universe.hpp"
  31 #include "oops/arrayOop.hpp"
  32 #include "prims/jvmtiExport.hpp"
  33 #include "runtime/sharedRuntime.hpp"
  34 #include "runtime/thread.inline.hpp"
  35 #include "services/lowMemoryDetector.hpp"
  36 #include "utilities/copy.hpp"
  37 
  38 // Inline allocation implementations.
  39 
  40 void CollectedHeap::post_allocation_setup_common(KlassHandle klass,
  41                                                  HeapWord* obj) {
  42   post_allocation_setup_no_klass_install(klass, obj);
  43   post_allocation_install_obj_klass(klass, oop(obj));
  44 }
  45 
  46 void CollectedHeap::post_allocation_setup_no_klass_install(KlassHandle klass,
  47                                                            HeapWord* objPtr) {
  48   oop obj = (oop)objPtr;
  49 
  50   assert(obj != NULL, "NULL object pointer");
  51   if (UseBiasedLocking && (klass() != NULL)) {
  52     obj->set_mark(klass->prototype_header());
  53   } else {
  54     // May be bootstrapping
  55     obj->set_mark(markOopDesc::prototype());
  56   }
  57 }
  58 
  59 void CollectedHeap::post_allocation_install_obj_klass(KlassHandle klass,
  60                                                    oop obj) {
  61   // These asserts are kind of complicated because of klassKlass
  62   // and the beginning of the world.
  63   assert(klass() != NULL || !Universe::is_fully_initialized(), "NULL klass");
  64   assert(klass() == NULL || klass()->is_klass(), "not a klass");
  65   assert(obj != NULL, "NULL object pointer");
  66   obj->set_klass(klass());
  67   assert(!Universe::is_fully_initialized() || obj->klass() != NULL,
  68          "missing klass");
  69 }
  70 
  71 // Support for jvmti and dtrace
  72 inline void post_allocation_notify(KlassHandle klass, oop obj) {
  73   // support low memory notifications (no-op if not enabled)
  74   LowMemoryDetector::detect_low_memory_for_collected_pools();
  75 
  76   // support for JVMTI VMObjectAlloc event (no-op if not enabled)
  77   JvmtiExport::vm_object_alloc_event_collector(obj);
  78 
  79   if (DTraceAllocProbes) {
  80     // support for Dtrace object alloc event (no-op most of the time)
  81     if (klass() != NULL && klass()->name() != NULL) {
  82       SharedRuntime::dtrace_object_alloc(obj);
  83     }
  84   }
  85 }
  86 
  87 void CollectedHeap::post_allocation_setup_obj(KlassHandle klass,
  88                                               HeapWord* obj) {
  89   post_allocation_setup_common(klass, obj);
  90   assert(Universe::is_bootstrapping() ||
  91          !((oop)obj)->is_array(), "must not be an array");
  92   // notify jvmti and dtrace
  93   post_allocation_notify(klass, (oop)obj);
  94 }
  95 
  96 void CollectedHeap::post_allocation_setup_array(KlassHandle klass,
  97                                                 HeapWord* obj,
  98                                                 int length) {
  99   // Set array length before setting the _klass field
 100   // in post_allocation_setup_common() because the klass field
 101   // indicates that the object is parsable by concurrent GC.
 102   assert(length >= 0, "length should be non-negative");
 103   ((arrayOop)obj)->set_length(length);
 104   post_allocation_setup_common(klass, obj);
 105   assert(((oop)obj)->is_array(), "must be an array");
 106   // notify jvmti and dtrace (must be after length is set for dtrace)
 107   post_allocation_notify(klass, (oop)obj);
 108 }
 109 
 110 HeapWord* CollectedHeap::common_mem_allocate_noinit(size_t size, TRAPS) {
 111 
 112   // Clear unhandled oops for memory allocation.  Memory allocation might
 113   // not take out a lock if from tlab, so clear here.
 114   CHECK_UNHANDLED_OOPS_ONLY(THREAD->clear_unhandled_oops();)
 115 
 116   if (HAS_PENDING_EXCEPTION) {
 117     NOT_PRODUCT(guarantee(false, "Should not allocate with exception pending"));
 118     return NULL;  // caller does a CHECK_0 too
 119   }
 120 
 121   HeapWord* result = NULL;
 122   if (UseTLAB) {
 123     result = CollectedHeap::allocate_from_tlab(THREAD, size);
 124     if (result != NULL) {
 125       assert(!HAS_PENDING_EXCEPTION,
 126              "Unexpected exception, will result in uninitialized storage");
 127       return result;
 128     }
 129   }
 130   bool gc_overhead_limit_was_exceeded = false;
 131   result = Universe::heap()->mem_allocate(size,
 132                                           &gc_overhead_limit_was_exceeded);
 133   if (result != NULL) {
 134     NOT_PRODUCT(Universe::heap()->
 135       check_for_non_bad_heap_word_value(result, size));
 136     assert(!HAS_PENDING_EXCEPTION,
 137            "Unexpected exception, will result in uninitialized storage");
 138     THREAD->incr_allocated_bytes(size * HeapWordSize);
 139     return result;
 140   }
 141 
 142 
 143   if (!gc_overhead_limit_was_exceeded) {
 144     // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
 145     report_java_out_of_memory("Java heap space");
 146 
 147     if (JvmtiExport::should_post_resource_exhausted()) {
 148       JvmtiExport::post_resource_exhausted(
 149         JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR | JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP,
 150         "Java heap space");
 151     }
 152 
 153     THROW_OOP_0(Universe::out_of_memory_error_java_heap());
 154   } else {
 155     // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
 156     report_java_out_of_memory("GC overhead limit exceeded");
 157 
 158     if (JvmtiExport::should_post_resource_exhausted()) {
 159       JvmtiExport::post_resource_exhausted(
 160         JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR | JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP,
 161         "GC overhead limit exceeded");
 162     }
 163 
 164     THROW_OOP_0(Universe::out_of_memory_error_gc_overhead_limit());
 165   }
 166 }
 167 
 168 HeapWord* CollectedHeap::common_mem_allocate_init(size_t size, TRAPS) {
 169   HeapWord* obj = common_mem_allocate_noinit(size, CHECK_NULL);
 170   init_obj(obj, size);
 171   return obj;
 172 }
 173 
 174 HeapWord* CollectedHeap::allocate_from_tlab(Thread* thread, size_t size) {
 175   assert(UseTLAB, "should use UseTLAB");
 176 
 177   HeapWord* obj = thread->tlab().allocate(size);
 178   if (obj != NULL) {
 179     return obj;
 180   }
 181   // Otherwise...
 182   return allocate_from_tlab_slow(thread, size);
 183 }
 184 
 185 void CollectedHeap::init_obj(HeapWord* obj, size_t size) {
 186   assert(obj != NULL, "cannot initialize NULL object");
 187   const size_t hs = oopDesc::header_size();
 188   assert(size >= hs, "unexpected object size");
 189   ((oop)obj)->set_klass_gap(0);
 190   Copy::fill_to_aligned_words(obj + hs, size - hs);
 191 }
 192 
 193 oop CollectedHeap::obj_allocate(KlassHandle klass, int size, TRAPS) {
 194   debug_only(check_for_valid_allocation_state());
 195   assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
 196   assert(size >= 0, "int won't convert to size_t");
 197   HeapWord* obj = common_mem_allocate_init(size, CHECK_NULL);
 198   post_allocation_setup_obj(klass, obj);
 199   NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
 200   return (oop)obj;
 201 }
 202 
 203 oop CollectedHeap::array_allocate(KlassHandle klass,
 204                                   int size,
 205                                   int length,
 206                                   TRAPS) {
 207   debug_only(check_for_valid_allocation_state());
 208   assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
 209   assert(size >= 0, "int won't convert to size_t");
 210   HeapWord* obj = common_mem_allocate_init(size, CHECK_NULL);
 211   post_allocation_setup_array(klass, obj, length);
 212   NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
 213   return (oop)obj;
 214 }
 215 
 216 oop CollectedHeap::array_allocate_nozero(KlassHandle klass,
 217                                          int size,
 218                                          int length,
 219                                          TRAPS) {
 220   debug_only(check_for_valid_allocation_state());
 221   assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
 222   assert(size >= 0, "int won't convert to size_t");
 223   HeapWord* obj = common_mem_allocate_noinit(size, CHECK_NULL);
 224   ((oop)obj)->set_klass_gap(0);
 225   post_allocation_setup_array(klass, obj, length);
 226 #ifndef PRODUCT
 227   const size_t hs = oopDesc::header_size()+1;
 228   Universe::heap()->check_for_non_bad_heap_word_value(obj+hs, size-hs);
 229 #endif
 230   return (oop)obj;
 231 }
 232 
 233 inline void CollectedHeap::oop_iterate_no_header(OopClosure* cl) {
 234   NoHeaderExtendedOopClosure no_header_cl(cl);
 235   oop_iterate(&no_header_cl);
 236 }
 237 
 238 #ifndef PRODUCT
 239 
 240 inline bool
 241 CollectedHeap::promotion_should_fail(volatile size_t* count) {
 242   // Access to count is not atomic; the value does not have to be exact.
 243   if (PromotionFailureALot) {
 244     const size_t gc_num = total_collections();
 245     const size_t elapsed_gcs = gc_num - _promotion_failure_alot_gc_number;
 246     if (elapsed_gcs >= PromotionFailureALotInterval) {
 247       // Test for unsigned arithmetic wrap-around.
 248       if (++*count >= PromotionFailureALotCount) {
 249         *count = 0;
 250         return true;
 251       }
 252     }
 253   }
 254   return false;
 255 }
 256 
 257 inline bool CollectedHeap::promotion_should_fail() {
 258   return promotion_should_fail(&_promotion_failure_alot_count);
 259 }
 260 
 261 inline void CollectedHeap::reset_promotion_should_fail(volatile size_t* count) {
 262   if (PromotionFailureALot) {
 263     _promotion_failure_alot_gc_number = total_collections();
 264     *count = 0;
 265   }
 266 }
 267 
 268 inline void CollectedHeap::reset_promotion_should_fail() {
 269   reset_promotion_should_fail(&_promotion_failure_alot_count);
 270 }
 271 #endif  // #ifndef PRODUCT
 272 
 273 #endif // SHARE_VM_GC_INTERFACE_COLLECTEDHEAP_INLINE_HPP