1 /*
   2  * Copyright (c) 2001, 2017, 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_SHARED_COLLECTEDHEAP_INLINE_HPP
  26 #define SHARE_VM_GC_SHARED_COLLECTEDHEAP_INLINE_HPP
  27 
  28 #include "classfile/javaClasses.hpp"
  29 #include "gc/shared/allocTracer.hpp"
  30 #include "gc/shared/collectedHeap.hpp"
  31 #include "gc/shared/threadLocalAllocBuffer.inline.hpp"
  32 #include "memory/universe.hpp"
  33 #include "oops/arrayOop.hpp"
  34 #include "oops/oop.inline.hpp"
  35 #include "prims/jvmtiExport.hpp"
  36 #include "runtime/sharedRuntime.hpp"
  37 #include "runtime/thread.inline.hpp"
  38 #include "services/lowMemoryDetector.hpp"
  39 #include "utilities/align.hpp"
  40 #include "utilities/copy.hpp"
  41 
  42 // Inline allocation implementations.
  43 
  44 void CollectedHeap::post_allocation_setup_common(Klass* klass,
  45                                                  HeapWord* obj_ptr) {
  46   post_allocation_setup_no_klass_install(klass, obj_ptr);
  47   oop obj = (oop)obj_ptr;
  48 #if ! INCLUDE_ALL_GCS
  49   obj->set_klass(klass);
  50 #else
  51   // Need a release store to ensure array/class length, mark word, and
  52   // object zeroing are visible before setting the klass non-NULL, for
  53   // concurrent collectors.
  54   obj->release_set_klass(klass);
  55 #endif
  56 }
  57 
  58 void CollectedHeap::post_allocation_setup_no_klass_install(Klass* klass,
  59                                                            HeapWord* obj_ptr) {
  60   oop obj = (oop)obj_ptr;
  61 
  62   assert(obj != NULL, "NULL object pointer");
  63   if (UseBiasedLocking && (klass != NULL)) {
  64     obj->set_mark(klass->prototype_header());
  65   } else {
  66     // May be bootstrapping
  67     obj->set_mark(markOopDesc::prototype());
  68   }
  69 }
  70 
  71 // Support for jvmti and dtrace
  72 inline void post_allocation_notify(Klass* klass, oop obj, int size) {
  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, size);
  83     }
  84   }
  85 }
  86 
  87 void CollectedHeap::post_allocation_setup_obj(Klass* klass,
  88                                               HeapWord* obj_ptr,
  89                                               int size) {
  90   post_allocation_setup_common(klass, obj_ptr);
  91   oop obj = (oop)obj_ptr;
  92   assert(Universe::is_bootstrapping() ||
  93          !obj->is_array(), "must not be an array");
  94   // notify jvmti and dtrace
  95   post_allocation_notify(klass, obj, size);
  96 }
  97 
  98 void CollectedHeap::post_allocation_setup_class(Klass* klass,
  99                                                 HeapWord* obj_ptr,
 100                                                 int size) {
 101   // Set oop_size field before setting the _klass field because a
 102   // non-NULL _klass field indicates that the object is parsable by
 103   // concurrent GC.
 104   oop new_cls = (oop)obj_ptr;
 105   assert(size > 0, "oop_size must be positive.");
 106   java_lang_Class::set_oop_size(new_cls, size);
 107   post_allocation_setup_common(klass, obj_ptr);
 108   assert(Universe::is_bootstrapping() ||
 109          !new_cls->is_array(), "must not be an array");
 110   // notify jvmti and dtrace
 111   post_allocation_notify(klass, new_cls, size);
 112 }
 113 
 114 void CollectedHeap::post_allocation_setup_array(Klass* klass,
 115                                                 HeapWord* obj_ptr,
 116                                                 int length) {
 117   // Set array length before setting the _klass field because a
 118   // non-NULL klass field indicates that the object is parsable by
 119   // concurrent GC.
 120   assert(length >= 0, "length should be non-negative");
 121   ((arrayOop)obj_ptr)->set_length(length);
 122   post_allocation_setup_common(klass, obj_ptr);
 123   oop new_obj = (oop)obj_ptr;
 124   assert(new_obj->is_array(), "must be an array");
 125   // notify jvmti and dtrace (must be after length is set for dtrace)
 126   post_allocation_notify(klass, new_obj, new_obj->size());
 127 }
 128 
 129 HeapWord* CollectedHeap::common_mem_allocate_noinit(Klass* klass, size_t size, TRAPS) {
 130 
 131   // Clear unhandled oops for memory allocation.  Memory allocation might
 132   // not take out a lock if from tlab, so clear here.
 133   CHECK_UNHANDLED_OOPS_ONLY(THREAD->clear_unhandled_oops();)
 134 
 135   if (HAS_PENDING_EXCEPTION) {
 136     NOT_PRODUCT(guarantee(false, "Should not allocate with exception pending"));
 137     return NULL;  // caller does a CHECK_0 too
 138   }
 139 
 140   HeapWord* result = NULL;
 141   if (UseTLAB) {
 142     result = allocate_from_tlab(klass, THREAD, size);
 143     if (result != NULL) {
 144       assert(!HAS_PENDING_EXCEPTION,
 145              "Unexpected exception, will result in uninitialized storage");
 146       return result;
 147     }
 148   }
 149   bool gc_overhead_limit_was_exceeded = false;
 150   result = Universe::heap()->mem_allocate(size,
 151                                           &gc_overhead_limit_was_exceeded);
 152   if (result != NULL) {
 153     NOT_PRODUCT(Universe::heap()->
 154       check_for_non_bad_heap_word_value(result, size));
 155     assert(!HAS_PENDING_EXCEPTION,
 156            "Unexpected exception, will result in uninitialized storage");
 157     THREAD->incr_allocated_bytes(size * HeapWordSize);
 158 
 159     AllocTracer::send_allocation_outside_tlab_event(klass, size * HeapWordSize);
 160 
 161     return result;
 162   }
 163 
 164 
 165   if (!gc_overhead_limit_was_exceeded) {
 166     // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
 167     report_java_out_of_memory("Java heap space");
 168 
 169     if (JvmtiExport::should_post_resource_exhausted()) {
 170       JvmtiExport::post_resource_exhausted(
 171         JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR | JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP,
 172         "Java heap space");
 173     }
 174 
 175     THROW_OOP_0(Universe::out_of_memory_error_java_heap());
 176   } else {
 177     // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
 178     report_java_out_of_memory("GC overhead limit exceeded");
 179 
 180     if (JvmtiExport::should_post_resource_exhausted()) {
 181       JvmtiExport::post_resource_exhausted(
 182         JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR | JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP,
 183         "GC overhead limit exceeded");
 184     }
 185 
 186     THROW_OOP_0(Universe::out_of_memory_error_gc_overhead_limit());
 187   }
 188 }
 189 
 190 HeapWord* CollectedHeap::common_mem_allocate_init(Klass* klass, size_t size, TRAPS) {
 191   HeapWord* obj = common_mem_allocate_noinit(klass, size, CHECK_NULL);
 192   init_obj(obj, size);
 193   return obj;
 194 }
 195 
 196 HeapWord* CollectedHeap::allocate_from_tlab(Klass* klass, Thread* thread, size_t size) {
 197   assert(UseTLAB, "should use UseTLAB");
 198 
 199   HeapWord* obj = thread->tlab().allocate(size);
 200   if (obj != NULL) {
 201     return obj;
 202   }
 203   // Otherwise...
 204   return allocate_from_tlab_slow(klass, thread, size);
 205 }
 206 
 207 void CollectedHeap::init_obj(HeapWord* obj, size_t size) {
 208   assert(obj != NULL, "cannot initialize NULL object");
 209   const size_t hs = oopDesc::header_size();
 210   assert(size >= hs, "unexpected object size");
 211   ((oop)obj)->set_klass_gap(0);
 212   Copy::fill_to_aligned_words(obj + hs, size - hs);
 213 }
 214 
 215 oop CollectedHeap::obj_allocate(Klass* klass, int size, TRAPS) {
 216   debug_only(check_for_valid_allocation_state());
 217   assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
 218   assert(size >= 0, "int won't convert to size_t");
 219   HeapWord* obj = common_mem_allocate_init(klass, size, CHECK_NULL);
 220   post_allocation_setup_obj(klass, obj, size);
 221   NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
 222   return (oop)obj;
 223 }
 224 
 225 oop CollectedHeap::class_allocate(Klass* klass, int size, TRAPS) {
 226   debug_only(check_for_valid_allocation_state());
 227   assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
 228   assert(size >= 0, "int won't convert to size_t");
 229   HeapWord* obj = common_mem_allocate_init(klass, size, CHECK_NULL);
 230   post_allocation_setup_class(klass, obj, size); // set oop_size
 231   NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
 232   return (oop)obj;
 233 }
 234 
 235 oop CollectedHeap::array_allocate(Klass* klass,
 236                                   int size,
 237                                   int length,
 238                                   TRAPS) {
 239   debug_only(check_for_valid_allocation_state());
 240   assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
 241   assert(size >= 0, "int won't convert to size_t");
 242   HeapWord* obj = common_mem_allocate_init(klass, size, CHECK_NULL);
 243   post_allocation_setup_array(klass, obj, length);
 244   NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
 245   return (oop)obj;
 246 }
 247 
 248 oop CollectedHeap::array_allocate_nozero(Klass* klass,
 249                                          int size,
 250                                          int length,
 251                                          TRAPS) {
 252   debug_only(check_for_valid_allocation_state());
 253   assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
 254   assert(size >= 0, "int won't convert to size_t");
 255   HeapWord* obj = common_mem_allocate_noinit(klass, size, CHECK_NULL);
 256   ((oop)obj)->set_klass_gap(0);
 257   post_allocation_setup_array(klass, obj, length);
 258 #ifndef PRODUCT
 259   const size_t hs = oopDesc::header_size()+1;
 260   Universe::heap()->check_for_non_bad_heap_word_value(obj+hs, size-hs);
 261 #endif
 262   return (oop)obj;
 263 }
 264 
 265 inline HeapWord* CollectedHeap::align_allocation_or_fail(HeapWord* addr,
 266                                                          HeapWord* end,
 267                                                          unsigned short alignment_in_bytes) {
 268   if (alignment_in_bytes <= ObjectAlignmentInBytes) {
 269     return addr;
 270   }
 271 
 272   assert(is_aligned(addr, HeapWordSize),
 273          "Address " PTR_FORMAT " is not properly aligned.", p2i(addr));
 274   assert(is_aligned(alignment_in_bytes, HeapWordSize),
 275          "Alignment size %u is incorrect.", alignment_in_bytes);
 276 
 277   HeapWord* new_addr = align_up(addr, alignment_in_bytes);
 278   size_t padding = pointer_delta(new_addr, addr);
 279 
 280   if (padding == 0) {
 281     return addr;
 282   }
 283 
 284   if (padding < CollectedHeap::min_fill_size()) {
 285     padding += alignment_in_bytes / HeapWordSize;
 286     assert(padding >= CollectedHeap::min_fill_size(),
 287            "alignment_in_bytes %u is expect to be larger "
 288            "than the minimum object size", alignment_in_bytes);
 289     new_addr = addr + padding;
 290   }
 291 
 292   assert(new_addr > addr, "Unexpected arithmetic overflow "
 293          PTR_FORMAT " not greater than " PTR_FORMAT, p2i(new_addr), p2i(addr));
 294   if(new_addr < end) {
 295     CollectedHeap::fill_with_object(addr, padding);
 296     return new_addr;
 297   } else {
 298     return NULL;
 299   }
 300 }
 301 
 302 #ifndef PRODUCT
 303 
 304 inline bool
 305 CollectedHeap::promotion_should_fail(volatile size_t* count) {
 306   // Access to count is not atomic; the value does not have to be exact.
 307   if (PromotionFailureALot) {
 308     const size_t gc_num = total_collections();
 309     const size_t elapsed_gcs = gc_num - _promotion_failure_alot_gc_number;
 310     if (elapsed_gcs >= PromotionFailureALotInterval) {
 311       // Test for unsigned arithmetic wrap-around.
 312       if (++*count >= PromotionFailureALotCount) {
 313         *count = 0;
 314         return true;
 315       }
 316     }
 317   }
 318   return false;
 319 }
 320 
 321 inline bool CollectedHeap::promotion_should_fail() {
 322   return promotion_should_fail(&_promotion_failure_alot_count);
 323 }
 324 
 325 inline void CollectedHeap::reset_promotion_should_fail(volatile size_t* count) {
 326   if (PromotionFailureALot) {
 327     _promotion_failure_alot_gc_number = total_collections();
 328     *count = 0;
 329   }
 330 }
 331 
 332 inline void CollectedHeap::reset_promotion_should_fail() {
 333   reset_promotion_should_fail(&_promotion_failure_alot_count);
 334 }
 335 #endif  // #ifndef PRODUCT
 336 
 337 #endif // SHARE_VM_GC_SHARED_COLLECTEDHEAP_INLINE_HPP