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/copy.hpp"
  40 
  41 // Inline allocation implementations.
  42 
  43 void CollectedHeap::post_allocation_setup_common(Klass* klass,
  44                                                  HeapWord* obj_ptr) {
  45   post_allocation_setup_no_klass_install(klass, obj_ptr);
  46   oop obj = (oop)obj_ptr;
  47 #if ! INCLUDE_ALL_GCS
  48   obj->set_klass(klass);
  49 #else
  50   // Need a release store to ensure array/class length, mark word, and
  51   // object zeroing are visible before setting the klass non-NULL, for
  52   // concurrent collectors.
  53   obj->release_set_klass(klass);
  54 #endif
  55 }
  56 
  57 void CollectedHeap::post_allocation_setup_no_klass_install(Klass* klass,
  58                                                            HeapWord* obj_ptr) {
  59   oop obj = (oop)obj_ptr;
  60 
  61   assert(obj != NULL, "NULL object pointer");
  62   if (UseBiasedLocking && (klass != NULL)) {
  63     obj->set_mark(klass->prototype_header());
  64   } else {
  65     // May be bootstrapping
  66     obj->set_mark(markOopDesc::prototype());
  67   }
  68 }
  69 
  70 // Support for jvmti and dtrace
  71 inline void post_allocation_notify(Klass* klass, oop obj, int size) {
  72   // support low memory notifications (no-op if not enabled)
  73   LowMemoryDetector::detect_low_memory_for_collected_pools();
  74 
  75   // support for JVMTI VMObjectAlloc event (no-op if not enabled)
  76   JvmtiExport::vm_object_alloc_event_collector(obj);
  77 
  78   if (DTraceAllocProbes) {
  79     // support for Dtrace object alloc event (no-op most of the time)
  80     if (klass != NULL && klass->name() != NULL) {
  81       SharedRuntime::dtrace_object_alloc(obj, size);
  82     }
  83   }
  84 }
  85 
  86 void CollectedHeap::post_allocation_setup_obj(Klass* klass,
  87                                               HeapWord* obj_ptr,
  88                                               int size) {
  89   post_allocation_setup_common(klass, obj_ptr);
  90   oop obj = (oop)obj_ptr;
  91   assert(Universe::is_bootstrapping() ||
  92          !obj->is_array(), "must not be an array");
  93   // notify jvmti and dtrace
  94   post_allocation_notify(klass, obj, size);
  95 }
  96 
  97 void CollectedHeap::post_allocation_setup_class(Klass* klass,
  98                                                 HeapWord* obj_ptr,
  99                                                 int size) {
 100   // Set oop_size field before setting the _klass field because a
 101   // non-NULL _klass field indicates that the object is parsable by
 102   // concurrent GC.
 103   oop new_cls = (oop)obj_ptr;
 104   assert(size > 0, "oop_size must be positive.");
 105   java_lang_Class::set_oop_size(new_cls, size);
 106   post_allocation_setup_common(klass, obj_ptr);
 107   assert(Universe::is_bootstrapping() ||
 108          !new_cls->is_array(), "must not be an array");
 109   // notify jvmti and dtrace
 110   post_allocation_notify(klass, new_cls, size);
 111 }
 112 
 113 void CollectedHeap::post_allocation_setup_array(Klass* klass,
 114                                                 HeapWord* obj_ptr,
 115                                                 int length) {
 116   // Set array length before setting the _klass field because a
 117   // non-NULL klass field indicates that the object is parsable by
 118   // concurrent GC.
 119   assert(length >= 0, "length should be non-negative");
 120   ((arrayOop)obj_ptr)->set_length(length);
 121   post_allocation_setup_common(klass, obj_ptr);
 122   oop new_obj = (oop)obj_ptr;
 123   assert(new_obj->is_array(), "must be an array");
 124   // notify jvmti and dtrace (must be after length is set for dtrace)
 125   post_allocation_notify(klass, new_obj, new_obj->size());
 126 }
 127 
 128 HeapWord* CollectedHeap::common_mem_allocate_noinit(Klass* klass, size_t size, TRAPS) {
 129 
 130   // Clear unhandled oops for memory allocation.  Memory allocation might
 131   // not take out a lock if from tlab, so clear here.
 132   CHECK_UNHANDLED_OOPS_ONLY(THREAD->clear_unhandled_oops();)
 133 
 134   if (HAS_PENDING_EXCEPTION) {
 135     NOT_PRODUCT(guarantee(false, "Should not allocate with exception pending"));
 136     return NULL;  // caller does a CHECK_0 too
 137   }
 138 
 139   HeapWord* result = NULL;
 140   if (UseTLAB) {
 141     result = allocate_from_tlab(klass, THREAD, size);
 142     if (result != NULL) {
 143       assert(!HAS_PENDING_EXCEPTION,
 144              "Unexpected exception, will result in uninitialized storage");
 145       return result;
 146     }
 147   }
 148   bool gc_overhead_limit_was_exceeded = false;
 149   result = Universe::heap()->mem_allocate(size,
 150                                           &gc_overhead_limit_was_exceeded);
 151   if (result != NULL) {
 152     NOT_PRODUCT(Universe::heap()->
 153       check_for_non_bad_heap_word_value(result, size));
 154     assert(!HAS_PENDING_EXCEPTION,
 155            "Unexpected exception, will result in uninitialized storage");
 156     THREAD->incr_allocated_bytes(size * HeapWordSize);
 157 
 158     AllocTracer::send_allocation_outside_tlab_event(klass, size * HeapWordSize);
 159 
 160     return result;
 161   }
 162 
 163 
 164   if (!gc_overhead_limit_was_exceeded) {
 165     // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
 166     report_java_out_of_memory("Java heap space");
 167 
 168     if (JvmtiExport::should_post_resource_exhausted()) {
 169       JvmtiExport::post_resource_exhausted(
 170         JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR | JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP,
 171         "Java heap space");
 172     }
 173 
 174     THROW_OOP_0(Universe::out_of_memory_error_java_heap());
 175   } else {
 176     // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
 177     report_java_out_of_memory("GC overhead limit exceeded");
 178 
 179     if (JvmtiExport::should_post_resource_exhausted()) {
 180       JvmtiExport::post_resource_exhausted(
 181         JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR | JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP,
 182         "GC overhead limit exceeded");
 183     }
 184 
 185     THROW_OOP_0(Universe::out_of_memory_error_gc_overhead_limit());
 186   }
 187 }
 188 
 189 HeapWord* CollectedHeap::common_mem_allocate_init(Klass* klass, size_t size, TRAPS) {
 190   HeapWord* obj = common_mem_allocate_noinit(klass, size, CHECK_NULL);
 191   init_obj(obj, size);
 192   return obj;
 193 }
 194 
 195 HeapWord* CollectedHeap::allocate_from_tlab(Klass* klass, Thread* thread, size_t size) {
 196   assert(UseTLAB, "should use UseTLAB");
 197 
 198   HeapWord* obj = thread->tlab().allocate(size);
 199   if (obj != NULL) {
 200     return obj;
 201   }
 202   // Otherwise...
 203   return allocate_from_tlab_slow(klass, thread, size);
 204 }
 205 
 206 void CollectedHeap::init_obj(HeapWord* obj, size_t size) {
 207   assert(obj != NULL, "cannot initialize NULL object");
 208   const size_t hs = oopDesc::header_size();
 209   assert(size >= hs, "unexpected object size");
 210   ((oop)obj)->set_klass_gap(0);
 211   Copy::fill_to_aligned_words(obj + hs, size - hs);
 212 }
 213 
 214 oop CollectedHeap::obj_allocate(Klass* klass, int size, TRAPS) {
 215   debug_only(check_for_valid_allocation_state());
 216   assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
 217   assert(size >= 0, "int won't convert to size_t");
 218   HeapWord* obj = common_mem_allocate_init(klass, size, CHECK_NULL);
 219   post_allocation_setup_obj(klass, obj, size);
 220   NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
 221   return (oop)obj;
 222 }
 223 
 224 oop CollectedHeap::class_allocate(Klass* klass, int size, TRAPS) {
 225   debug_only(check_for_valid_allocation_state());
 226   assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
 227   assert(size >= 0, "int won't convert to size_t");
 228   HeapWord* obj = common_mem_allocate_init(klass, size, CHECK_NULL);
 229   post_allocation_setup_class(klass, obj, size); // set oop_size
 230   NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
 231   return (oop)obj;
 232 }
 233 
 234 oop CollectedHeap::array_allocate(Klass* klass,
 235                                   int size,
 236                                   int length,
 237                                   TRAPS) {
 238   debug_only(check_for_valid_allocation_state());
 239   assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
 240   assert(size >= 0, "int won't convert to size_t");
 241   HeapWord* obj = common_mem_allocate_init(klass, size, CHECK_NULL);
 242   post_allocation_setup_array(klass, obj, length);
 243   NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
 244   return (oop)obj;
 245 }
 246 
 247 oop CollectedHeap::array_allocate_nozero(Klass* klass,
 248                                          int size,
 249                                          int length,
 250                                          TRAPS) {
 251   debug_only(check_for_valid_allocation_state());
 252   assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
 253   assert(size >= 0, "int won't convert to size_t");
 254   HeapWord* obj = common_mem_allocate_noinit(klass, size, CHECK_NULL);
 255   ((oop)obj)->set_klass_gap(0);
 256   post_allocation_setup_array(klass, obj, length);
 257 #ifndef PRODUCT
 258   const size_t hs = oopDesc::header_size()+1;
 259   Universe::heap()->check_for_non_bad_heap_word_value(obj+hs, size-hs);
 260 #endif
 261   return (oop)obj;
 262 }
 263 
 264 inline HeapWord* CollectedHeap::align_allocation_or_fail(HeapWord* addr,
 265                                                          HeapWord* end,
 266                                                          unsigned short alignment_in_bytes) {
 267   if (alignment_in_bytes <= ObjectAlignmentInBytes) {
 268     return addr;
 269   }
 270 
 271   assert(is_aligned(addr, HeapWordSize),
 272          "Address " PTR_FORMAT " is not properly aligned.", p2i(addr));
 273   assert(is_aligned(alignment_in_bytes, HeapWordSize),
 274          "Alignment size %u is incorrect.", alignment_in_bytes);
 275 
 276   HeapWord* new_addr = align_up(addr, alignment_in_bytes);
 277   size_t padding = pointer_delta(new_addr, addr);
 278 
 279   if (padding == 0) {
 280     return addr;
 281   }
 282 
 283   if (padding < CollectedHeap::min_fill_size()) {
 284     padding += alignment_in_bytes / HeapWordSize;
 285     assert(padding >= CollectedHeap::min_fill_size(),
 286            "alignment_in_bytes %u is expect to be larger "
 287            "than the minimum object size", alignment_in_bytes);
 288     new_addr = addr + padding;
 289   }
 290 
 291   assert(new_addr > addr, "Unexpected arithmetic overflow "
 292          PTR_FORMAT " not greater than " PTR_FORMAT, p2i(new_addr), p2i(addr));
 293   if(new_addr < end) {
 294     CollectedHeap::fill_with_object(addr, padding);
 295     return new_addr;
 296   } else {
 297     return NULL;
 298   }
 299 }
 300 
 301 #ifndef PRODUCT
 302 
 303 inline bool
 304 CollectedHeap::promotion_should_fail(volatile size_t* count) {
 305   // Access to count is not atomic; the value does not have to be exact.
 306   if (PromotionFailureALot) {
 307     const size_t gc_num = total_collections();
 308     const size_t elapsed_gcs = gc_num - _promotion_failure_alot_gc_number;
 309     if (elapsed_gcs >= PromotionFailureALotInterval) {
 310       // Test for unsigned arithmetic wrap-around.
 311       if (++*count >= PromotionFailureALotCount) {
 312         *count = 0;
 313         return true;
 314       }
 315     }
 316   }
 317   return false;
 318 }
 319 
 320 inline bool CollectedHeap::promotion_should_fail() {
 321   return promotion_should_fail(&_promotion_failure_alot_count);
 322 }
 323 
 324 inline void CollectedHeap::reset_promotion_should_fail(volatile size_t* count) {
 325   if (PromotionFailureALot) {
 326     _promotion_failure_alot_gc_number = total_collections();
 327     *count = 0;
 328   }
 329 }
 330 
 331 inline void CollectedHeap::reset_promotion_should_fail() {
 332   reset_promotion_should_fail(&_promotion_failure_alot_count);
 333 }
 334 #endif  // #ifndef PRODUCT
 335 
 336 #endif // SHARE_VM_GC_SHARED_COLLECTEDHEAP_INLINE_HPP