heap-inl.h revision 5ccd498d4aa450b0381344724b072a932709a59a 
1/*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef ART_RUNTIME_GC_HEAP_INL_H_
18#define ART_RUNTIME_GC_HEAP_INL_H_
19
20#include "heap.h"
21
22#include "debugger.h"
23#include "gc/space/bump_pointer_space-inl.h"
24#include "gc/space/dlmalloc_space-inl.h"
25#include "gc/space/large_object_space.h"
26#include "gc/space/rosalloc_space-inl.h"
27#include "runtime.h"
28#include "sirt_ref-inl.h"
29#include "thread.h"
30#include "thread-inl.h"
31#include "verify_object-inl.h"
32
33namespace art {
34namespace gc {
35
36template <bool kInstrumented, bool kCheckLargeObject, typename PreFenceVisitor>
37inline mirror::Object* Heap::AllocObjectWithAllocator(Thread* self, mirror::Class* klass,
38                                                      size_t byte_count, AllocatorType allocator,
39                                                      const PreFenceVisitor& pre_fence_visitor) {
40  if (kIsDebugBuild) {
41    CheckPreconditionsForAllocObject(klass, byte_count);
42  }
43  // Since allocation can cause a GC which will need to SuspendAll, make sure all allocations are
44  // done in the runnable state where suspension is expected.
45  DCHECK_EQ(self->GetState(), kRunnable);
46  self->AssertThreadSuspensionIsAllowable();
47  // Need to check that we arent the large object allocator since the large object allocation code
48  // path this function. If we didn't check we would have an infinite loop.
49  if (kCheckLargeObject && UNLIKELY(ShouldAllocLargeObject(klass, byte_count))) {
50    return AllocLargeObject<kInstrumented, PreFenceVisitor>(self, klass, byte_count,
51                                                            pre_fence_visitor);
52  }
53  mirror::Object* obj;
54  AllocationTimer alloc_timer(this, &obj);
55  size_t bytes_allocated, usable_size;
56  obj = TryToAllocate<kInstrumented, false>(self, allocator, byte_count, &bytes_allocated,
57                                            &usable_size);
58  if (UNLIKELY(obj == nullptr)) {
59    bool is_current_allocator = allocator == GetCurrentAllocator();
60    obj = AllocateInternalWithGc(self, allocator, byte_count, &bytes_allocated, &usable_size,
61                                 &klass);
62    if (obj == nullptr) {
63      bool after_is_current_allocator = allocator == GetCurrentAllocator();
64      if (is_current_allocator && !after_is_current_allocator) {
65        // If the allocator changed, we need to restart the allocation.
66        return AllocObject<kInstrumented>(self, klass, byte_count);
67      }
68      return nullptr;
69    }
70  }
71  DCHECK_GT(bytes_allocated, 0u);
72  DCHECK_GT(usable_size, 0u);
73  obj->SetClass(klass);
74  if (kUseBrooksPointer) {
75    obj->SetBrooksPointer(obj);
76    obj->AssertSelfBrooksPointer();
77  }
78  pre_fence_visitor(obj, usable_size);
79  if (kIsDebugBuild && Runtime::Current()->IsStarted()) {
80    CHECK_LE(obj->SizeOf(), usable_size);
81  }
82  const size_t new_num_bytes_allocated =
83      static_cast<size_t>(num_bytes_allocated_.FetchAndAdd(bytes_allocated)) + bytes_allocated;
84  // TODO: Deprecate.
85  if (kInstrumented) {
86    if (Runtime::Current()->HasStatsEnabled()) {
87      RuntimeStats* thread_stats = self->GetStats();
88      ++thread_stats->allocated_objects;
89      thread_stats->allocated_bytes += bytes_allocated;
90      RuntimeStats* global_stats = Runtime::Current()->GetStats();
91      ++global_stats->allocated_objects;
92      global_stats->allocated_bytes += bytes_allocated;
93    }
94  } else {
95    DCHECK(!Runtime::Current()->HasStatsEnabled());
96  }
97  if (AllocatorHasAllocationStack(allocator)) {
98    PushOnAllocationStack(self, obj);
99  }
100  if (kInstrumented) {
101    if (Dbg::IsAllocTrackingEnabled()) {
102      Dbg::RecordAllocation(klass, bytes_allocated);
103    }
104  } else {
105    DCHECK(!Dbg::IsAllocTrackingEnabled());
106  }
107  // concurrent_gc_ isn't known at compile time so we can optimize by not checking it for
108  // the BumpPointer or TLAB allocators. This is nice since it allows the entire if statement to be
109  // optimized out. And for the other allocators, AllocatorMayHaveConcurrentGC is a constant since
110  // the allocator_type should be constant propagated.
111  if (AllocatorMayHaveConcurrentGC(allocator) && concurrent_gc_) {
112    CheckConcurrentGC(self, new_num_bytes_allocated, &obj);
113  }
114  VerifyObject(obj);
115  self->VerifyStack();
116  return obj;
117}
118
119// The size of a thread-local allocation stack in the number of references.
120static constexpr size_t kThreadLocalAllocationStackSize = 128;
121
122inline void Heap::PushOnAllocationStack(Thread* self, mirror::Object* obj) {
123  if (kUseThreadLocalAllocationStack) {
124    bool success = self->PushOnThreadLocalAllocationStack(obj);
125    if (UNLIKELY(!success)) {
126      // Slow path. Allocate a new thread-local allocation stack.
127      mirror::Object** start_address;
128      mirror::Object** end_address;
129      while (!allocation_stack_->AtomicBumpBack(kThreadLocalAllocationStackSize,
130                                                &start_address, &end_address)) {
131        CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false);
132      }
133      self->SetThreadLocalAllocationStack(start_address, end_address);
134      // Retry on the new thread-local allocation stack.
135      success = self->PushOnThreadLocalAllocationStack(obj);
136      // Must succeed.
137      CHECK(success);
138    }
139  } else {
140    // This is safe to do since the GC will never free objects which are neither in the allocation
141    // stack or the live bitmap.
142    while (!allocation_stack_->AtomicPushBack(obj)) {
143      CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false);
144    }
145  }
146}
147
148template <bool kInstrumented, typename PreFenceVisitor>
149inline mirror::Object* Heap::AllocLargeObject(Thread* self, mirror::Class* klass,
150                                              size_t byte_count,
151                                              const PreFenceVisitor& pre_fence_visitor) {
152  return AllocObjectWithAllocator<kInstrumented, false, PreFenceVisitor>(self, klass, byte_count,
153                                                                         kAllocatorTypeLOS,
154                                                                         pre_fence_visitor);
155}
156
157template <const bool kInstrumented, const bool kGrow>
158inline mirror::Object* Heap::TryToAllocate(Thread* self, AllocatorType allocator_type,
159                                           size_t alloc_size, size_t* bytes_allocated,
160                                           size_t* usable_size) {
161  if (UNLIKELY(IsOutOfMemoryOnAllocation<kGrow>(allocator_type, alloc_size))) {
162    return nullptr;
163  }
164  mirror::Object* ret;
165  switch (allocator_type) {
166    case kAllocatorTypeBumpPointer: {
167      DCHECK(bump_pointer_space_ != nullptr);
168      alloc_size = RoundUp(alloc_size, space::BumpPointerSpace::kAlignment);
169      ret = bump_pointer_space_->AllocNonvirtual(alloc_size);
170      if (LIKELY(ret != nullptr)) {
171        *bytes_allocated = alloc_size;
172        *usable_size = alloc_size;
173      }
174      break;
175    }
176    case kAllocatorTypeRosAlloc: {
177      if (kInstrumented && UNLIKELY(running_on_valgrind_)) {
178        // If running on valgrind, we should be using the instrumented path.
179        ret = rosalloc_space_->Alloc(self, alloc_size, bytes_allocated, usable_size);
180      } else {
181        DCHECK(!running_on_valgrind_);
182        ret = rosalloc_space_->AllocNonvirtual(self, alloc_size, bytes_allocated, usable_size);
183      }
184      break;
185    }
186    case kAllocatorTypeDlMalloc: {
187      if (kInstrumented && UNLIKELY(running_on_valgrind_)) {
188        // If running on valgrind, we should be using the instrumented path.
189        ret = dlmalloc_space_->Alloc(self, alloc_size, bytes_allocated, usable_size);
190      } else {
191        DCHECK(!running_on_valgrind_);
192        ret = dlmalloc_space_->AllocNonvirtual(self, alloc_size, bytes_allocated, usable_size);
193      }
194      break;
195    }
196    case kAllocatorTypeNonMoving: {
197      ret = non_moving_space_->Alloc(self, alloc_size, bytes_allocated, usable_size);
198      break;
199    }
200    case kAllocatorTypeLOS: {
201      ret = large_object_space_->Alloc(self, alloc_size, bytes_allocated, usable_size);
202      // Note that the bump pointer spaces aren't necessarily next to
203      // the other continuous spaces like the non-moving alloc space or
204      // the zygote space.
205      DCHECK(ret == nullptr || large_object_space_->Contains(ret));
206      break;
207    }
208    case kAllocatorTypeTLAB: {
209      alloc_size = RoundUp(alloc_size, space::BumpPointerSpace::kAlignment);
210      if (UNLIKELY(self->TlabSize() < alloc_size)) {
211        // Try allocating a new thread local buffer, if the allocaiton fails the space must be
212        // full so return nullptr.
213        if (!bump_pointer_space_->AllocNewTlab(self, alloc_size + kDefaultTLABSize)) {
214          return nullptr;
215        }
216      }
217      // The allocation can't fail.
218      ret = self->AllocTlab(alloc_size);
219      DCHECK(ret != nullptr);
220      *bytes_allocated = alloc_size;
221      *usable_size = alloc_size;
222      break;
223    }
224    default: {
225      LOG(FATAL) << "Invalid allocator type";
226      ret = nullptr;
227    }
228  }
229  return ret;
230}
231
232inline Heap::AllocationTimer::AllocationTimer(Heap* heap, mirror::Object** allocated_obj_ptr)
233    : heap_(heap), allocated_obj_ptr_(allocated_obj_ptr) {
234  if (kMeasureAllocationTime) {
235    allocation_start_time_ = NanoTime() / kTimeAdjust;
236  }
237}
238
239inline Heap::AllocationTimer::~AllocationTimer() {
240  if (kMeasureAllocationTime) {
241    mirror::Object* allocated_obj = *allocated_obj_ptr_;
242    // Only if the allocation succeeded, record the time.
243    if (allocated_obj != nullptr) {
244      uint64_t allocation_end_time = NanoTime() / kTimeAdjust;
245      heap_->total_allocation_time_.FetchAndAdd(allocation_end_time - allocation_start_time_);
246    }
247  }
248};
249
250inline bool Heap::ShouldAllocLargeObject(mirror::Class* c, size_t byte_count) const {
251  // We need to have a zygote space or else our newly allocated large object can end up in the
252  // Zygote resulting in it being prematurely freed.
253  // We can only do this for primitive objects since large objects will not be within the card table
254  // range. This also means that we rely on SetClass not dirtying the object's card.
255  return byte_count >= large_object_threshold_ && c->IsPrimitiveArray();
256}
257
258template <bool kGrow>
259inline bool Heap::IsOutOfMemoryOnAllocation(AllocatorType allocator_type, size_t alloc_size) {
260  size_t new_footprint = num_bytes_allocated_ + alloc_size;
261  if (UNLIKELY(new_footprint > max_allowed_footprint_)) {
262    if (UNLIKELY(new_footprint > growth_limit_)) {
263      return true;
264    }
265    if (!AllocatorMayHaveConcurrentGC(allocator_type) || !concurrent_gc_) {
266      if (!kGrow) {
267        return true;
268      }
269      // TODO: Grow for allocation is racy, fix it.
270      VLOG(heap) << "Growing heap from " << PrettySize(max_allowed_footprint_) << " to "
271          << PrettySize(new_footprint) << " for a " << PrettySize(alloc_size) << " allocation";
272      max_allowed_footprint_ = new_footprint;
273    }
274  }
275  return false;
276}
277
278inline void Heap::CheckConcurrentGC(Thread* self, size_t new_num_bytes_allocated,
279                                    mirror::Object** obj) {
280  if (UNLIKELY(new_num_bytes_allocated >= concurrent_start_bytes_)) {
281    // The SirtRef is necessary since the calls in RequestConcurrentGC are a safepoint.
282    SirtRef<mirror::Object> ref(self, *obj);
283    RequestConcurrentGC(self);
284    // Restore obj in case it moved.
285    *obj = ref.get();
286  }
287}
288
289}  // namespace gc
290}  // namespace art
291
292#endif  // ART_RUNTIME_GC_HEAP_INL_H_
293