heap-inl.h revision 9d04a20bde1b1855cefc64aebc1a44e253b1a13b 
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 "object_utils.h"
28#include "runtime.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  DebugCheckPreconditionsForAllocObject(klass, byte_count);
41  // Since allocation can cause a GC which will need to SuspendAll, make sure all allocations are
42  // done in the runnable state where suspension is expected.
43  DCHECK_EQ(self->GetState(), kRunnable);
44  self->AssertThreadSuspensionIsAllowable();
45  // Need to check that we arent the large object allocator since the large object allocation code
46  // path this function. If we didn't check we would have an infinite loop.
47  if (kCheckLargeObject && UNLIKELY(ShouldAllocLargeObject(klass, byte_count))) {
48    return AllocLargeObject<kInstrumented, PreFenceVisitor>(self, klass, byte_count,
49                                                            pre_fence_visitor);
50  }
51  mirror::Object* obj;
52  AllocationTimer alloc_timer(this, &obj);
53  size_t bytes_allocated;
54  obj = TryToAllocate<kInstrumented, false>(self, allocator, byte_count, &bytes_allocated);
55  if (UNLIKELY(obj == nullptr)) {
56    bool is_current_allocator = allocator == GetCurrentAllocator();
57    obj = AllocateInternalWithGc(self, allocator, byte_count, &bytes_allocated, &klass);
58    if (obj == nullptr) {
59      bool after_is_current_allocator = allocator == GetCurrentAllocator();
60      if (is_current_allocator && !after_is_current_allocator) {
61        // If the allocator changed, we need to restart the allocation.
62        return AllocObject<kInstrumented>(self, klass, byte_count);
63      }
64      return nullptr;
65    }
66  }
67  obj->SetClass(klass);
68  if (kUseBrooksPointer) {
69    obj->SetBrooksPointer(obj);
70    obj->AssertSelfBrooksPointer();
71  }
72  pre_fence_visitor(obj);
73  DCHECK_GT(bytes_allocated, 0u);
74  const size_t new_num_bytes_allocated =
75      static_cast<size_t>(num_bytes_allocated_.FetchAndAdd(bytes_allocated)) + bytes_allocated;
76  // TODO: Deprecate.
77  if (kInstrumented) {
78    if (Runtime::Current()->HasStatsEnabled()) {
79      RuntimeStats* thread_stats = self->GetStats();
80      ++thread_stats->allocated_objects;
81      thread_stats->allocated_bytes += bytes_allocated;
82      RuntimeStats* global_stats = Runtime::Current()->GetStats();
83      ++global_stats->allocated_objects;
84      global_stats->allocated_bytes += bytes_allocated;
85    }
86  } else {
87    DCHECK(!Runtime::Current()->HasStatsEnabled());
88  }
89  if (AllocatorHasAllocationStack(allocator)) {
90    PushOnAllocationStack(self, obj);
91  }
92  if (kInstrumented) {
93    if (Dbg::IsAllocTrackingEnabled()) {
94      Dbg::RecordAllocation(klass, bytes_allocated);
95    }
96  } else {
97    DCHECK(!Dbg::IsAllocTrackingEnabled());
98  }
99  // concurrent_gc_ isn't known at compile time so we can optimize by not checking it for
100  // the BumpPointer or TLAB allocators. This is nice since it allows the entire if statement to be
101  // optimized out. And for the other allocators, AllocatorMayHaveConcurrentGC is a constant since
102  // the allocator_type should be constant propagated.
103  if (AllocatorMayHaveConcurrentGC(allocator) && concurrent_gc_) {
104    CheckConcurrentGC(self, new_num_bytes_allocated, obj);
105  }
106  VerifyObject(obj);
107  self->VerifyStack();
108  return obj;
109}
110
111// The size of a thread-local allocation stack in the number of references.
112static constexpr size_t kThreadLocalAllocationStackSize = 128;
113
114inline void Heap::PushOnAllocationStack(Thread* self, mirror::Object* obj) {
115  if (kUseThreadLocalAllocationStack) {
116    bool success = self->PushOnThreadLocalAllocationStack(obj);
117    if (UNLIKELY(!success)) {
118      // Slow path. Allocate a new thread-local allocation stack.
119      mirror::Object** start_address;
120      mirror::Object** end_address;
121      while (!allocation_stack_->AtomicBumpBack(kThreadLocalAllocationStackSize,
122                                                &start_address, &end_address)) {
123        CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false);
124      }
125      self->SetThreadLocalAllocationStack(start_address, end_address);
126      // Retry on the new thread-local allocation stack.
127      success = self->PushOnThreadLocalAllocationStack(obj);
128      // Must succeed.
129      CHECK(success);
130    }
131  } else {
132    // This is safe to do since the GC will never free objects which are neither in the allocation
133    // stack or the live bitmap.
134    while (!allocation_stack_->AtomicPushBack(obj)) {
135      CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false);
136    }
137  }
138}
139
140template <bool kInstrumented, typename PreFenceVisitor>
141inline mirror::Object* Heap::AllocLargeObject(Thread* self, mirror::Class* klass,
142                                              size_t byte_count,
143                                              const PreFenceVisitor& pre_fence_visitor) {
144  return AllocObjectWithAllocator<kInstrumented, false, PreFenceVisitor>(self, klass, byte_count,
145                                                                         kAllocatorTypeLOS,
146                                                                         pre_fence_visitor);
147}
148
149template <const bool kInstrumented, const bool kGrow>
150inline mirror::Object* Heap::TryToAllocate(Thread* self, AllocatorType allocator_type,
151                                           size_t alloc_size, size_t* bytes_allocated) {
152  if (UNLIKELY(IsOutOfMemoryOnAllocation<kGrow>(allocator_type, alloc_size))) {
153    return nullptr;
154  }
155  mirror::Object* ret;
156  switch (allocator_type) {
157    case kAllocatorTypeBumpPointer: {
158      DCHECK(bump_pointer_space_ != nullptr);
159      alloc_size = RoundUp(alloc_size, space::BumpPointerSpace::kAlignment);
160      ret = bump_pointer_space_->AllocNonvirtual(alloc_size);
161      if (LIKELY(ret != nullptr)) {
162        *bytes_allocated = alloc_size;
163      }
164      break;
165    }
166    case kAllocatorTypeRosAlloc: {
167      if (kInstrumented && UNLIKELY(running_on_valgrind_)) {
168        // If running on valgrind, we should be using the instrumented path.
169        ret = rosalloc_space_->Alloc(self, alloc_size, bytes_allocated);
170      } else {
171        DCHECK(!running_on_valgrind_);
172        ret = rosalloc_space_->AllocNonvirtual(self, alloc_size, bytes_allocated);
173      }
174      break;
175    }
176    case kAllocatorTypeDlMalloc: {
177      if (kInstrumented && UNLIKELY(running_on_valgrind_)) {
178        // If running on valgrind, we should be using the instrumented path.
179        ret = dlmalloc_space_->Alloc(self, alloc_size, bytes_allocated);
180      } else {
181        DCHECK(!running_on_valgrind_);
182        ret = dlmalloc_space_->AllocNonvirtual(self, alloc_size, bytes_allocated);
183      }
184      break;
185    }
186    case kAllocatorTypeNonMoving: {
187      ret = non_moving_space_->Alloc(self, alloc_size, bytes_allocated);
188      break;
189    }
190    case kAllocatorTypeLOS: {
191      ret = large_object_space_->Alloc(self, alloc_size, bytes_allocated);
192      // Note that the bump pointer spaces aren't necessarily next to
193      // the other continuous spaces like the non-moving alloc space or
194      // the zygote space.
195      DCHECK(ret == nullptr || large_object_space_->Contains(ret));
196      break;
197    }
198    case kAllocatorTypeTLAB: {
199      alloc_size = RoundUp(alloc_size, space::BumpPointerSpace::kAlignment);
200      if (UNLIKELY(self->TlabSize() < alloc_size)) {
201        // Try allocating a new thread local buffer, if the allocaiton fails the space must be
202        // full so return nullptr.
203        if (!bump_pointer_space_->AllocNewTlab(self, alloc_size + kDefaultTLABSize)) {
204          return nullptr;
205        }
206      }
207      // The allocation can't fail.
208      ret = self->AllocTlab(alloc_size);
209      DCHECK(ret != nullptr);
210      *bytes_allocated = alloc_size;
211      break;
212    }
213    default: {
214      LOG(FATAL) << "Invalid allocator type";
215      ret = nullptr;
216    }
217  }
218  return ret;
219}
220
221inline void Heap::DebugCheckPreconditionsForAllocObject(mirror::Class* c, size_t byte_count) {
222  DCHECK(c == NULL || (c->IsClassClass() && byte_count >= sizeof(mirror::Class)) ||
223         (c->IsVariableSize() || c->GetObjectSize() == byte_count) ||
224         strlen(ClassHelper(c).GetDescriptor()) == 0);
225  DCHECK_GE(byte_count, sizeof(mirror::Object));
226}
227
228inline Heap::AllocationTimer::AllocationTimer(Heap* heap, mirror::Object** allocated_obj_ptr)
229    : heap_(heap), allocated_obj_ptr_(allocated_obj_ptr) {
230  if (kMeasureAllocationTime) {
231    allocation_start_time_ = NanoTime() / kTimeAdjust;
232  }
233}
234
235inline Heap::AllocationTimer::~AllocationTimer() {
236  if (kMeasureAllocationTime) {
237    mirror::Object* allocated_obj = *allocated_obj_ptr_;
238    // Only if the allocation succeeded, record the time.
239    if (allocated_obj != nullptr) {
240      uint64_t allocation_end_time = NanoTime() / kTimeAdjust;
241      heap_->total_allocation_time_.FetchAndAdd(allocation_end_time - allocation_start_time_);
242    }
243  }
244};
245
246inline bool Heap::ShouldAllocLargeObject(mirror::Class* c, size_t byte_count) const {
247  // We need to have a zygote space or else our newly allocated large object can end up in the
248  // Zygote resulting in it being prematurely freed.
249  // We can only do this for primitive objects since large objects will not be within the card table
250  // range. This also means that we rely on SetClass not dirtying the object's card.
251  return byte_count >= kLargeObjectThreshold && have_zygote_space_ && c->IsPrimitiveArray();
252}
253
254template <bool kGrow>
255inline bool Heap::IsOutOfMemoryOnAllocation(AllocatorType allocator_type, size_t alloc_size) {
256  size_t new_footprint = num_bytes_allocated_ + alloc_size;
257  if (UNLIKELY(new_footprint > max_allowed_footprint_)) {
258    if (UNLIKELY(new_footprint > growth_limit_)) {
259      return true;
260    }
261    if (!AllocatorMayHaveConcurrentGC(allocator_type) || !concurrent_gc_) {
262      if (!kGrow) {
263        return true;
264      }
265      // TODO: Grow for allocation is racy, fix it.
266      VLOG(heap) << "Growing heap from " << PrettySize(max_allowed_footprint_) << " to "
267          << PrettySize(new_footprint) << " for a " << PrettySize(alloc_size) << " allocation";
268      max_allowed_footprint_ = new_footprint;
269    }
270  }
271  return false;
272}
273
274inline void Heap::CheckConcurrentGC(Thread* self, size_t new_num_bytes_allocated,
275                                    mirror::Object* obj) {
276  if (UNLIKELY(new_num_bytes_allocated >= concurrent_start_bytes_)) {
277    // The SirtRef is necessary since the calls in RequestConcurrentGC are a safepoint.
278    SirtRef<mirror::Object> ref(self, obj);
279    RequestConcurrentGC(self);
280  }
281}
282
283}  // namespace gc
284}  // namespace art
285
286#endif  // ART_RUNTIME_GC_HEAP_INL_H_
287