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1 /* Copyright 2015 The TensorFlow Authors. All Rights Reserved.
2 
3 Licensed under the Apache License, Version 2.0 (the "License");
4 you may not use this file except in compliance with the License.
5 You may obtain a copy of the License at
6 
7     http://www.apache.org/licenses/LICENSE-2.0
8 
9 Unless required by applicable law or agreed to in writing, software
10 distributed under the License is distributed on an "AS IS" BASIS,
11 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 See the License for the specific language governing permissions and
13 limitations under the License.
14 ==============================================================================*/
15 
16 #ifndef TENSORFLOW_CORE_FRAMEWORK_TRACKING_ALLOCATOR_H_
17 #define TENSORFLOW_CORE_FRAMEWORK_TRACKING_ALLOCATOR_H_
18 
19 #include <unordered_map>
20 #include "tensorflow/core/framework/allocator.h"
21 #include "tensorflow/core/lib/gtl/inlined_vector.h"
22 #include "tensorflow/core/platform/mutex.h"
23 #include "tensorflow/core/platform/thread_annotations.h"
24 #include "tensorflow/core/platform/types.h"
25 
26 namespace tensorflow {
27 
28 // TrackingAllocator is a wrapper for an Allocator. It keeps a running
29 // count of the number of bytes allocated through the wrapper. It is
30 // used by the Executor to "charge" allocations to particular Op
31 // executions. Each Op gets a separate TrackingAllocator wrapper
32 // around the underlying allocator.
33 //
34 // The implementation assumes the invariant that all calls to
35 // AllocateRaw by an Op (or work items spawned by the Op) will occur
36 // before the Op's Compute method returns. Thus the high watermark is
37 // established once Compute returns.
38 //
39 // DeallocateRaw can be called long after the Op has finished,
40 // e.g. when an output tensor is deallocated, and the wrapper cannot
41 // be deleted until the last of these calls has occurred.  The
42 // TrackingAllocator keeps track of outstanding calls using a
43 // reference count, and deletes itself once the last call has been
44 // received and the high watermark has been retrieved.
45 struct AllocRecord {
AllocRecordAllocRecord46   AllocRecord(int64 a_btyes, int64 a_micros)
47       : alloc_bytes(a_btyes), alloc_micros(a_micros) {}
AllocRecordAllocRecord48   AllocRecord() : AllocRecord(0, 0) {}
49 
50   int64 alloc_bytes;
51   int64 alloc_micros;
52 };
53 
54 class TrackingAllocator : public Allocator {
55  public:
56   explicit TrackingAllocator(Allocator* allocator, bool track_ids);
Name()57   std::string Name() override { return allocator_->Name(); }
AllocateRaw(size_t alignment,size_t num_bytes)58   void* AllocateRaw(size_t alignment, size_t num_bytes) override {
59     return AllocateRaw(alignment, num_bytes, AllocationAttributes());
60   }
61   void* AllocateRaw(size_t alignment, size_t num_bytes,
62                     const AllocationAttributes& allocation_attr) override;
63   void DeallocateRaw(void* ptr) override;
64   bool TracksAllocationSizes() const override;
65   size_t RequestedSize(const void* ptr) const override;
66   size_t AllocatedSize(const void* ptr) const override;
67   int64 AllocationId(const void* ptr) const override;
68   absl::optional<AllocatorStats> GetStats() override;
69   void ClearStats() override;
70 
71   // If the underlying allocator tracks allocation sizes, this returns
72   // a tuple where the first value is the total number of bytes
73   // allocated through this wrapper, the second value is the high
74   // watermark of bytes allocated through this wrapper and the third value is
75   // the allocated bytes through this wrapper that are still alive. If the
76   // underlying allocator does not track allocation sizes the first
77   // value is the total number of bytes requested through this wrapper
78   // and the second and the third are 0.
79   //
80   std::tuple<size_t, size_t, size_t> GetSizes();
81   // After GetRecordsAndUnRef is called, the only further calls allowed
82   // on this wrapper are calls to DeallocateRaw with pointers that
83   // were allocated by this wrapper and have not yet been
84   // deallocated. After this call completes and all allocated pointers
85   // have been deallocated the wrapper will delete itself.
86   gtl::InlinedVector<AllocRecord, 4> GetRecordsAndUnRef();
87   // Returns a copy of allocation records collected so far.
88   gtl::InlinedVector<AllocRecord, 4> GetCurrentRecords();
89 
90  protected:
~TrackingAllocator()91   ~TrackingAllocator() override {}
92 
93  private:
94   bool UnRef() TF_EXCLUSIVE_LOCKS_REQUIRED(mu_);
95 
96   Allocator* allocator_;  // not owned.
97   mutable mutex mu_;
98   // the number of calls to AllocateRaw that have not yet been matched
99   // by a corresponding call to DeAllocateRaw, plus 1 if the Executor
100   // has not yet read out the high watermark.
101   int ref_ TF_GUARDED_BY(mu_);
102   // the current number of outstanding bytes that have been allocated
103   // by this wrapper, or 0 if the underlying allocator does not track
104   // allocation sizes.
105   size_t allocated_ TF_GUARDED_BY(mu_);
106   // the maximum number of outstanding bytes that have been allocated
107   // by this wrapper, or 0 if the underlying allocator does not track
108   // allocation sizes.
109   size_t high_watermark_ TF_GUARDED_BY(mu_);
110   // the total number of bytes that have been allocated by this
111   // wrapper if the underlying allocator tracks allocation sizes,
112   // otherwise the total number of bytes that have been requested by
113   // this allocator.
114   size_t total_bytes_ TF_GUARDED_BY(mu_);
115 
116   gtl::InlinedVector<AllocRecord, 4> allocations_ TF_GUARDED_BY(mu_);
117 
118   // Track allocations locally if requested in the constructor and the
119   // underlying allocator doesn't already do it for us.
120   const bool track_sizes_locally_;
121   struct Chunk {
122     size_t requested_size;
123     size_t allocated_size;
124     int64 allocation_id;
125   };
126   std::unordered_map<const void*, Chunk> in_use_ TF_GUARDED_BY(mu_);
127   int64 next_allocation_id_ TF_GUARDED_BY(mu_);
128 };
129 
130 }  // end namespace tensorflow
131 
132 #endif  // TENSORFLOW_CORE_FRAMEWORK_TRACKING_ALLOCATOR_H_
133