| // -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- |
| // Copyright (c) 2013, Google Inc. |
| // All rights reserved. |
| // |
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| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
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| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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| |
| // This file defines structs to accumulate memory allocation and deallocation |
| // counts. These structs are commonly used for malloc (in HeapProfileTable) |
| // and mmap (in MemoryRegionMap). |
| |
| // A bucket is data structure for heap profiling to store a pair of a stack |
| // trace and counts of (de)allocation. Buckets are stored in a hash table |
| // which is declared as "HeapProfileBucket**". |
| // |
| // A hash value is computed from a stack trace. Collision in the hash table |
| // is resolved by separate chaining with linked lists. The links in the list |
| // are implemented with the member "HeapProfileBucket* next". |
| // |
| // A structure of a hash table HeapProfileBucket** bucket_table would be like: |
| // bucket_table[0] => NULL |
| // bucket_table[1] => HeapProfileBucket() => HeapProfileBucket() => NULL |
| // ... |
| // bucket_table[i] => HeapProfileBucket() => NULL |
| // ... |
| // bucket_table[n] => HeapProfileBucket() => NULL |
| |
| #ifndef HEAP_PROFILE_STATS_H_ |
| #define HEAP_PROFILE_STATS_H_ |
| |
| struct HeapProfileStats { |
| // Returns true if the two HeapProfileStats are semantically equal. |
| bool Equivalent(const HeapProfileStats& other) const { |
| return allocs - frees == other.allocs - other.frees && |
| alloc_size - free_size == other.alloc_size - other.free_size; |
| } |
| |
| int64_t allocs; // Number of allocation calls. |
| int64_t frees; // Number of free calls. |
| int64_t alloc_size; // Total size of all allocated objects so far. |
| int64_t free_size; // Total size of all freed objects so far. |
| }; |
| |
| // Allocation and deallocation statistics per each stack trace. |
| struct HeapProfileBucket : public HeapProfileStats { |
| // Longest stack trace we record. |
| static const int kMaxStackDepth = 32; |
| |
| uintptr_t hash; // Hash value of the stack trace. |
| int depth; // Depth of stack trace. |
| const void** stack; // Stack trace. |
| HeapProfileBucket* next; // Next entry in hash-table. |
| }; |
| |
| #endif // HEAP_PROFILE_STATS_H_ |