1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
|
// Copyright (c) 2006, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// 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
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// ---
// Author: Sanjay Ghemawat
// Maxim Lifantsev (refactoring)
//
#ifndef BASE_HEAP_PROFILE_TABLE_H_
#define BASE_HEAP_PROFILE_TABLE_H_
#include "addressmap-inl.h"
#include "base/basictypes.h"
#include "base/logging.h" // for RawFD
// Table to maintain a heap profile data inside,
// i.e. the set of currently active heap memory allocations.
// thread-unsafe and non-reentrant code:
// each instance object must be used by one thread
// at a time w/o self-recursion.
//
// TODO(maxim): add a unittest for this class.
class HeapProfileTable {
public:
// Extension to be used for heap pforile files.
static const char kFileExt[];
// Longest stack trace we record.
static const int kMaxStackDepth = 32;
// data types ----------------------------
// Profile stats.
struct Stats {
int32 allocs; // Number of allocation calls
int32 frees; // Number of free calls
int64 alloc_size; // Total size of all allocated objects so far
int64 free_size; // Total size of all freed objects so far
// semantic equality
bool Equivalent(const Stats& x) const {
return allocs - frees == x.allocs - x.frees &&
alloc_size - free_size == x.alloc_size - x.free_size;
}
};
// Info we can return about an allocation.
struct AllocInfo {
size_t object_size; // size of the allocation
const void* const* call_stack; // call stack that made the allocation call
int stack_depth; // depth of call_stack
bool live;
bool ignored;
};
// Info we return about an allocation context.
// An allocation context is a unique caller stack trace
// of an allocation operation.
struct AllocContextInfo : public Stats {
int stack_depth; // Depth of stack trace
const void* const* call_stack; // Stack trace
};
// Memory (de)allocator interface we'll use.
typedef void* (*Allocator)(size_t size);
typedef void (*DeAllocator)(void* ptr);
// interface ---------------------------
HeapProfileTable(Allocator alloc, DeAllocator dealloc);
~HeapProfileTable();
// Collect the stack trace for the function that asked to do the
// allocation for passing to RecordAlloc() below.
//
// The stack trace is stored in 'stack'. The stack depth is returned.
//
// 'skip_count' gives the number of stack frames between this call
// and the memory allocation function.
static int GetCallerStackTrace(int skip_count, void* stack[kMaxStackDepth]);
// Record an allocation at 'ptr' of 'bytes' bytes. 'stack_depth'
// and 'call_stack' identifying the function that requested the
// allocation. They can be generated using GetCallerStackTrace() above.
void RecordAlloc(const void* ptr, size_t bytes,
int stack_depth, const void* const call_stack[]);
// Record the deallocation of memory at 'ptr'.
void RecordFree(const void* ptr);
// Return true iff we have recorded an allocation at 'ptr'.
// If yes, fill *object_size with the allocation byte size.
bool FindAlloc(const void* ptr, size_t* object_size) const;
// Same as FindAlloc, but fills all of *info.
bool FindAllocDetails(const void* ptr, AllocInfo* info) const;
// Return true iff "ptr" points into a recorded allocation
// If yes, fill *object_ptr with the actual allocation address
// and *object_size with the allocation byte size.
// max_size specifies largest currently possible allocation size.
bool FindInsideAlloc(const void* ptr, size_t max_size,
const void** object_ptr, size_t* object_size) const;
// If "ptr" points to a recorded allocation and it's not marked as live
// mark it as live and return true. Else return false.
// All allocations start as non-live.
bool MarkAsLive(const void* ptr);
// If "ptr" points to a recorded allocation, mark it as "ignored".
// Ignored objects are treated like other objects, except that they
// are skipped in heap checking reports.
void MarkAsIgnored(const void* ptr);
// Return current total (de)allocation statistics. It doesn't contain
// mmap'ed regions.
const Stats& total() const { return total_; }
// Allocation data iteration callback: gets passed object pointer and
// fully-filled AllocInfo.
typedef void (*AllocIterator)(const void* ptr, const AllocInfo& info);
// Iterate over the allocation profile data calling "callback"
// for every allocation.
void IterateAllocs(AllocIterator callback) const {
alloc_address_map_->Iterate(MapArgsAllocIterator, callback);
}
// Allocation context profile data iteration callback
typedef void (*AllocContextIterator)(const AllocContextInfo& info);
// Iterate over the allocation context profile data calling "callback"
// for every allocation context. Allocation contexts are ordered by the
// size of allocated space.
void IterateOrderedAllocContexts(AllocContextIterator callback) const;
// Fill profile data into buffer 'buf' of size 'size'
// and return the actual size occupied by the dump in 'buf'.
// The profile buckets are dumped in the decreasing order
// of currently allocated bytes.
// We do not provision for 0-terminating 'buf'.
int FillOrderedProfile(char buf[], int size) const;
// Cleanup any old profile files matching prefix + ".*" + kFileExt.
static void CleanupOldProfiles(const char* prefix);
// Return a snapshot of the current contents of *this.
// Caller must call ReleaseSnapshot() on result when no longer needed.
// The result is only valid while this exists and until
// the snapshot is discarded by calling ReleaseSnapshot().
class Snapshot;
Snapshot* TakeSnapshot();
// Release a previously taken snapshot. snapshot must not
// be used after this call.
void ReleaseSnapshot(Snapshot* snapshot);
// Return a snapshot of every non-live, non-ignored object in *this.
// If "base" is non-NULL, skip any objects present in "base".
// As a side-effect, clears the "live" bit on every live object in *this.
// Caller must call ReleaseSnapshot() on result when no longer needed.
Snapshot* NonLiveSnapshot(Snapshot* base);
// Refresh the internal mmap information from MemoryRegionMap. Results of
// FillOrderedProfile and IterateOrderedAllocContexts will contain mmap'ed
// memory regions as at calling RefreshMMapData.
// 'mmap_alloc' is an allocator for an address map. A function which calls
// LowLevelAlloc::AllocWithArena is expected like the constractor.
// 'mmap_dealloc' is a corresponding deallocator to 'mmap_alloc'.
// They are introduced to avoid expected memory fragmentation and bloat in
// an arena. A dedicated arena for this function allows disposing whole the
// arena after ClearMMapData.
void RefreshMMapData(Allocator mmap_alloc, DeAllocator mmap_dealloc);
// Clear the internal mmap information. Results of FillOrderedProfile and
// IterateOrderedAllocContexts won't contain mmap'ed memory regions after
// calling ClearMMapData.
void ClearMMapData();
private:
friend class DeepHeapProfile;
// data types ----------------------------
// Hash table bucket to hold (de)allocation stats
// for a given allocation call stack trace.
struct Bucket : public Stats {
uintptr_t hash; // Hash value of the stack trace
int depth; // Depth of stack trace
const void** stack; // Stack trace
Bucket* next; // Next entry in hash-table
};
// Info stored in the address map
struct AllocValue {
// Access to the stack-trace bucket
Bucket* bucket() const {
return reinterpret_cast<Bucket*>(bucket_rep & ~uintptr_t(kMask));
}
// This also does set_live(false).
void set_bucket(Bucket* b) { bucket_rep = reinterpret_cast<uintptr_t>(b); }
size_t bytes; // Number of bytes in this allocation
// Access to the allocation liveness flag (for leak checking)
bool live() const { return bucket_rep & kLive; }
void set_live(bool l) {
bucket_rep = (bucket_rep & ~uintptr_t(kLive)) | (l ? kLive : 0);
}
// Should this allocation be ignored if it looks like a leak?
bool ignore() const { return bucket_rep & kIgnore; }
void set_ignore(bool r) {
bucket_rep = (bucket_rep & ~uintptr_t(kIgnore)) | (r ? kIgnore : 0);
}
private:
// We store a few bits in the bottom bits of bucket_rep.
// (Alignment is at least four, so we have at least two bits.)
static const int kLive = 1;
static const int kIgnore = 2;
static const int kMask = kLive | kIgnore;
uintptr_t bucket_rep;
};
// helper for FindInsideAlloc
static size_t AllocValueSize(const AllocValue& v) { return v.bytes; }
typedef AddressMap<AllocValue> AllocationMap;
// Arguments that need to be passed DumpNonLiveIterator callback below.
struct DumpArgs {
RawFD fd; // file to write to
Stats* profile_stats; // stats to update (may be NULL)
DumpArgs(RawFD a, Stats* d)
: fd(a), profile_stats(d) { }
};
// helpers ----------------------------
// Unparse bucket b and print its portion of profile dump into buf.
// We return the amount of space in buf that we use. We start printing
// at buf + buflen, and promise not to go beyond buf + bufsize.
// We do not provision for 0-terminating 'buf'.
//
// If profile_stats is non-NULL, we update *profile_stats by
// counting bucket b.
//
// "extra" is appended to the unparsed bucket. Typically it is empty,
// but may be set to something like " heapprofile" for the total
// bucket to indicate the type of the profile.
static int UnparseBucket(const Bucket& b,
char* buf, int buflen, int bufsize,
const char* extra,
Stats* profile_stats);
// Deallocate a given allocation map.
void DeallocateAllocationMap(AllocationMap* allocation);
// Deallocate a given bucket table.
void DeallocateBucketTable(Bucket** table);
// Get the bucket for the caller stack trace 'key' of depth 'depth' from a
// bucket hash map 'table' creating the bucket if needed. '*bucket_count'
// is incremented both when 'bucket_count' is not NULL and when a new
// bucket object is created.
Bucket* GetBucket(int depth, const void* const key[], Bucket** table,
int* bucket_count);
// Helper for IterateAllocs to do callback signature conversion
// from AllocationMap::Iterate to AllocIterator.
static void MapArgsAllocIterator(const void* ptr, AllocValue* v,
AllocIterator callback) {
AllocInfo info;
info.object_size = v->bytes;
info.call_stack = v->bucket()->stack;
info.stack_depth = v->bucket()->depth;
info.live = v->live();
info.ignored = v->ignore();
callback(ptr, info);
}
// Helper for DumpNonLiveProfile to do object-granularity
// heap profile dumping. It gets passed to AllocationMap::Iterate.
inline static void DumpNonLiveIterator(const void* ptr, AllocValue* v,
const DumpArgs& args);
// Helper for filling size variables in buckets by zero.
inline static void ZeroBucketCountsIterator(
const void* ptr, AllocValue* v, HeapProfileTable* heap_profile);
// Helper for IterateOrderedAllocContexts and FillOrderedProfile.
// Creates a sorted list of Buckets whose length is num_alloc_buckets_ +
// num_avaliable_mmap_buckets_.
// The caller is responsible for deallocating the returned list.
Bucket** MakeSortedBucketList() const;
// Helper for TakeSnapshot. Saves object to snapshot.
static void AddToSnapshot(const void* ptr, AllocValue* v, Snapshot* s);
// Arguments passed to AddIfNonLive
struct AddNonLiveArgs {
Snapshot* dest;
Snapshot* base;
};
// Helper for NonLiveSnapshot. Adds the object to the destination
// snapshot if it is non-live.
static void AddIfNonLive(const void* ptr, AllocValue* v,
AddNonLiveArgs* arg);
// Write contents of "*allocations" as a heap profile to
// "file_name". "total" must contain the total of all entries in
// "*allocations".
static bool WriteProfile(const char* file_name,
const Bucket& total,
AllocationMap* allocations);
// data ----------------------------
// Memory (de)allocator that we use.
Allocator alloc_;
DeAllocator dealloc_;
// Overall profile stats; we use only the Stats part,
// but make it a Bucket to pass to UnparseBucket.
// It doesn't contain mmap'ed regions.
Bucket total_;
// Bucket hash table for malloc.
// We hand-craft one instead of using one of the pre-written
// ones because we do not want to use malloc when operating on the table.
// It is only few lines of code, so no big deal.
Bucket** alloc_table_;
int num_alloc_buckets_;
// Bucket hash table for mmap.
// This table is filled with the information from MemoryRegionMap by calling
// RefreshMMapData.
Bucket** mmap_table_;
int num_available_mmap_buckets_;
// Map of all currently allocated objects and mapped regions we know about.
AllocationMap* alloc_address_map_;
AllocationMap* mmap_address_map_;
DISALLOW_COPY_AND_ASSIGN(HeapProfileTable);
};
class HeapProfileTable::Snapshot {
public:
const Stats& total() const { return total_; }
// Report anything in this snapshot as a leak.
// May use new/delete for temporary storage.
// If should_symbolize is true, will fork (which is not threadsafe)
// to turn addresses into symbol names. Set to false for maximum safety.
// Also writes a heap profile to "filename" that contains
// all of the objects in this snapshot.
void ReportLeaks(const char* checker_name, const char* filename,
bool should_symbolize);
// Report the addresses of all leaked objects.
// May use new/delete for temporary storage.
void ReportIndividualObjects();
bool Empty() const {
return (total_.allocs == 0) && (total_.alloc_size == 0);
}
private:
friend class HeapProfileTable;
// Total count/size are stored in a Bucket so we can reuse UnparseBucket
Bucket total_;
// We share the Buckets managed by the parent table, but have our
// own object->bucket map.
AllocationMap map_;
Snapshot(Allocator alloc, DeAllocator dealloc) : map_(alloc, dealloc) {
memset(&total_, 0, sizeof(total_));
}
// Callback used to populate a Snapshot object with entries found
// in another allocation map.
inline void Add(const void* ptr, const AllocValue& v) {
map_.Insert(ptr, v);
total_.allocs++;
total_.alloc_size += v.bytes;
}
// Helpers for sorting and generating leak reports
struct Entry;
struct ReportState;
static void ReportCallback(const void* ptr, AllocValue* v, ReportState*);
static void ReportObject(const void* ptr, AllocValue* v, char*);
DISALLOW_COPY_AND_ASSIGN(Snapshot);
};
#endif // BASE_HEAP_PROFILE_TABLE_H_
|