1 /*
2 * Copyright (C) 2008 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 /*
18 * Preparation and completion of hprof data generation. The output is
19 * written into two files and then combined. This is necessary because
20 * we generate some of the data (strings and classes) while we dump the
21 * heap, and some analysis tools require that the class and string data
22 * appear first.
23 */
24
25 #include "hprof.h"
26
27 #include <errno.h>
28 #include <fcntl.h>
29 #include <stdio.h>
30 #include <string.h>
31 #include <sys/time.h>
32 #include <sys/uio.h>
33 #include <time.h>
34 #include <unistd.h>
35
36 #include <set>
37
38 #include <android-base/logging.h>
39 #include <android-base/stringprintf.h>
40
41 #include "art_field-inl.h"
42 #include "art_method-inl.h"
43 #include "base/array_ref.h"
44 #include "base/file_utils.h"
45 #include "base/logging.h"
46 #include "base/macros.h"
47 #include "base/mutex.h"
48 #include "base/os.h"
49 #include "base/safe_map.h"
50 #include "base/time_utils.h"
51 #include "base/unix_file/fd_file.h"
52 #include "class_linker.h"
53 #include "class_root-inl.h"
54 #include "common_throws.h"
55 #include "debugger.h"
56 #include "dex/dex_file-inl.h"
57 #include "gc/accounting/heap_bitmap.h"
58 #include "gc/allocation_record.h"
59 #include "gc/heap-visit-objects-inl.h"
60 #include "gc/heap.h"
61 #include "gc/scoped_gc_critical_section.h"
62 #include "gc/space/space.h"
63 #include "gc_root.h"
64 #include "mirror/class-inl.h"
65 #include "mirror/class.h"
66 #include "mirror/object-refvisitor-inl.h"
67 #include "runtime_globals.h"
68 #include "scoped_thread_state_change-inl.h"
69 #include "thread_list.h"
70
71 namespace art HIDDEN {
72
73 namespace hprof {
74
75 static constexpr bool kDirectStream = true;
76
77 static constexpr uint32_t kHprofTime = 0;
78 static constexpr uint32_t kHprofNullThread = 0;
79
80 static constexpr size_t kMaxObjectsPerSegment = 128;
81 static constexpr size_t kMaxBytesPerSegment = 4096;
82
83 // The static field-name for the synthetic object generated to account for class static overhead.
84 static constexpr const char* kClassOverheadName = "$classOverhead";
85
86 enum HprofTag {
87 HPROF_TAG_STRING = 0x01,
88 HPROF_TAG_LOAD_CLASS = 0x02,
89 HPROF_TAG_UNLOAD_CLASS = 0x03,
90 HPROF_TAG_STACK_FRAME = 0x04,
91 HPROF_TAG_STACK_TRACE = 0x05,
92 HPROF_TAG_ALLOC_SITES = 0x06,
93 HPROF_TAG_HEAP_SUMMARY = 0x07,
94 HPROF_TAG_START_THREAD = 0x0A,
95 HPROF_TAG_END_THREAD = 0x0B,
96 HPROF_TAG_HEAP_DUMP = 0x0C,
97 HPROF_TAG_HEAP_DUMP_SEGMENT = 0x1C,
98 HPROF_TAG_HEAP_DUMP_END = 0x2C,
99 HPROF_TAG_CPU_SAMPLES = 0x0D,
100 HPROF_TAG_CONTROL_SETTINGS = 0x0E,
101 };
102
103 // Values for the first byte of HEAP_DUMP and HEAP_DUMP_SEGMENT records:
104 enum HprofHeapTag {
105 // Traditional.
106 HPROF_ROOT_UNKNOWN = 0xFF,
107 HPROF_ROOT_JNI_GLOBAL = 0x01,
108 HPROF_ROOT_JNI_LOCAL = 0x02,
109 HPROF_ROOT_JAVA_FRAME = 0x03,
110 HPROF_ROOT_NATIVE_STACK = 0x04,
111 HPROF_ROOT_STICKY_CLASS = 0x05,
112 HPROF_ROOT_THREAD_BLOCK = 0x06,
113 HPROF_ROOT_MONITOR_USED = 0x07,
114 HPROF_ROOT_THREAD_OBJECT = 0x08,
115 HPROF_CLASS_DUMP = 0x20,
116 HPROF_INSTANCE_DUMP = 0x21,
117 HPROF_OBJECT_ARRAY_DUMP = 0x22,
118 HPROF_PRIMITIVE_ARRAY_DUMP = 0x23,
119
120 // Android.
121 HPROF_HEAP_DUMP_INFO = 0xfe,
122 HPROF_ROOT_INTERNED_STRING = 0x89,
123 HPROF_ROOT_FINALIZING = 0x8a, // Obsolete.
124 HPROF_ROOT_DEBUGGER = 0x8b,
125 HPROF_ROOT_REFERENCE_CLEANUP = 0x8c, // Obsolete.
126 HPROF_ROOT_VM_INTERNAL = 0x8d,
127 HPROF_ROOT_JNI_MONITOR = 0x8e,
128 HPROF_UNREACHABLE = 0x90, // Obsolete.
129 HPROF_PRIMITIVE_ARRAY_NODATA_DUMP = 0xc3, // Obsolete.
130 };
131
132 enum HprofHeapId {
133 HPROF_HEAP_DEFAULT = 0,
134 HPROF_HEAP_ZYGOTE = 'Z',
135 HPROF_HEAP_APP = 'A',
136 HPROF_HEAP_IMAGE = 'I',
137 };
138
139 enum HprofBasicType {
140 hprof_basic_object = 2,
141 hprof_basic_boolean = 4,
142 hprof_basic_char = 5,
143 hprof_basic_float = 6,
144 hprof_basic_double = 7,
145 hprof_basic_byte = 8,
146 hprof_basic_short = 9,
147 hprof_basic_int = 10,
148 hprof_basic_long = 11,
149 };
150
151 using HprofStringId = uint32_t;
152 using HprofClassObjectId = uint32_t;
153 using HprofClassSerialNumber = uint32_t;
154 using HprofStackTraceSerialNumber = uint32_t;
155 using HprofStackFrameId = uint32_t;
156 static constexpr HprofStackTraceSerialNumber kHprofNullStackTrace = 0;
157
158 class EndianOutput {
159 public:
EndianOutput()160 EndianOutput() : length_(0), sum_length_(0), max_length_(0), started_(false) {}
~EndianOutput()161 virtual ~EndianOutput() {}
162
StartNewRecord(uint8_t tag,uint32_t time)163 void StartNewRecord(uint8_t tag, uint32_t time) {
164 if (length_ > 0) {
165 EndRecord();
166 }
167 DCHECK_EQ(length_, 0U);
168 AddU1(tag);
169 AddU4(time);
170 AddU4(0xdeaddead); // Length, replaced on flush.
171 started_ = true;
172 }
173
EndRecord()174 void EndRecord() {
175 // Replace length in header.
176 if (started_) {
177 UpdateU4(sizeof(uint8_t) + sizeof(uint32_t),
178 length_ - sizeof(uint8_t) - 2 * sizeof(uint32_t));
179 }
180
181 HandleEndRecord();
182
183 sum_length_ += length_;
184 max_length_ = std::max(max_length_, length_);
185 length_ = 0;
186 started_ = false;
187 }
188
AddU1(uint8_t value)189 void AddU1(uint8_t value) {
190 AddU1List(&value, 1);
191 }
AddU2(uint16_t value)192 void AddU2(uint16_t value) {
193 AddU2List(&value, 1);
194 }
AddU4(uint32_t value)195 void AddU4(uint32_t value) {
196 AddU4List(&value, 1);
197 }
198
AddU8(uint64_t value)199 void AddU8(uint64_t value) {
200 AddU8List(&value, 1);
201 }
202
AddObjectId(const mirror::Object * value)203 void AddObjectId(const mirror::Object* value) {
204 AddU4(PointerToLowMemUInt32(value));
205 }
206
AddStackTraceSerialNumber(HprofStackTraceSerialNumber value)207 void AddStackTraceSerialNumber(HprofStackTraceSerialNumber value) {
208 AddU4(value);
209 }
210
211 // The ID for the synthetic object generated to account for class static overhead.
AddClassStaticsId(const mirror::Class * value)212 void AddClassStaticsId(const mirror::Class* value) {
213 AddU4(1 | PointerToLowMemUInt32(value));
214 }
215
AddJniGlobalRefId(jobject value)216 void AddJniGlobalRefId(jobject value) {
217 AddU4(PointerToLowMemUInt32(value));
218 }
219
AddClassId(HprofClassObjectId value)220 void AddClassId(HprofClassObjectId value) {
221 AddU4(value);
222 }
223
AddStringId(HprofStringId value)224 void AddStringId(HprofStringId value) {
225 AddU4(value);
226 }
227
AddU1List(const uint8_t * values,size_t count)228 void AddU1List(const uint8_t* values, size_t count) {
229 HandleU1List(values, count);
230 length_ += count;
231 }
AddU2List(const uint16_t * values,size_t count)232 void AddU2List(const uint16_t* values, size_t count) {
233 HandleU2List(values, count);
234 length_ += count * sizeof(uint16_t);
235 }
AddU4List(const uint32_t * values,size_t count)236 void AddU4List(const uint32_t* values, size_t count) {
237 HandleU4List(values, count);
238 length_ += count * sizeof(uint32_t);
239 }
UpdateU4(size_t offset,uint32_t new_value)240 virtual void UpdateU4(size_t offset, [[maybe_unused]] uint32_t new_value) {
241 DCHECK_LE(offset, length_ - 4);
242 }
AddU8List(const uint64_t * values,size_t count)243 void AddU8List(const uint64_t* values, size_t count) {
244 HandleU8List(values, count);
245 length_ += count * sizeof(uint64_t);
246 }
247
AddIdList(mirror::ObjectArray<mirror::Object> * values)248 void AddIdList(mirror::ObjectArray<mirror::Object>* values)
249 REQUIRES_SHARED(Locks::mutator_lock_) {
250 const int32_t length = values->GetLength();
251 for (int32_t i = 0; i < length; ++i) {
252 AddObjectId(values->GetWithoutChecks(i).Ptr());
253 }
254 }
255
AddUtf8String(const char * str)256 void AddUtf8String(const char* str) {
257 // The terminating NUL character is NOT written.
258 AddU1List((const uint8_t*)str, strlen(str));
259 }
260
Length() const261 size_t Length() const {
262 return length_;
263 }
264
SumLength() const265 size_t SumLength() const {
266 return sum_length_;
267 }
268
MaxLength() const269 size_t MaxLength() const {
270 return max_length_;
271 }
272
273 protected:
HandleU1List(const uint8_t * values,size_t count)274 virtual void HandleU1List([[maybe_unused]] const uint8_t* values, [[maybe_unused]] size_t count) {
275 }
HandleU1AsU2List(const uint8_t * values,size_t count)276 virtual void HandleU1AsU2List([[maybe_unused]] const uint8_t* values,
277 [[maybe_unused]] size_t count) {}
HandleU2List(const uint16_t * values,size_t count)278 virtual void HandleU2List([[maybe_unused]] const uint16_t* values,
279 [[maybe_unused]] size_t count) {}
HandleU4List(const uint32_t * values,size_t count)280 virtual void HandleU4List([[maybe_unused]] const uint32_t* values,
281 [[maybe_unused]] size_t count) {}
HandleU8List(const uint64_t * values,size_t count)282 virtual void HandleU8List([[maybe_unused]] const uint64_t* values,
283 [[maybe_unused]] size_t count) {}
HandleEndRecord()284 virtual void HandleEndRecord() {
285 }
286
287 size_t length_; // Current record size.
288 size_t sum_length_; // Size of all data.
289 size_t max_length_; // Maximum seen length.
290 bool started_; // Was StartRecord called?
291 };
292
293 // This keeps things buffered until flushed.
294 class EndianOutputBuffered : public EndianOutput {
295 public:
EndianOutputBuffered(size_t reserve_size)296 explicit EndianOutputBuffered(size_t reserve_size) {
297 buffer_.reserve(reserve_size);
298 }
~EndianOutputBuffered()299 virtual ~EndianOutputBuffered() {}
300
UpdateU4(size_t offset,uint32_t new_value)301 void UpdateU4(size_t offset, uint32_t new_value) override {
302 DCHECK_LE(offset, length_ - 4);
303 buffer_[offset + 0] = static_cast<uint8_t>((new_value >> 24) & 0xFF);
304 buffer_[offset + 1] = static_cast<uint8_t>((new_value >> 16) & 0xFF);
305 buffer_[offset + 2] = static_cast<uint8_t>((new_value >> 8) & 0xFF);
306 buffer_[offset + 3] = static_cast<uint8_t>((new_value >> 0) & 0xFF);
307 }
308
309 protected:
HandleU1List(const uint8_t * values,size_t count)310 void HandleU1List(const uint8_t* values, size_t count) override {
311 DCHECK_EQ(length_, buffer_.size());
312 buffer_.insert(buffer_.end(), values, values + count);
313 }
314
HandleU1AsU2List(const uint8_t * values,size_t count)315 void HandleU1AsU2List(const uint8_t* values, size_t count) override {
316 DCHECK_EQ(length_, buffer_.size());
317 // All 8-bits are grouped in 2 to make 16-bit block like Java Char
318 if (count & 1) {
319 buffer_.push_back(0);
320 }
321 for (size_t i = 0; i < count; ++i) {
322 uint8_t value = *values;
323 buffer_.push_back(value);
324 values++;
325 }
326 }
327
HandleU2List(const uint16_t * values,size_t count)328 void HandleU2List(const uint16_t* values, size_t count) override {
329 DCHECK_EQ(length_, buffer_.size());
330 for (size_t i = 0; i < count; ++i) {
331 uint16_t value = *values;
332 buffer_.push_back(static_cast<uint8_t>((value >> 8) & 0xFF));
333 buffer_.push_back(static_cast<uint8_t>((value >> 0) & 0xFF));
334 values++;
335 }
336 }
337
HandleU4List(const uint32_t * values,size_t count)338 void HandleU4List(const uint32_t* values, size_t count) override {
339 DCHECK_EQ(length_, buffer_.size());
340 for (size_t i = 0; i < count; ++i) {
341 uint32_t value = *values;
342 buffer_.push_back(static_cast<uint8_t>((value >> 24) & 0xFF));
343 buffer_.push_back(static_cast<uint8_t>((value >> 16) & 0xFF));
344 buffer_.push_back(static_cast<uint8_t>((value >> 8) & 0xFF));
345 buffer_.push_back(static_cast<uint8_t>((value >> 0) & 0xFF));
346 values++;
347 }
348 }
349
HandleU8List(const uint64_t * values,size_t count)350 void HandleU8List(const uint64_t* values, size_t count) override {
351 DCHECK_EQ(length_, buffer_.size());
352 for (size_t i = 0; i < count; ++i) {
353 uint64_t value = *values;
354 buffer_.push_back(static_cast<uint8_t>((value >> 56) & 0xFF));
355 buffer_.push_back(static_cast<uint8_t>((value >> 48) & 0xFF));
356 buffer_.push_back(static_cast<uint8_t>((value >> 40) & 0xFF));
357 buffer_.push_back(static_cast<uint8_t>((value >> 32) & 0xFF));
358 buffer_.push_back(static_cast<uint8_t>((value >> 24) & 0xFF));
359 buffer_.push_back(static_cast<uint8_t>((value >> 16) & 0xFF));
360 buffer_.push_back(static_cast<uint8_t>((value >> 8) & 0xFF));
361 buffer_.push_back(static_cast<uint8_t>((value >> 0) & 0xFF));
362 values++;
363 }
364 }
365
HandleEndRecord()366 void HandleEndRecord() override {
367 DCHECK_EQ(buffer_.size(), length_);
368 if (kIsDebugBuild && started_) {
369 uint32_t stored_length =
370 static_cast<uint32_t>(buffer_[5]) << 24 |
371 static_cast<uint32_t>(buffer_[6]) << 16 |
372 static_cast<uint32_t>(buffer_[7]) << 8 |
373 static_cast<uint32_t>(buffer_[8]);
374 DCHECK_EQ(stored_length, length_ - sizeof(uint8_t) - 2 * sizeof(uint32_t));
375 }
376 HandleFlush(buffer_.data(), length_);
377 buffer_.clear();
378 }
379
HandleFlush(const uint8_t * buffer,size_t length)380 virtual void HandleFlush([[maybe_unused]] const uint8_t* buffer, [[maybe_unused]] size_t length) {
381 }
382
383 std::vector<uint8_t> buffer_;
384 };
385
386 class FileEndianOutput final : public EndianOutputBuffered {
387 public:
FileEndianOutput(File * fp,size_t reserved_size)388 FileEndianOutput(File* fp, size_t reserved_size)
389 : EndianOutputBuffered(reserved_size), fp_(fp), errors_(false) {
390 DCHECK(fp != nullptr);
391 }
~FileEndianOutput()392 ~FileEndianOutput() {
393 }
394
Errors()395 bool Errors() {
396 return errors_;
397 }
398
399 protected:
HandleFlush(const uint8_t * buffer,size_t length)400 void HandleFlush(const uint8_t* buffer, size_t length) override {
401 if (!errors_) {
402 errors_ = !fp_->WriteFully(buffer, length);
403 }
404 }
405
406 private:
407 File* fp_;
408 bool errors_;
409 };
410
411 class VectorEndianOuputput final : public EndianOutputBuffered {
412 public:
VectorEndianOuputput(std::vector<uint8_t> & data,size_t reserved_size)413 VectorEndianOuputput(std::vector<uint8_t>& data, size_t reserved_size)
414 : EndianOutputBuffered(reserved_size), full_data_(data) {}
~VectorEndianOuputput()415 ~VectorEndianOuputput() {}
416
417 protected:
HandleFlush(const uint8_t * buf,size_t length)418 void HandleFlush(const uint8_t* buf, size_t length) override {
419 size_t old_size = full_data_.size();
420 full_data_.resize(old_size + length);
421 memcpy(full_data_.data() + old_size, buf, length);
422 }
423
424 private:
425 std::vector<uint8_t>& full_data_;
426 };
427
428 #define __ output_->
429
430 class Hprof : public SingleRootVisitor {
431 public:
Hprof(const char * output_filename,int fd,bool direct_to_ddms)432 Hprof(const char* output_filename, int fd, bool direct_to_ddms)
433 : filename_(output_filename),
434 fd_(fd),
435 direct_to_ddms_(direct_to_ddms) {
436 LOG(INFO) << "hprof: heap dump \"" << filename_ << "\" starting...";
437 }
438
Dump()439 void Dump()
440 REQUIRES(Locks::mutator_lock_)
441 REQUIRES(!Locks::heap_bitmap_lock_, !Locks::alloc_tracker_lock_) {
442 {
443 MutexLock mu(Thread::Current(), *Locks::alloc_tracker_lock_);
444 if (Runtime::Current()->GetHeap()->IsAllocTrackingEnabled()) {
445 PopulateAllocationTrackingTraces();
446 }
447 }
448
449 // First pass to measure the size of the dump.
450 size_t overall_size;
451 size_t max_length;
452 {
453 EndianOutput count_output;
454 output_ = &count_output;
455 ProcessHeap(false);
456 overall_size = count_output.SumLength();
457 max_length = count_output.MaxLength();
458 output_ = nullptr;
459 }
460
461 bool okay;
462 visited_objects_.clear();
463 if (direct_to_ddms_) {
464 if (kDirectStream) {
465 okay = DumpToDdmsDirect(overall_size, max_length, CHUNK_TYPE("HPDS"));
466 } else {
467 okay = DumpToDdmsBuffered(overall_size, max_length);
468 }
469 } else {
470 okay = DumpToFile(overall_size, max_length);
471 }
472
473 if (okay) {
474 const uint64_t duration = NanoTime() - start_ns_;
475 LOG(INFO) << "hprof: heap dump completed (" << PrettySize(RoundUp(overall_size, KB))
476 << ") in " << PrettyDuration(duration)
477 << " objects " << total_objects_
478 << " objects with stack traces " << total_objects_with_stack_trace_;
479 }
480 }
481
482 private:
483 void DumpHeapObject(mirror::Object* obj)
484 REQUIRES_SHARED(Locks::mutator_lock_);
485
486 void DumpHeapClass(mirror::Class* klass)
487 REQUIRES_SHARED(Locks::mutator_lock_);
488
489 void DumpHeapArray(mirror::Array* obj, mirror::Class* klass)
490 REQUIRES_SHARED(Locks::mutator_lock_);
491
492 void DumpFakeObjectArray(mirror::Object* obj, const std::set<mirror::Object*>& elements)
493 REQUIRES_SHARED(Locks::mutator_lock_);
494
495 void DumpHeapInstanceObject(mirror::Object* obj,
496 mirror::Class* klass,
497 const std::set<mirror::Object*>& fake_roots)
498 REQUIRES_SHARED(Locks::mutator_lock_);
499
500 bool AddRuntimeInternalObjectsField(mirror::Class* klass) REQUIRES_SHARED(Locks::mutator_lock_);
501
ProcessHeap(bool header_first)502 void ProcessHeap(bool header_first)
503 REQUIRES(Locks::mutator_lock_) {
504 // Reset current heap and object count.
505 current_heap_ = HPROF_HEAP_DEFAULT;
506 objects_in_segment_ = 0;
507
508 if (header_first) {
509 ProcessHeader(true);
510 ProcessBody();
511 } else {
512 ProcessBody();
513 ProcessHeader(false);
514 }
515 }
516
ProcessBody()517 void ProcessBody() REQUIRES(Locks::mutator_lock_) {
518 Runtime* const runtime = Runtime::Current();
519 // Walk the roots and the heap.
520 output_->StartNewRecord(HPROF_TAG_HEAP_DUMP_SEGMENT, kHprofTime);
521
522 simple_roots_.clear();
523 runtime->VisitRoots(this);
524 runtime->VisitImageRoots(this);
525 auto dump_object = [this](mirror::Object* obj) REQUIRES_SHARED(Locks::mutator_lock_) {
526 DCHECK(obj != nullptr);
527 DumpHeapObject(obj);
528 };
529 runtime->GetHeap()->VisitObjectsPaused(dump_object);
530 output_->StartNewRecord(HPROF_TAG_HEAP_DUMP_END, kHprofTime);
531 output_->EndRecord();
532 }
533
ProcessHeader(bool string_first)534 void ProcessHeader(bool string_first) REQUIRES(Locks::mutator_lock_) {
535 // Write the header.
536 WriteFixedHeader();
537 // Write the string and class tables, and any stack traces, to the header.
538 // (jhat requires that these appear before any of the data in the body that refers to them.)
539 // jhat also requires the string table appear before class table and stack traces.
540 // However, WriteStackTraces() can modify the string table, so it's necessary to call
541 // WriteStringTable() last in the first pass, to compute the correct length of the output.
542 if (string_first) {
543 WriteStringTable();
544 }
545 WriteClassTable();
546 WriteStackTraces();
547 if (!string_first) {
548 WriteStringTable();
549 }
550 output_->EndRecord();
551 }
552
WriteClassTable()553 void WriteClassTable() REQUIRES_SHARED(Locks::mutator_lock_) {
554 for (const auto& p : classes_) {
555 mirror::Class* c = p.first;
556 HprofClassSerialNumber sn = p.second;
557 CHECK(c != nullptr);
558 output_->StartNewRecord(HPROF_TAG_LOAD_CLASS, kHprofTime);
559 // LOAD CLASS format:
560 // U4: class serial number (always > 0)
561 // ID: class object ID. We use the address of the class object structure as its ID.
562 // U4: stack trace serial number
563 // ID: class name string ID
564 __ AddU4(sn);
565 __ AddObjectId(c);
566 __ AddStackTraceSerialNumber(LookupStackTraceSerialNumber(c));
567 __ AddStringId(LookupClassNameId(c));
568 }
569 }
570
WriteStringTable()571 void WriteStringTable() {
572 for (const auto& p : strings_) {
573 const std::string& string = p.first;
574 const HprofStringId id = p.second;
575
576 output_->StartNewRecord(HPROF_TAG_STRING, kHprofTime);
577
578 // STRING format:
579 // ID: ID for this string
580 // U1*: UTF8 characters for string (NOT null terminated)
581 // (the record format encodes the length)
582 __ AddU4(id);
583 __ AddUtf8String(string.c_str());
584 }
585 }
586
StartNewHeapDumpSegment()587 void StartNewHeapDumpSegment() {
588 // This flushes the old segment and starts a new one.
589 output_->StartNewRecord(HPROF_TAG_HEAP_DUMP_SEGMENT, kHprofTime);
590 objects_in_segment_ = 0;
591 // Starting a new HEAP_DUMP resets the heap to default.
592 current_heap_ = HPROF_HEAP_DEFAULT;
593 }
594
CheckHeapSegmentConstraints()595 void CheckHeapSegmentConstraints() {
596 if (objects_in_segment_ >= kMaxObjectsPerSegment || output_->Length() >= kMaxBytesPerSegment) {
597 StartNewHeapDumpSegment();
598 }
599 }
600
601 void VisitRoot(mirror::Object* obj, const RootInfo& root_info)
602 override REQUIRES_SHARED(Locks::mutator_lock_);
603 void MarkRootObject(const mirror::Object* obj, jobject jni_obj, HprofHeapTag heap_tag,
604 uint32_t thread_serial);
605
LookupClassId(mirror::Class * c)606 HprofClassObjectId LookupClassId(mirror::Class* c) REQUIRES_SHARED(Locks::mutator_lock_) {
607 if (c != nullptr) {
608 auto it = classes_.find(c);
609 if (it == classes_.end()) {
610 // first time to see this class
611 HprofClassSerialNumber sn = next_class_serial_number_++;
612 classes_.Put(c, sn);
613 // Make sure that we've assigned a string ID for this class' name
614 LookupClassNameId(c);
615 }
616 }
617 return PointerToLowMemUInt32(c);
618 }
619
LookupStackTraceSerialNumber(const mirror::Object * obj)620 HprofStackTraceSerialNumber LookupStackTraceSerialNumber(const mirror::Object* obj)
621 REQUIRES_SHARED(Locks::mutator_lock_) {
622 auto r = allocation_records_.find(obj);
623 if (r == allocation_records_.end()) {
624 return kHprofNullStackTrace;
625 } else {
626 const gc::AllocRecordStackTrace* trace = r->second;
627 auto result = traces_.find(trace);
628 CHECK(result != traces_.end());
629 return result->second;
630 }
631 }
632
LookupStringId(mirror::String * string)633 HprofStringId LookupStringId(mirror::String* string) REQUIRES_SHARED(Locks::mutator_lock_) {
634 return LookupStringId(string->ToModifiedUtf8());
635 }
636
LookupStringId(const char * string)637 HprofStringId LookupStringId(const char* string) {
638 return LookupStringId(std::string(string));
639 }
640
LookupStringId(const std::string & string)641 HprofStringId LookupStringId(const std::string& string) {
642 auto it = strings_.find(string);
643 if (it != strings_.end()) {
644 return it->second;
645 }
646 HprofStringId id = next_string_id_++;
647 strings_.Put(string, id);
648 return id;
649 }
650
LookupClassNameId(mirror::Class * c)651 HprofStringId LookupClassNameId(mirror::Class* c) REQUIRES_SHARED(Locks::mutator_lock_) {
652 return LookupStringId(c->PrettyDescriptor());
653 }
654
WriteFixedHeader()655 void WriteFixedHeader() {
656 // Write the file header.
657 // U1: NUL-terminated magic string.
658 const char magic[] = "JAVA PROFILE 1.0.3";
659 __ AddU1List(reinterpret_cast<const uint8_t*>(magic), sizeof(magic));
660
661 // U4: size of identifiers. We're using addresses as IDs and our heap references are stored
662 // as uint32_t.
663 // Note of warning: hprof-conv hard-codes the size of identifiers to 4.
664 static_assert(sizeof(mirror::HeapReference<mirror::Object>) == sizeof(uint32_t),
665 "Unexpected HeapReference size");
666 __ AddU4(sizeof(uint32_t));
667
668 // The current time, in milliseconds since 0:00 GMT, 1/1/70.
669 timeval now;
670 const uint64_t nowMs = (gettimeofday(&now, nullptr) < 0) ? 0 :
671 (uint64_t)now.tv_sec * 1000 + now.tv_usec / 1000;
672 // TODO: It seems it would be correct to use U8.
673 // U4: high word of the 64-bit time.
674 __ AddU4(static_cast<uint32_t>(nowMs >> 32));
675 // U4: low word of the 64-bit time.
676 __ AddU4(static_cast<uint32_t>(nowMs & 0xFFFFFFFF));
677 }
678
WriteStackTraces()679 void WriteStackTraces() REQUIRES_SHARED(Locks::mutator_lock_) {
680 // Write a fake stack trace record so the analysis tools don't freak out.
681 output_->StartNewRecord(HPROF_TAG_STACK_TRACE, kHprofTime);
682 __ AddStackTraceSerialNumber(kHprofNullStackTrace);
683 __ AddU4(kHprofNullThread);
684 __ AddU4(0); // no frames
685
686 // TODO: jhat complains "WARNING: Stack trace not found for serial # -1", but no trace should
687 // have -1 as its serial number (as long as HprofStackTraceSerialNumber doesn't overflow).
688 for (const auto& it : traces_) {
689 const gc::AllocRecordStackTrace* trace = it.first;
690 HprofStackTraceSerialNumber trace_sn = it.second;
691 size_t depth = trace->GetDepth();
692
693 // First write stack frames of the trace
694 for (size_t i = 0; i < depth; ++i) {
695 const gc::AllocRecordStackTraceElement* frame = &trace->GetStackElement(i);
696 ArtMethod* method = frame->GetMethod();
697 CHECK(method != nullptr);
698 output_->StartNewRecord(HPROF_TAG_STACK_FRAME, kHprofTime);
699 // STACK FRAME format:
700 // ID: stack frame ID. We use the address of the AllocRecordStackTraceElement object as its ID.
701 // ID: method name string ID
702 // ID: method signature string ID
703 // ID: source file name string ID
704 // U4: class serial number
705 // U4: >0, line number; 0, no line information available; -1, unknown location
706 auto frame_result = frames_.find(frame);
707 CHECK(frame_result != frames_.end());
708 __ AddU4(frame_result->second);
709 __ AddStringId(LookupStringId(method->GetName()));
710 __ AddStringId(LookupStringId(method->GetSignature().ToString()));
711 const char* source_file = method->GetDeclaringClassSourceFile();
712 if (source_file == nullptr) {
713 source_file = "";
714 }
715 __ AddStringId(LookupStringId(source_file));
716 auto class_result = classes_.find(method->GetDeclaringClass().Ptr());
717 CHECK(class_result != classes_.end());
718 __ AddU4(class_result->second);
719 __ AddU4(frame->ComputeLineNumber());
720 }
721
722 // Then write the trace itself
723 output_->StartNewRecord(HPROF_TAG_STACK_TRACE, kHprofTime);
724 // STACK TRACE format:
725 // U4: stack trace serial number. We use the address of the AllocRecordStackTrace object as its serial number.
726 // U4: thread serial number. We use Thread::GetTid().
727 // U4: number of frames
728 // [ID]*: series of stack frame ID's
729 __ AddStackTraceSerialNumber(trace_sn);
730 __ AddU4(trace->GetTid());
731 __ AddU4(depth);
732 for (size_t i = 0; i < depth; ++i) {
733 const gc::AllocRecordStackTraceElement* frame = &trace->GetStackElement(i);
734 auto frame_result = frames_.find(frame);
735 CHECK(frame_result != frames_.end());
736 __ AddU4(frame_result->second);
737 }
738 }
739 }
740
DumpToDdmsBuffered(size_t overall_size,size_t max_length)741 bool DumpToDdmsBuffered([[maybe_unused]] size_t overall_size, [[maybe_unused]] size_t max_length)
742 REQUIRES(Locks::mutator_lock_) {
743 LOG(FATAL) << "Unimplemented";
744 UNREACHABLE();
745 // // Send the data off to DDMS.
746 // iovec iov[2];
747 // iov[0].iov_base = header_data_ptr_;
748 // iov[0].iov_len = header_data_size_;
749 // iov[1].iov_base = body_data_ptr_;
750 // iov[1].iov_len = body_data_size_;
751 // Dbg::DdmSendChunkV(CHUNK_TYPE("HPDS"), iov, 2);
752 }
753
DumpToFile(size_t overall_size,size_t max_length)754 bool DumpToFile(size_t overall_size, size_t max_length)
755 REQUIRES(Locks::mutator_lock_) {
756 // Where exactly are we writing to?
757 int out_fd;
758 if (fd_ >= 0) {
759 out_fd = DupCloexec(fd_);
760 if (out_fd < 0) {
761 ThrowRuntimeException("Couldn't dump heap; dup(%d) failed: %s", fd_, strerror(errno));
762 return false;
763 }
764 } else {
765 out_fd = open(filename_.c_str(), O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC, 0644);
766 if (out_fd < 0) {
767 ThrowRuntimeException("Couldn't dump heap; open(\"%s\") failed: %s", filename_.c_str(),
768 strerror(errno));
769 return false;
770 }
771 }
772
773 std::unique_ptr<File> file(new File(out_fd, filename_, true));
774 bool okay;
775 {
776 FileEndianOutput file_output(file.get(), max_length);
777 output_ = &file_output;
778 ProcessHeap(true);
779 okay = !file_output.Errors();
780
781 if (okay) {
782 // Check for expected size. Output is expected to be less-or-equal than first phase, see
783 // b/23521263.
784 DCHECK_LE(file_output.SumLength(), overall_size);
785 }
786 output_ = nullptr;
787 }
788
789 if (okay) {
790 okay = file->FlushCloseOrErase() == 0;
791 } else {
792 file->Erase();
793 }
794 if (!okay) {
795 std::string msg(android::base::StringPrintf("Couldn't dump heap; writing \"%s\" failed: %s",
796 filename_.c_str(),
797 strerror(errno)));
798 ThrowRuntimeException("%s", msg.c_str());
799 LOG(ERROR) << msg;
800 }
801
802 return okay;
803 }
804
DumpToDdmsDirect(size_t overall_size,size_t max_length,uint32_t chunk_type)805 bool DumpToDdmsDirect(size_t overall_size, size_t max_length, uint32_t chunk_type)
806 REQUIRES(Locks::mutator_lock_) {
807 CHECK(direct_to_ddms_);
808
809 std::vector<uint8_t> out_data;
810
811 // TODO It would be really good to have some streaming thing again. b/73084059
812 VectorEndianOuputput output(out_data, max_length);
813 output_ = &output;
814
815 // Write the dump.
816 ProcessHeap(true);
817
818 Runtime::Current()->GetRuntimeCallbacks()->DdmPublishChunk(
819 chunk_type, ArrayRef<const uint8_t>(out_data.data(), out_data.size()));
820
821 // Check for expected size. See DumpToFile for comment.
822 DCHECK_LE(output.SumLength(), overall_size);
823 output_ = nullptr;
824
825 return true;
826 }
827
PopulateAllocationTrackingTraces()828 void PopulateAllocationTrackingTraces()
829 REQUIRES(Locks::mutator_lock_, Locks::alloc_tracker_lock_) {
830 gc::AllocRecordObjectMap* records = Runtime::Current()->GetHeap()->GetAllocationRecords();
831 CHECK(records != nullptr);
832 HprofStackTraceSerialNumber next_trace_sn = kHprofNullStackTrace + 1;
833 HprofStackFrameId next_frame_id = 0;
834 size_t count = 0;
835
836 for (auto it = records->Begin(), end = records->End(); it != end; ++it) {
837 const mirror::Object* obj = it->first.Read();
838 if (obj == nullptr) {
839 continue;
840 }
841 ++count;
842 const gc::AllocRecordStackTrace* trace = it->second.GetStackTrace();
843
844 // Copy the pair into a real hash map to speed up look up.
845 auto records_result = allocation_records_.emplace(obj, trace);
846 // The insertion should always succeed, i.e. no duplicate object pointers in "records"
847 CHECK(records_result.second);
848
849 // Generate serial numbers for traces, and IDs for frames.
850 auto traces_result = traces_.find(trace);
851 if (traces_result == traces_.end()) {
852 traces_.emplace(trace, next_trace_sn++);
853 // only check frames if the trace is newly discovered
854 for (size_t i = 0, depth = trace->GetDepth(); i < depth; ++i) {
855 const gc::AllocRecordStackTraceElement* frame = &trace->GetStackElement(i);
856 auto frames_result = frames_.find(frame);
857 if (frames_result == frames_.end()) {
858 frames_.emplace(frame, next_frame_id++);
859 }
860 }
861 }
862 }
863 CHECK_EQ(traces_.size(), next_trace_sn - kHprofNullStackTrace - 1);
864 CHECK_EQ(frames_.size(), next_frame_id);
865 total_objects_with_stack_trace_ = count;
866 }
867
868 // If direct_to_ddms_ is set, "filename_" and "fd" will be ignored.
869 // Otherwise, "filename_" must be valid, though if "fd" >= 0 it will
870 // only be used for debug messages.
871 std::string filename_;
872 int fd_;
873 bool direct_to_ddms_;
874
875 uint64_t start_ns_ = NanoTime();
876
877 EndianOutput* output_ = nullptr;
878
879 HprofHeapId current_heap_ = HPROF_HEAP_DEFAULT; // Which heap we're currently dumping.
880 size_t objects_in_segment_ = 0;
881
882 size_t total_objects_ = 0u;
883 size_t total_objects_with_stack_trace_ = 0u;
884
885 HprofStringId next_string_id_ = 0x400000;
886 SafeMap<std::string, HprofStringId> strings_;
887 HprofClassSerialNumber next_class_serial_number_ = 1;
888 SafeMap<mirror::Class*, HprofClassSerialNumber> classes_;
889
890 std::unordered_map<const gc::AllocRecordStackTrace*, HprofStackTraceSerialNumber,
891 gc::HashAllocRecordTypesPtr<gc::AllocRecordStackTrace>,
892 gc::EqAllocRecordTypesPtr<gc::AllocRecordStackTrace>> traces_;
893 std::unordered_map<const gc::AllocRecordStackTraceElement*, HprofStackFrameId,
894 gc::HashAllocRecordTypesPtr<gc::AllocRecordStackTraceElement>,
895 gc::EqAllocRecordTypesPtr<gc::AllocRecordStackTraceElement>> frames_;
896 std::unordered_map<const mirror::Object*, const gc::AllocRecordStackTrace*> allocation_records_;
897
898 // Set used to keep track of what simple root records we have already
899 // emitted, to avoid emitting duplicate entries. The simple root records are
900 // those that contain no other information than the root type and the object
901 // id. A pair of root type and object id is packed into a uint64_t, with
902 // the root type in the upper 32 bits and the object id in the lower 32
903 // bits.
904 std::unordered_set<uint64_t> simple_roots_;
905
906 // To make sure we don't dump the same object multiple times. b/34967844
907 std::unordered_set<mirror::Object*> visited_objects_;
908
909 friend class GcRootVisitor;
910 DISALLOW_COPY_AND_ASSIGN(Hprof);
911 };
912
SignatureToBasicTypeAndSize(const char * sig,size_t * size_out)913 static HprofBasicType SignatureToBasicTypeAndSize(const char* sig, size_t* size_out) {
914 char c = sig[0];
915 HprofBasicType ret;
916 size_t size;
917
918 switch (c) {
919 case '[':
920 case 'L':
921 ret = hprof_basic_object;
922 size = 4;
923 break;
924 case 'Z':
925 ret = hprof_basic_boolean;
926 size = 1;
927 break;
928 case 'C':
929 ret = hprof_basic_char;
930 size = 2;
931 break;
932 case 'F':
933 ret = hprof_basic_float;
934 size = 4;
935 break;
936 case 'D':
937 ret = hprof_basic_double;
938 size = 8;
939 break;
940 case 'B':
941 ret = hprof_basic_byte;
942 size = 1;
943 break;
944 case 'S':
945 ret = hprof_basic_short;
946 size = 2;
947 break;
948 case 'I':
949 ret = hprof_basic_int;
950 size = 4;
951 break;
952 case 'J':
953 ret = hprof_basic_long;
954 size = 8;
955 break;
956 default:
957 LOG(FATAL) << "UNREACHABLE";
958 UNREACHABLE();
959 }
960
961 if (size_out != nullptr) {
962 *size_out = size;
963 }
964
965 return ret;
966 }
967
968 // Always called when marking objects, but only does
969 // something when ctx->gc_scan_state_ is non-zero, which is usually
970 // only true when marking the root set or unreachable
971 // objects. Used to add rootset references to obj.
MarkRootObject(const mirror::Object * obj,jobject jni_obj,HprofHeapTag heap_tag,uint32_t thread_serial)972 void Hprof::MarkRootObject(const mirror::Object* obj, jobject jni_obj, HprofHeapTag heap_tag,
973 uint32_t thread_serial) {
974 if (heap_tag == 0) {
975 return;
976 }
977
978 CheckHeapSegmentConstraints();
979
980 switch (heap_tag) {
981 // ID: object ID
982 case HPROF_ROOT_UNKNOWN:
983 case HPROF_ROOT_STICKY_CLASS:
984 case HPROF_ROOT_MONITOR_USED:
985 case HPROF_ROOT_INTERNED_STRING:
986 case HPROF_ROOT_DEBUGGER:
987 case HPROF_ROOT_VM_INTERNAL: {
988 uint64_t key = (static_cast<uint64_t>(heap_tag) << 32) | PointerToLowMemUInt32(obj);
989 if (simple_roots_.insert(key).second) {
990 __ AddU1(heap_tag);
991 __ AddObjectId(obj);
992 }
993 break;
994 }
995
996 // ID: object ID
997 // ID: JNI global ref ID
998 case HPROF_ROOT_JNI_GLOBAL:
999 __ AddU1(heap_tag);
1000 __ AddObjectId(obj);
1001 __ AddJniGlobalRefId(jni_obj);
1002 break;
1003
1004 // ID: object ID
1005 // U4: thread serial number
1006 // U4: frame number in stack trace (-1 for empty)
1007 case HPROF_ROOT_JNI_LOCAL:
1008 case HPROF_ROOT_JNI_MONITOR:
1009 case HPROF_ROOT_JAVA_FRAME:
1010 __ AddU1(heap_tag);
1011 __ AddObjectId(obj);
1012 __ AddU4(thread_serial);
1013 __ AddU4((uint32_t)-1);
1014 break;
1015
1016 // ID: object ID
1017 // U4: thread serial number
1018 case HPROF_ROOT_NATIVE_STACK:
1019 case HPROF_ROOT_THREAD_BLOCK:
1020 __ AddU1(heap_tag);
1021 __ AddObjectId(obj);
1022 __ AddU4(thread_serial);
1023 break;
1024
1025 // ID: thread object ID
1026 // U4: thread serial number
1027 // U4: stack trace serial number
1028 case HPROF_ROOT_THREAD_OBJECT:
1029 __ AddU1(heap_tag);
1030 __ AddObjectId(obj);
1031 __ AddU4(thread_serial);
1032 __ AddU4((uint32_t)-1); // xxx
1033 break;
1034
1035 case HPROF_CLASS_DUMP:
1036 case HPROF_INSTANCE_DUMP:
1037 case HPROF_OBJECT_ARRAY_DUMP:
1038 case HPROF_PRIMITIVE_ARRAY_DUMP:
1039 case HPROF_HEAP_DUMP_INFO:
1040 case HPROF_PRIMITIVE_ARRAY_NODATA_DUMP:
1041 // Ignored.
1042 break;
1043
1044 case HPROF_ROOT_FINALIZING:
1045 case HPROF_ROOT_REFERENCE_CLEANUP:
1046 case HPROF_UNREACHABLE:
1047 LOG(FATAL) << "obsolete tag " << static_cast<int>(heap_tag);
1048 UNREACHABLE();
1049 }
1050
1051 ++objects_in_segment_;
1052 }
1053
AddRuntimeInternalObjectsField(mirror::Class * klass)1054 bool Hprof::AddRuntimeInternalObjectsField(mirror::Class* klass) {
1055 if (klass->IsDexCacheClass()) {
1056 return true;
1057 }
1058 // IsClassLoaderClass is true for subclasses of classloader but we only want to add the fake
1059 // field to the java.lang.ClassLoader class.
1060 if (klass->IsClassLoaderClass() && klass->GetSuperClass()->IsObjectClass()) {
1061 return true;
1062 }
1063 return false;
1064 }
1065
DumpHeapObject(mirror::Object * obj)1066 void Hprof::DumpHeapObject(mirror::Object* obj) {
1067 // Ignore classes that are retired.
1068 if (obj->IsClass() && obj->AsClass()->IsRetired()) {
1069 return;
1070 }
1071 DCHECK(visited_objects_.insert(obj).second)
1072 << "Already visited " << obj << "(" << obj->PrettyTypeOf() << ")";
1073
1074 ++total_objects_;
1075
1076 class RootCollector {
1077 public:
1078 RootCollector() {}
1079
1080 void operator()(mirror::Object*, MemberOffset, bool) const {}
1081
1082 // Note that these don't have read barriers. Its OK however since the GC is guaranteed to not be
1083 // running during the hprof dumping process.
1084 void VisitRootIfNonNull(mirror::CompressedReference<mirror::Object>* root) const
1085 REQUIRES_SHARED(Locks::mutator_lock_) {
1086 if (!root->IsNull()) {
1087 VisitRoot(root);
1088 }
1089 }
1090
1091 void VisitRoot(mirror::CompressedReference<mirror::Object>* root) const
1092 REQUIRES_SHARED(Locks::mutator_lock_) {
1093 roots_.insert(root->AsMirrorPtr());
1094 }
1095
1096 const std::set<mirror::Object*>& GetRoots() const {
1097 return roots_;
1098 }
1099
1100 private:
1101 // These roots are actually live from the object. Avoid marking them as roots in hprof to make
1102 // it easier to debug class unloading.
1103 mutable std::set<mirror::Object*> roots_;
1104 };
1105
1106 RootCollector visitor;
1107 // Collect all native roots.
1108 if (!obj->IsClass()) {
1109 obj->VisitReferences(visitor, VoidFunctor());
1110 }
1111
1112 gc::Heap* const heap = Runtime::Current()->GetHeap();
1113 const gc::space::ContinuousSpace* const space = heap->FindContinuousSpaceFromObject(obj, true);
1114 HprofHeapId heap_type = HPROF_HEAP_APP;
1115 if (space != nullptr) {
1116 if (space->IsZygoteSpace()) {
1117 heap_type = HPROF_HEAP_ZYGOTE;
1118 VisitRoot(obj, RootInfo(kRootVMInternal));
1119 } else if (space->IsImageSpace() && heap->ObjectIsInBootImageSpace(obj)) {
1120 // Only count objects in the boot image as HPROF_HEAP_IMAGE, this leaves app image objects as
1121 // HPROF_HEAP_APP. b/35762934
1122 heap_type = HPROF_HEAP_IMAGE;
1123 VisitRoot(obj, RootInfo(kRootVMInternal));
1124 }
1125 } else {
1126 const auto* los = heap->GetLargeObjectsSpace();
1127 if (los->Contains(obj) && los->IsZygoteLargeObject(Thread::Current(), obj)) {
1128 heap_type = HPROF_HEAP_ZYGOTE;
1129 VisitRoot(obj, RootInfo(kRootVMInternal));
1130 }
1131 }
1132 CheckHeapSegmentConstraints();
1133
1134 if (heap_type != current_heap_) {
1135 HprofStringId nameId;
1136
1137 // This object is in a different heap than the current one.
1138 // Emit a HEAP_DUMP_INFO tag to change heaps.
1139 __ AddU1(HPROF_HEAP_DUMP_INFO);
1140 __ AddU4(static_cast<uint32_t>(heap_type)); // uint32_t: heap type
1141 switch (heap_type) {
1142 case HPROF_HEAP_APP:
1143 nameId = LookupStringId("app");
1144 break;
1145 case HPROF_HEAP_ZYGOTE:
1146 nameId = LookupStringId("zygote");
1147 break;
1148 case HPROF_HEAP_IMAGE:
1149 nameId = LookupStringId("image");
1150 break;
1151 default:
1152 // Internal error
1153 LOG(ERROR) << "Unexpected desiredHeap";
1154 nameId = LookupStringId("<ILLEGAL>");
1155 break;
1156 }
1157 __ AddStringId(nameId);
1158 current_heap_ = heap_type;
1159 }
1160
1161 mirror::Class* c = obj->GetClass();
1162 if (c == nullptr) {
1163 // This object will bother HprofReader, because it has a null
1164 // class, so just don't dump it. It could be
1165 // gDvm.unlinkedJavaLangClass or it could be an object just
1166 // allocated which hasn't been initialized yet.
1167 } else {
1168 if (obj->IsClass()) {
1169 DumpHeapClass(obj->AsClass().Ptr());
1170 } else if (c->IsArrayClass()) {
1171 DumpHeapArray(obj->AsArray().Ptr(), c);
1172 } else {
1173 DumpHeapInstanceObject(obj, c, visitor.GetRoots());
1174 }
1175 }
1176
1177 ++objects_in_segment_;
1178 }
1179
DumpHeapClass(mirror::Class * klass)1180 void Hprof::DumpHeapClass(mirror::Class* klass) {
1181 if (!klass->IsResolved()) {
1182 // Class is allocated but not yet resolved: we cannot access its fields or super class.
1183 return;
1184 }
1185
1186 // Note: We will emit instance fields of Class as synthetic static fields with a prefix of
1187 // "$class$" so the class fields are visible in hprof dumps. For tools to account for that
1188 // correctly, we'll emit an instance size of zero for java.lang.Class, and also emit the
1189 // instance fields of java.lang.Object.
1190 //
1191 // For other overhead (currently only the embedded vtable), we will generate a synthetic
1192 // byte array (or field[s] in case the overhead size is of reference size or less).
1193
1194 const size_t num_static_fields = klass->NumStaticFields();
1195
1196 // Total class size:
1197 // * class instance fields (including Object instance fields)
1198 // * vtable
1199 // * class static fields
1200 const size_t total_class_size = klass->GetClassSize();
1201
1202 // Base class size (common parts of all Class instances):
1203 // * class instance fields (including Object instance fields)
1204 constexpr size_t base_class_size = sizeof(mirror::Class);
1205 CHECK_LE(base_class_size, total_class_size);
1206
1207 // Difference of Total and Base:
1208 // * vtable
1209 // * class static fields
1210 const size_t base_overhead_size = total_class_size - base_class_size;
1211
1212 // Tools (ahat/Studio) will count the static fields and account for them in the class size. We
1213 // must thus subtract them from base_overhead_size or they will be double-counted.
1214 size_t class_static_fields_size = 0;
1215 for (ArtField& class_static_field : klass->GetSFields()) {
1216 size_t size = 0;
1217 SignatureToBasicTypeAndSize(class_static_field.GetTypeDescriptor(), &size);
1218 class_static_fields_size += size;
1219 }
1220
1221 CHECK_GE(base_overhead_size, class_static_fields_size);
1222 // Now we have:
1223 // * vtable
1224 const size_t base_no_statics_overhead_size = base_overhead_size - class_static_fields_size;
1225
1226 // We may decide to display native overhead (the actual IMT, ArtFields and ArtMethods) in the
1227 // future.
1228 const size_t java_heap_overhead_size = base_no_statics_overhead_size;
1229
1230 // For overhead greater 4, we'll allocate a synthetic array.
1231 if (java_heap_overhead_size > 4) {
1232 // Create a byte array to reflect the allocation of the
1233 // StaticField array at the end of this class.
1234 __ AddU1(HPROF_PRIMITIVE_ARRAY_DUMP);
1235 __ AddClassStaticsId(klass);
1236 __ AddStackTraceSerialNumber(LookupStackTraceSerialNumber(klass));
1237 __ AddU4(java_heap_overhead_size - 4);
1238 __ AddU1(hprof_basic_byte);
1239 for (size_t i = 0; i < java_heap_overhead_size - 4; ++i) {
1240 __ AddU1(0);
1241 }
1242 }
1243 const size_t java_heap_overhead_field_count = java_heap_overhead_size > 0
1244 ? (java_heap_overhead_size == 3 ? 2u : 1u)
1245 : 0;
1246
1247 __ AddU1(HPROF_CLASS_DUMP);
1248 __ AddClassId(LookupClassId(klass));
1249 __ AddStackTraceSerialNumber(LookupStackTraceSerialNumber(klass));
1250 __ AddClassId(LookupClassId(klass->GetSuperClass().Ptr()));
1251 __ AddObjectId(klass->GetClassLoader().Ptr());
1252 __ AddObjectId(nullptr); // no signer
1253 __ AddObjectId(nullptr); // no prot domain
1254 __ AddObjectId(nullptr); // reserved
1255 __ AddObjectId(nullptr); // reserved
1256 // Instance size.
1257 if (klass->IsClassClass()) {
1258 // As mentioned above, we will emit instance fields as synthetic static fields. So the
1259 // base object is "empty."
1260 __ AddU4(0);
1261 } else if (klass->IsStringClass()) {
1262 // Strings are variable length with character data at the end like arrays.
1263 // This outputs the size of an empty string.
1264 __ AddU4(sizeof(mirror::String));
1265 } else if (klass->IsArrayClass() || klass->IsPrimitive()) {
1266 __ AddU4(0);
1267 } else {
1268 __ AddU4(klass->GetObjectSize()); // instance size
1269 }
1270
1271 __ AddU2(0); // empty const pool
1272
1273 // Static fields
1274 //
1275 // Note: we report Class' and Object's instance fields here, too. This is for visibility reasons.
1276 // (b/38167721)
1277 mirror::Class* class_class = klass->GetClass();
1278
1279 DCHECK(class_class->GetSuperClass()->IsObjectClass());
1280 const size_t static_fields_reported = class_class->NumInstanceFields()
1281 + class_class->GetSuperClass()->NumInstanceFields()
1282 + java_heap_overhead_field_count
1283 + num_static_fields;
1284 __ AddU2(dchecked_integral_cast<uint16_t>(static_fields_reported));
1285
1286 if (java_heap_overhead_size != 0) {
1287 __ AddStringId(LookupStringId(kClassOverheadName));
1288 size_t overhead_fields = 0;
1289 if (java_heap_overhead_size > 4) {
1290 __ AddU1(hprof_basic_object);
1291 __ AddClassStaticsId(klass);
1292 ++overhead_fields;
1293 } else {
1294 switch (java_heap_overhead_size) {
1295 case 4: {
1296 __ AddU1(hprof_basic_int);
1297 __ AddU4(0);
1298 ++overhead_fields;
1299 break;
1300 }
1301
1302 case 2: {
1303 __ AddU1(hprof_basic_short);
1304 __ AddU2(0);
1305 ++overhead_fields;
1306 break;
1307 }
1308
1309 case 3: {
1310 __ AddU1(hprof_basic_short);
1311 __ AddU2(0);
1312 __ AddStringId(LookupStringId(std::string(kClassOverheadName) + "2"));
1313 ++overhead_fields;
1314 }
1315 FALLTHROUGH_INTENDED;
1316
1317 case 1: {
1318 __ AddU1(hprof_basic_byte);
1319 __ AddU1(0);
1320 ++overhead_fields;
1321 break;
1322 }
1323 }
1324 }
1325 DCHECK_EQ(java_heap_overhead_field_count, overhead_fields);
1326 }
1327
1328 // Helper lambda to emit the given static field. The second argument name_fn will be called to
1329 // generate the name to emit. This can be used to emit something else than the field's actual
1330 // name.
1331 auto static_field_writer = [&](ArtField& field, auto name_fn)
1332 REQUIRES_SHARED(Locks::mutator_lock_) {
1333 __ AddStringId(LookupStringId(name_fn(field)));
1334
1335 size_t size;
1336 HprofBasicType t = SignatureToBasicTypeAndSize(field.GetTypeDescriptor(), &size);
1337 __ AddU1(t);
1338 switch (t) {
1339 case hprof_basic_byte:
1340 __ AddU1(field.GetByte(klass));
1341 return;
1342 case hprof_basic_boolean:
1343 __ AddU1(field.GetBoolean(klass));
1344 return;
1345 case hprof_basic_char:
1346 __ AddU2(field.GetChar(klass));
1347 return;
1348 case hprof_basic_short:
1349 __ AddU2(field.GetShort(klass));
1350 return;
1351 case hprof_basic_float:
1352 case hprof_basic_int:
1353 case hprof_basic_object:
1354 __ AddU4(field.Get32(klass));
1355 return;
1356 case hprof_basic_double:
1357 case hprof_basic_long:
1358 __ AddU8(field.Get64(klass));
1359 return;
1360 }
1361 LOG(FATAL) << "Unexpected size " << size;
1362 UNREACHABLE();
1363 };
1364
1365 {
1366 auto class_instance_field_name_fn = [](ArtField& field) REQUIRES_SHARED(Locks::mutator_lock_) {
1367 return std::string("$class$") + field.GetName();
1368 };
1369 for (ArtField& class_instance_field : class_class->GetIFields()) {
1370 static_field_writer(class_instance_field, class_instance_field_name_fn);
1371 }
1372 for (ArtField& object_instance_field : class_class->GetSuperClass()->GetIFields()) {
1373 static_field_writer(object_instance_field, class_instance_field_name_fn);
1374 }
1375 }
1376
1377 {
1378 auto class_static_field_name_fn = [](ArtField& field) REQUIRES_SHARED(Locks::mutator_lock_) {
1379 return field.GetName();
1380 };
1381 for (ArtField& class_static_field : klass->GetSFields()) {
1382 static_field_writer(class_static_field, class_static_field_name_fn);
1383 }
1384 }
1385
1386 // Instance fields for this class (no superclass fields)
1387 int iFieldCount = klass->NumInstanceFields();
1388 // add_internal_runtime_objects is only for classes that may retain objects live through means
1389 // other than fields. It is never the case for strings.
1390 const bool add_internal_runtime_objects = AddRuntimeInternalObjectsField(klass);
1391 if (klass->IsStringClass() || add_internal_runtime_objects) {
1392 __ AddU2((uint16_t)iFieldCount + 1);
1393 } else {
1394 __ AddU2((uint16_t)iFieldCount);
1395 }
1396 for (int i = 0; i < iFieldCount; ++i) {
1397 ArtField* f = klass->GetInstanceField(i);
1398 __ AddStringId(LookupStringId(f->GetName()));
1399 HprofBasicType t = SignatureToBasicTypeAndSize(f->GetTypeDescriptor(), nullptr);
1400 __ AddU1(t);
1401 }
1402 // Add native value character array for strings / byte array for compressed strings.
1403 if (klass->IsStringClass()) {
1404 __ AddStringId(LookupStringId("value"));
1405 __ AddU1(hprof_basic_object);
1406 } else if (add_internal_runtime_objects) {
1407 __ AddStringId(LookupStringId("runtimeInternalObjects"));
1408 __ AddU1(hprof_basic_object);
1409 }
1410 }
1411
DumpFakeObjectArray(mirror::Object * obj,const std::set<mirror::Object * > & elements)1412 void Hprof::DumpFakeObjectArray(mirror::Object* obj, const std::set<mirror::Object*>& elements) {
1413 __ AddU1(HPROF_OBJECT_ARRAY_DUMP);
1414 __ AddObjectId(obj);
1415 __ AddStackTraceSerialNumber(LookupStackTraceSerialNumber(obj));
1416 __ AddU4(elements.size());
1417 __ AddClassId(LookupClassId(GetClassRoot<mirror::ObjectArray<mirror::Object>>().Ptr()));
1418 for (mirror::Object* e : elements) {
1419 __ AddObjectId(e);
1420 }
1421 }
1422
DumpHeapArray(mirror::Array * obj,mirror::Class * klass)1423 void Hprof::DumpHeapArray(mirror::Array* obj, mirror::Class* klass) {
1424 uint32_t length = obj->GetLength();
1425
1426 if (obj->IsObjectArray()) {
1427 // obj is an object array.
1428 __ AddU1(HPROF_OBJECT_ARRAY_DUMP);
1429
1430 __ AddObjectId(obj);
1431 __ AddStackTraceSerialNumber(LookupStackTraceSerialNumber(obj));
1432 __ AddU4(length);
1433 __ AddClassId(LookupClassId(klass));
1434
1435 // Dump the elements, which are always objects or null.
1436 __ AddIdList(obj->AsObjectArray<mirror::Object>().Ptr());
1437 } else {
1438 size_t size;
1439 HprofBasicType t = SignatureToBasicTypeAndSize(
1440 Primitive::Descriptor(klass->GetComponentType()->GetPrimitiveType()), &size);
1441
1442 // obj is a primitive array.
1443 __ AddU1(HPROF_PRIMITIVE_ARRAY_DUMP);
1444
1445 __ AddObjectId(obj);
1446 __ AddStackTraceSerialNumber(LookupStackTraceSerialNumber(obj));
1447 __ AddU4(length);
1448 __ AddU1(t);
1449
1450 // Dump the raw, packed element values.
1451 if (size == 1) {
1452 __ AddU1List(reinterpret_cast<const uint8_t*>(obj->GetRawData(sizeof(uint8_t), 0)), length);
1453 } else if (size == 2) {
1454 __ AddU2List(reinterpret_cast<const uint16_t*>(obj->GetRawData(sizeof(uint16_t), 0)), length);
1455 } else if (size == 4) {
1456 __ AddU4List(reinterpret_cast<const uint32_t*>(obj->GetRawData(sizeof(uint32_t), 0)), length);
1457 } else if (size == 8) {
1458 __ AddU8List(reinterpret_cast<const uint64_t*>(obj->GetRawData(sizeof(uint64_t), 0)), length);
1459 }
1460 }
1461 }
1462
DumpHeapInstanceObject(mirror::Object * obj,mirror::Class * klass,const std::set<mirror::Object * > & fake_roots)1463 void Hprof::DumpHeapInstanceObject(mirror::Object* obj,
1464 mirror::Class* klass,
1465 const std::set<mirror::Object*>& fake_roots) {
1466 // obj is an instance object.
1467 __ AddU1(HPROF_INSTANCE_DUMP);
1468 __ AddObjectId(obj);
1469 __ AddStackTraceSerialNumber(LookupStackTraceSerialNumber(obj));
1470 __ AddClassId(LookupClassId(klass));
1471
1472 // Reserve some space for the length of the instance data, which we won't
1473 // know until we're done writing it.
1474 size_t size_patch_offset = output_->Length();
1475 __ AddU4(0x77777777);
1476
1477 // What we will use for the string value if the object is a string.
1478 mirror::Object* string_value = nullptr;
1479 mirror::Object* fake_object_array = nullptr;
1480
1481 // Write the instance data; fields for this class, followed by super class fields, and so on.
1482 do {
1483 const size_t instance_fields = klass->NumInstanceFields();
1484 for (size_t i = 0; i < instance_fields; ++i) {
1485 ArtField* f = klass->GetInstanceField(i);
1486 size_t size;
1487 HprofBasicType t = SignatureToBasicTypeAndSize(f->GetTypeDescriptor(), &size);
1488 switch (t) {
1489 case hprof_basic_byte:
1490 __ AddU1(f->GetByte(obj));
1491 break;
1492 case hprof_basic_boolean:
1493 __ AddU1(f->GetBoolean(obj));
1494 break;
1495 case hprof_basic_char:
1496 __ AddU2(f->GetChar(obj));
1497 break;
1498 case hprof_basic_short:
1499 __ AddU2(f->GetShort(obj));
1500 break;
1501 case hprof_basic_int:
1502 if (mirror::kUseStringCompression &&
1503 klass->IsStringClass() &&
1504 f->GetOffset().SizeValue() == mirror::String::CountOffset().SizeValue()) {
1505 // Store the string length instead of the raw count field with compression flag.
1506 __ AddU4(obj->AsString()->GetLength());
1507 break;
1508 }
1509 FALLTHROUGH_INTENDED;
1510 case hprof_basic_float:
1511 case hprof_basic_object:
1512 __ AddU4(f->Get32(obj));
1513 break;
1514 case hprof_basic_double:
1515 case hprof_basic_long:
1516 __ AddU8(f->Get64(obj));
1517 break;
1518 }
1519 }
1520 // Add value field for String if necessary.
1521 if (klass->IsStringClass()) {
1522 ObjPtr<mirror::String> s = obj->AsString();
1523 if (s->GetLength() == 0) {
1524 // If string is empty, use an object-aligned address within the string for the value.
1525 string_value = reinterpret_cast<mirror::Object*>(
1526 reinterpret_cast<uintptr_t>(s.Ptr()) + kObjectAlignment);
1527 } else {
1528 if (s->IsCompressed()) {
1529 string_value = reinterpret_cast<mirror::Object*>(s->GetValueCompressed());
1530 } else {
1531 string_value = reinterpret_cast<mirror::Object*>(s->GetValue());
1532 }
1533 }
1534 __ AddObjectId(string_value);
1535 } else if (AddRuntimeInternalObjectsField(klass)) {
1536 // We need an id that is guaranteed to not be used, use 1/2 of the object alignment.
1537 fake_object_array = reinterpret_cast<mirror::Object*>(
1538 reinterpret_cast<uintptr_t>(obj) + kObjectAlignment / 2);
1539 __ AddObjectId(fake_object_array);
1540 }
1541 klass = klass->GetSuperClass().Ptr();
1542 } while (klass != nullptr);
1543
1544 // Patch the instance field length.
1545 __ UpdateU4(size_patch_offset, output_->Length() - (size_patch_offset + 4));
1546
1547 // Output native value character array for strings.
1548 CHECK_EQ(obj->IsString(), string_value != nullptr);
1549 if (string_value != nullptr) {
1550 ObjPtr<mirror::String> s = obj->AsString();
1551 __ AddU1(HPROF_PRIMITIVE_ARRAY_DUMP);
1552 __ AddObjectId(string_value);
1553 __ AddStackTraceSerialNumber(LookupStackTraceSerialNumber(obj));
1554 __ AddU4(s->GetLength());
1555 if (s->IsCompressed()) {
1556 __ AddU1(hprof_basic_byte);
1557 __ AddU1List(s->GetValueCompressed(), s->GetLength());
1558 } else {
1559 __ AddU1(hprof_basic_char);
1560 __ AddU2List(s->GetValue(), s->GetLength());
1561 }
1562 } else if (fake_object_array != nullptr) {
1563 DumpFakeObjectArray(fake_object_array, fake_roots);
1564 }
1565 }
1566
VisitRoot(mirror::Object * obj,const RootInfo & info)1567 void Hprof::VisitRoot(mirror::Object* obj, const RootInfo& info) {
1568 static const HprofHeapTag xlate[] = {
1569 HPROF_ROOT_UNKNOWN,
1570 HPROF_ROOT_JNI_GLOBAL,
1571 HPROF_ROOT_JNI_LOCAL,
1572 HPROF_ROOT_JAVA_FRAME,
1573 HPROF_ROOT_NATIVE_STACK,
1574 HPROF_ROOT_STICKY_CLASS,
1575 HPROF_ROOT_THREAD_BLOCK,
1576 HPROF_ROOT_MONITOR_USED,
1577 HPROF_ROOT_THREAD_OBJECT,
1578 HPROF_ROOT_INTERNED_STRING,
1579 HPROF_ROOT_FINALIZING,
1580 HPROF_ROOT_DEBUGGER,
1581 HPROF_ROOT_REFERENCE_CLEANUP,
1582 HPROF_ROOT_VM_INTERNAL,
1583 HPROF_ROOT_JNI_MONITOR,
1584 };
1585 CHECK_LT(info.GetType(), sizeof(xlate) / sizeof(HprofHeapTag));
1586 if (obj == nullptr) {
1587 return;
1588 }
1589 MarkRootObject(obj, nullptr, xlate[info.GetType()], info.GetThreadId());
1590 }
1591
1592 // If "direct_to_ddms" is true, the other arguments are ignored, and data is
1593 // sent directly to DDMS.
1594 // If "fd" is >= 0, the output will be written to that file descriptor.
1595 // Otherwise, "filename" is used to create an output file.
DumpHeap(const char * filename,int fd,bool direct_to_ddms)1596 void DumpHeap(const char* filename, int fd, bool direct_to_ddms) {
1597 CHECK(filename != nullptr);
1598 Thread* self = Thread::Current();
1599 // Need to take a heap dump while GC isn't running. See the comment in Heap::VisitObjects().
1600 // Also we need the critical section to avoid visiting the same object twice. See b/34967844
1601 gc::ScopedGCCriticalSection gcs(self,
1602 gc::kGcCauseHprof,
1603 gc::kCollectorTypeHprof);
1604 ScopedSuspendAll ssa(__FUNCTION__, true /* long suspend */);
1605 Hprof hprof(filename, fd, direct_to_ddms);
1606 hprof.Dump();
1607 }
1608
1609 } // namespace hprof
1610 } // namespace art
1611