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Save heap object tracking data in heap snapshot

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Every time embedder calls v8::HeapProfiler::GetHeapStats we store next unuassigned heap object id and timestamp of the request. This patch serializes all that data into heap snapshot so that embedder can restore allocation timeline.

BUG=chromium:467222
LOG=Y

Review URL: https://codereview.chromium.org/1019813004

Cr-Commit-Position: refs/heads/master@{#27384}
This commit is contained in:
yurys 2015-03-23 22:49:54 -07:00 committed by Commit bot
parent fe0d860ba8
commit aca7895353
2 changed files with 50 additions and 11 deletions
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43
src/heap-snapshot-generator.cc
View File

@ -2743,6 +2743,11 @@ void HeapSnapshotJSONSerializer::SerializeImpl() {
if (writer_->aborted()) return;
writer_->AddString("],\n");
writer_->AddString("\"samples\":[");
SerializeSamples();
if (writer_->aborted()) return;
writer_->AddString("],\n");
writer_->AddString("\"strings\":[");
SerializeStrings();
if (writer_->aborted()) return;
@ -2939,7 +2944,10 @@ void HeapSnapshotJSONSerializer::SerializeSnapshot() {
JSON_S("function_info_index") ","
JSON_S("count") ","
JSON_S("size") ","
JSON_S("children"))));
JSON_S("children")) ","
JSON_S("sample_fields") ":" JSON_A(
JSON_S("timestamp_us") ","
JSON_S("last_assigned_id"))));
#undef JSON_S
#undef JSON_O
#undef JSON_A
@ -3028,13 +3036,10 @@ void HeapSnapshotJSONSerializer::SerializeTraceNodeInfos() {
EmbeddedVector<char, kBufferSize> buffer;
const List<AllocationTracker::FunctionInfo*>& list =
tracker->function_info_list();
bool first_entry = true;
for (int i = 0; i < list.length(); i++) {
AllocationTracker::FunctionInfo* info = list[i];
int buffer_pos = 0;
if (first_entry) {
first_entry = false;
} else {
if (i > 0) {
buffer[buffer_pos++] = ',';
}
buffer_pos = utoa(info->function_id, buffer, buffer_pos);
@ -3057,6 +3062,34 @@ void HeapSnapshotJSONSerializer::SerializeTraceNodeInfos() {
}
void HeapSnapshotJSONSerializer::SerializeSamples() {
const List<HeapObjectsMap::TimeInterval>& samples =
snapshot_->profiler()->heap_object_map()->samples();
if (samples.is_empty()) return;
base::TimeTicks start_time = samples[0].timestamp;
// The buffer needs space for 2 unsigned ints, 2 commas, \n and \0
const int kBufferSize = MaxDecimalDigitsIn<sizeof(
base::TimeDelta().InMicroseconds())>::kUnsigned +
MaxDecimalDigitsIn<sizeof(samples[0].id)>::kUnsigned +
2 + 1 + 1;
EmbeddedVector<char, kBufferSize> buffer;
for (int i = 0; i < samples.length(); i++) {
HeapObjectsMap::TimeInterval& sample = samples[i];
int buffer_pos = 0;
if (i > 0) {
buffer[buffer_pos++] = ',';
}
base::TimeDelta time_delta = sample.timestamp - start_time;
buffer_pos = utoa(time_delta.InMicroseconds(), buffer, buffer_pos);
buffer[buffer_pos++] = ',';
buffer_pos = utoa(sample.last_assigned_id(), buffer, buffer_pos);
buffer[buffer_pos++] = '\n';
buffer[buffer_pos++] = '\0';
writer_->AddString(buffer.start());
}
}
void HeapSnapshotJSONSerializer::SerializeString(const unsigned char* s) {
writer_->AddCharacter('\n');
writer_->AddCharacter('\"');

18
src/heap-snapshot-generator.h
View File

@ -194,6 +194,16 @@ class HeapSnapshot {
class HeapObjectsMap {
public:
struct TimeInterval {
explicit TimeInterval(SnapshotObjectId id)
: id(id), size(0), count(0), timestamp(base::TimeTicks::Now()) {}
SnapshotObjectId last_assigned_id() const { return id - kObjectIdStep; }
SnapshotObjectId id;
uint32_t size;
uint32_t count;
base::TimeTicks timestamp;
};
explicit HeapObjectsMap(Heap* heap);
Heap* heap() const { return heap_; }
@ -210,6 +220,7 @@ class HeapObjectsMap {
void StopHeapObjectsTracking();
SnapshotObjectId PushHeapObjectsStats(OutputStream* stream);
const List<TimeInterval>& samples() const { return time_intervals_; }
size_t GetUsedMemorySize() const;
SnapshotObjectId GenerateId(v8::RetainedObjectInfo* info);
@ -236,12 +247,6 @@ class HeapObjectsMap {
unsigned int size;
bool accessed;
};
struct TimeInterval {
explicit TimeInterval(SnapshotObjectId id) : id(id), size(0), count(0) { }
SnapshotObjectId id;
uint32_t size;
uint32_t count;
};
SnapshotObjectId next_id_;
HashMap entries_map_;
@ -584,6 +589,7 @@ class HeapSnapshotJSONSerializer {
void SerializeTraceTree();
void SerializeTraceNode(AllocationTraceNode* node);
void SerializeTraceNodeInfos();
void SerializeSamples();
void SerializeString(const unsigned char* s);
void SerializeStrings();