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1 // Copyright 2013 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #include "src/v8.h"
6 
7 #include "src/allocation-tracker.h"
8 #include "src/frames-inl.h"
9 #include "src/heap-snapshot-generator.h"
10 
11 namespace v8 {
12 namespace internal {
13 
AllocationTraceNode(AllocationTraceTree * tree,unsigned function_info_index)14 AllocationTraceNode::AllocationTraceNode(
15     AllocationTraceTree* tree, unsigned function_info_index)
16     : tree_(tree),
17       function_info_index_(function_info_index),
18       total_size_(0),
19       allocation_count_(0),
20       id_(tree->next_node_id()) {
21 }
22 
23 
~AllocationTraceNode()24 AllocationTraceNode::~AllocationTraceNode() {
25   for (int i = 0; i < children_.length(); i++) delete children_[i];
26 }
27 
28 
FindChild(unsigned function_info_index)29 AllocationTraceNode* AllocationTraceNode::FindChild(
30     unsigned function_info_index) {
31   for (int i = 0; i < children_.length(); i++) {
32     AllocationTraceNode* node = children_[i];
33     if (node->function_info_index() == function_info_index) return node;
34   }
35   return NULL;
36 }
37 
38 
FindOrAddChild(unsigned function_info_index)39 AllocationTraceNode* AllocationTraceNode::FindOrAddChild(
40     unsigned function_info_index) {
41   AllocationTraceNode* child = FindChild(function_info_index);
42   if (child == NULL) {
43     child = new AllocationTraceNode(tree_, function_info_index);
44     children_.Add(child);
45   }
46   return child;
47 }
48 
49 
AddAllocation(unsigned size)50 void AllocationTraceNode::AddAllocation(unsigned size) {
51   total_size_ += size;
52   ++allocation_count_;
53 }
54 
55 
Print(int indent,AllocationTracker * tracker)56 void AllocationTraceNode::Print(int indent, AllocationTracker* tracker) {
57   base::OS::Print("%10u %10u %*c", total_size_, allocation_count_, indent, ' ');
58   if (tracker != NULL) {
59     AllocationTracker::FunctionInfo* info =
60         tracker->function_info_list()[function_info_index_];
61     base::OS::Print("%s #%u", info->name, id_);
62   } else {
63     base::OS::Print("%u #%u", function_info_index_, id_);
64   }
65   base::OS::Print("\n");
66   indent += 2;
67   for (int i = 0; i < children_.length(); i++) {
68     children_[i]->Print(indent, tracker);
69   }
70 }
71 
72 
AllocationTraceTree()73 AllocationTraceTree::AllocationTraceTree()
74     : next_node_id_(1),
75       root_(this, 0) {
76 }
77 
78 
~AllocationTraceTree()79 AllocationTraceTree::~AllocationTraceTree() {
80 }
81 
82 
AddPathFromEnd(const Vector<unsigned> & path)83 AllocationTraceNode* AllocationTraceTree::AddPathFromEnd(
84     const Vector<unsigned>& path) {
85   AllocationTraceNode* node = root();
86   for (unsigned* entry = path.start() + path.length() - 1;
87        entry != path.start() - 1;
88        --entry) {
89     node = node->FindOrAddChild(*entry);
90   }
91   return node;
92 }
93 
94 
Print(AllocationTracker * tracker)95 void AllocationTraceTree::Print(AllocationTracker* tracker) {
96   base::OS::Print("[AllocationTraceTree:]\n");
97   base::OS::Print("Total size | Allocation count | Function id | id\n");
98   root()->Print(0, tracker);
99 }
100 
101 
DeleteUnresolvedLocation(UnresolvedLocation ** location)102 void AllocationTracker::DeleteUnresolvedLocation(
103     UnresolvedLocation** location) {
104   delete *location;
105 }
106 
107 
FunctionInfo()108 AllocationTracker::FunctionInfo::FunctionInfo()
109     : name(""),
110       function_id(0),
111       script_name(""),
112       script_id(0),
113       line(-1),
114       column(-1) {
115 }
116 
117 
AddRange(Address start,int size,unsigned trace_node_id)118 void AddressToTraceMap::AddRange(Address start, int size,
119                                  unsigned trace_node_id) {
120   Address end = start + size;
121   RemoveRange(start, end);
122 
123   RangeStack new_range(start, trace_node_id);
124   ranges_.insert(RangeMap::value_type(end, new_range));
125 }
126 
127 
GetTraceNodeId(Address addr)128 unsigned AddressToTraceMap::GetTraceNodeId(Address addr) {
129   RangeMap::const_iterator it = ranges_.upper_bound(addr);
130   if (it == ranges_.end()) return 0;
131   if (it->second.start <= addr) {
132     return it->second.trace_node_id;
133   }
134   return 0;
135 }
136 
137 
MoveObject(Address from,Address to,int size)138 void AddressToTraceMap::MoveObject(Address from, Address to, int size) {
139   unsigned trace_node_id = GetTraceNodeId(from);
140   if (trace_node_id == 0) return;
141   RemoveRange(from, from + size);
142   AddRange(to, size, trace_node_id);
143 }
144 
145 
Clear()146 void AddressToTraceMap::Clear() {
147   ranges_.clear();
148 }
149 
150 
Print()151 void AddressToTraceMap::Print() {
152   PrintF("[AddressToTraceMap (%" V8PRIuPTR "): \n", ranges_.size());
153   for (RangeMap::iterator it = ranges_.begin(); it != ranges_.end(); ++it) {
154     PrintF("[%p - %p] => %u\n", it->second.start, it->first,
155         it->second.trace_node_id);
156   }
157   PrintF("]\n");
158 }
159 
160 
RemoveRange(Address start,Address end)161 void AddressToTraceMap::RemoveRange(Address start, Address end) {
162   RangeMap::iterator it = ranges_.upper_bound(start);
163   if (it == ranges_.end()) return;
164 
165   RangeStack prev_range(0, 0);
166 
167   RangeMap::iterator to_remove_begin = it;
168   if (it->second.start < start) {
169     prev_range = it->second;
170   }
171   do {
172     if (it->first > end) {
173       if (it->second.start < end) {
174         it->second.start = end;
175       }
176       break;
177     }
178     ++it;
179   }
180   while (it != ranges_.end());
181 
182   ranges_.erase(to_remove_begin, it);
183 
184   if (prev_range.start != 0) {
185     ranges_.insert(RangeMap::value_type(start, prev_range));
186   }
187 }
188 
189 
DeleteFunctionInfo(FunctionInfo ** info)190 void AllocationTracker::DeleteFunctionInfo(FunctionInfo** info) {
191     delete *info;
192 }
193 
194 
AllocationTracker(HeapObjectsMap * ids,StringsStorage * names)195 AllocationTracker::AllocationTracker(
196     HeapObjectsMap* ids, StringsStorage* names)
197     : ids_(ids),
198       names_(names),
199       id_to_function_info_index_(HashMap::PointersMatch),
200       info_index_for_other_state_(0) {
201   FunctionInfo* info = new FunctionInfo();
202   info->name = "(root)";
203   function_info_list_.Add(info);
204 }
205 
206 
~AllocationTracker()207 AllocationTracker::~AllocationTracker() {
208   unresolved_locations_.Iterate(DeleteUnresolvedLocation);
209   function_info_list_.Iterate(&DeleteFunctionInfo);
210 }
211 
212 
PrepareForSerialization()213 void AllocationTracker::PrepareForSerialization() {
214   List<UnresolvedLocation*> copy(unresolved_locations_.length());
215   copy.AddAll(unresolved_locations_);
216   unresolved_locations_.Clear();
217   for (int i = 0; i < copy.length(); i++) {
218     copy[i]->Resolve();
219     delete copy[i];
220   }
221 }
222 
223 
AllocationEvent(Address addr,int size)224 void AllocationTracker::AllocationEvent(Address addr, int size) {
225   DisallowHeapAllocation no_allocation;
226   Heap* heap = ids_->heap();
227 
228   // Mark the new block as FreeSpace to make sure the heap is iterable
229   // while we are capturing stack trace.
230   FreeListNode::FromAddress(addr)->set_size(heap, size);
231   DCHECK_EQ(HeapObject::FromAddress(addr)->Size(), size);
232   DCHECK(FreeListNode::IsFreeListNode(HeapObject::FromAddress(addr)));
233 
234   Isolate* isolate = heap->isolate();
235   int length = 0;
236   StackTraceFrameIterator it(isolate);
237   while (!it.done() && length < kMaxAllocationTraceLength) {
238     JavaScriptFrame* frame = it.frame();
239     SharedFunctionInfo* shared = frame->function()->shared();
240     SnapshotObjectId id = ids_->FindOrAddEntry(
241         shared->address(), shared->Size(), false);
242     allocation_trace_buffer_[length++] = AddFunctionInfo(shared, id);
243     it.Advance();
244   }
245   if (length == 0) {
246     unsigned index = functionInfoIndexForVMState(isolate->current_vm_state());
247     if (index != 0) {
248       allocation_trace_buffer_[length++] = index;
249     }
250   }
251   AllocationTraceNode* top_node = trace_tree_.AddPathFromEnd(
252       Vector<unsigned>(allocation_trace_buffer_, length));
253   top_node->AddAllocation(size);
254 
255   address_to_trace_.AddRange(addr, size, top_node->id());
256 }
257 
258 
SnapshotObjectIdHash(SnapshotObjectId id)259 static uint32_t SnapshotObjectIdHash(SnapshotObjectId id) {
260   return ComputeIntegerHash(static_cast<uint32_t>(id),
261                             v8::internal::kZeroHashSeed);
262 }
263 
264 
AddFunctionInfo(SharedFunctionInfo * shared,SnapshotObjectId id)265 unsigned AllocationTracker::AddFunctionInfo(SharedFunctionInfo* shared,
266                                             SnapshotObjectId id) {
267   HashMap::Entry* entry = id_to_function_info_index_.Lookup(
268       reinterpret_cast<void*>(id), SnapshotObjectIdHash(id), true);
269   if (entry->value == NULL) {
270     FunctionInfo* info = new FunctionInfo();
271     info->name = names_->GetFunctionName(shared->DebugName());
272     info->function_id = id;
273     if (shared->script()->IsScript()) {
274       Script* script = Script::cast(shared->script());
275       if (script->name()->IsName()) {
276         Name* name = Name::cast(script->name());
277         info->script_name = names_->GetName(name);
278       }
279       info->script_id = script->id()->value();
280       // Converting start offset into line and column may cause heap
281       // allocations so we postpone them until snapshot serialization.
282       unresolved_locations_.Add(new UnresolvedLocation(
283           script,
284           shared->start_position(),
285           info));
286     }
287     entry->value = reinterpret_cast<void*>(function_info_list_.length());
288     function_info_list_.Add(info);
289   }
290   return static_cast<unsigned>(reinterpret_cast<intptr_t>((entry->value)));
291 }
292 
293 
functionInfoIndexForVMState(StateTag state)294 unsigned AllocationTracker::functionInfoIndexForVMState(StateTag state) {
295   if (state != OTHER) return 0;
296   if (info_index_for_other_state_ == 0) {
297     FunctionInfo* info = new FunctionInfo();
298     info->name = "(V8 API)";
299     info_index_for_other_state_ = function_info_list_.length();
300     function_info_list_.Add(info);
301   }
302   return info_index_for_other_state_;
303 }
304 
305 
UnresolvedLocation(Script * script,int start,FunctionInfo * info)306 AllocationTracker::UnresolvedLocation::UnresolvedLocation(
307     Script* script, int start, FunctionInfo* info)
308     : start_position_(start),
309       info_(info) {
310   script_ = Handle<Script>::cast(
311       script->GetIsolate()->global_handles()->Create(script));
312   GlobalHandles::MakeWeak(reinterpret_cast<Object**>(script_.location()),
313                           this,
314                           &HandleWeakScript);
315 }
316 
317 
~UnresolvedLocation()318 AllocationTracker::UnresolvedLocation::~UnresolvedLocation() {
319   if (!script_.is_null()) {
320     GlobalHandles::Destroy(reinterpret_cast<Object**>(script_.location()));
321   }
322 }
323 
324 
Resolve()325 void AllocationTracker::UnresolvedLocation::Resolve() {
326   if (script_.is_null()) return;
327   HandleScope scope(script_->GetIsolate());
328   info_->line = Script::GetLineNumber(script_, start_position_);
329   info_->column = Script::GetColumnNumber(script_, start_position_);
330 }
331 
332 
HandleWeakScript(const v8::WeakCallbackData<v8::Value,void> & data)333 void AllocationTracker::UnresolvedLocation::HandleWeakScript(
334     const v8::WeakCallbackData<v8::Value, void>& data) {
335   UnresolvedLocation* loc =
336       reinterpret_cast<UnresolvedLocation*>(data.GetParameter());
337   GlobalHandles::Destroy(reinterpret_cast<Object**>(loc->script_.location()));
338   loc->script_ = Handle<Script>::null();
339 }
340 
341 
342 } }  // namespace v8::internal
343