1 // Copyright 2017 The Chromium 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 "base/memory/shared_memory_tracker.h"
6
7 #include "base/memory/shared_memory.h"
8 #include "base/strings/stringprintf.h"
9 #include "base/trace_event/memory_dump_manager.h"
10 #include "base/trace_event/process_memory_dump.h"
11
12 namespace base {
13
14 SharedMemoryTracker::Usage::Usage() = default;
15
16 SharedMemoryTracker::Usage::Usage(const Usage& rhs) = default;
17
18 SharedMemoryTracker::Usage::~Usage() = default;
19
20 // static
GetInstance()21 SharedMemoryTracker* SharedMemoryTracker::GetInstance() {
22 static SharedMemoryTracker* instance = new SharedMemoryTracker;
23 return instance;
24 }
25
IncrementMemoryUsage(const SharedMemory & shared_memory)26 void SharedMemoryTracker::IncrementMemoryUsage(
27 const SharedMemory& shared_memory) {
28 Usage usage;
29 // |shared_memory|'s unique ID must be generated here and it'd be too late at
30 // OnMemoryDump. An ID is generated with a SharedMemoryHandle, but the handle
31 // might already be closed at that time. Now IncrementMemoryUsage is called
32 // just after mmap and the handle must live then. See the discussion at
33 // crbug.com/604726#c30.
34 SharedMemory::UniqueId id;
35 if (!shared_memory.GetUniqueId(&id))
36 return;
37 usage.unique_id = id;
38 usage.size = shared_memory.mapped_size();
39 AutoLock hold(usages_lock_);
40 usages_[&shared_memory] = usage;
41 }
42
DecrementMemoryUsage(const SharedMemory & shared_memory)43 void SharedMemoryTracker::DecrementMemoryUsage(
44 const SharedMemory& shared_memory) {
45 AutoLock hold(usages_lock_);
46 usages_.erase(&shared_memory);
47 }
48
OnMemoryDump(const trace_event::MemoryDumpArgs & args,trace_event::ProcessMemoryDump * pmd)49 bool SharedMemoryTracker::OnMemoryDump(const trace_event::MemoryDumpArgs& args,
50 trace_event::ProcessMemoryDump* pmd) {
51 std::unordered_map<SharedMemory::UniqueId, size_t, SharedMemory::UniqueIdHash>
52 sizes;
53 {
54 AutoLock hold(usages_lock_);
55 for (const auto& usage : usages_)
56 sizes[usage.second.unique_id] += usage.second.size;
57 }
58 for (auto& size : sizes) {
59 const SharedMemory::UniqueId& id = size.first;
60 std::string dump_name = StringPrintf("%s/%lld.%lld", "shared_memory",
61 static_cast<long long>(id.first),
62 static_cast<long long>(id.second));
63 auto guid = trace_event::MemoryAllocatorDumpGuid(dump_name);
64 trace_event::MemoryAllocatorDump* local_dump =
65 pmd->CreateAllocatorDump(dump_name);
66 // TODO(hajimehoshi): The size is not resident size but virtual size so far.
67 // Fix this to record resident size.
68 local_dump->AddScalar(trace_event::MemoryAllocatorDump::kNameSize,
69 trace_event::MemoryAllocatorDump::kUnitsBytes,
70 size.second);
71 trace_event::MemoryAllocatorDump* global_dump =
72 pmd->CreateSharedGlobalAllocatorDump(guid);
73 global_dump->AddScalar(trace_event::MemoryAllocatorDump::kNameSize,
74 trace_event::MemoryAllocatorDump::kUnitsBytes,
75 size.second);
76 // TOOD(hajimehoshi): Detect which the shared memory comes from browser,
77 // renderer or GPU process.
78 // TODO(hajimehoshi): Shared memory reported by GPU and discardable is
79 // currently double-counted. Add ownership edges to avoid this.
80 pmd->AddOwnershipEdge(local_dump->guid(), global_dump->guid());
81 }
82 return true;
83 }
84
SharedMemoryTracker()85 SharedMemoryTracker::SharedMemoryTracker() {
86 trace_event::MemoryDumpManager::GetInstance()->RegisterDumpProvider(
87 this, "SharedMemoryTracker", nullptr);
88 }
89
90 SharedMemoryTracker::~SharedMemoryTracker() = default;
91
92 } // namespace
93