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/strings/string_number_conversions.h"
8 #include "base/trace_event/memory_allocator_dump_guid.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 const char SharedMemoryTracker::kDumpRootName[] = "shared_memory";
15
16 // static
GetInstance()17 SharedMemoryTracker* SharedMemoryTracker::GetInstance() {
18 static SharedMemoryTracker* instance = new SharedMemoryTracker;
19 return instance;
20 }
21
22 // static
GetDumpNameForTracing(const UnguessableToken & id)23 std::string SharedMemoryTracker::GetDumpNameForTracing(
24 const UnguessableToken& id) {
25 DCHECK(!id.is_empty());
26 return std::string(kDumpRootName) + "/" + id.ToString();
27 }
28
29 // static
30 trace_event::MemoryAllocatorDumpGuid
GetGlobalDumpIdForTracing(const UnguessableToken & id)31 SharedMemoryTracker::GetGlobalDumpIdForTracing(const UnguessableToken& id) {
32 std::string dump_name = GetDumpNameForTracing(id);
33 return trace_event::MemoryAllocatorDumpGuid(dump_name);
34 }
35
36 const trace_event::MemoryAllocatorDump*
GetOrCreateSharedMemoryDump(const SharedMemoryMapping & shared_memory,trace_event::ProcessMemoryDump * pmd)37 SharedMemoryTracker::GetOrCreateSharedMemoryDump(
38 const SharedMemoryMapping& shared_memory,
39 trace_event::ProcessMemoryDump* pmd) {
40 return GetOrCreateSharedMemoryDumpInternal(shared_memory.raw_memory_ptr(),
41 shared_memory.mapped_size(),
42 shared_memory.guid(), pmd);
43 }
44
IncrementMemoryUsage(const SharedMemoryMapping & mapping)45 void SharedMemoryTracker::IncrementMemoryUsage(
46 const SharedMemoryMapping& mapping) {
47 AutoLock hold(usages_lock_);
48 DCHECK(usages_.find(mapping.raw_memory_ptr()) == usages_.end());
49 usages_.emplace(mapping.raw_memory_ptr(),
50 UsageInfo(mapping.mapped_size(), mapping.guid()));
51 }
52
DecrementMemoryUsage(const SharedMemoryMapping & mapping)53 void SharedMemoryTracker::DecrementMemoryUsage(
54 const SharedMemoryMapping& mapping) {
55 AutoLock hold(usages_lock_);
56 DCHECK(usages_.find(mapping.raw_memory_ptr()) != usages_.end());
57 usages_.erase(mapping.raw_memory_ptr());
58 }
59
SharedMemoryTracker()60 SharedMemoryTracker::SharedMemoryTracker() {
61 trace_event::MemoryDumpManager::GetInstance()->RegisterDumpProvider(
62 this, "SharedMemoryTracker", nullptr);
63 }
64
65 SharedMemoryTracker::~SharedMemoryTracker() = default;
66
OnMemoryDump(const trace_event::MemoryDumpArgs & args,trace_event::ProcessMemoryDump * pmd)67 bool SharedMemoryTracker::OnMemoryDump(const trace_event::MemoryDumpArgs& args,
68 trace_event::ProcessMemoryDump* pmd) {
69 AutoLock hold(usages_lock_);
70 for (const auto& usage : usages_) {
71 const trace_event::MemoryAllocatorDump* dump =
72 GetOrCreateSharedMemoryDumpInternal(
73 usage.first, usage.second.mapped_size, usage.second.mapped_id, pmd);
74 DCHECK(dump);
75 }
76 return true;
77 }
78
79 // static
80 const trace_event::MemoryAllocatorDump*
GetOrCreateSharedMemoryDumpInternal(void * mapped_memory,size_t mapped_size,const UnguessableToken & mapped_id,trace_event::ProcessMemoryDump * pmd)81 SharedMemoryTracker::GetOrCreateSharedMemoryDumpInternal(
82 void* mapped_memory,
83 size_t mapped_size,
84 const UnguessableToken& mapped_id,
85 trace_event::ProcessMemoryDump* pmd) {
86 const std::string dump_name = GetDumpNameForTracing(mapped_id);
87 trace_event::MemoryAllocatorDump* local_dump =
88 pmd->GetAllocatorDump(dump_name);
89 if (local_dump)
90 return local_dump;
91
92 size_t virtual_size = mapped_size;
93 // If resident size is not available, a virtual size is used as fallback.
94 size_t size = virtual_size;
95 #if defined(COUNT_RESIDENT_BYTES_SUPPORTED)
96 base::Optional<size_t> resident_size =
97 trace_event::ProcessMemoryDump::CountResidentBytesInSharedMemory(
98 mapped_memory, mapped_size);
99 if (resident_size.has_value())
100 size = resident_size.value();
101 #endif
102
103 local_dump = pmd->CreateAllocatorDump(dump_name);
104 local_dump->AddScalar(trace_event::MemoryAllocatorDump::kNameSize,
105 trace_event::MemoryAllocatorDump::kUnitsBytes, size);
106 local_dump->AddScalar("virtual_size",
107 trace_event::MemoryAllocatorDump::kUnitsBytes,
108 virtual_size);
109 auto global_dump_guid = GetGlobalDumpIdForTracing(mapped_id);
110 trace_event::MemoryAllocatorDump* global_dump =
111 pmd->CreateSharedGlobalAllocatorDump(global_dump_guid);
112 global_dump->AddScalar(trace_event::MemoryAllocatorDump::kNameSize,
113 trace_event::MemoryAllocatorDump::kUnitsBytes, size);
114
115 // The edges will be overriden by the clients with correct importance.
116 pmd->AddOverridableOwnershipEdge(local_dump->guid(), global_dump->guid(),
117 0 /* importance */);
118 return local_dump;
119 }
120
121 } // namespace
122