• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright (C) 2018 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 #ifndef SRC_TRACED_PROBES_PS_PROCESS_STATS_DATA_SOURCE_H_
18 #define SRC_TRACED_PROBES_PS_PROCESS_STATS_DATA_SOURCE_H_
19 
20 #include <limits>
21 #include <memory>
22 #include <set>
23 #include <unordered_map>
24 #include <vector>
25 
26 #include "perfetto/base/scoped_file.h"
27 #include "perfetto/base/weak_ptr.h"
28 #include "perfetto/tracing/core/basic_types.h"
29 #include "perfetto/tracing/core/data_source_config.h"
30 #include "perfetto/tracing/core/trace_writer.h"
31 #include "src/traced/probes/probes_data_source.h"
32 
33 namespace perfetto {
34 
35 namespace base {
36 class TaskRunner;
37 }
38 
39 namespace protos {
40 namespace pbzero {
41 class ProcessTree;
42 class ProcessStats;
43 class ProcessStats_Process;
44 }  // namespace pbzero
45 }  // namespace protos
46 
47 class ProcessStatsDataSource : public ProbesDataSource {
48  public:
49   static constexpr int kTypeId = 3;
50 
51   ProcessStatsDataSource(base::TaskRunner*,
52                          TracingSessionID,
53                          std::unique_ptr<TraceWriter> writer,
54                          const DataSourceConfig&);
55   ~ProcessStatsDataSource() override;
56 
57   base::WeakPtr<ProcessStatsDataSource> GetWeakPtr() const;
58   void WriteAllProcesses();
59   void OnPids(const std::vector<int32_t>& pids);
60   void OnRenamePids(const std::vector<int32_t>& pids);
61 
62   // ProbesDataSource implementation.
63   void Start() override;
64   void Flush(FlushRequestID, std::function<void()> callback) override;
65   void ClearIncrementalState() override;
66 
on_demand_dumps_enabled()67   bool on_demand_dumps_enabled() const { return enable_on_demand_dumps_; }
68 
69   // Virtual for testing.
70   virtual base::ScopedDir OpenProcDir();
71   virtual std::string ReadProcPidFile(int32_t pid, const std::string& file);
72 
73  private:
74   struct CachedProcessStats {
75     uint32_t vm_size_kb = std::numeric_limits<uint32_t>::max();
76     uint32_t vm_rss_kb = std::numeric_limits<uint32_t>::max();
77     uint32_t rss_anon_kb = std::numeric_limits<uint32_t>::max();
78     uint32_t rss_file_kb = std::numeric_limits<uint32_t>::max();
79     uint32_t rss_shmem_kb = std::numeric_limits<uint32_t>::max();
80     uint32_t vm_swap_kb = std::numeric_limits<uint32_t>::max();
81     uint32_t vm_locked_kb = std::numeric_limits<uint32_t>::max();
82     uint32_t vm_hvm_kb = std::numeric_limits<uint32_t>::max();
83     int oom_score_adj = std::numeric_limits<int>::max();
84   };
85 
86   // Common functions.
87   ProcessStatsDataSource(const ProcessStatsDataSource&) = delete;
88   ProcessStatsDataSource& operator=(const ProcessStatsDataSource&) = delete;
89 
90   void StartNewPacketIfNeeded();
91   void FinalizeCurPacket();
92   protos::pbzero::ProcessTree* GetOrCreatePsTree();
93   protos::pbzero::ProcessStats* GetOrCreateStats();
94   protos::pbzero::ProcessStats_Process* GetOrCreateStatsProcess(int32_t pid);
95 
96   // Functions for snapshotting process/thread long-term info and relationships.
97   void WriteProcess(int32_t pid, const std::string& proc_status);
98   void WriteThread(int32_t tid, int32_t tgid, const char* optional_name);
99   void WriteProcessOrThread(int32_t pid);
100   std::string ReadProcStatusEntry(const std::string& buf, const char* key);
101 
102   // Functions for periodically sampling process stats/counters.
103   static void Tick(base::WeakPtr<ProcessStatsDataSource>);
104   void WriteAllProcessStats();
105   bool WriteMemCounters(int32_t pid, const std::string& proc_status);
106 
107   // Read and "latch" the current procfs scan-start timestamp, which
108   // we reset only in FinalizeCurPacket.
109   uint64_t CacheProcFsScanStartTimestamp();
110 
111   // Common fields used for both process/tree relationships and stats/counters.
112   base::TaskRunner* const task_runner_;
113   std::unique_ptr<TraceWriter> writer_;
114   TraceWriter::TracePacketHandle cur_packet_;
115 
116   // Cached before-scan timestamp; zero means cached time is absent.
117   // By the time we create the trace packet into which we dump procfs
118   // scan results, we've already read at least one bit of data from
119   // procfs, and by that point, it's too late to snap a timestamp from
120   // before we started looking at procfs at all, which is what trace
121   // analysis wants.  To solve this problem, we record the scan-start
122   // timestamp here when we first open something in procfs and use
123   // that time when we create the packet.
124   // We reset this field after each FinalizeCurPacket().
125   uint64_t cur_procfs_scan_start_timestamp_ = 0;
126 
127   // Fields for keeping track of the state of process/tree relationships.
128   protos::pbzero::ProcessTree* cur_ps_tree_ = nullptr;
129   bool record_thread_names_ = false;
130   bool enable_on_demand_dumps_ = true;
131   bool dump_all_procs_on_start_ = false;
132 
133   // This set contains PIDs as per the Linux kernel notion of a PID (which is
134   // really a TID). In practice this set will contain all TIDs for all processes
135   // seen, not just the main thread id (aka thread group ID).
136   std::set<int32_t> seen_pids_;
137 
138   // Fields for keeping track of the periodic stats/counters.
139   uint32_t poll_period_ms_ = 0;
140   uint64_t cache_ticks_ = 0;
141   protos::pbzero::ProcessStats* cur_ps_stats_ = nullptr;
142   protos::pbzero::ProcessStats_Process* cur_ps_stats_process_ = nullptr;
143   std::vector<bool> skip_stats_for_pids_;
144 
145   // Cached process stats per process. Cleared every |cache_ttl_ticks_| *
146   // |poll_period_ms_| ms.
147   uint32_t process_stats_cache_ttl_ticks_ = 0;
148   std::unordered_map<int32_t, CachedProcessStats> process_stats_cache_;
149 
150   // If true, the next trace packet will have the |incremental_state_cleared|
151   // flag set. Set when handling a ClearIncrementalState call.
152   //
153   // TODO(rsavitski): initialized to true since the first packet also doesn't
154   // have any prior state to refer to. It might make more sense to let the
155   // tracing service set this for every first packet (as it does for
156   // |previous_packet_dropped|).
157   bool did_clear_incremental_state_ = true;
158 
159   base::WeakPtrFactory<ProcessStatsDataSource> weak_factory_;  // Keep last.
160 };
161 
162 }  // namespace perfetto
163 
164 #endif  // SRC_TRACED_PROBES_PS_PROCESS_STATS_DATA_SOURCE_H_
165