1 // Copyright 2014 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 #ifndef CHROME_BROWSER_CHROMEOS_POWER_CPU_DATA_COLLECTOR_H_
6 #define CHROME_BROWSER_CHROMEOS_POWER_CPU_DATA_COLLECTOR_H_
7 
8 #include <stdint.h>
9 
10 #include <map>
11 #include <string>
12 #include <vector>
13 
14 #include "base/containers/circular_deque.h"
15 #include "base/files/file_util.h"
16 #include "base/macros.h"
17 #include "base/memory/weak_ptr.h"
18 #include "base/time/time.h"
19 #include "base/timer/timer.h"
20 
21 namespace chromeos {
22 
23 // A class to sample CPU idle state occupancy and freq state occupancy.
24 // Collects raw data from sysfs and does not convert it to percentage
25 // occupancy. As CPUs can be offline at times, or the system can be suspended at
26 // other times, it is best for the consumer of this data to calculate percentage
27 // occupancy information using suspend time data from
28 // PowerDataCollector::system_resumed_data.
29 class CpuDataCollector {
30  public:
31   struct StateOccupancySample {
32     StateOccupancySample();
33     StateOccupancySample(const StateOccupancySample& other);
34     ~StateOccupancySample();
35 
36     // The time when the data was sampled.
37     base::Time time;
38 
39     // Indicates whether the CPU is online.
40     bool cpu_online;
41 
42     // A mapping from a CPU state to time spent in that state. For idle state
43     // samples, the name of the state at index i in this vector is the name at
44     // index i in the vector returned by cpu_idle_state_names(). Similarly, for
45     // freq state occupancy, similar information is in the vector returned by
46     // cpu_freq_state_names().
47     std::vector<base::TimeDelta> time_in_state;
48   };
49 
50   using StateOccupancySampleDeque = base::circular_deque<StateOccupancySample>;
51 
cpu_idle_state_names()52   const std::vector<std::string>& cpu_idle_state_names() const {
53     return cpu_idle_state_names_;
54   }
55 
cpu_idle_state_data()56   const std::vector<StateOccupancySampleDeque>& cpu_idle_state_data() const {
57     return cpu_idle_state_data_;
58   }
59 
cpu_freq_state_names()60   const std::vector<std::string>& cpu_freq_state_names() const {
61     return cpu_freq_state_names_;
62   }
63 
cpu_freq_state_data()64   const std::vector<StateOccupancySampleDeque>& cpu_freq_state_data() const {
65     return cpu_freq_state_data_;
66   }
67 
68   CpuDataCollector();
69   ~CpuDataCollector();
70 
71   // Starts a repeating timer which periodically runs a callback to collect
72   // CPU state occupancy samples.
73   void Start();
74 
75   // Read CPU frequency data of a specific CPU from the file in |path| and fill
76   // |cpu_freq_state_names| and |freq_sample| with the data.
77   // Sample file looks like:
78   // 126000 223344
79   // 216000 93495
80   // ...
81   // 1800000 321907
82   static bool ReadCpuFreqTimeInState(
83       const base::FilePath& path,
84       std::vector<std::string>* cpu_freq_state_names,
85       CpuDataCollector::StateOccupancySample* freq_sample);
86 
87   // Read CPU frequency data of all CPUs from the file in |path| and fill
88   // |cpu_freq_state_names| and |freq_samples| with the data. |cpu_count| is the
89   // number of possible CPUs on the system. Note that |freq_samples| is not
90   // empty and sample at index i in |freq_samples| corresponds to the freq state
91   // information of the i-th CPU. |cpu_online| of each sample must be set before
92   // calling this function.
93   // Sample file looks like:
94   // freq   cpu0    cpu1
95   // 126000   223344    223311
96   // 216000   93495   93450
97   // ...
98   // 1800000    321907    331897
99   static bool ReadCpuFreqAllTimeInState(
100       int cpu_count,
101       const base::FilePath& path,
102       std::vector<std::string>* cpu_freq_state_names,
103       std::vector<CpuDataCollector::StateOccupancySample>* freq_samples);
104 
105  private:
106   // Posts callbacks to the blocking pool which collect CPU state occupancy
107   // samples from the sysfs.
108   void PostSampleCpuState();
109 
110   // This function commits the CPU count and samples read by
111   // SampleCpuStateAsync to |cpu_idle_state_data_| and
112   // |cpu_freq_state_data_|. Since UI is the consumer of CPU idle and freq data,
113   // this function should run on the UI thread.
114   void SaveCpuStateSamplesOnUIThread(
115       const int* cpu_count,
116       const std::vector<std::string>* cpu_idle_state_names,
117       const std::vector<StateOccupancySample>* idle_samples,
118       const std::vector<std::string>* cpu_freq_state_names,
119       const std::vector<StateOccupancySample>* freq_samples);
120 
121   base::RepeatingTimer timer_;
122 
123   // Names of the idle states.
124   std::vector<std::string> cpu_idle_state_names_;
125 
126   // The deque at index <i> in the vector corresponds to the idle state
127   // occupancy data of CPU<i>.
128   std::vector<StateOccupancySampleDeque> cpu_idle_state_data_;
129 
130   // Names of the freq states.
131   std::vector<std::string> cpu_freq_state_names_;
132 
133   // The deque at index <i> in the vector corresponds to the frequency state
134   // occupancy data of CPU<i>.
135   std::vector<StateOccupancySampleDeque> cpu_freq_state_data_;
136 
137   // The number of CPUs on the system. This value is read from the sysfs, and
138   // hence should be read/written to only from the blocking pool.
139   int cpu_count_;
140 
141   base::WeakPtrFactory<CpuDataCollector> weak_ptr_factory_{this};
142   DISALLOW_COPY_AND_ASSIGN(CpuDataCollector);
143 };
144 
145 }  // namespace chromeos
146 
147 #endif  // CHROME_BROWSER_CHROMEOS_POWER_CPU_DATA_COLLECTOR_H_
148