1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
|
/*
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef SRC_TRACED_PROBES_FTRACE_FTRACE_PROCFS_H_
#define SRC_TRACED_PROBES_FTRACE_FTRACE_PROCFS_H_
#include <memory>
#include <set>
#include <string>
#include <vector>
#include "perfetto/ext/base/scoped_file.h"
namespace perfetto {
class FtraceProcfs {
public:
static const char* const kTracingPaths[];
// Tries creating an |FtraceProcfs| at the standard tracefs mount points.
// Takes an optional |instance_path| such as "instances/wifi/", in which case
// the returned object will be for that ftrace instance path.
static std::unique_ptr<FtraceProcfs> CreateGuessingMountPoint(
const std::string& instance_path = "");
static std::unique_ptr<FtraceProcfs> Create(const std::string& root);
static int g_kmesg_fd;
explicit FtraceProcfs(const std::string& root);
virtual ~FtraceProcfs();
// Enable the event under with the given |group| and |name|.
bool EnableEvent(const std::string& group, const std::string& name);
// Disable the event under with the given |group| and |name|.
bool DisableEvent(const std::string& group, const std::string& name);
// Disable all events by writing to the global enable file.
bool DisableAllEvents();
// Read the format for event with the given |group| and |name|.
// virtual for testing.
virtual std::string ReadEventFormat(const std::string& group,
const std::string& name) const;
virtual std::string ReadPageHeaderFormat() const;
// Get all triggers for event with the given |group| and |name|.
std::vector<std::string> ReadEventTriggers(const std::string& group,
const std::string& name) const;
// Create an event trigger for the given |group| and |name|.
bool CreateEventTrigger(const std::string& group,
const std::string& name,
const std::string& trigger);
// Remove an event trigger for the given |group| and |name|.
bool RemoveEventTrigger(const std::string& group,
const std::string& name,
const std::string& trigger);
// Remove all event trigger for the given |group| and |name|.
bool RemoveAllEventTriggers(const std::string& group,
const std::string& name);
// Sets up any associated event trigger before enabling the event
bool MaybeSetUpEventTriggers(const std::string& group,
const std::string& name);
// Tears down any associated event trigger after disabling the event
bool MaybeTearDownEventTriggers(const std::string& group,
const std::string& name);
// Returns true if rss_stat_throttled synthetic event is supported
bool SupportsRssStatThrottled();
// Read the printk formats file.
std::string ReadPrintkFormats() const;
// Opens the "/per_cpu/cpuXX/stats" file for the given |cpu|.
base::ScopedFile OpenCpuStats(size_t cpu) const;
// Read the "/per_cpu/cpuXX/stats" file for the given |cpu|.
std::string ReadCpuStats(size_t cpu) const;
// Set ftrace buffer size in pages.
// This size is *per cpu* so for the total size you have to multiply
// by the number of CPUs.
bool SetCpuBufferSizeInPages(size_t pages);
// Returns the number of CPUs.
// This will match the number of tracing/per_cpu/cpuXX directories.
size_t virtual NumberOfCpus() const;
// Clears the trace buffers for all CPUs. Blocks until this is done.
void ClearTrace();
// Clears the trace buffer for cpu. Blocks until this is done.
void ClearPerCpuTrace(size_t cpu);
// Writes the string |str| as an event into the trace buffer.
bool WriteTraceMarker(const std::string& str);
// Enable tracing.
bool EnableTracing();
// Disables tracing, does not clear the buffer.
bool DisableTracing();
// Enables/disables tracing, does not clear the buffer.
bool SetTracingOn(bool enable);
// Returns true iff tracing is enabled.
// Necessarily racy: another program could enable/disable tracing at any
// point.
bool IsTracingEnabled();
// Set the clock. |clock_name| should be one of the names returned by
// AvailableClocks. Setting the clock clears the buffer.
bool SetClock(const std::string& clock_name);
// Get the currently set clock.
std::string GetClock();
// Get all the available clocks.
std::set<std::string> AvailableClocks();
// Get all the enabled events.
virtual std::vector<std::string> ReadEnabledEvents();
// Open the raw pipe for |cpu|.
virtual base::ScopedFile OpenPipeForCpu(size_t cpu);
virtual const std::set<std::string> GetEventNamesForGroup(
const std::string& path) const;
// Returns the |id| for event with the given |group| and |name|. Returns 0 if
// the event doesn't exist, or its /id file could not be read. Not typically
// needed if already parsing the format file.
uint32_t ReadEventId(const std::string& group, const std::string& name) const;
std::string GetRootPath() const { return root_; }
protected:
// virtual and protected for testing.
virtual bool WriteToFile(const std::string& path, const std::string& str);
virtual bool AppendToFile(const std::string& path, const std::string& str);
virtual bool ClearFile(const std::string& path);
virtual char ReadOneCharFromFile(const std::string& path);
virtual std::string ReadFileIntoString(const std::string& path) const;
private:
// Checks the trace file is present at the given root path.
static bool CheckRootPath(const std::string& root);
bool WriteNumberToFile(const std::string& path, size_t value);
const std::string root_;
};
} // namespace perfetto
#endif // SRC_TRACED_PROBES_FTRACE_FTRACE_PROCFS_H_
|
