1 // Copyright (c) 2012 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/threading/platform_thread.h"
6
7 #include <errno.h>
8 #include <sched.h>
9 #include <stddef.h>
10
11 #include "base/files/file_util.h"
12 #include "base/lazy_instance.h"
13 #include "base/logging.h"
14 #include "base/strings/string_number_conversions.h"
15 #include "base/threading/platform_thread_internal_posix.h"
16 #include "base/threading/thread_id_name_manager.h"
17 #include "base/tracked_objects.h"
18 #include "build/build_config.h"
19
20 #if !defined(OS_NACL)
21 #include <pthread.h>
22 #include <sys/prctl.h>
23 #include <sys/resource.h>
24 #include <sys/time.h>
25 #include <sys/types.h>
26 #include <unistd.h>
27 #endif
28
29 namespace base {
30 namespace {
31 #if !defined(OS_NACL)
32 const FilePath::CharType kCgroupDirectory[] =
33 FILE_PATH_LITERAL("/sys/fs/cgroup");
34
ThreadPriorityToCgroupDirectory(const FilePath & cgroup_filepath,ThreadPriority priority)35 FilePath ThreadPriorityToCgroupDirectory(const FilePath& cgroup_filepath,
36 ThreadPriority priority) {
37 switch (priority) {
38 case ThreadPriority::NORMAL:
39 return cgroup_filepath;
40 case ThreadPriority::BACKGROUND:
41 return cgroup_filepath.Append(FILE_PATH_LITERAL("non-urgent"));
42 case ThreadPriority::DISPLAY:
43 case ThreadPriority::REALTIME_AUDIO:
44 return cgroup_filepath.Append(FILE_PATH_LITERAL("urgent"));
45 }
46 NOTREACHED();
47 return FilePath();
48 }
49
SetThreadCgroup(PlatformThreadId thread_id,const FilePath & cgroup_directory)50 void SetThreadCgroup(PlatformThreadId thread_id,
51 const FilePath& cgroup_directory) {
52 FilePath tasks_filepath = cgroup_directory.Append(FILE_PATH_LITERAL("tasks"));
53 std::string tid = IntToString(thread_id);
54 int bytes_written = WriteFile(tasks_filepath, tid.c_str(), tid.size());
55 if (bytes_written != static_cast<int>(tid.size())) {
56 DVLOG(1) << "Failed to add " << tid << " to " << tasks_filepath.value();
57 }
58 }
59
SetThreadCgroupForThreadPriority(PlatformThreadId thread_id,const FilePath & cgroup_filepath,ThreadPriority priority)60 void SetThreadCgroupForThreadPriority(PlatformThreadId thread_id,
61 const FilePath& cgroup_filepath,
62 ThreadPriority priority) {
63 // Append "chrome" suffix.
64 FilePath cgroup_directory = ThreadPriorityToCgroupDirectory(
65 cgroup_filepath.Append(FILE_PATH_LITERAL("chrome")), priority);
66
67 // Silently ignore request if cgroup directory doesn't exist.
68 if (!DirectoryExists(cgroup_directory))
69 return;
70
71 SetThreadCgroup(thread_id, cgroup_directory);
72 }
73
SetThreadCgroupsForThreadPriority(PlatformThreadId thread_id,ThreadPriority priority)74 void SetThreadCgroupsForThreadPriority(PlatformThreadId thread_id,
75 ThreadPriority priority) {
76 FilePath cgroup_filepath(kCgroupDirectory);
77 SetThreadCgroupForThreadPriority(
78 thread_id, cgroup_filepath.Append(FILE_PATH_LITERAL("cpuset")), priority);
79 SetThreadCgroupForThreadPriority(
80 thread_id, cgroup_filepath.Append(FILE_PATH_LITERAL("schedtune")),
81 priority);
82 }
83 #endif
84 } // namespace
85
86 namespace internal {
87
88 namespace {
89 #if !defined(OS_NACL)
90 const struct sched_param kRealTimePrio = {8};
91 #endif
92 } // namespace
93
94 const ThreadPriorityToNiceValuePair kThreadPriorityToNiceValueMap[4] = {
95 {ThreadPriority::BACKGROUND, 10},
96 {ThreadPriority::NORMAL, 0},
97 {ThreadPriority::DISPLAY, -8},
98 {ThreadPriority::REALTIME_AUDIO, -10},
99 };
100
SetCurrentThreadPriorityForPlatform(ThreadPriority priority)101 bool SetCurrentThreadPriorityForPlatform(ThreadPriority priority) {
102 #if !defined(OS_NACL)
103 SetThreadCgroupsForThreadPriority(PlatformThread::CurrentId(), priority);
104 return priority == ThreadPriority::REALTIME_AUDIO &&
105 pthread_setschedparam(pthread_self(), SCHED_RR, &kRealTimePrio) == 0;
106 #else
107 return false;
108 #endif
109 }
110
GetCurrentThreadPriorityForPlatform(ThreadPriority * priority)111 bool GetCurrentThreadPriorityForPlatform(ThreadPriority* priority) {
112 #if !defined(OS_NACL)
113 int maybe_sched_rr = 0;
114 struct sched_param maybe_realtime_prio = {0};
115 if (pthread_getschedparam(pthread_self(), &maybe_sched_rr,
116 &maybe_realtime_prio) == 0 &&
117 maybe_sched_rr == SCHED_RR &&
118 maybe_realtime_prio.sched_priority == kRealTimePrio.sched_priority) {
119 *priority = ThreadPriority::REALTIME_AUDIO;
120 return true;
121 }
122 #endif
123 return false;
124 }
125
126 } // namespace internal
127
128 // static
SetName(const std::string & name)129 void PlatformThread::SetName(const std::string& name) {
130 ThreadIdNameManager::GetInstance()->SetName(CurrentId(), name);
131 tracked_objects::ThreadData::InitializeThreadContext(name);
132
133 #if !defined(OS_NACL)
134 // On linux we can get the thread names to show up in the debugger by setting
135 // the process name for the LWP. We don't want to do this for the main
136 // thread because that would rename the process, causing tools like killall
137 // to stop working.
138 if (PlatformThread::CurrentId() == getpid())
139 return;
140
141 // http://0pointer.de/blog/projects/name-your-threads.html
142 // Set the name for the LWP (which gets truncated to 15 characters).
143 // Note that glibc also has a 'pthread_setname_np' api, but it may not be
144 // available everywhere and it's only benefit over using prctl directly is
145 // that it can set the name of threads other than the current thread.
146 int err = prctl(PR_SET_NAME, name.c_str());
147 // We expect EPERM failures in sandboxed processes, just ignore those.
148 if (err < 0 && errno != EPERM)
149 DPLOG(ERROR) << "prctl(PR_SET_NAME)";
150 #endif // !defined(OS_NACL)
151 }
152
153 #if !defined(OS_NACL)
154 // static
SetThreadPriority(PlatformThreadId thread_id,ThreadPriority priority)155 void PlatformThread::SetThreadPriority(PlatformThreadId thread_id,
156 ThreadPriority priority) {
157 // Changing current main threads' priority is not permitted in favor of
158 // security, this interface is restricted to change only non-main thread
159 // priority.
160 CHECK_NE(thread_id, getpid());
161
162 SetThreadCgroupsForThreadPriority(thread_id, priority);
163
164 const int nice_setting = internal::ThreadPriorityToNiceValue(priority);
165 if (setpriority(PRIO_PROCESS, thread_id, nice_setting)) {
166 DVPLOG(1) << "Failed to set nice value of thread (" << thread_id << ") to "
167 << nice_setting;
168 }
169 }
170 #endif // !defined(OS_NACL)
171
InitThreading()172 void InitThreading() {}
173
TerminateOnThread()174 void TerminateOnThread() {}
175
GetDefaultThreadStackSize(const pthread_attr_t & attributes)176 size_t GetDefaultThreadStackSize(const pthread_attr_t& attributes) {
177 #if !defined(THREAD_SANITIZER)
178 return 0;
179 #else
180 // ThreadSanitizer bloats the stack heavily. Evidence has been that the
181 // default stack size isn't enough for some browser tests.
182 return 2 * (1 << 23); // 2 times 8192K (the default stack size on Linux).
183 #endif
184 }
185
186 } // namespace base
187