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 <pthread.h>
9 #include <sched.h>
10 #include <stddef.h>
11 #include <stdint.h>
12 #include <sys/resource.h>
13 #include <sys/time.h>
14
15 #include "base/lazy_instance.h"
16 #include "base/logging.h"
17 #include "base/memory/scoped_ptr.h"
18 #include "base/threading/platform_thread_internal_posix.h"
19 #include "base/threading/thread_id_name_manager.h"
20 #include "base/threading/thread_restrictions.h"
21 #include "build/build_config.h"
22
23 #if defined(OS_LINUX)
24 #include <sys/syscall.h>
25 #elif defined(OS_ANDROID)
26 #include <sys/types.h>
27 #endif
28
29 namespace base {
30
31 void InitThreading();
32 void InitOnThread();
33 void TerminateOnThread();
34 size_t GetDefaultThreadStackSize(const pthread_attr_t& attributes);
35
36 namespace {
37
38 struct ThreadParams {
ThreadParamsbase::__anon833f19860111::ThreadParams39 ThreadParams()
40 : delegate(NULL), joinable(false), priority(ThreadPriority::NORMAL) {}
41
42 PlatformThread::Delegate* delegate;
43 bool joinable;
44 ThreadPriority priority;
45 };
46
ThreadFunc(void * params)47 void* ThreadFunc(void* params) {
48 base::InitOnThread();
49
50 PlatformThread::Delegate* delegate = nullptr;
51
52 {
53 scoped_ptr<ThreadParams> thread_params(static_cast<ThreadParams*>(params));
54
55 delegate = thread_params->delegate;
56 if (!thread_params->joinable)
57 base::ThreadRestrictions::SetSingletonAllowed(false);
58
59 if (thread_params->priority != ThreadPriority::NORMAL)
60 PlatformThread::SetCurrentThreadPriority(thread_params->priority);
61 }
62
63 ThreadIdNameManager::GetInstance()->RegisterThread(
64 PlatformThread::CurrentHandle().platform_handle(),
65 PlatformThread::CurrentId());
66
67 delegate->ThreadMain();
68
69 ThreadIdNameManager::GetInstance()->RemoveName(
70 PlatformThread::CurrentHandle().platform_handle(),
71 PlatformThread::CurrentId());
72
73 base::TerminateOnThread();
74 return NULL;
75 }
76
CreateThread(size_t stack_size,bool joinable,PlatformThread::Delegate * delegate,PlatformThreadHandle * thread_handle,ThreadPriority priority)77 bool CreateThread(size_t stack_size,
78 bool joinable,
79 PlatformThread::Delegate* delegate,
80 PlatformThreadHandle* thread_handle,
81 ThreadPriority priority) {
82 DCHECK(thread_handle);
83 base::InitThreading();
84
85 pthread_attr_t attributes;
86 pthread_attr_init(&attributes);
87
88 // Pthreads are joinable by default, so only specify the detached
89 // attribute if the thread should be non-joinable.
90 if (!joinable)
91 pthread_attr_setdetachstate(&attributes, PTHREAD_CREATE_DETACHED);
92
93 // Get a better default if available.
94 if (stack_size == 0)
95 stack_size = base::GetDefaultThreadStackSize(attributes);
96
97 if (stack_size > 0)
98 pthread_attr_setstacksize(&attributes, stack_size);
99
100 scoped_ptr<ThreadParams> params(new ThreadParams);
101 params->delegate = delegate;
102 params->joinable = joinable;
103 params->priority = priority;
104
105 pthread_t handle;
106 int err = pthread_create(&handle, &attributes, ThreadFunc, params.get());
107 bool success = !err;
108 if (success) {
109 // ThreadParams should be deleted on the created thread after used.
110 ignore_result(params.release());
111 } else {
112 // Value of |handle| is undefined if pthread_create fails.
113 handle = 0;
114 errno = err;
115 PLOG(ERROR) << "pthread_create";
116 }
117 *thread_handle = PlatformThreadHandle(handle);
118
119 pthread_attr_destroy(&attributes);
120
121 return success;
122 }
123
124 } // namespace
125
126 // static
CurrentId()127 PlatformThreadId PlatformThread::CurrentId() {
128 // Pthreads doesn't have the concept of a thread ID, so we have to reach down
129 // into the kernel.
130 #if defined(OS_MACOSX)
131 return pthread_mach_thread_np(pthread_self());
132 #elif defined(OS_LINUX)
133 return syscall(__NR_gettid);
134 #elif defined(OS_ANDROID)
135 return gettid();
136 #elif defined(OS_SOLARIS) || defined(OS_QNX)
137 return pthread_self();
138 #elif defined(OS_NACL) && defined(__GLIBC__)
139 return pthread_self();
140 #elif defined(OS_NACL) && !defined(__GLIBC__)
141 // Pointers are 32-bits in NaCl.
142 return reinterpret_cast<int32_t>(pthread_self());
143 #elif defined(OS_POSIX)
144 return reinterpret_cast<int64_t>(pthread_self());
145 #endif
146 }
147
148 // static
CurrentRef()149 PlatformThreadRef PlatformThread::CurrentRef() {
150 return PlatformThreadRef(pthread_self());
151 }
152
153 // static
CurrentHandle()154 PlatformThreadHandle PlatformThread::CurrentHandle() {
155 return PlatformThreadHandle(pthread_self());
156 }
157
158 // static
YieldCurrentThread()159 void PlatformThread::YieldCurrentThread() {
160 sched_yield();
161 }
162
163 // static
Sleep(TimeDelta duration)164 void PlatformThread::Sleep(TimeDelta duration) {
165 struct timespec sleep_time, remaining;
166
167 // Break the duration into seconds and nanoseconds.
168 // NOTE: TimeDelta's microseconds are int64s while timespec's
169 // nanoseconds are longs, so this unpacking must prevent overflow.
170 sleep_time.tv_sec = duration.InSeconds();
171 duration -= TimeDelta::FromSeconds(sleep_time.tv_sec);
172 sleep_time.tv_nsec = duration.InMicroseconds() * 1000; // nanoseconds
173
174 while (nanosleep(&sleep_time, &remaining) == -1 && errno == EINTR)
175 sleep_time = remaining;
176 }
177
178 // static
GetName()179 const char* PlatformThread::GetName() {
180 return ThreadIdNameManager::GetInstance()->GetName(CurrentId());
181 }
182
183 // static
CreateWithPriority(size_t stack_size,Delegate * delegate,PlatformThreadHandle * thread_handle,ThreadPriority priority)184 bool PlatformThread::CreateWithPriority(size_t stack_size, Delegate* delegate,
185 PlatformThreadHandle* thread_handle,
186 ThreadPriority priority) {
187 return CreateThread(stack_size, true, // joinable thread
188 delegate, thread_handle, priority);
189 }
190
191 // static
CreateNonJoinable(size_t stack_size,Delegate * delegate)192 bool PlatformThread::CreateNonJoinable(size_t stack_size, Delegate* delegate) {
193 PlatformThreadHandle unused;
194
195 bool result = CreateThread(stack_size, false /* non-joinable thread */,
196 delegate, &unused, ThreadPriority::NORMAL);
197 return result;
198 }
199
200 // static
Join(PlatformThreadHandle thread_handle)201 void PlatformThread::Join(PlatformThreadHandle thread_handle) {
202 // Joining another thread may block the current thread for a long time, since
203 // the thread referred to by |thread_handle| may still be running long-lived /
204 // blocking tasks.
205 base::ThreadRestrictions::AssertIOAllowed();
206 CHECK_EQ(0, pthread_join(thread_handle.platform_handle(), NULL));
207 }
208
209 // Mac has its own Set/GetCurrentThreadPriority() implementations.
210 #if !defined(OS_MACOSX)
211
212 // static
SetCurrentThreadPriority(ThreadPriority priority)213 void PlatformThread::SetCurrentThreadPriority(ThreadPriority priority) {
214 #if defined(OS_NACL)
215 NOTIMPLEMENTED();
216 #else
217 if (internal::SetCurrentThreadPriorityForPlatform(priority))
218 return;
219
220 // setpriority(2) should change the whole thread group's (i.e. process)
221 // priority. However, as stated in the bugs section of
222 // http://man7.org/linux/man-pages/man2/getpriority.2.html: "under the current
223 // Linux/NPTL implementation of POSIX threads, the nice value is a per-thread
224 // attribute". Also, 0 is prefered to the current thread id since it is
225 // equivalent but makes sandboxing easier (https://crbug.com/399473).
226 const int nice_setting = internal::ThreadPriorityToNiceValue(priority);
227 if (setpriority(PRIO_PROCESS, 0, nice_setting)) {
228 DVPLOG(1) << "Failed to set nice value of thread ("
229 << PlatformThread::CurrentId() << ") to " << nice_setting;
230 }
231 #endif // defined(OS_NACL)
232 }
233
234 // static
GetCurrentThreadPriority()235 ThreadPriority PlatformThread::GetCurrentThreadPriority() {
236 #if defined(OS_NACL)
237 NOTIMPLEMENTED();
238 return ThreadPriority::NORMAL;
239 #else
240 // Mirrors SetCurrentThreadPriority()'s implementation.
241 ThreadPriority platform_specific_priority;
242 if (internal::GetCurrentThreadPriorityForPlatform(
243 &platform_specific_priority)) {
244 return platform_specific_priority;
245 }
246
247 // Need to clear errno before calling getpriority():
248 // http://man7.org/linux/man-pages/man2/getpriority.2.html
249 errno = 0;
250 int nice_value = getpriority(PRIO_PROCESS, 0);
251 if (errno != 0) {
252 DVPLOG(1) << "Failed to get nice value of thread ("
253 << PlatformThread::CurrentId() << ")";
254 return ThreadPriority::NORMAL;
255 }
256
257 return internal::NiceValueToThreadPriority(nice_value);
258 #endif // !defined(OS_NACL)
259 }
260
261 #endif // !defined(OS_MACOSX)
262
263 } // namespace base
264