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/time.h>
13 #include <sys/types.h>
14 #include <unistd.h>
15
16 #include <memory>
17
18 #include "base/debug/activity_tracker.h"
19 #include "base/lazy_instance.h"
20 #include "base/logging.h"
21 #include "base/threading/platform_thread_internal_posix.h"
22 #include "base/threading/thread_id_name_manager.h"
23 #include "base/threading/thread_restrictions.h"
24 #include "build/build_config.h"
25
26 #if defined(OS_LINUX)
27 #include <sys/syscall.h>
28 #endif
29
30 #if defined(OS_FUCHSIA)
31 #include <zircon/process.h>
32 #else
33 #include <sys/resource.h>
34 #endif
35
36 namespace base {
37
38 void InitThreading();
39 void TerminateOnThread();
40 size_t GetDefaultThreadStackSize(const pthread_attr_t& attributes);
41
42 namespace {
43
44 struct ThreadParams {
ThreadParamsbase::__anon1604760f0111::ThreadParams45 ThreadParams()
46 : delegate(nullptr), joinable(false), priority(ThreadPriority::NORMAL) {}
47
48 PlatformThread::Delegate* delegate;
49 bool joinable;
50 ThreadPriority priority;
51 };
52
ThreadFunc(void * params)53 void* ThreadFunc(void* params) {
54 PlatformThread::Delegate* delegate = nullptr;
55
56 {
57 std::unique_ptr<ThreadParams> thread_params(
58 static_cast<ThreadParams*>(params));
59
60 delegate = thread_params->delegate;
61 if (!thread_params->joinable)
62 base::ThreadRestrictions::SetSingletonAllowed(false);
63
64 #if !defined(OS_NACL)
65 // Threads on linux/android may inherit their priority from the thread
66 // where they were created. This explicitly sets the priority of all new
67 // threads.
68 PlatformThread::SetCurrentThreadPriority(thread_params->priority);
69 #endif
70 }
71
72 ThreadIdNameManager::GetInstance()->RegisterThread(
73 PlatformThread::CurrentHandle().platform_handle(),
74 PlatformThread::CurrentId());
75
76 delegate->ThreadMain();
77
78 ThreadIdNameManager::GetInstance()->RemoveName(
79 PlatformThread::CurrentHandle().platform_handle(),
80 PlatformThread::CurrentId());
81
82 base::TerminateOnThread();
83 return nullptr;
84 }
85
CreateThread(size_t stack_size,bool joinable,PlatformThread::Delegate * delegate,PlatformThreadHandle * thread_handle,ThreadPriority priority)86 bool CreateThread(size_t stack_size,
87 bool joinable,
88 PlatformThread::Delegate* delegate,
89 PlatformThreadHandle* thread_handle,
90 ThreadPriority priority) {
91 DCHECK(thread_handle);
92 base::InitThreading();
93
94 pthread_attr_t attributes;
95 pthread_attr_init(&attributes);
96
97 // Pthreads are joinable by default, so only specify the detached
98 // attribute if the thread should be non-joinable.
99 if (!joinable)
100 pthread_attr_setdetachstate(&attributes, PTHREAD_CREATE_DETACHED);
101
102 // Get a better default if available.
103 if (stack_size == 0)
104 stack_size = base::GetDefaultThreadStackSize(attributes);
105
106 if (stack_size > 0)
107 pthread_attr_setstacksize(&attributes, stack_size);
108
109 std::unique_ptr<ThreadParams> params(new ThreadParams);
110 params->delegate = delegate;
111 params->joinable = joinable;
112 params->priority = priority;
113
114 pthread_t handle;
115 int err = pthread_create(&handle, &attributes, ThreadFunc, params.get());
116 bool success = !err;
117 if (success) {
118 // ThreadParams should be deleted on the created thread after used.
119 ignore_result(params.release());
120 } else {
121 // Value of |handle| is undefined if pthread_create fails.
122 handle = 0;
123 errno = err;
124 PLOG(ERROR) << "pthread_create";
125 }
126 *thread_handle = PlatformThreadHandle(handle);
127
128 pthread_attr_destroy(&attributes);
129
130 return success;
131 }
132
133 } // namespace
134
135 // static
CurrentId()136 PlatformThreadId PlatformThread::CurrentId() {
137 // Pthreads doesn't have the concept of a thread ID, so we have to reach down
138 // into the kernel.
139 #if defined(OS_MACOSX)
140 return pthread_mach_thread_np(pthread_self());
141 #elif defined(OS_LINUX)
142 return syscall(__NR_gettid);
143 #elif defined(OS_ANDROID)
144 return gettid();
145 #elif defined(OS_FUCHSIA)
146 return zx_thread_self();
147 #elif defined(OS_SOLARIS) || defined(OS_QNX)
148 return pthread_self();
149 #elif defined(OS_NACL) && defined(__GLIBC__)
150 return pthread_self();
151 #elif defined(OS_NACL) && !defined(__GLIBC__)
152 // Pointers are 32-bits in NaCl.
153 return reinterpret_cast<int32_t>(pthread_self());
154 #elif defined(OS_POSIX) && defined(OS_AIX)
155 return pthread_self();
156 #elif defined(OS_POSIX) && !defined(OS_AIX)
157 return reinterpret_cast<int64_t>(pthread_self());
158 #endif
159 }
160
161 // static
CurrentRef()162 PlatformThreadRef PlatformThread::CurrentRef() {
163 return PlatformThreadRef(pthread_self());
164 }
165
166 // static
CurrentHandle()167 PlatformThreadHandle PlatformThread::CurrentHandle() {
168 return PlatformThreadHandle(pthread_self());
169 }
170
171 // static
YieldCurrentThread()172 void PlatformThread::YieldCurrentThread() {
173 sched_yield();
174 }
175
176 // static
Sleep(TimeDelta duration)177 void PlatformThread::Sleep(TimeDelta duration) {
178 struct timespec sleep_time, remaining;
179
180 // Break the duration into seconds and nanoseconds.
181 // NOTE: TimeDelta's microseconds are int64s while timespec's
182 // nanoseconds are longs, so this unpacking must prevent overflow.
183 sleep_time.tv_sec = duration.InSeconds();
184 duration -= TimeDelta::FromSeconds(sleep_time.tv_sec);
185 sleep_time.tv_nsec = duration.InMicroseconds() * 1000; // nanoseconds
186
187 while (nanosleep(&sleep_time, &remaining) == -1 && errno == EINTR)
188 sleep_time = remaining;
189 }
190
191 // static
GetName()192 const char* PlatformThread::GetName() {
193 return ThreadIdNameManager::GetInstance()->GetName(CurrentId());
194 }
195
196 // static
CreateWithPriority(size_t stack_size,Delegate * delegate,PlatformThreadHandle * thread_handle,ThreadPriority priority)197 bool PlatformThread::CreateWithPriority(size_t stack_size, Delegate* delegate,
198 PlatformThreadHandle* thread_handle,
199 ThreadPriority priority) {
200 return CreateThread(stack_size, true /* joinable thread */, delegate,
201 thread_handle, priority);
202 }
203
204 // static
CreateNonJoinable(size_t stack_size,Delegate * delegate)205 bool PlatformThread::CreateNonJoinable(size_t stack_size, Delegate* delegate) {
206 return CreateNonJoinableWithPriority(stack_size, delegate,
207 ThreadPriority::NORMAL);
208 }
209
210 // static
CreateNonJoinableWithPriority(size_t stack_size,Delegate * delegate,ThreadPriority priority)211 bool PlatformThread::CreateNonJoinableWithPriority(size_t stack_size,
212 Delegate* delegate,
213 ThreadPriority priority) {
214 PlatformThreadHandle unused;
215
216 bool result = CreateThread(stack_size, false /* non-joinable thread */,
217 delegate, &unused, priority);
218 return result;
219 }
220
221 // static
Join(PlatformThreadHandle thread_handle)222 void PlatformThread::Join(PlatformThreadHandle thread_handle) {
223 // Record the event that this thread is blocking upon (for hang diagnosis).
224 base::debug::ScopedThreadJoinActivity thread_activity(&thread_handle);
225
226 // Joining another thread may block the current thread for a long time, since
227 // the thread referred to by |thread_handle| may still be running long-lived /
228 // blocking tasks.
229 AssertBlockingAllowed();
230 CHECK_EQ(0, pthread_join(thread_handle.platform_handle(), nullptr));
231 }
232
233 // static
Detach(PlatformThreadHandle thread_handle)234 void PlatformThread::Detach(PlatformThreadHandle thread_handle) {
235 CHECK_EQ(0, pthread_detach(thread_handle.platform_handle()));
236 }
237
238 // Mac and Fuchsia have their own Set/GetCurrentThreadPriority()
239 // implementations.
240 #if !defined(OS_MACOSX) && !defined(OS_FUCHSIA)
241
242 // static
CanIncreaseCurrentThreadPriority()243 bool PlatformThread::CanIncreaseCurrentThreadPriority() {
244 #if defined(OS_NACL)
245 return false;
246 #else
247 // Only root can raise thread priority on POSIX environment. On Linux, users
248 // who have CAP_SYS_NICE permission also can raise the thread priority, but
249 // libcap.so would be needed to check the capability.
250 return geteuid() == 0;
251 #endif // defined(OS_NACL)
252 }
253
254 // static
SetCurrentThreadPriority(ThreadPriority priority)255 void PlatformThread::SetCurrentThreadPriority(ThreadPriority priority) {
256 #if defined(OS_NACL)
257 NOTIMPLEMENTED();
258 #else
259 if (internal::SetCurrentThreadPriorityForPlatform(priority))
260 return;
261
262 // setpriority(2) should change the whole thread group's (i.e. process)
263 // priority. However, as stated in the bugs section of
264 // http://man7.org/linux/man-pages/man2/getpriority.2.html: "under the current
265 // Linux/NPTL implementation of POSIX threads, the nice value is a per-thread
266 // attribute". Also, 0 is prefered to the current thread id since it is
267 // equivalent but makes sandboxing easier (https://crbug.com/399473).
268 const int nice_setting = internal::ThreadPriorityToNiceValue(priority);
269 if (setpriority(PRIO_PROCESS, 0, nice_setting)) {
270 DVPLOG(1) << "Failed to set nice value of thread ("
271 << PlatformThread::CurrentId() << ") to " << nice_setting;
272 }
273 #endif // defined(OS_NACL)
274 }
275
276 // static
GetCurrentThreadPriority()277 ThreadPriority PlatformThread::GetCurrentThreadPriority() {
278 #if defined(OS_NACL)
279 NOTIMPLEMENTED();
280 return ThreadPriority::NORMAL;
281 #else
282 // Mirrors SetCurrentThreadPriority()'s implementation.
283 ThreadPriority platform_specific_priority;
284 if (internal::GetCurrentThreadPriorityForPlatform(
285 &platform_specific_priority)) {
286 return platform_specific_priority;
287 }
288
289 // Need to clear errno before calling getpriority():
290 // http://man7.org/linux/man-pages/man2/getpriority.2.html
291 errno = 0;
292 int nice_value = getpriority(PRIO_PROCESS, 0);
293 if (errno != 0) {
294 DVPLOG(1) << "Failed to get nice value of thread ("
295 << PlatformThread::CurrentId() << ")";
296 return ThreadPriority::NORMAL;
297 }
298
299 return internal::NiceValueToThreadPriority(nice_value);
300 #endif // !defined(OS_NACL)
301 }
302
303 #endif // !defined(OS_MACOSX) && !defined(OS_FUCHSIA)
304
305 } // namespace base
306