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
29namespace base {
30
31void InitThreading();
32void InitOnThread();
33void TerminateOnThread();
34size_t GetDefaultThreadStackSize(const pthread_attr_t& attributes);
35
36namespace {
37
38struct ThreadParams {
39  ThreadParams()
40      : delegate(NULL), joinable(false), priority(ThreadPriority::NORMAL) {}
41
42  PlatformThread::Delegate* delegate;
43  bool joinable;
44  ThreadPriority priority;
45};
46
47void* 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
77bool 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
127PlatformThreadId 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
149PlatformThreadRef PlatformThread::CurrentRef() {
150  return PlatformThreadRef(pthread_self());
151}
152
153// static
154PlatformThreadHandle PlatformThread::CurrentHandle() {
155  return PlatformThreadHandle(pthread_self());
156}
157
158// static
159void PlatformThread::YieldCurrentThread() {
160  sched_yield();
161}
162
163// static
164void 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
179const char* PlatformThread::GetName() {
180  return ThreadIdNameManager::GetInstance()->GetName(CurrentId());
181}
182
183// static
184bool 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
192bool 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
201void 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
213void 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
235ThreadPriority 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