base/threading/platform_thread_posix.cc

   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 <sys/resource.h>
  11 #include <sys/time.h>
  12
  13 #include "base/lazy_instance.h"
  14 #include "base/logging.h"
  15 #include "base/memory/scoped_ptr.h"
  16 #include "base/safe_strerror_posix.h"
  17 #include "base/synchronization/waitable_event.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 "base/tracked_objects.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 {
  39   ThreadParams()
  40       : delegate(NULL),
  41         joinable(false),
  42         priority(ThreadPriority::NORMAL),
  43         handle(NULL),
  44         handle_set(false, false) {
  45   }
  46
  47   PlatformThread::Delegate* delegate;
  48   bool joinable;
  49   ThreadPriority priority;
  50   PlatformThreadHandle* handle;
  51   WaitableEvent handle_set;
  52 };
  53
  54 void* ThreadFunc(void* params) {
  55   base::InitOnThread();
  56   ThreadParams* thread_params = static_cast<ThreadParams*>(params);
  57
  58   PlatformThread::Delegate* delegate = thread_params->delegate;
  59   if (!thread_params->joinable)
  60     base::ThreadRestrictions::SetSingletonAllowed(false);
  61
  62   if (thread_params->priority != ThreadPriority::NORMAL) {
  63     PlatformThread::SetThreadPriority(PlatformThread::CurrentHandle(),
  64                                       thread_params->priority);
  65   }
  66
  67   // Stash the id in the handle so the calling thread has a complete
  68   // handle, and unblock the parent thread.
  69   *(thread_params->handle) = PlatformThreadHandle(pthread_self(),
  70                                                   PlatformThread::CurrentId());
  71   thread_params->handle_set.Signal();
  72
  73   ThreadIdNameManager::GetInstance()->RegisterThread(
  74       PlatformThread::CurrentHandle().platform_handle(),
  75       PlatformThread::CurrentId());
  76
  77   delegate->ThreadMain();
  78
  79   ThreadIdNameManager::GetInstance()->RemoveName(
  80       PlatformThread::CurrentHandle().platform_handle(),
  81       PlatformThread::CurrentId());
  82
  83   base::TerminateOnThread();
  84   return NULL;
  85 }
  86
  87 bool CreateThread(size_t stack_size, bool joinable,
  88                   PlatformThread::Delegate* delegate,
  89                   PlatformThreadHandle* thread_handle,
  90                   ThreadPriority priority) {
  91   base::InitThreading();
  92
  93   bool success = false;
  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
 103   // Get a better default if available.
 104   if (stack_size == 0)
 105     stack_size = base::GetDefaultThreadStackSize(attributes);
 106
 107   if (stack_size > 0)
 108     pthread_attr_setstacksize(&attributes, stack_size);
 109
 110   ThreadParams params;
 111   params.delegate = delegate;
 112   params.joinable = joinable;
 113   params.priority = priority;
 114   params.handle = thread_handle;
 115
 116   pthread_t handle;
 117   int err = pthread_create(&handle,
 118                            &attributes,
 119                            ThreadFunc,
 120                            &params);
 121   success = !err;
 122   if (!success) {
 123     // Value of |handle| is undefined if pthread_create fails.
 124     handle = 0;
 125     errno = err;
 126     PLOG(ERROR) << "pthread_create";
 127   }
 128
 129   pthread_attr_destroy(&attributes);
 130
 131   // Don't let this call complete until the thread id
 132   // is set in the handle.
 133   if (success)
 134     params.handle_set.Wait();
 135   CHECK_EQ(handle, thread_handle->platform_handle());
 136
 137   return success;
 138 }
 139
 140 }  // namespace
 141
 142 // static
 143 PlatformThreadId PlatformThread::CurrentId() {
 144   // Pthreads doesn't have the concept of a thread ID, so we have to reach down
 145   // into the kernel.
 146 #if defined(OS_MACOSX)
 147   return pthread_mach_thread_np(pthread_self());
 148 #elif defined(OS_LINUX)
 149   return syscall(__NR_gettid);
 150 #elif defined(OS_ANDROID)
 151   return gettid();
 152 #elif defined(OS_SOLARIS) || defined(OS_QNX)
 153   return pthread_self();
 154 #elif defined(OS_NACL) && defined(__GLIBC__)
 155   return pthread_self();
 156 #elif defined(OS_NACL) && !defined(__GLIBC__)
 157   // Pointers are 32-bits in NaCl.
 158   return reinterpret_cast<int32>(pthread_self());
 159 #elif defined(OS_POSIX)
 160   return reinterpret_cast<int64>(pthread_self());
 161 #endif
 162 }
 163
 164 // static
 165 PlatformThreadRef PlatformThread::CurrentRef() {
 166   return PlatformThreadRef(pthread_self());
 167 }
 168
 169 // static
 170 PlatformThreadHandle PlatformThread::CurrentHandle() {
 171   return PlatformThreadHandle(pthread_self(), CurrentId());
 172 }
 173
 174 // static
 175 void PlatformThread::YieldCurrentThread() {
 176   sched_yield();
 177 }
 178
 179 // static
 180 void PlatformThread::Sleep(TimeDelta duration) {
 181   struct timespec sleep_time, remaining;
 182
 183   // Break the duration into seconds and nanoseconds.
 184   // NOTE: TimeDelta's microseconds are int64s while timespec's
 185   // nanoseconds are longs, so this unpacking must prevent overflow.
 186   sleep_time.tv_sec = duration.InSeconds();
 187   duration -= TimeDelta::FromSeconds(sleep_time.tv_sec);
 188   sleep_time.tv_nsec = duration.InMicroseconds() * 1000;  // nanoseconds
 189
 190   while (nanosleep(&sleep_time, &remaining) == -1 && errno == EINTR)
 191     sleep_time = remaining;
 192 }
 193
 194 // static
 195 const char* PlatformThread::GetName() {
 196   return ThreadIdNameManager::GetInstance()->GetName(CurrentId());
 197 }
 198
 199 // static
 200 bool PlatformThread::Create(size_t stack_size, Delegate* delegate,
 201                             PlatformThreadHandle* thread_handle) {
 202   base::ThreadRestrictions::ScopedAllowWait allow_wait;
 203   return CreateThread(stack_size, true /* joinable thread */,
 204                       delegate, thread_handle, ThreadPriority::NORMAL);
 205 }
 206
 207 // static
 208 bool PlatformThread::CreateWithPriority(size_t stack_size, Delegate* delegate,
 209                                         PlatformThreadHandle* thread_handle,
 210                                         ThreadPriority priority) {
 211   base::ThreadRestrictions::ScopedAllowWait allow_wait;
 212   return CreateThread(stack_size, true,  // joinable thread
 213                       delegate, thread_handle, priority);
 214 }
 215
 216 // static
 217 bool PlatformThread::CreateNonJoinable(size_t stack_size, Delegate* delegate) {
 218   PlatformThreadHandle unused;
 219
 220   base::ThreadRestrictions::ScopedAllowWait allow_wait;
 221   bool result = CreateThread(stack_size, false /* non-joinable thread */,
 222                              delegate, &unused, ThreadPriority::NORMAL);
 223   return result;
 224 }
 225
 226 // static
 227 void PlatformThread::Join(PlatformThreadHandle thread_handle) {
 228   // Joining another thread may block the current thread for a long time, since
 229   // the thread referred to by |thread_handle| may still be running long-lived /
 230   // blocking tasks.
 231   base::ThreadRestrictions::AssertIOAllowed();
 232   CHECK_EQ(0, pthread_join(thread_handle.handle_, NULL));
 233 }
 234
 235 // Mac has its own Set/GetThreadPriority() implementations.
 236 #if !defined(OS_MACOSX)
 237
 238 // static
 239 void PlatformThread::SetThreadPriority(PlatformThreadHandle handle,
 240                                        ThreadPriority priority) {
 241 #if defined(OS_NACL)
 242   NOTIMPLEMENTED();
 243 #else
 244   if (internal::SetThreadPriorityForPlatform(handle, priority))
 245     return;
 246
 247   // setpriority(2) should change the whole thread group's (i.e. process)
 248   // priority. However, as stated in the bugs section of
 249   // http://man7.org/linux/man-pages/man2/getpriority.2.html: "under the current
 250   // Linux/NPTL implementation of POSIX threads, the nice value is a per-thread
 251   // attribute". Also, 0 is prefered to the current thread id since it is
 252   // equivalent but makes sandboxing easier (https://crbug.com/399473).
 253   DCHECK_NE(handle.id_, kInvalidThreadId);
 254   const int nice_setting = internal::ThreadPriorityToNiceValue(priority);
 255   const PlatformThreadId current_id = PlatformThread::CurrentId();
 256   if (setpriority(PRIO_PROCESS, handle.id_ == current_id ? 0 : handle.id_,
 257                   nice_setting)) {
 258     DVPLOG(1) << "Failed to set nice value of thread (" << handle.id_ << ") to "
 259               << nice_setting;
 260   }
 261 #endif  // defined(OS_NACL)
 262 }
 263
 264 // static
 265 ThreadPriority PlatformThread::GetThreadPriority(PlatformThreadHandle handle) {
 266 #if defined(OS_NACL)
 267   NOTIMPLEMENTED();
 268   return ThreadPriority::NORMAL;
 269 #else
 270   // Mirrors SetThreadPriority()'s implementation.
 271   ThreadPriority platform_specific_priority;
 272   if (internal::GetThreadPriorityForPlatform(handle,
 273                                              &platform_specific_priority)) {
 274     return platform_specific_priority;
 275   }
 276
 277   DCHECK_NE(handle.id_, kInvalidThreadId);
 278   const PlatformThreadId current_id = PlatformThread::CurrentId();
 279   // Need to clear errno before calling getpriority():
 280   // http://man7.org/linux/man-pages/man2/getpriority.2.html
 281   errno = 0;
 282   int nice_value =
 283       getpriority(PRIO_PROCESS, handle.id_ == current_id ? 0 : handle.id_);
 284   if (errno != 0) {
 285     DVPLOG(1) << "Failed to get nice value of thread (" << handle.id_ << ")";
 286     return ThreadPriority::NORMAL;
 287   }
 288
 289   return internal::NiceValueToThreadPriority(nice_value);
 290 #endif  // !defined(OS_NACL)
 291 }
 292
 293 #endif  // !defined(OS_MACOSX)
 294
 295 }  // namespace base