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/synchronization/waitable_event.h"
  17 #include "base/threading/platform_thread_internal_posix.h"
  18 #include "base/threading/thread_id_name_manager.h"
  19 #include "base/threading/thread_restrictions.h"
  20 #include "base/tracked_objects.h"
  21
  22 #if defined(OS_LINUX)
  23 #include <sys/syscall.h>
  24 #elif defined(OS_ANDROID)
  25 #include <sys/types.h>
  26 #endif
  27
  28 namespace base {
  29
  30 void InitThreading();
  31 void InitOnThread();
  32 void TerminateOnThread();
  33 size_t GetDefaultThreadStackSize(const pthread_attr_t& attributes);
  34
  35 namespace {
  36
  37 struct ThreadParams {
  38   ThreadParams()
  39       : delegate(NULL),
  40         joinable(false),
  41         priority(ThreadPriority::NORMAL),
  42         handle(NULL),
  43         handle_set(false, false) {
  44   }
  45
  46   PlatformThread::Delegate* delegate;
  47   bool joinable;
  48   ThreadPriority priority;
  49   PlatformThreadHandle* handle;
  50   WaitableEvent handle_set;
  51 };
  52
  53 void* ThreadFunc(void* params) {
  54   base::InitOnThread();
  55   ThreadParams* thread_params = static_cast<ThreadParams*>(params);
  56
  57   PlatformThread::Delegate* delegate = thread_params->delegate;
  58   if (!thread_params->joinable)
  59     base::ThreadRestrictions::SetSingletonAllowed(false);
  60
  61   if (thread_params->priority != ThreadPriority::NORMAL)
  62     PlatformThread::SetCurrentThreadPriority(thread_params->priority);
  63
  64   // Stash the id in the handle so the calling thread has a complete
  65   // handle, and unblock the parent thread.
  66   *(thread_params->handle) = PlatformThreadHandle(pthread_self(),
  67                                                   PlatformThread::CurrentId());
  68   thread_params->handle_set.Signal();
  69
  70   ThreadIdNameManager::GetInstance()->RegisterThread(
  71       PlatformThread::CurrentHandle().platform_handle(),
  72       PlatformThread::CurrentId());
  73
  74   delegate->ThreadMain();
  75
  76   ThreadIdNameManager::GetInstance()->RemoveName(
  77       PlatformThread::CurrentHandle().platform_handle(),
  78       PlatformThread::CurrentId());
  79
  80   base::TerminateOnThread();
  81   return NULL;
  82 }
  83
  84 bool CreateThread(size_t stack_size, bool joinable,
  85                   PlatformThread::Delegate* delegate,
  86                   PlatformThreadHandle* thread_handle,
  87                   ThreadPriority priority) {
  88   base::InitThreading();
  89
  90   bool success = false;
  91   pthread_attr_t attributes;
  92   pthread_attr_init(&attributes);
  93
  94   // Pthreads are joinable by default, so only specify the detached
  95   // attribute if the thread should be non-joinable.
  96   if (!joinable) {
  97     pthread_attr_setdetachstate(&attributes, PTHREAD_CREATE_DETACHED);
  98   }
  99
 100   // Get a better default if available.
 101   if (stack_size == 0)
 102     stack_size = base::GetDefaultThreadStackSize(attributes);
 103
 104   if (stack_size > 0)
 105     pthread_attr_setstacksize(&attributes, stack_size);
 106
 107   ThreadParams params;
 108   params.delegate = delegate;
 109   params.joinable = joinable;
 110   params.priority = priority;
 111   params.handle = thread_handle;
 112
 113   pthread_t handle;
 114   int err = pthread_create(&handle,
 115                            &attributes,
 116                            ThreadFunc,
 117                            &params);
 118   success = !err;
 119   if (!success) {
 120     // Value of |handle| is undefined if pthread_create fails.
 121     handle = 0;
 122     errno = err;
 123     PLOG(ERROR) << "pthread_create";
 124   }
 125
 126   pthread_attr_destroy(&attributes);
 127
 128   // Don't let this call complete until the thread id
 129   // is set in the handle.
 130   if (success)
 131     params.handle_set.Wait();
 132   CHECK_EQ(handle, thread_handle->platform_handle());
 133
 134   return success;
 135 }
 136
 137 }  // namespace
 138
 139 // static
 140 PlatformThreadId PlatformThread::CurrentId() {
 141   // Pthreads doesn't have the concept of a thread ID, so we have to reach down
 142   // into the kernel.
 143 #if defined(OS_MACOSX)
 144   return pthread_mach_thread_np(pthread_self());
 145 #elif defined(OS_LINUX)
 146   return syscall(__NR_gettid);
 147 #elif defined(OS_ANDROID)
 148   return gettid();
 149 #elif defined(OS_SOLARIS) || defined(OS_QNX)
 150   return pthread_self();
 151 #elif defined(OS_NACL) && defined(__GLIBC__)
 152   return pthread_self();
 153 #elif defined(OS_NACL) && !defined(__GLIBC__)
 154   // Pointers are 32-bits in NaCl.
 155   return reinterpret_cast<int32>(pthread_self());
 156 #elif defined(OS_POSIX)
 157   return reinterpret_cast<int64>(pthread_self());
 158 #endif
 159 }
 160
 161 // static
 162 PlatformThreadRef PlatformThread::CurrentRef() {
 163   return PlatformThreadRef(pthread_self());
 164 }
 165
 166 // static
 167 PlatformThreadHandle PlatformThread::CurrentHandle() {
 168   return PlatformThreadHandle(pthread_self(), CurrentId());
 169 }
 170
 171 // static
 172 void PlatformThread::YieldCurrentThread() {
 173   sched_yield();
 174 }
 175
 176 // static
 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
 192 const char* PlatformThread::GetName() {
 193   return ThreadIdNameManager::GetInstance()->GetName(CurrentId());
 194 }
 195
 196 // static
 197 bool PlatformThread::CreateWithPriority(size_t stack_size, Delegate* delegate,
 198                                         PlatformThreadHandle* thread_handle,
 199                                         ThreadPriority priority) {
 200   base::ThreadRestrictions::ScopedAllowWait allow_wait;
 201   return CreateThread(stack_size, true,  // joinable thread
 202                       delegate, thread_handle, priority);
 203 }
 204
 205 // static
 206 bool PlatformThread::CreateNonJoinable(size_t stack_size, Delegate* delegate) {
 207   PlatformThreadHandle unused;
 208
 209   base::ThreadRestrictions::ScopedAllowWait allow_wait;
 210   bool result = CreateThread(stack_size, false /* non-joinable thread */,
 211                              delegate, &unused, ThreadPriority::NORMAL);
 212   return result;
 213 }
 214
 215 // static
 216 void PlatformThread::Join(PlatformThreadHandle thread_handle) {
 217   // Joining another thread may block the current thread for a long time, since
 218   // the thread referred to by |thread_handle| may still be running long-lived /
 219   // blocking tasks.
 220   base::ThreadRestrictions::AssertIOAllowed();
 221   CHECK_EQ(0, pthread_join(thread_handle.platform_handle(), NULL));
 222 }
 223
 224 // Mac has its own Set/GetCurrentThreadPriority() implementations.
 225 #if !defined(OS_MACOSX)
 226
 227 // static
 228 void PlatformThread::SetCurrentThreadPriority(ThreadPriority priority) {
 229 #if defined(OS_NACL)
 230   NOTIMPLEMENTED();
 231 #else
 232   if (internal::SetCurrentThreadPriorityForPlatform(priority))
 233     return;
 234
 235   // setpriority(2) should change the whole thread group's (i.e. process)
 236   // priority. However, as stated in the bugs section of
 237   // http://man7.org/linux/man-pages/man2/getpriority.2.html: "under the current
 238   // Linux/NPTL implementation of POSIX threads, the nice value is a per-thread
 239   // attribute". Also, 0 is prefered to the current thread id since it is
 240   // equivalent but makes sandboxing easier (https://crbug.com/399473).
 241   const int nice_setting = internal::ThreadPriorityToNiceValue(priority);
 242   if (setpriority(PRIO_PROCESS, 0, nice_setting)) {
 243     DVPLOG(1) << "Failed to set nice value of thread ("
 244               << PlatformThread::CurrentId() << ") to " << nice_setting;
 245   }
 246 #endif  // defined(OS_NACL)
 247 }
 248
 249 // static
 250 ThreadPriority PlatformThread::GetCurrentThreadPriority() {
 251 #if defined(OS_NACL)
 252   NOTIMPLEMENTED();
 253   return ThreadPriority::NORMAL;
 254 #else
 255   // Mirrors SetCurrentThreadPriority()'s implementation.
 256   ThreadPriority platform_specific_priority;
 257   if (internal::GetCurrentThreadPriorityForPlatform(
 258           &platform_specific_priority)) {
 259     return platform_specific_priority;
 260   }
 261
 262   // Need to clear errno before calling getpriority():
 263   // http://man7.org/linux/man-pages/man2/getpriority.2.html
 264   errno = 0;
 265   int nice_value = getpriority(PRIO_PROCESS, 0);
 266   if (errno != 0) {
 267     DVPLOG(1) << "Failed to get nice value of thread ("
 268               << PlatformThread::CurrentId() << ")";
 269     return ThreadPriority::NORMAL;
 270   }
 271
 272   return internal::NiceValueToThreadPriority(nice_value);
 273 #endif  // !defined(OS_NACL)
 274 }
 275
 276 #endif  // !defined(OS_MACOSX)
 277
 278 }  // namespace base