base/threading/platform_thread_linux.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 <sched.h>
   9
  10 #include "base/lazy_instance.h"
  11 #include "base/logging.h"
  12 #include "base/threading/platform_thread_internal_posix.h"
  13 #include "base/threading/thread_id_name_manager.h"
  14 #include "base/tracked_objects.h"
  15
  16 #if !defined(OS_NACL)
  17 #include <pthread.h>
  18 #include <sys/prctl.h>
  19 #include <sys/types.h>
  20 #include <unistd.h>
  21 #endif
  22
  23 namespace base {
  24
  25 namespace internal {
  26
  27 namespace {
  28 #if !defined(OS_NACL)
  29 const struct sched_param kRealTimePrio = {8};
  30 #endif
  31 }  // namespace
  32
  33 const ThreadPriorityToNiceValuePair kThreadPriorityToNiceValueMap[4] = {
  34     {ThreadPriority::BACKGROUND, 10},
  35     {ThreadPriority::NORMAL, 0},
  36     {ThreadPriority::DISPLAY, -6},
  37     {ThreadPriority::REALTIME_AUDIO, -10},
  38 };
  39
  40 bool SetThreadPriorityForPlatform(PlatformThreadHandle handle,
  41                                   ThreadPriority priority) {
  42 #if !defined(OS_NACL)
  43   // TODO(gab): Assess the correctness of using |pthread_self()| below instead
  44   // of |handle|. http://crbug.com/468793.
  45   return priority == ThreadPriority::REALTIME_AUDIO  &&
  46          pthread_setschedparam(pthread_self(), SCHED_RR, &kRealTimePrio) == 0;
  47 #else
  48   return false;
  49 #endif
  50 }
  51
  52 bool GetThreadPriorityForPlatform(PlatformThreadHandle handle,
  53                                   ThreadPriority* priority) {
  54 #if !defined(OS_NACL)
  55   int maybe_sched_rr = 0;
  56   struct sched_param maybe_realtime_prio = {0};
  57   // TODO(gab): Assess the correctness of using |pthread_self()| below instead
  58   // of |handle|. http://crbug.com/468793.
  59   if (pthread_getschedparam(pthread_self(), &maybe_sched_rr,
  60                             &maybe_realtime_prio) == 0 &&
  61       maybe_sched_rr == SCHED_RR &&
  62       maybe_realtime_prio.sched_priority == kRealTimePrio.sched_priority) {
  63     *priority = ThreadPriority::REALTIME_AUDIO;
  64     return true;
  65   }
  66 #endif
  67   return false;
  68 }
  69
  70 }  // namespace internal
  71
  72 // static
  73 void PlatformThread::SetName(const std::string& name) {
  74   ThreadIdNameManager::GetInstance()->SetName(CurrentId(), name);
  75   tracked_objects::ThreadData::InitializeThreadContext(name);
  76
  77 #if !defined(OS_NACL)
  78   // On linux we can get the thread names to show up in the debugger by setting
  79   // the process name for the LWP.  We don't want to do this for the main
  80   // thread because that would rename the process, causing tools like killall
  81   // to stop working.
  82   if (PlatformThread::CurrentId() == getpid())
  83     return;
  84
  85   // http://0pointer.de/blog/projects/name-your-threads.html
  86   // Set the name for the LWP (which gets truncated to 15 characters).
  87   // Note that glibc also has a 'pthread_setname_np' api, but it may not be
  88   // available everywhere and it's only benefit over using prctl directly is
  89   // that it can set the name of threads other than the current thread.
  90   int err = prctl(PR_SET_NAME, name.c_str());
  91   // We expect EPERM failures in sandboxed processes, just ignore those.
  92   if (err < 0 && errno != EPERM)
  93     DPLOG(ERROR) << "prctl(PR_SET_NAME)";
  94 #endif  //  !defined(OS_NACL)
  95 }
  96
  97 void InitThreading() {}
  98
  99 void InitOnThread() {}
 100
 101 void TerminateOnThread() {}
 102
 103 size_t GetDefaultThreadStackSize(const pthread_attr_t& attributes) {
 104 #if !defined(THREAD_SANITIZER)
 105   return 0;
 106 #else
 107   // ThreadSanitizer bloats the stack heavily. Evidence has been that the
 108   // default stack size isn't enough for some browser tests.
 109   return 2 * (1 << 23);  // 2 times 8192K (the default stack size on Linux).
 110 #endif
 111 }
 112
 113 }  // namespace base