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/memory/scoped_ptr.h"
  13 #include "base/safe_strerror_posix.h"
  14 #include "base/threading/thread_id_name_manager.h"
  15 #include "base/threading/thread_restrictions.h"
  16 #include "base/tracked_objects.h"
  17
  18 #if !defined(OS_NACL)
  19 #include <sys/prctl.h>
  20 #include <sys/resource.h>
  21 #include <sys/syscall.h>
  22 #include <sys/time.h>
  23 #include <unistd.h>
  24 #endif
  25
  26 namespace base {
  27
  28 namespace {
  29
  30 int ThreadNiceValue(ThreadPriority priority) {
  31   switch (priority) {
  32     case kThreadPriority_RealtimeAudio:
  33       return -10;
  34     case kThreadPriority_Background:
  35       return 10;
  36     case kThreadPriority_Normal:
  37       return 0;
  38     case kThreadPriority_Display:
  39       return -6;
  40     default:
  41       NOTREACHED() << "Unknown priority.";
  42       return 0;
  43   }
  44 }
  45
  46 }  // namespace
  47
  48 // static
  49 void PlatformThread::SetName(const char* name) {
  50   ThreadIdNameManager::GetInstance()->SetName(CurrentId(), name);
  51   tracked_objects::ThreadData::InitializeThreadContext(name);
  52
  53 #if !defined(OS_NACL)
  54   // On linux we can get the thread names to show up in the debugger by setting
  55   // the process name for the LWP.  We don't want to do this for the main
  56   // thread because that would rename the process, causing tools like killall
  57   // to stop working.
  58   if (PlatformThread::CurrentId() == getpid())
  59     return;
  60
  61   // http://0pointer.de/blog/projects/name-your-threads.html
  62   // Set the name for the LWP (which gets truncated to 15 characters).
  63   // Note that glibc also has a 'pthread_setname_np' api, but it may not be
  64   // available everywhere and it's only benefit over using prctl directly is
  65   // that it can set the name of threads other than the current thread.
  66   int err = prctl(PR_SET_NAME, name);
  67   // We expect EPERM failures in sandboxed processes, just ignore those.
  68   if (err < 0 && errno != EPERM)
  69     DPLOG(ERROR) << "prctl(PR_SET_NAME)";
  70 #endif  //  !defined(OS_NACL)
  71 }
  72
  73 // static
  74 void PlatformThread::SetThreadPriority(PlatformThreadHandle handle,
  75                                        ThreadPriority priority) {
  76 #if !defined(OS_NACL)
  77   if (priority == kThreadPriority_RealtimeAudio) {
  78     const struct sched_param kRealTimePrio = {8};
  79     if (pthread_setschedparam(pthread_self(), SCHED_RR, &kRealTimePrio) == 0) {
  80       // Got real time priority, no need to set nice level.
  81       return;
  82     }
  83   }
  84
  85   // setpriority(2) should change the whole thread group's (i.e. process)
  86   // priority. however, on linux it will only change the target thread's
  87   // priority. see the bugs section in
  88   // http://man7.org/linux/man-pages/man2/getpriority.2.html.
  89   // we prefer using 0 rather than the current thread id since they are
  90   // equivalent but it makes sandboxing easier (https://crbug.com/399473).
  91   DCHECK_NE(handle.id_, kInvalidThreadId);
  92   const int kNiceSetting = ThreadNiceValue(priority);
  93   const PlatformThreadId current_id = PlatformThread::CurrentId();
  94   if (setpriority(PRIO_PROCESS,
  95                   handle.id_ == current_id ? 0 : handle.id_,
  96                   kNiceSetting)) {
  97     DVPLOG(1) << "Failed to set nice value of thread (" << handle.id_ << ") to "
  98               << kNiceSetting;
  99   }
 100 #endif  //  !defined(OS_NACL)
 101 }
 102
 103 void InitThreading() {}
 104
 105 void InitOnThread() {}
 106
 107 void TerminateOnThread() {}
 108
 109 size_t GetDefaultThreadStackSize(const pthread_attr_t& attributes) {
 110 #if !defined(THREAD_SANITIZER)
 111   return 0;
 112 #else
 113   // ThreadSanitizer bloats the stack heavily. Evidence has been that the
 114   // default stack size isn't enough for some browser tests.
 115   return 2 * (1 << 23);  // 2 times 8192K (the default stack size on Linux).
 116 #endif
 117 }
 118
 119 }  // namespace base