platform_thread_linux.cc revision 23730a6e56a168d1879203e4b3819bb36e3d8f1f 
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
26namespace base {
27
28namespace {
29int ThreadNiceValue(ThreadPriority priority) {
30  switch (priority) {
31    case kThreadPriority_RealtimeAudio:
32      return -10;
33    case kThreadPriority_Background:
34      return 10;
35    case kThreadPriority_Normal:
36      return 0;
37    case kThreadPriority_Display:
38      return -6;
39    default:
40      NOTREACHED() << "Unknown priority.";
41      return 0;
42  }
43}
44} // namespace
45
46// static
47void PlatformThread::SetName(const char* name) {
48  ThreadIdNameManager::GetInstance()->SetName(CurrentId(), name);
49  tracked_objects::ThreadData::InitializeThreadContext(name);
50
51#if !defined(OS_NACL)
52  // On linux we can get the thread names to show up in the debugger by setting
53  // the process name for the LWP.  We don't want to do this for the main
54  // thread because that would rename the process, causing tools like killall
55  // to stop working.
56  if (PlatformThread::CurrentId() == getpid())
57    return;
58
59  // http://0pointer.de/blog/projects/name-your-threads.html
60  // Set the name for the LWP (which gets truncated to 15 characters).
61  // Note that glibc also has a 'pthread_setname_np' api, but it may not be
62  // available everywhere and it's only benefit over using prctl directly is
63  // that it can set the name of threads other than the current thread.
64  int err = prctl(PR_SET_NAME, name);
65  // We expect EPERM failures in sandboxed processes, just ignore those.
66  if (err < 0 && errno != EPERM)
67    DPLOG(ERROR) << "prctl(PR_SET_NAME)";
68#endif  //  !defined(OS_NACL)
69}
70
71// static
72void PlatformThread::SetThreadPriority(PlatformThreadHandle handle,
73                                       ThreadPriority priority) {
74#if !defined(OS_NACL)
75  if (priority == kThreadPriority_RealtimeAudio) {
76    const struct sched_param kRealTimePrio = { 8 };
77    if (pthread_setschedparam(pthread_self(), SCHED_RR, &kRealTimePrio) == 0) {
78      // Got real time priority, no need to set nice level.
79      return;
80    }
81  }
82
83  // setpriority(2) will set a thread's priority if it is passed a tid as
84  // the 'process identifier', not affecting the rest of the threads in the
85  // process. Setting this priority will only succeed if the user has been
86  // granted permission to adjust nice values on the system.
87  DCHECK_NE(handle.id_, kInvalidThreadId);
88  const int kNiceSetting = ThreadNiceValue(priority);
89  if (setpriority(PRIO_PROCESS, handle.id_, kNiceSetting)) {
90    DVPLOG(1) << "Failed to set nice value of thread ("
91              << handle.id_ << ") to " << kNiceSetting;
92  }
93#endif  //  !defined(OS_NACL)
94}
95
96void InitThreading() {}
97
98void InitOnThread() {}
99
100void TerminateOnThread() {}
101
102size_t GetDefaultThreadStackSize(const pthread_attr_t& attributes) {
103#if !defined(THREAD_SANITIZER) && !defined(MEMORY_SANITIZER)
104  return 0;
105#else
106  // ThreadSanitizer bloats the stack heavily. Evidence has been that the
107  // default stack size isn't enough for some browser tests.
108  // MemorySanitizer needs this as a temporary fix for http://crbug.com/353687
109  return 2 * (1 << 23);  // 2 times 8192K (the default stack size on Linux).
110#endif
111}
112
113}  // namespace base
114