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 #include <stddef.h>
10
11 #include "base/lazy_instance.h"
12 #include "base/logging.h"
13 #include "base/threading/platform_thread_internal_posix.h"
14 #include "base/threading/thread_id_name_manager.h"
15 #include "base/tracked_objects.h"
16 #include "build/build_config.h"
17
18 #if !defined(OS_NACL)
19 #include <pthread.h>
20 #include <sys/prctl.h>
21 #include <sys/types.h>
22 #include <unistd.h>
23 #endif
24
25 namespace base {
26
27 namespace internal {
28
29 namespace {
30 #if !defined(OS_NACL)
31 const struct sched_param kRealTimePrio = {8};
32 const struct sched_param kResetPrio = {0};
33 #endif
34 } // namespace
35
36 const ThreadPriorityToNiceValuePair kThreadPriorityToNiceValueMap[4] = {
37 {ThreadPriority::BACKGROUND, 10},
38 {ThreadPriority::NORMAL, 0},
39 {ThreadPriority::DISPLAY, -6},
40 {ThreadPriority::REALTIME_AUDIO, -10},
41 };
42
SetCurrentThreadPriorityForPlatform(ThreadPriority priority)43 bool SetCurrentThreadPriorityForPlatform(ThreadPriority priority) {
44 #if !defined(OS_NACL)
45 ThreadPriority current_priority;
46 if (priority != ThreadPriority::REALTIME_AUDIO &&
47 GetCurrentThreadPriorityForPlatform(¤t_priority) &&
48 current_priority == ThreadPriority::REALTIME_AUDIO) {
49 // If the pthread's round-robin scheduler is already enabled, and the new
50 // priority will use setpriority() instead, the pthread scheduler should be
51 // reset to use SCHED_OTHER so that setpriority() just works.
52 pthread_setschedparam(pthread_self(), SCHED_OTHER, &kResetPrio);
53 return false;
54 }
55 return priority == ThreadPriority::REALTIME_AUDIO &&
56 pthread_setschedparam(pthread_self(), SCHED_RR, &kRealTimePrio) == 0;
57 #else
58 return false;
59 #endif
60 }
61
GetCurrentThreadPriorityForPlatform(ThreadPriority * priority)62 bool GetCurrentThreadPriorityForPlatform(ThreadPriority* priority) {
63 #if !defined(OS_NACL)
64 int maybe_sched_rr = 0;
65 struct sched_param maybe_realtime_prio = {0};
66 if (pthread_getschedparam(pthread_self(), &maybe_sched_rr,
67 &maybe_realtime_prio) == 0 &&
68 maybe_sched_rr == SCHED_RR &&
69 maybe_realtime_prio.sched_priority == kRealTimePrio.sched_priority) {
70 *priority = ThreadPriority::REALTIME_AUDIO;
71 return true;
72 }
73 #endif
74 return false;
75 }
76
77 } // namespace internal
78
79 // static
SetName(const std::string & name)80 void PlatformThread::SetName(const std::string& name) {
81 ThreadIdNameManager::GetInstance()->SetName(CurrentId(), name);
82 tracked_objects::ThreadData::InitializeThreadContext(name);
83
84 #if !defined(OS_NACL)
85 // On linux we can get the thread names to show up in the debugger by setting
86 // the process name for the LWP. We don't want to do this for the main
87 // thread because that would rename the process, causing tools like killall
88 // to stop working.
89 if (PlatformThread::CurrentId() == getpid())
90 return;
91
92 // http://0pointer.de/blog/projects/name-your-threads.html
93 // Set the name for the LWP (which gets truncated to 15 characters).
94 // Note that glibc also has a 'pthread_setname_np' api, but it may not be
95 // available everywhere and it's only benefit over using prctl directly is
96 // that it can set the name of threads other than the current thread.
97 int err = prctl(PR_SET_NAME, name.c_str());
98 // We expect EPERM failures in sandboxed processes, just ignore those.
99 if (err < 0 && errno != EPERM)
100 DPLOG(ERROR) << "prctl(PR_SET_NAME)";
101 #endif // !defined(OS_NACL)
102 }
103
InitThreading()104 void InitThreading() {}
105
InitOnThread()106 void InitOnThread() {}
107
TerminateOnThread()108 void TerminateOnThread() {}
109
GetDefaultThreadStackSize(const pthread_attr_t &)110 size_t GetDefaultThreadStackSize(const pthread_attr_t& /* attributes */) {
111 #if !defined(THREAD_SANITIZER)
112 return 0;
113 #else
114 // ThreadSanitizer bloats the stack heavily. Evidence has been that the
115 // default stack size isn't enough for some browser tests.
116 return 2 * (1 << 23); // 2 times 8192K (the default stack size on Linux).
117 #endif
118 }
119
120 } // namespace base
121