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_win.h"
6
7 #include <stddef.h>
8
9 #include "base/debug/activity_tracker.h"
10 #include "base/debug/alias.h"
11 #include "base/debug/crash_logging.h"
12 #include "base/debug/profiler.h"
13 #include "base/logging.h"
14 #include "base/metrics/histogram_macros.h"
15 #include "base/process/memory.h"
16 #include "base/strings/string_number_conversions.h"
17 #include "base/strings/utf_string_conversions.h"
18 #include "base/threading/scoped_blocking_call.h"
19 #include "base/threading/scoped_thread_priority.h"
20 #include "base/threading/thread_id_name_manager.h"
21 #include "base/threading/thread_restrictions.h"
22 #include "base/time/time_override.h"
23 #include "base/win/scoped_handle.h"
24 #include "base/win/windows_version.h"
25 #include "build/build_config.h"
26
27 #include <windows.h>
28
29 namespace base {
30
31 namespace {
32
33 // The most common value returned by ::GetThreadPriority() after background
34 // thread mode is enabled on Windows 7.
35 constexpr int kWin7BackgroundThreadModePriority = 4;
36
37 // Value sometimes returned by ::GetThreadPriority() after thread priority is
38 // set to normal on Windows 7.
39 constexpr int kWin7NormalPriority = 3;
40
41 // These values are sometimes returned by ::GetThreadPriority().
42 constexpr int kWinNormalPriority1 = 5;
43 constexpr int kWinNormalPriority2 = 6;
44
45 // The information on how to set the thread name comes from
46 // a MSDN article: http://msdn2.microsoft.com/en-us/library/xcb2z8hs.aspx
47 const DWORD kVCThreadNameException = 0x406D1388;
48
49 typedef struct tagTHREADNAME_INFO {
50 DWORD dwType; // Must be 0x1000.
51 LPCSTR szName; // Pointer to name (in user addr space).
52 DWORD dwThreadID; // Thread ID (-1=caller thread).
53 DWORD dwFlags; // Reserved for future use, must be zero.
54 } THREADNAME_INFO;
55
56 // The SetThreadDescription API was brought in version 1607 of Windows 10.
57 typedef HRESULT(WINAPI* SetThreadDescription)(HANDLE hThread,
58 PCWSTR lpThreadDescription);
59
60 // This function has try handling, so it is separated out of its caller.
SetNameInternal(PlatformThreadId thread_id,const char * name)61 void SetNameInternal(PlatformThreadId thread_id, const char* name) {
62 THREADNAME_INFO info;
63 info.dwType = 0x1000;
64 info.szName = name;
65 info.dwThreadID = thread_id;
66 info.dwFlags = 0;
67
68 __try {
69 RaiseException(kVCThreadNameException, 0, sizeof(info)/sizeof(DWORD),
70 reinterpret_cast<DWORD_PTR*>(&info));
71 } __except(EXCEPTION_CONTINUE_EXECUTION) {
72 }
73 }
74
75 struct ThreadParams {
76 PlatformThread::Delegate* delegate;
77 bool joinable;
78 ThreadPriority priority;
79 };
80
ThreadFunc(void * params)81 DWORD __stdcall ThreadFunc(void* params) {
82 ThreadParams* thread_params = static_cast<ThreadParams*>(params);
83 PlatformThread::Delegate* delegate = thread_params->delegate;
84 if (!thread_params->joinable)
85 base::ThreadRestrictions::SetSingletonAllowed(false);
86
87 if (thread_params->priority != ThreadPriority::NORMAL)
88 PlatformThread::SetCurrentThreadPriority(thread_params->priority);
89
90 // Retrieve a copy of the thread handle to use as the key in the
91 // thread name mapping.
92 PlatformThreadHandle::Handle platform_handle;
93 BOOL did_dup = DuplicateHandle(GetCurrentProcess(),
94 GetCurrentThread(),
95 GetCurrentProcess(),
96 &platform_handle,
97 0,
98 FALSE,
99 DUPLICATE_SAME_ACCESS);
100
101 win::ScopedHandle scoped_platform_handle;
102
103 if (did_dup) {
104 scoped_platform_handle.Set(platform_handle);
105 ThreadIdNameManager::GetInstance()->RegisterThread(
106 scoped_platform_handle.Get(),
107 PlatformThread::CurrentId());
108 }
109
110 delete thread_params;
111 delegate->ThreadMain();
112
113 if (did_dup) {
114 ThreadIdNameManager::GetInstance()->RemoveName(
115 scoped_platform_handle.Get(),
116 PlatformThread::CurrentId());
117 }
118
119 // Ensure thread priority is at least NORMAL before initiating thread
120 // destruction. Thread destruction on Windows holds the LdrLock while
121 // performing TLS destruction which causes hangs if performed at background
122 // priority (priority inversion) (see: http://crbug.com/1096203).
123 if (PlatformThread::GetCurrentThreadPriority() < ThreadPriority::NORMAL)
124 PlatformThread::SetCurrentThreadPriority(ThreadPriority::NORMAL);
125
126 return 0;
127 }
128
129 // CreateThreadInternal() matches PlatformThread::CreateWithPriority(), except
130 // that |out_thread_handle| may be nullptr, in which case a non-joinable thread
131 // is created.
CreateThreadInternal(size_t stack_size,PlatformThread::Delegate * delegate,PlatformThreadHandle * out_thread_handle,ThreadPriority priority)132 bool CreateThreadInternal(size_t stack_size,
133 PlatformThread::Delegate* delegate,
134 PlatformThreadHandle* out_thread_handle,
135 ThreadPriority priority) {
136 unsigned int flags = 0;
137 if (stack_size > 0) {
138 flags = STACK_SIZE_PARAM_IS_A_RESERVATION;
139 #if defined(ARCH_CPU_32_BITS)
140 } else {
141 // The process stack size is increased to give spaces to |RendererMain| in
142 // |chrome/BUILD.gn|, but keep the default stack size of other threads to
143 // 1MB for the address space pressure.
144 flags = STACK_SIZE_PARAM_IS_A_RESERVATION;
145 static BOOL is_wow64 = -1;
146 if (is_wow64 == -1 && !IsWow64Process(GetCurrentProcess(), &is_wow64))
147 is_wow64 = FALSE;
148 // When is_wow64 is set that means we are running on 64-bit Windows and we
149 // get 4 GiB of address space. In that situation we can afford to use 1 MiB
150 // of address space for stacks. When running on 32-bit Windows we only get
151 // 2 GiB of address space so we need to conserve. Typically stack usage on
152 // these threads is only about 100 KiB.
153 if (is_wow64)
154 stack_size = 1024 * 1024;
155 else
156 stack_size = 512 * 1024;
157 #endif
158 }
159
160 ThreadParams* params = new ThreadParams;
161 params->delegate = delegate;
162 params->joinable = out_thread_handle != nullptr;
163 params->priority = priority;
164
165 // Using CreateThread here vs _beginthreadex makes thread creation a bit
166 // faster and doesn't require the loader lock to be available. Our code will
167 // have to work running on CreateThread() threads anyway, since we run code on
168 // the Windows thread pool, etc. For some background on the difference:
169 // http://www.microsoft.com/msj/1099/win32/win321099.aspx
170 void* thread_handle =
171 ::CreateThread(nullptr, stack_size, ThreadFunc, params, flags, nullptr);
172
173 if (!thread_handle) {
174 DWORD last_error = ::GetLastError();
175
176 switch (last_error) {
177 case ERROR_NOT_ENOUGH_MEMORY:
178 case ERROR_OUTOFMEMORY:
179 case ERROR_COMMITMENT_LIMIT:
180 TerminateBecauseOutOfMemory(stack_size);
181 break;
182
183 default:
184 static auto* last_error_crash_key = debug::AllocateCrashKeyString(
185 "create_thread_last_error", debug::CrashKeySize::Size32);
186 debug::SetCrashKeyString(last_error_crash_key,
187 base::NumberToString(last_error));
188 break;
189 }
190
191 delete params;
192 return false;
193 }
194
195 if (out_thread_handle)
196 *out_thread_handle = PlatformThreadHandle(thread_handle);
197 else
198 CloseHandle(thread_handle);
199 return true;
200 }
201
202 } // namespace
203
204 namespace internal {
205
AssertMemoryPriority(HANDLE thread,int memory_priority)206 void AssertMemoryPriority(HANDLE thread, int memory_priority) {
207 #if DCHECK_IS_ON()
208 static const auto get_thread_information_fn =
209 reinterpret_cast<decltype(&::GetThreadInformation)>(::GetProcAddress(
210 ::GetModuleHandle(L"Kernel32.dll"), "GetThreadInformation"));
211
212 if (!get_thread_information_fn) {
213 DCHECK_EQ(win::GetVersion(), win::Version::WIN7);
214 return;
215 }
216
217 MEMORY_PRIORITY_INFORMATION memory_priority_information = {};
218 DCHECK(get_thread_information_fn(thread, ::ThreadMemoryPriority,
219 &memory_priority_information,
220 sizeof(memory_priority_information)));
221
222 DCHECK_EQ(memory_priority,
223 static_cast<int>(memory_priority_information.MemoryPriority));
224 #endif
225 }
226
227 } // namespace internal
228
229 // static
CurrentId()230 PlatformThreadId PlatformThread::CurrentId() {
231 return ::GetCurrentThreadId();
232 }
233
234 // static
CurrentRef()235 PlatformThreadRef PlatformThread::CurrentRef() {
236 return PlatformThreadRef(::GetCurrentThreadId());
237 }
238
239 // static
CurrentHandle()240 PlatformThreadHandle PlatformThread::CurrentHandle() {
241 return PlatformThreadHandle(::GetCurrentThread());
242 }
243
244 // static
YieldCurrentThread()245 void PlatformThread::YieldCurrentThread() {
246 ::Sleep(0);
247 }
248
249 // static
Sleep(TimeDelta duration)250 void PlatformThread::Sleep(TimeDelta duration) {
251 // When measured with a high resolution clock, Sleep() sometimes returns much
252 // too early. We may need to call it repeatedly to get the desired duration.
253 // PlatformThread::Sleep doesn't support mock-time, so this always uses
254 // real-time.
255 const TimeTicks end = subtle::TimeTicksNowIgnoringOverride() + duration;
256 for (TimeTicks now = subtle::TimeTicksNowIgnoringOverride(); now < end;
257 now = subtle::TimeTicksNowIgnoringOverride()) {
258 ::Sleep(static_cast<DWORD>((end - now).InMillisecondsRoundedUp()));
259 }
260 }
261
262 // static
SetName(const std::string & name)263 void PlatformThread::SetName(const std::string& name) {
264 ThreadIdNameManager::GetInstance()->SetName(name);
265
266 // The SetThreadDescription API works even if no debugger is attached.
267 static auto set_thread_description_func =
268 reinterpret_cast<SetThreadDescription>(::GetProcAddress(
269 ::GetModuleHandle(L"Kernel32.dll"), "SetThreadDescription"));
270 if (set_thread_description_func) {
271 set_thread_description_func(::GetCurrentThread(),
272 base::UTF8ToWide(name).c_str());
273 }
274
275 // The debugger needs to be around to catch the name in the exception. If
276 // there isn't a debugger, we are just needlessly throwing an exception.
277 if (!::IsDebuggerPresent())
278 return;
279
280 SetNameInternal(CurrentId(), name.c_str());
281 }
282
283 // static
GetName()284 const char* PlatformThread::GetName() {
285 return ThreadIdNameManager::GetInstance()->GetName(CurrentId());
286 }
287
288 // static
CreateWithPriority(size_t stack_size,Delegate * delegate,PlatformThreadHandle * thread_handle,ThreadPriority priority)289 bool PlatformThread::CreateWithPriority(size_t stack_size, Delegate* delegate,
290 PlatformThreadHandle* thread_handle,
291 ThreadPriority priority) {
292 DCHECK(thread_handle);
293 return CreateThreadInternal(stack_size, delegate, thread_handle, priority);
294 }
295
296 // static
CreateNonJoinable(size_t stack_size,Delegate * delegate)297 bool PlatformThread::CreateNonJoinable(size_t stack_size, Delegate* delegate) {
298 return CreateNonJoinableWithPriority(stack_size, delegate,
299 ThreadPriority::NORMAL);
300 }
301
302 // static
CreateNonJoinableWithPriority(size_t stack_size,Delegate * delegate,ThreadPriority priority)303 bool PlatformThread::CreateNonJoinableWithPriority(size_t stack_size,
304 Delegate* delegate,
305 ThreadPriority priority) {
306 return CreateThreadInternal(stack_size, delegate, nullptr /* non-joinable */,
307 priority);
308 }
309
310 // static
Join(PlatformThreadHandle thread_handle)311 void PlatformThread::Join(PlatformThreadHandle thread_handle) {
312 DCHECK(thread_handle.platform_handle());
313
314 DWORD thread_id = 0;
315 thread_id = ::GetThreadId(thread_handle.platform_handle());
316 DWORD last_error = 0;
317 if (!thread_id)
318 last_error = ::GetLastError();
319
320 // Record information about the exiting thread in case joining hangs.
321 base::debug::Alias(&thread_id);
322 base::debug::Alias(&last_error);
323
324 // Record the event that this thread is blocking upon (for hang diagnosis).
325 base::debug::ScopedThreadJoinActivity thread_activity(&thread_handle);
326
327 base::internal::ScopedBlockingCallWithBaseSyncPrimitives scoped_blocking_call(
328 FROM_HERE, base::BlockingType::MAY_BLOCK);
329
330 // Wait for the thread to exit. It should already have terminated but make
331 // sure this assumption is valid.
332 CHECK_EQ(WAIT_OBJECT_0,
333 WaitForSingleObject(thread_handle.platform_handle(), INFINITE));
334 CloseHandle(thread_handle.platform_handle());
335 }
336
337 // static
Detach(PlatformThreadHandle thread_handle)338 void PlatformThread::Detach(PlatformThreadHandle thread_handle) {
339 CloseHandle(thread_handle.platform_handle());
340 }
341
342 // static
CanIncreaseThreadPriority(ThreadPriority priority)343 bool PlatformThread::CanIncreaseThreadPriority(ThreadPriority priority) {
344 return true;
345 }
346
347 // static
SetCurrentThreadPriorityImpl(ThreadPriority priority)348 void PlatformThread::SetCurrentThreadPriorityImpl(ThreadPriority priority) {
349 PlatformThreadHandle::Handle thread_handle =
350 PlatformThread::CurrentHandle().platform_handle();
351
352 if (priority != ThreadPriority::BACKGROUND) {
353 // Exit background mode if the new priority is not BACKGROUND. This is a
354 // no-op if not in background mode.
355 ::SetThreadPriority(thread_handle, THREAD_MODE_BACKGROUND_END);
356 internal::AssertMemoryPriority(thread_handle, MEMORY_PRIORITY_NORMAL);
357 }
358
359 int desired_priority = THREAD_PRIORITY_ERROR_RETURN;
360 switch (priority) {
361 case ThreadPriority::BACKGROUND:
362 // Using THREAD_MODE_BACKGROUND_BEGIN instead of THREAD_PRIORITY_LOWEST
363 // improves input latency and navigation time. See
364 // https://docs.google.com/document/d/16XrOwuwTwKWdgPbcKKajTmNqtB4Am8TgS9GjbzBYLc0
365 //
366 // MSDN recommends THREAD_MODE_BACKGROUND_BEGIN for threads that perform
367 // background work, as it reduces disk and memory priority in addition to
368 // CPU priority.
369 desired_priority = THREAD_MODE_BACKGROUND_BEGIN;
370 break;
371 case ThreadPriority::NORMAL:
372 desired_priority = THREAD_PRIORITY_NORMAL;
373 break;
374 case ThreadPriority::DISPLAY:
375 desired_priority = THREAD_PRIORITY_ABOVE_NORMAL;
376 break;
377 case ThreadPriority::REALTIME_AUDIO:
378 desired_priority = THREAD_PRIORITY_TIME_CRITICAL;
379 break;
380 default:
381 NOTREACHED() << "Unknown priority.";
382 break;
383 }
384 DCHECK_NE(desired_priority, THREAD_PRIORITY_ERROR_RETURN);
385
386 #if DCHECK_IS_ON()
387 const BOOL success =
388 #endif
389 ::SetThreadPriority(thread_handle, desired_priority);
390 DPLOG_IF(ERROR, !success) << "Failed to set thread priority to "
391 << desired_priority;
392
393 if (priority == ThreadPriority::BACKGROUND) {
394 // In a background process, THREAD_MODE_BACKGROUND_BEGIN lowers the memory
395 // and I/O priorities but not the CPU priority (kernel bug?). Use
396 // THREAD_PRIORITY_LOWEST to also lower the CPU priority.
397 // https://crbug.com/901483
398 if (GetCurrentThreadPriority() != ThreadPriority::BACKGROUND) {
399 ::SetThreadPriority(thread_handle, THREAD_PRIORITY_LOWEST);
400 // Make sure that using THREAD_PRIORITY_LOWEST didn't affect the memory
401 // priority set by THREAD_MODE_BACKGROUND_BEGIN. There is no practical
402 // way to verify the I/O priority.
403 internal::AssertMemoryPriority(thread_handle, MEMORY_PRIORITY_VERY_LOW);
404 }
405 }
406 }
407
408 // static
GetCurrentThreadPriority()409 ThreadPriority PlatformThread::GetCurrentThreadPriority() {
410 static_assert(
411 THREAD_PRIORITY_IDLE < 0,
412 "THREAD_PRIORITY_IDLE is >= 0 and will incorrectly cause errors.");
413 static_assert(
414 THREAD_PRIORITY_LOWEST < 0,
415 "THREAD_PRIORITY_LOWEST is >= 0 and will incorrectly cause errors.");
416 static_assert(THREAD_PRIORITY_BELOW_NORMAL < 0,
417 "THREAD_PRIORITY_BELOW_NORMAL is >= 0 and will incorrectly "
418 "cause errors.");
419 static_assert(
420 THREAD_PRIORITY_NORMAL == 0,
421 "The logic below assumes that THREAD_PRIORITY_NORMAL is zero. If it is "
422 "not, ThreadPriority::BACKGROUND may be incorrectly detected.");
423 static_assert(THREAD_PRIORITY_ABOVE_NORMAL >= 0,
424 "THREAD_PRIORITY_ABOVE_NORMAL is < 0 and will incorrectly be "
425 "translated to ThreadPriority::BACKGROUND.");
426 static_assert(THREAD_PRIORITY_HIGHEST >= 0,
427 "THREAD_PRIORITY_HIGHEST is < 0 and will incorrectly be "
428 "translated to ThreadPriority::BACKGROUND.");
429 static_assert(THREAD_PRIORITY_TIME_CRITICAL >= 0,
430 "THREAD_PRIORITY_TIME_CRITICAL is < 0 and will incorrectly be "
431 "translated to ThreadPriority::BACKGROUND.");
432 static_assert(THREAD_PRIORITY_ERROR_RETURN >= 0,
433 "THREAD_PRIORITY_ERROR_RETURN is < 0 and will incorrectly be "
434 "translated to ThreadPriority::BACKGROUND.");
435
436 const int priority =
437 ::GetThreadPriority(PlatformThread::CurrentHandle().platform_handle());
438
439 // Negative values represent a background priority. We have observed -3, -4,
440 // -6 when THREAD_MODE_BACKGROUND_* is used. THREAD_PRIORITY_IDLE,
441 // THREAD_PRIORITY_LOWEST and THREAD_PRIORITY_BELOW_NORMAL are other possible
442 // negative values.
443 if (priority < THREAD_PRIORITY_NORMAL)
444 return ThreadPriority::BACKGROUND;
445
446 switch (priority) {
447 case kWin7BackgroundThreadModePriority:
448 DCHECK_EQ(win::GetVersion(), win::Version::WIN7);
449 return ThreadPriority::BACKGROUND;
450 case kWin7NormalPriority:
451 DCHECK_EQ(win::GetVersion(), win::Version::WIN7);
452 FALLTHROUGH;
453 case THREAD_PRIORITY_NORMAL:
454 return ThreadPriority::NORMAL;
455 case kWinNormalPriority1:
456 FALLTHROUGH;
457 case kWinNormalPriority2:
458 return ThreadPriority::NORMAL;
459 case THREAD_PRIORITY_ABOVE_NORMAL:
460 case THREAD_PRIORITY_HIGHEST:
461 return ThreadPriority::DISPLAY;
462 case THREAD_PRIORITY_TIME_CRITICAL:
463 return ThreadPriority::REALTIME_AUDIO;
464 case THREAD_PRIORITY_ERROR_RETURN:
465 DPCHECK(false) << "::GetThreadPriority error";
466 }
467
468 NOTREACHED() << "::GetThreadPriority returned " << priority << ".";
469 return ThreadPriority::NORMAL;
470 }
471
472 // static
GetDefaultThreadStackSize()473 size_t PlatformThread::GetDefaultThreadStackSize() {
474 return 0;
475 }
476
477 } // namespace base
478