blob: d97c1bf774f741348152ab81c94ac8b0083e2e47 [file] [log] [blame]
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/threading/platform_thread_win.h"
#include "base/debug/activity_tracker.h"
#include "base/debug/alias.h"
#include "base/debug/profiler.h"
#include "base/logging.h"
#include "base/metrics/histogram_macros.h"
#include "base/strings/utf_string_conversions.h"
#include "base/threading/thread_id_name_manager.h"
#include "base/threading/thread_restrictions.h"
#include "base/win/scoped_handle.h"
#include "base/win/windows_version.h"
#include <windows.h>
#include "starboard/types.h"
namespace base {
namespace {
// The value returned by ::GetThreadPriority() after background thread mode is
// enabled on Windows 7.
constexpr int kWin7BackgroundThreadModePriority = 4;
// The value returned by ::GetThreadPriority() after background thread mode is
// enabled on Windows 8+.
constexpr int kWin8AboveBackgroundThreadModePriority = -4;
// The information on how to set the thread name comes from
// a MSDN article: http://msdn2.microsoft.com/en-us/library/xcb2z8hs.aspx
const DWORD kVCThreadNameException = 0x406D1388;
typedef struct tagTHREADNAME_INFO {
DWORD dwType; // Must be 0x1000.
LPCSTR szName; // Pointer to name (in user addr space).
DWORD dwThreadID; // Thread ID (-1=caller thread).
DWORD dwFlags; // Reserved for future use, must be zero.
} THREADNAME_INFO;
// The SetThreadDescription API was brought in version 1607 of Windows 10.
typedef HRESULT(WINAPI* SetThreadDescription)(HANDLE hThread,
PCWSTR lpThreadDescription);
// This function has try handling, so it is separated out of its caller.
void SetNameInternal(PlatformThreadId thread_id, const char* name) {
THREADNAME_INFO info;
info.dwType = 0x1000;
info.szName = name;
info.dwThreadID = thread_id;
info.dwFlags = 0;
__try {
RaiseException(kVCThreadNameException, 0, sizeof(info)/sizeof(DWORD),
reinterpret_cast<DWORD_PTR*>(&info));
} __except(EXCEPTION_CONTINUE_EXECUTION) {
}
}
struct ThreadParams {
PlatformThread::Delegate* delegate;
bool joinable;
ThreadPriority priority;
};
DWORD __stdcall ThreadFunc(void* params) {
ThreadParams* thread_params = static_cast<ThreadParams*>(params);
PlatformThread::Delegate* delegate = thread_params->delegate;
if (!thread_params->joinable)
base::ThreadRestrictions::SetSingletonAllowed(false);
if (thread_params->priority != ThreadPriority::NORMAL)
PlatformThread::SetCurrentThreadPriority(thread_params->priority);
// Retrieve a copy of the thread handle to use as the key in the
// thread name mapping.
PlatformThreadHandle::Handle platform_handle;
BOOL did_dup = DuplicateHandle(GetCurrentProcess(),
GetCurrentThread(),
GetCurrentProcess(),
&platform_handle,
0,
FALSE,
DUPLICATE_SAME_ACCESS);
win::ScopedHandle scoped_platform_handle;
if (did_dup) {
scoped_platform_handle.Set(platform_handle);
ThreadIdNameManager::GetInstance()->RegisterThread(
scoped_platform_handle.Get(),
PlatformThread::CurrentId());
}
delete thread_params;
delegate->ThreadMain();
if (did_dup) {
ThreadIdNameManager::GetInstance()->RemoveName(
scoped_platform_handle.Get(),
PlatformThread::CurrentId());
}
return 0;
}
// CreateThreadInternal() matches PlatformThread::CreateWithPriority(), except
// that |out_thread_handle| may be nullptr, in which case a non-joinable thread
// is created.
bool CreateThreadInternal(size_t stack_size,
PlatformThread::Delegate* delegate,
PlatformThreadHandle* out_thread_handle,
ThreadPriority priority) {
unsigned int flags = 0;
if (stack_size > 0) {
flags = STACK_SIZE_PARAM_IS_A_RESERVATION;
}
ThreadParams* params = new ThreadParams;
params->delegate = delegate;
params->joinable = out_thread_handle != nullptr;
params->priority = priority;
void* thread_handle;
{
SCOPED_UMA_HISTOGRAM_TIMER("Windows.CreateThreadTime");
// Using CreateThread here vs _beginthreadex makes thread creation a bit
// faster and doesn't require the loader lock to be available. Our code
// will have to work running on CreateThread() threads anyway, since we run
// code on the Windows thread pool, etc. For some background on the
// difference:
// http://www.microsoft.com/msj/1099/win32/win321099.aspx
thread_handle =
::CreateThread(nullptr, stack_size, ThreadFunc, params, flags, nullptr);
}
if (!thread_handle) {
delete params;
return false;
}
if (out_thread_handle)
*out_thread_handle = PlatformThreadHandle(thread_handle);
else
CloseHandle(thread_handle);
return true;
}
} // namespace
namespace features {
const Feature kWindowsThreadModeBackground{"WindowsThreadModeBackground",
FEATURE_DISABLED_BY_DEFAULT};
} // namespace features
// static
PlatformThreadId PlatformThread::CurrentId() {
return ::GetCurrentThreadId();
}
// static
PlatformThreadRef PlatformThread::CurrentRef() {
return PlatformThreadRef(::GetCurrentThreadId());
}
// static
PlatformThreadHandle PlatformThread::CurrentHandle() {
return PlatformThreadHandle(::GetCurrentThread());
}
// static
void PlatformThread::YieldCurrentThread() {
::Sleep(0);
}
// static
void PlatformThread::Sleep(TimeDelta duration) {
// When measured with a high resolution clock, Sleep() sometimes returns much
// too early. We may need to call it repeatedly to get the desired duration.
TimeTicks end = TimeTicks::Now() + duration;
for (TimeTicks now = TimeTicks::Now(); now < end; now = TimeTicks::Now())
::Sleep(static_cast<DWORD>((end - now).InMillisecondsRoundedUp()));
}
// static
void PlatformThread::SetName(const std::string& name) {
ThreadIdNameManager::GetInstance()->SetName(name);
// The SetThreadDescription API works even if no debugger is attached.
auto set_thread_description_func =
reinterpret_cast<SetThreadDescription>(::GetProcAddress(
::GetModuleHandle(L"Kernel32.dll"), "SetThreadDescription"));
if (set_thread_description_func) {
set_thread_description_func(::GetCurrentThread(),
base::UTF8ToWide(name).c_str());
}
// The debugger needs to be around to catch the name in the exception. If
// there isn't a debugger, we are just needlessly throwing an exception.
if (!::IsDebuggerPresent())
return;
SetNameInternal(CurrentId(), name.c_str());
}
// static
const char* PlatformThread::GetName() {
return ThreadIdNameManager::GetInstance()->GetName(CurrentId());
}
// static
bool PlatformThread::CreateWithPriority(size_t stack_size, Delegate* delegate,
PlatformThreadHandle* thread_handle,
ThreadPriority priority) {
DCHECK(thread_handle);
return CreateThreadInternal(stack_size, delegate, thread_handle, priority);
}
// static
bool PlatformThread::CreateNonJoinable(size_t stack_size, Delegate* delegate) {
return CreateNonJoinableWithPriority(stack_size, delegate,
ThreadPriority::NORMAL);
}
// static
bool PlatformThread::CreateNonJoinableWithPriority(size_t stack_size,
Delegate* delegate,
ThreadPriority priority) {
return CreateThreadInternal(stack_size, delegate, nullptr /* non-joinable */,
priority);
}
// static
void PlatformThread::Join(PlatformThreadHandle thread_handle) {
DCHECK(thread_handle.platform_handle());
// TODO(willchan): Enable this check once I can get it to work for Windows
// shutdown.
// Joining another thread may block the current thread for a long time, since
// the thread referred to by |thread_handle| may still be running long-lived /
// blocking tasks.
// AssertBlockingAllowed();
DWORD thread_id = 0;
thread_id = ::GetThreadId(thread_handle.platform_handle());
DWORD last_error = 0;
if (!thread_id)
last_error = ::GetLastError();
// Record information about the exiting thread in case joining hangs.
base::debug::Alias(&thread_id);
base::debug::Alias(&last_error);
// Record the event that this thread is blocking upon (for hang diagnosis).
base::debug::ScopedThreadJoinActivity thread_activity(&thread_handle);
// Wait for the thread to exit. It should already have terminated but make
// sure this assumption is valid.
CHECK_EQ(WAIT_OBJECT_0,
WaitForSingleObject(thread_handle.platform_handle(), INFINITE));
CloseHandle(thread_handle.platform_handle());
}
// static
void PlatformThread::Detach(PlatformThreadHandle thread_handle) {
CloseHandle(thread_handle.platform_handle());
}
// static
bool PlatformThread::CanIncreaseThreadPriority(ThreadPriority priority) {
return true;
}
// static
void PlatformThread::SetCurrentThreadPriority(ThreadPriority priority) {
// A DCHECK is triggered on FeatureList initialization if the state of a
// feature has been checked before. We only want to trigger that DCHECK if the
// priority has been set to BACKGROUND before, so we are careful not to access
// the state of the feature needlessly. We don't DCHECK here because it is ok
// if the FeatureList is never initialized in the process (e.g. in tests).
//
// TODO(fdoray): Remove experiment code. https://crbug.com/872820
const bool use_thread_mode_background =
(priority == ThreadPriority::BACKGROUND
? FeatureList::IsEnabled(features::kWindowsThreadModeBackground)
: (FeatureList::GetInstance() &&
FeatureList::IsEnabled(features::kWindowsThreadModeBackground)));
if (use_thread_mode_background && priority != ThreadPriority::BACKGROUND) {
// Exit background mode if the new priority is not BACKGROUND. This is a
// no-op if not in background mode.
::SetThreadPriority(PlatformThread::CurrentHandle().platform_handle(),
THREAD_MODE_BACKGROUND_END);
}
int desired_priority = THREAD_PRIORITY_ERROR_RETURN;
switch (priority) {
case ThreadPriority::BACKGROUND:
desired_priority = use_thread_mode_background
? THREAD_MODE_BACKGROUND_BEGIN
: THREAD_PRIORITY_LOWEST;
break;
case ThreadPriority::NORMAL:
desired_priority = THREAD_PRIORITY_NORMAL;
break;
case ThreadPriority::DISPLAY:
desired_priority = THREAD_PRIORITY_ABOVE_NORMAL;
break;
case ThreadPriority::REALTIME_AUDIO:
desired_priority = THREAD_PRIORITY_TIME_CRITICAL;
break;
default:
NOTREACHED() << "Unknown priority.";
break;
}
DCHECK_NE(desired_priority, THREAD_PRIORITY_ERROR_RETURN);
#if DCHECK_IS_ON()
const BOOL success =
#endif
::SetThreadPriority(PlatformThread::CurrentHandle().platform_handle(),
desired_priority);
DPLOG_IF(ERROR, !success) << "Failed to set thread priority to "
<< desired_priority;
// Sanity check that GetCurrentThreadPriority() is consistent with
// SetCurrentThreadPriority().
DCHECK_EQ(GetCurrentThreadPriority(), priority);
}
// static
ThreadPriority PlatformThread::GetCurrentThreadPriority() {
const int priority =
::GetThreadPriority(PlatformThread::CurrentHandle().platform_handle());
switch (priority) {
case THREAD_PRIORITY_IDLE:
case kWin7BackgroundThreadModePriority:
DCHECK_EQ(win::GetVersion(), win::VERSION_WIN7);
FALLTHROUGH;
case kWin8AboveBackgroundThreadModePriority:
case THREAD_PRIORITY_LOWEST:
return ThreadPriority::BACKGROUND;
case THREAD_PRIORITY_NORMAL:
return ThreadPriority::NORMAL;
case THREAD_PRIORITY_ABOVE_NORMAL:
return ThreadPriority::DISPLAY;
case THREAD_PRIORITY_TIME_CRITICAL:
return ThreadPriority::REALTIME_AUDIO;
case THREAD_PRIORITY_ERROR_RETURN:
DPCHECK(false) << "GetThreadPriority error";
}
NOTREACHED() << "GetCurrentThreadPriority returned " << priority << ".";
return ThreadPriority::NORMAL;
}
} // namespace base