blob: 9d2917d9a02d795c48783fed01338ed5b32e769e [file] [log] [blame]
/*
* Copyright 2004 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "webrtc/base/thread.h"
#ifndef __has_feature
#define __has_feature(x) 0 // Compatibility with non-clang or LLVM compilers.
#endif // __has_feature
#if defined(WEBRTC_WIN)
#include <comdef.h>
#elif defined(WEBRTC_POSIX)
#include <time.h>
#endif
#include "webrtc/base/common.h"
#include "webrtc/base/logging.h"
#include "webrtc/base/stringutils.h"
#include "webrtc/base/timeutils.h"
#if !__has_feature(objc_arc) && (defined(WEBRTC_MAC))
#include "webrtc/base/maccocoathreadhelper.h"
#include "webrtc/base/scoped_autorelease_pool.h"
#endif
namespace rtc {
ThreadManager* ThreadManager::Instance() {
LIBJINGLE_DEFINE_STATIC_LOCAL(ThreadManager, thread_manager, ());
return &thread_manager;
}
// static
Thread* Thread::Current() {
return ThreadManager::Instance()->CurrentThread();
}
#if defined(WEBRTC_POSIX)
ThreadManager::ThreadManager() {
pthread_key_create(&key_, NULL);
#ifndef NO_MAIN_THREAD_WRAPPING
WrapCurrentThread();
#endif
#if !__has_feature(objc_arc) && (defined(WEBRTC_MAC))
// Under Automatic Reference Counting (ARC), you cannot use autorelease pools
// directly. Instead, you use @autoreleasepool blocks instead. Also, we are
// maintaining thread safety using immutability within context of GCD dispatch
// queues in this case.
InitCocoaMultiThreading();
#endif
}
ThreadManager::~ThreadManager() {
#if __has_feature(objc_arc)
@autoreleasepool
#elif defined(WEBRTC_MAC)
// This is called during exit, at which point apparently no NSAutoreleasePools
// are available; but we might still need them to do cleanup (or we get the
// "no autoreleasepool in place, just leaking" warning when exiting).
ScopedAutoreleasePool pool;
#endif
{
UnwrapCurrentThread();
pthread_key_delete(key_);
}
}
Thread *ThreadManager::CurrentThread() {
return static_cast<Thread *>(pthread_getspecific(key_));
}
void ThreadManager::SetCurrentThread(Thread *thread) {
pthread_setspecific(key_, thread);
}
#endif
#if defined(WEBRTC_WIN)
ThreadManager::ThreadManager() {
key_ = TlsAlloc();
#ifndef NO_MAIN_THREAD_WRAPPING
WrapCurrentThread();
#endif
}
ThreadManager::~ThreadManager() {
UnwrapCurrentThread();
TlsFree(key_);
}
Thread *ThreadManager::CurrentThread() {
return static_cast<Thread *>(TlsGetValue(key_));
}
void ThreadManager::SetCurrentThread(Thread *thread) {
TlsSetValue(key_, thread);
}
#endif
Thread *ThreadManager::WrapCurrentThread() {
Thread* result = CurrentThread();
if (NULL == result) {
result = new Thread();
result->WrapCurrentWithThreadManager(this, true);
}
return result;
}
void ThreadManager::UnwrapCurrentThread() {
Thread* t = CurrentThread();
if (t && !(t->IsOwned())) {
t->UnwrapCurrent();
delete t;
}
}
struct ThreadInit {
Thread* thread;
Runnable* runnable;
};
Thread::ScopedDisallowBlockingCalls::ScopedDisallowBlockingCalls()
: thread_(Thread::Current()),
previous_state_(thread_->SetAllowBlockingCalls(false)) {
}
Thread::ScopedDisallowBlockingCalls::~ScopedDisallowBlockingCalls() {
ASSERT(thread_->IsCurrent());
thread_->SetAllowBlockingCalls(previous_state_);
}
Thread::Thread(SocketServer* ss)
: MessageQueue(ss),
priority_(PRIORITY_NORMAL),
running_(true, false),
#if defined(WEBRTC_WIN)
thread_(NULL),
thread_id_(0),
#endif
owned_(true),
blocking_calls_allowed_(true) {
SetName("Thread", this); // default name
}
Thread::~Thread() {
Stop();
Clear(NULL);
}
bool Thread::SleepMs(int milliseconds) {
AssertBlockingIsAllowedOnCurrentThread();
#if defined(WEBRTC_WIN)
::Sleep(milliseconds);
return true;
#else
// POSIX has both a usleep() and a nanosleep(), but the former is deprecated,
// so we use nanosleep() even though it has greater precision than necessary.
struct timespec ts;
ts.tv_sec = milliseconds / 1000;
ts.tv_nsec = (milliseconds % 1000) * 1000000;
int ret = nanosleep(&ts, NULL);
if (ret != 0) {
LOG_ERR(LS_WARNING) << "nanosleep() returning early";
return false;
}
return true;
#endif
}
bool Thread::SetName(const std::string& name, const void* obj) {
if (running()) return false;
name_ = name;
if (obj) {
char buf[16];
sprintfn(buf, sizeof(buf), " 0x%p", obj);
name_ += buf;
}
return true;
}
bool Thread::SetPriority(ThreadPriority priority) {
#if defined(WEBRTC_WIN)
if (running()) {
ASSERT(thread_ != NULL);
BOOL ret = FALSE;
if (priority == PRIORITY_NORMAL) {
ret = ::SetThreadPriority(thread_, THREAD_PRIORITY_NORMAL);
} else if (priority == PRIORITY_HIGH) {
ret = ::SetThreadPriority(thread_, THREAD_PRIORITY_HIGHEST);
} else if (priority == PRIORITY_ABOVE_NORMAL) {
ret = ::SetThreadPriority(thread_, THREAD_PRIORITY_ABOVE_NORMAL);
} else if (priority == PRIORITY_IDLE) {
ret = ::SetThreadPriority(thread_, THREAD_PRIORITY_IDLE);
}
if (!ret) {
return false;
}
}
priority_ = priority;
return true;
#else
// TODO: Implement for Linux/Mac if possible.
if (running()) return false;
priority_ = priority;
return true;
#endif
}
bool Thread::Start(Runnable* runnable) {
ASSERT(owned_);
if (!owned_) return false;
ASSERT(!running());
if (running()) return false;
Restart(); // reset fStop_ if the thread is being restarted
// Make sure that ThreadManager is created on the main thread before
// we start a new thread.
ThreadManager::Instance();
ThreadInit* init = new ThreadInit;
init->thread = this;
init->runnable = runnable;
#if defined(WEBRTC_WIN)
DWORD flags = 0;
if (priority_ != PRIORITY_NORMAL) {
flags = CREATE_SUSPENDED;
}
thread_ = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)PreRun, init, flags,
&thread_id_);
if (thread_) {
running_.Set();
if (priority_ != PRIORITY_NORMAL) {
SetPriority(priority_);
::ResumeThread(thread_);
}
} else {
return false;
}
#elif defined(WEBRTC_POSIX)
pthread_attr_t attr;
pthread_attr_init(&attr);
// Thread priorities are not supported in NaCl.
#if !defined(__native_client__)
if (priority_ != PRIORITY_NORMAL) {
if (priority_ == PRIORITY_IDLE) {
// There is no POSIX-standard way to set a below-normal priority for an
// individual thread (only whole process), so let's not support it.
LOG(LS_WARNING) << "PRIORITY_IDLE not supported";
} else {
// Set real-time round-robin policy.
if (pthread_attr_setschedpolicy(&attr, SCHED_RR) != 0) {
LOG(LS_ERROR) << "pthread_attr_setschedpolicy";
}
struct sched_param param;
if (pthread_attr_getschedparam(&attr, &param) != 0) {
LOG(LS_ERROR) << "pthread_attr_getschedparam";
} else {
// The numbers here are arbitrary.
if (priority_ == PRIORITY_HIGH) {
param.sched_priority = 6; // 6 = HIGH
} else {
ASSERT(priority_ == PRIORITY_ABOVE_NORMAL);
param.sched_priority = 4; // 4 = ABOVE_NORMAL
}
if (pthread_attr_setschedparam(&attr, &param) != 0) {
LOG(LS_ERROR) << "pthread_attr_setschedparam";
}
}
}
}
#endif // !defined(__native_client__)
int error_code = pthread_create(&thread_, &attr, PreRun, init);
if (0 != error_code) {
LOG(LS_ERROR) << "Unable to create pthread, error " << error_code;
return false;
}
running_.Set();
#endif
return true;
}
bool Thread::WrapCurrent() {
return WrapCurrentWithThreadManager(ThreadManager::Instance(), true);
}
void Thread::UnwrapCurrent() {
// Clears the platform-specific thread-specific storage.
ThreadManager::Instance()->SetCurrentThread(NULL);
#if defined(WEBRTC_WIN)
if (thread_ != NULL) {
if (!CloseHandle(thread_)) {
LOG_GLE(LS_ERROR) << "When unwrapping thread, failed to close handle.";
}
thread_ = NULL;
}
#endif
running_.Reset();
}
void Thread::SafeWrapCurrent() {
WrapCurrentWithThreadManager(ThreadManager::Instance(), false);
}
void Thread::Join() {
AssertBlockingIsAllowedOnCurrentThread();
if (running()) {
ASSERT(!IsCurrent());
#if defined(WEBRTC_WIN)
ASSERT(thread_ != NULL);
WaitForSingleObject(thread_, INFINITE);
CloseHandle(thread_);
thread_ = NULL;
thread_id_ = 0;
#elif defined(WEBRTC_POSIX)
void *pv;
pthread_join(thread_, &pv);
#endif
running_.Reset();
}
}
bool Thread::SetAllowBlockingCalls(bool allow) {
ASSERT(IsCurrent());
bool previous = blocking_calls_allowed_;
blocking_calls_allowed_ = allow;
return previous;
}
// static
void Thread::AssertBlockingIsAllowedOnCurrentThread() {
#ifdef _DEBUG
Thread* current = Thread::Current();
ASSERT(!current || current->blocking_calls_allowed_);
#endif
}
#if defined(WEBRTC_WIN)
// As seen on MSDN.
// http://msdn.microsoft.com/en-us/library/xcb2z8hs(VS.71).aspx
#define MSDEV_SET_THREAD_NAME 0x406D1388
typedef struct tagTHREADNAME_INFO {
DWORD dwType;
LPCSTR szName;
DWORD dwThreadID;
DWORD dwFlags;
} THREADNAME_INFO;
void SetThreadName(DWORD dwThreadID, LPCSTR szThreadName) {
THREADNAME_INFO info;
info.dwType = 0x1000;
info.szName = szThreadName;
info.dwThreadID = dwThreadID;
info.dwFlags = 0;
__try {
RaiseException(MSDEV_SET_THREAD_NAME, 0, sizeof(info) / sizeof(DWORD),
reinterpret_cast<ULONG_PTR*>(&info));
}
__except(EXCEPTION_CONTINUE_EXECUTION) {
}
}
#endif // WEBRTC_WIN
void* Thread::PreRun(void* pv) {
ThreadInit* init = static_cast<ThreadInit*>(pv);
ThreadManager::Instance()->SetCurrentThread(init->thread);
#if defined(WEBRTC_WIN)
SetThreadName(GetCurrentThreadId(), init->thread->name_.c_str());
#elif defined(WEBRTC_POSIX)
// TODO: See if naming exists for pthreads.
#endif
#if __has_feature(objc_arc)
@autoreleasepool
#elif defined(WEBRTC_MAC)
// Make sure the new thread has an autoreleasepool
ScopedAutoreleasePool pool;
#endif
{
if (init->runnable) {
init->runnable->Run(init->thread);
} else {
init->thread->Run();
}
delete init;
return NULL;
}
}
void Thread::Run() {
ProcessMessages(kForever);
}
bool Thread::IsOwned() {
return owned_;
}
void Thread::Stop() {
MessageQueue::Quit();
Join();
}
void Thread::Send(MessageHandler *phandler, uint32 id, MessageData *pdata) {
AssertBlockingIsAllowedOnCurrentThread();
if (fStop_)
return;
// Sent messages are sent to the MessageHandler directly, in the context
// of "thread", like Win32 SendMessage. If in the right context,
// call the handler directly.
Message msg;
msg.phandler = phandler;
msg.message_id = id;
msg.pdata = pdata;
if (IsCurrent()) {
phandler->OnMessage(&msg);
return;
}
AutoThread thread;
Thread *current_thread = Thread::Current();
ASSERT(current_thread != NULL); // AutoThread ensures this
bool ready = false;
{
CritScope cs(&crit_);
_SendMessage smsg;
smsg.thread = current_thread;
smsg.msg = msg;
smsg.ready = &ready;
sendlist_.push_back(smsg);
}
// Wait for a reply
ss_->WakeUp();
bool waited = false;
crit_.Enter();
while (!ready) {
crit_.Leave();
current_thread->ReceiveSends();
current_thread->socketserver()->Wait(kForever, false);
waited = true;
crit_.Enter();
}
crit_.Leave();
// Our Wait loop above may have consumed some WakeUp events for this
// MessageQueue, that weren't relevant to this Send. Losing these WakeUps can
// cause problems for some SocketServers.
//
// Concrete example:
// Win32SocketServer on thread A calls Send on thread B. While processing the
// message, thread B Posts a message to A. We consume the wakeup for that
// Post while waiting for the Send to complete, which means that when we exit
// this loop, we need to issue another WakeUp, or else the Posted message
// won't be processed in a timely manner.
if (waited) {
current_thread->socketserver()->WakeUp();
}
}
void Thread::ReceiveSends() {
// Receive a sent message. Cleanup scenarios:
// - thread sending exits: We don't allow this, since thread can exit
// only via Join, so Send must complete.
// - thread receiving exits: Wakeup/set ready in Thread::Clear()
// - object target cleared: Wakeup/set ready in Thread::Clear()
crit_.Enter();
while (!sendlist_.empty()) {
_SendMessage smsg = sendlist_.front();
sendlist_.pop_front();
crit_.Leave();
smsg.msg.phandler->OnMessage(&smsg.msg);
crit_.Enter();
*smsg.ready = true;
smsg.thread->socketserver()->WakeUp();
}
crit_.Leave();
}
void Thread::Clear(MessageHandler *phandler, uint32 id,
MessageList* removed) {
CritScope cs(&crit_);
// Remove messages on sendlist_ with phandler
// Object target cleared: remove from send list, wakeup/set ready
// if sender not NULL.
std::list<_SendMessage>::iterator iter = sendlist_.begin();
while (iter != sendlist_.end()) {
_SendMessage smsg = *iter;
if (smsg.msg.Match(phandler, id)) {
if (removed) {
removed->push_back(smsg.msg);
} else {
delete smsg.msg.pdata;
}
iter = sendlist_.erase(iter);
*smsg.ready = true;
smsg.thread->socketserver()->WakeUp();
continue;
}
++iter;
}
MessageQueue::Clear(phandler, id, removed);
}
bool Thread::ProcessMessages(int cmsLoop) {
uint32 msEnd = (kForever == cmsLoop) ? 0 : TimeAfter(cmsLoop);
int cmsNext = cmsLoop;
while (true) {
#if __has_feature(objc_arc)
@autoreleasepool
#elif defined(WEBRTC_MAC)
// see: http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSAutoreleasePool_Class/Reference/Reference.html
// Each thread is supposed to have an autorelease pool. Also for event loops
// like this, autorelease pool needs to be created and drained/released
// for each cycle.
ScopedAutoreleasePool pool;
#endif
{
Message msg;
if (!Get(&msg, cmsNext))
return !IsQuitting();
Dispatch(&msg);
if (cmsLoop != kForever) {
cmsNext = TimeUntil(msEnd);
if (cmsNext < 0)
return true;
}
}
}
}
bool Thread::WrapCurrentWithThreadManager(ThreadManager* thread_manager,
bool need_synchronize_access) {
if (running())
return false;
#if defined(WEBRTC_WIN)
if (need_synchronize_access) {
// We explicitly ask for no rights other than synchronization.
// This gives us the best chance of succeeding.
thread_ = OpenThread(SYNCHRONIZE, FALSE, GetCurrentThreadId());
if (!thread_) {
LOG_GLE(LS_ERROR) << "Unable to get handle to thread.";
return false;
}
thread_id_ = GetCurrentThreadId();
}
#elif defined(WEBRTC_POSIX)
thread_ = pthread_self();
#endif
owned_ = false;
running_.Set();
thread_manager->SetCurrentThread(this);
return true;
}
AutoThread::AutoThread(SocketServer* ss) : Thread(ss) {
if (!ThreadManager::Instance()->CurrentThread()) {
ThreadManager::Instance()->SetCurrentThread(this);
}
}
AutoThread::~AutoThread() {
Stop();
if (ThreadManager::Instance()->CurrentThread() == this) {
ThreadManager::Instance()->SetCurrentThread(NULL);
}
}
#if defined(WEBRTC_WIN)
void ComThread::Run() {
HRESULT hr = CoInitializeEx(NULL, COINIT_MULTITHREADED);
ASSERT(SUCCEEDED(hr));
if (SUCCEEDED(hr)) {
Thread::Run();
CoUninitialize();
} else {
LOG(LS_ERROR) << "CoInitialize failed, hr=" << hr;
}
}
#endif
} // namespace rtc