Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 987 insertions, 0 deletions

diff --git a/third_party/libwebrtc/rtc_base/thread.cc b/third_party/libwebrtc/rtc_base/thread.cc
new file mode 100644
index 0000000000..0e5df64dde
--- /dev/null
+++ b/third_party/libwebrtc/rtc_base/thread.cc
@@ -0,0 +1,987 @@
+/*
+ *  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 "rtc_base/thread.h"
+
+#include "absl/strings/string_view.h"
+#include "api/task_queue/task_queue_base.h"
+#include "api/units/time_delta.h"
+#include "rtc_base/socket_server.h"
+
+#if defined(WEBRTC_WIN)
+#include <comdef.h>
+#elif defined(WEBRTC_POSIX)
+#include <time.h>
+#else
+#error "Either WEBRTC_WIN or WEBRTC_POSIX needs to be defined."
+#endif
+
+#if defined(WEBRTC_WIN)
+// Disable warning that we don't care about:
+// warning C4722: destructor never returns, potential memory leak
+#pragma warning(disable : 4722)
+#endif
+
+#include <stdio.h>
+
+#include <utility>
+
+#include "absl/algorithm/container.h"
+#include "absl/cleanup/cleanup.h"
+#include "api/sequence_checker.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/event.h"
+#include "rtc_base/internal/default_socket_server.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/null_socket_server.h"
+#include "rtc_base/synchronization/mutex.h"
+#include "rtc_base/time_utils.h"
+#include "rtc_base/trace_event.h"
+
+#if defined(WEBRTC_MAC)
+#include "rtc_base/system/cocoa_threading.h"
+
+/*
+ * These are forward-declarations for methods that are part of the
+ * ObjC runtime. They are declared in the private header objc-internal.h.
+ * These calls are what clang inserts when using @autoreleasepool in ObjC,
+ * but here they are used directly in order to keep this file C++.
+ * https://clang.llvm.org/docs/AutomaticReferenceCounting.html#runtime-support
+ */
+extern "C" {
+void* objc_autoreleasePoolPush(void);
+void objc_autoreleasePoolPop(void* pool);
+}
+
+namespace {
+class ScopedAutoReleasePool {
+ public:
+  ScopedAutoReleasePool() : pool_(objc_autoreleasePoolPush()) {}
+  ~ScopedAutoReleasePool() { objc_autoreleasePoolPop(pool_); }
+
+ private:
+  void* const pool_;
+};
+}  // namespace
+#endif
+
+namespace rtc {
+
+using ::webrtc::MutexLock;
+using ::webrtc::TimeDelta;
+
+ThreadManager* ThreadManager::Instance() {
+  static ThreadManager* const thread_manager = new ThreadManager();
+  return thread_manager;
+}
+
+ThreadManager::~ThreadManager() {
+  // By above RTC_DEFINE_STATIC_LOCAL.
+  RTC_DCHECK_NOTREACHED() << "ThreadManager should never be destructed.";
+}
+
+// static
+void ThreadManager::Add(Thread* message_queue) {
+  return Instance()->AddInternal(message_queue);
+}
+void ThreadManager::AddInternal(Thread* message_queue) {
+  MutexLock cs(&crit_);
+  message_queues_.push_back(message_queue);
+}
+
+// static
+void ThreadManager::Remove(Thread* message_queue) {
+  return Instance()->RemoveInternal(message_queue);
+}
+void ThreadManager::RemoveInternal(Thread* message_queue) {
+  {
+    MutexLock cs(&crit_);
+    std::vector<Thread*>::iterator iter;
+    iter = absl::c_find(message_queues_, message_queue);
+    if (iter != message_queues_.end()) {
+      message_queues_.erase(iter);
+    }
+#if RTC_DCHECK_IS_ON
+    RemoveFromSendGraph(message_queue);
+#endif
+  }
+}
+
+#if RTC_DCHECK_IS_ON
+void ThreadManager::RemoveFromSendGraph(Thread* thread) {
+  for (auto it = send_graph_.begin(); it != send_graph_.end();) {
+    if (it->first == thread) {
+      it = send_graph_.erase(it);
+    } else {
+      it->second.erase(thread);
+      ++it;
+    }
+  }
+}
+
+void ThreadManager::RegisterSendAndCheckForCycles(Thread* source,
+                                                  Thread* target) {
+  RTC_DCHECK(source);
+  RTC_DCHECK(target);
+
+  MutexLock cs(&crit_);
+  std::deque<Thread*> all_targets({target});
+  // We check the pre-existing who-sends-to-who graph for any path from target
+  // to source. This loop is guaranteed to terminate because per the send graph
+  // invariant, there are no cycles in the graph.
+  for (size_t i = 0; i < all_targets.size(); i++) {
+    const auto& targets = send_graph_[all_targets[i]];
+    all_targets.insert(all_targets.end(), targets.begin(), targets.end());
+  }
+  RTC_CHECK_EQ(absl::c_count(all_targets, source), 0)
+      << " send loop between " << source->name() << " and " << target->name();
+
+  // We may now insert source -> target without creating a cycle, since there
+  // was no path from target to source per the prior CHECK.
+  send_graph_[source].insert(target);
+}
+#endif
+
+// static
+void ThreadManager::ProcessAllMessageQueuesForTesting() {
+  return Instance()->ProcessAllMessageQueuesInternal();
+}
+
+void ThreadManager::ProcessAllMessageQueuesInternal() {
+  // This works by posting a delayed message at the current time and waiting
+  // for it to be dispatched on all queues, which will ensure that all messages
+  // that came before it were also dispatched.
+  std::atomic<int> queues_not_done(0);
+
+  {
+    MutexLock cs(&crit_);
+    for (Thread* queue : message_queues_) {
+      if (!queue->IsProcessingMessagesForTesting()) {
+        // If the queue is not processing messages, it can
+        // be ignored. If we tried to post a message to it, it would be dropped
+        // or ignored.
+        continue;
+      }
+      queues_not_done.fetch_add(1);
+      // Whether the task is processed, or the thread is simply cleared,
+      // queues_not_done gets decremented.
+      absl::Cleanup sub = [&queues_not_done] { queues_not_done.fetch_sub(1); };
+      // Post delayed task instead of regular task to wait for all delayed tasks
+      // that are ready for processing.
+      queue->PostDelayedTask([sub = std::move(sub)] {}, TimeDelta::Zero());
+    }
+  }
+
+  rtc::Thread* current = rtc::Thread::Current();
+  // Note: One of the message queues may have been on this thread, which is
+  // why we can't synchronously wait for queues_not_done to go to 0; we need
+  // to process messages as well.
+  while (queues_not_done.load() > 0) {
+    if (current) {
+      current->ProcessMessages(0);
+    }
+  }
+}
+
+// static
+Thread* Thread::Current() {
+  ThreadManager* manager = ThreadManager::Instance();
+  Thread* thread = manager->CurrentThread();
+
+  return thread;
+}
+
+#if defined(WEBRTC_POSIX)
+ThreadManager::ThreadManager() {
+#if defined(WEBRTC_MAC)
+  InitCocoaMultiThreading();
+#endif
+  pthread_key_create(&key_, nullptr);
+}
+
+Thread* ThreadManager::CurrentThread() {
+  return static_cast<Thread*>(pthread_getspecific(key_));
+}
+
+void ThreadManager::SetCurrentThreadInternal(Thread* thread) {
+  pthread_setspecific(key_, thread);
+}
+#endif
+
+#if defined(WEBRTC_WIN)
+ThreadManager::ThreadManager() : key_(TlsAlloc()) {}
+
+Thread* ThreadManager::CurrentThread() {
+  return static_cast<Thread*>(TlsGetValue(key_));
+}
+
+void ThreadManager::SetCurrentThreadInternal(Thread* thread) {
+  TlsSetValue(key_, thread);
+}
+#endif
+
+void ThreadManager::SetCurrentThread(Thread* thread) {
+#if RTC_DLOG_IS_ON
+  if (CurrentThread() && thread) {
+    RTC_DLOG(LS_ERROR) << "SetCurrentThread: Overwriting an existing value?";
+  }
+#endif  // RTC_DLOG_IS_ON
+
+  if (thread) {
+    thread->EnsureIsCurrentTaskQueue();
+  } else {
+    Thread* current = CurrentThread();
+    if (current) {
+      // The current thread is being cleared, e.g. as a result of
+      // UnwrapCurrent() being called or when a thread is being stopped
+      // (see PreRun()). This signals that the Thread instance is being detached
+      // from the thread, which also means that TaskQueue::Current() must not
+      // return a pointer to the Thread instance.
+      current->ClearCurrentTaskQueue();
+    }
+  }
+
+  SetCurrentThreadInternal(thread);
+}
+
+void rtc::ThreadManager::ChangeCurrentThreadForTest(rtc::Thread* thread) {
+  SetCurrentThreadInternal(thread);
+}
+
+Thread* ThreadManager::WrapCurrentThread() {
+  Thread* result = CurrentThread();
+  if (nullptr == result) {
+    result = new Thread(CreateDefaultSocketServer());
+    result->WrapCurrentWithThreadManager(this, true);
+  }
+  return result;
+}
+
+void ThreadManager::UnwrapCurrentThread() {
+  Thread* t = CurrentThread();
+  if (t && !(t->IsOwned())) {
+    t->UnwrapCurrent();
+    delete t;
+  }
+}
+
+Thread::ScopedDisallowBlockingCalls::ScopedDisallowBlockingCalls()
+    : thread_(Thread::Current()),
+      previous_state_(thread_->SetAllowBlockingCalls(false)) {}
+
+Thread::ScopedDisallowBlockingCalls::~ScopedDisallowBlockingCalls() {
+  RTC_DCHECK(thread_->IsCurrent());
+  thread_->SetAllowBlockingCalls(previous_state_);
+}
+
+#if RTC_DCHECK_IS_ON
+Thread::ScopedCountBlockingCalls::ScopedCountBlockingCalls(
+    std::function<void(uint32_t, uint32_t)> callback)
+    : thread_(Thread::Current()),
+      base_blocking_call_count_(thread_->GetBlockingCallCount()),
+      base_could_be_blocking_call_count_(
+          thread_->GetCouldBeBlockingCallCount()),
+      result_callback_(std::move(callback)) {}
+
+Thread::ScopedCountBlockingCalls::~ScopedCountBlockingCalls() {
+  if (GetTotalBlockedCallCount() >= min_blocking_calls_for_callback_) {
+    result_callback_(GetBlockingCallCount(), GetCouldBeBlockingCallCount());
+  }
+}
+
+uint32_t Thread::ScopedCountBlockingCalls::GetBlockingCallCount() const {
+  return thread_->GetBlockingCallCount() - base_blocking_call_count_;
+}
+
+uint32_t Thread::ScopedCountBlockingCalls::GetCouldBeBlockingCallCount() const {
+  return thread_->GetCouldBeBlockingCallCount() -
+         base_could_be_blocking_call_count_;
+}
+
+uint32_t Thread::ScopedCountBlockingCalls::GetTotalBlockedCallCount() const {
+  return GetBlockingCallCount() + GetCouldBeBlockingCallCount();
+}
+#endif
+
+Thread::Thread(SocketServer* ss) : Thread(ss, /*do_init=*/true) {}
+
+Thread::Thread(std::unique_ptr<SocketServer> ss)
+    : Thread(std::move(ss), /*do_init=*/true) {}
+
+Thread::Thread(SocketServer* ss, bool do_init)
+    : delayed_next_num_(0),
+      fInitialized_(false),
+      fDestroyed_(false),
+      stop_(0),
+      ss_(ss) {
+  RTC_DCHECK(ss);
+  ss_->SetMessageQueue(this);
+  SetName("Thread", this);  // default name
+  if (do_init) {
+    DoInit();
+  }
+}
+
+Thread::Thread(std::unique_ptr<SocketServer> ss, bool do_init)
+    : Thread(ss.get(), do_init) {
+  own_ss_ = std::move(ss);
+}
+
+Thread::~Thread() {
+  Stop();
+  DoDestroy();
+}
+
+void Thread::DoInit() {
+  if (fInitialized_) {
+    return;
+  }
+
+  fInitialized_ = true;
+  ThreadManager::Add(this);
+}
+
+void Thread::DoDestroy() {
+  if (fDestroyed_) {
+    return;
+  }
+
+  fDestroyed_ = true;
+  // The signal is done from here to ensure
+  // that it always gets called when the queue
+  // is going away.
+  if (ss_) {
+    ss_->SetMessageQueue(nullptr);
+  }
+  ThreadManager::Remove(this);
+  // Clear.
+  CurrentTaskQueueSetter set_current(this);
+  messages_ = {};
+  delayed_messages_ = {};
+}
+
+SocketServer* Thread::socketserver() {
+  return ss_;
+}
+
+void Thread::WakeUpSocketServer() {
+  ss_->WakeUp();
+}
+
+void Thread::Quit() {
+  stop_.store(1, std::memory_order_release);
+  WakeUpSocketServer();
+}
+
+bool Thread::IsQuitting() {
+  return stop_.load(std::memory_order_acquire) != 0;
+}
+
+void Thread::Restart() {
+  stop_.store(0, std::memory_order_release);
+}
+
+absl::AnyInvocable<void() &&> Thread::Get(int cmsWait) {
+  // Get w/wait + timer scan / dispatch + socket / event multiplexer dispatch
+
+  int64_t cmsTotal = cmsWait;
+  int64_t cmsElapsed = 0;
+  int64_t msStart = TimeMillis();
+  int64_t msCurrent = msStart;
+  while (true) {
+    // Check for posted events
+    int64_t cmsDelayNext = kForever;
+    {
+      // All queue operations need to be locked, but nothing else in this loop
+      // can happen while holding the `mutex_`.
+      MutexLock lock(&mutex_);
+      // Check for delayed messages that have been triggered and calculate the
+      // next trigger time.
+      while (!delayed_messages_.empty()) {
+        if (msCurrent < delayed_messages_.top().run_time_ms) {
+          cmsDelayNext =
+              TimeDiff(delayed_messages_.top().run_time_ms, msCurrent);
+          break;
+        }
+        messages_.push(std::move(delayed_messages_.top().functor));
+        delayed_messages_.pop();
+      }
+      // Pull a message off the message queue, if available.
+      if (!messages_.empty()) {
+        absl::AnyInvocable<void()&&> task = std::move(messages_.front());
+        messages_.pop();
+        return task;
+      }
+    }
+
+    if (IsQuitting())
+      break;
+
+    // Which is shorter, the delay wait or the asked wait?
+
+    int64_t cmsNext;
+    if (cmsWait == kForever) {
+      cmsNext = cmsDelayNext;
+    } else {
+      cmsNext = std::max<int64_t>(0, cmsTotal - cmsElapsed);
+      if ((cmsDelayNext != kForever) && (cmsDelayNext < cmsNext))
+        cmsNext = cmsDelayNext;
+    }
+
+    {
+      // Wait and multiplex in the meantime
+      if (!ss_->Wait(cmsNext == kForever ? SocketServer::kForever
+                                         : webrtc::TimeDelta::Millis(cmsNext),
+                     /*process_io=*/true))
+        return nullptr;
+    }
+
+    // If the specified timeout expired, return
+
+    msCurrent = TimeMillis();
+    cmsElapsed = TimeDiff(msCurrent, msStart);
+    if (cmsWait != kForever) {
+      if (cmsElapsed >= cmsWait)
+        return nullptr;
+    }
+  }
+  return nullptr;
+}
+
+void Thread::PostTask(absl::AnyInvocable<void() &&> task) {
+  if (IsQuitting()) {
+    return;
+  }
+
+  // Keep thread safe
+  // Add the message to the end of the queue
+  // Signal for the multiplexer to return
+
+  {
+    MutexLock lock(&mutex_);
+    messages_.push(std::move(task));
+  }
+  WakeUpSocketServer();
+}
+
+void Thread::PostDelayedHighPrecisionTask(absl::AnyInvocable<void() &&> task,
+                                          webrtc::TimeDelta delay) {
+  if (IsQuitting()) {
+    return;
+  }
+
+  // Keep thread safe
+  // Add to the priority queue. Gets sorted soonest first.
+  // Signal for the multiplexer to return.
+
+  int64_t delay_ms = delay.RoundUpTo(webrtc::TimeDelta::Millis(1)).ms<int>();
+  int64_t run_time_ms = TimeAfter(delay_ms);
+  {
+    MutexLock lock(&mutex_);
+    delayed_messages_.push({.delay_ms = delay_ms,
+                            .run_time_ms = run_time_ms,
+                            .message_number = delayed_next_num_,
+                            .functor = std::move(task)});
+    // If this message queue processes 1 message every millisecond for 50 days,
+    // we will wrap this number.  Even then, only messages with identical times
+    // will be misordered, and then only briefly.  This is probably ok.
+    ++delayed_next_num_;
+    RTC_DCHECK_NE(0, delayed_next_num_);
+  }
+  WakeUpSocketServer();
+}
+
+int Thread::GetDelay() {
+  MutexLock lock(&mutex_);
+
+  if (!messages_.empty())
+    return 0;
+
+  if (!delayed_messages_.empty()) {
+    int delay = TimeUntil(delayed_messages_.top().run_time_ms);
+    if (delay < 0)
+      delay = 0;
+    return delay;
+  }
+
+  return kForever;
+}
+
+void Thread::Dispatch(absl::AnyInvocable<void() &&> task) {
+  TRACE_EVENT0("webrtc", "Thread::Dispatch");
+  RTC_DCHECK_RUN_ON(this);
+  int64_t start_time = TimeMillis();
+  std::move(task)();
+  int64_t end_time = TimeMillis();
+  int64_t diff = TimeDiff(end_time, start_time);
+  if (diff >= dispatch_warning_ms_) {
+    RTC_LOG(LS_INFO) << "Message to " << name() << " took " << diff
+                     << "ms to dispatch.";
+    // To avoid log spew, move the warning limit to only give warning
+    // for delays that are larger than the one observed.
+    dispatch_warning_ms_ = diff + 1;
+  }
+}
+
+bool Thread::IsCurrent() const {
+  return ThreadManager::Instance()->CurrentThread() == this;
+}
+
+std::unique_ptr<Thread> Thread::CreateWithSocketServer() {
+  return std::unique_ptr<Thread>(new Thread(CreateDefaultSocketServer()));
+}
+
+std::unique_ptr<Thread> Thread::Create() {
+  return std::unique_ptr<Thread>(
+      new Thread(std::unique_ptr<SocketServer>(new NullSocketServer())));
+}
+
+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, nullptr);
+  if (ret != 0) {
+    RTC_LOG_ERR(LS_WARNING) << "nanosleep() returning early";
+    return false;
+  }
+  return true;
+#endif
+}
+
+bool Thread::SetName(absl::string_view name, const void* obj) {
+  RTC_DCHECK(!IsRunning());
+
+  name_ = std::string(name);
+  if (obj) {
+    // The %p specifier typically produce at most 16 hex digits, possibly with a
+    // 0x prefix. But format is implementation defined, so add some margin.
+    char buf[30];
+    snprintf(buf, sizeof(buf), " 0x%p", obj);
+    name_ += buf;
+  }
+  return true;
+}
+
+void Thread::SetDispatchWarningMs(int deadline) {
+  if (!IsCurrent()) {
+    PostTask([this, deadline]() { SetDispatchWarningMs(deadline); });
+    return;
+  }
+  RTC_DCHECK_RUN_ON(this);
+  dispatch_warning_ms_ = deadline;
+}
+
+bool Thread::Start() {
+  RTC_DCHECK(!IsRunning());
+
+  if (IsRunning())
+    return false;
+
+  Restart();  // reset IsQuitting() if the thread is being restarted
+
+  // Make sure that ThreadManager is created on the main thread before
+  // we start a new thread.
+  ThreadManager::Instance();
+
+  owned_ = true;
+
+#if defined(WEBRTC_WIN)
+  thread_ = CreateThread(nullptr, 0, PreRun, this, 0, &thread_id_);
+  if (!thread_) {
+    return false;
+  }
+#elif defined(WEBRTC_POSIX)
+  pthread_attr_t attr;
+  pthread_attr_init(&attr);
+
+  int error_code = pthread_create(&thread_, &attr, PreRun, this);
+  if (0 != error_code) {
+    RTC_LOG(LS_ERROR) << "Unable to create pthread, error " << error_code;
+    thread_ = 0;
+    return false;
+  }
+  RTC_DCHECK(thread_);
+#endif
+  return true;
+}
+
+bool Thread::WrapCurrent() {
+  return WrapCurrentWithThreadManager(ThreadManager::Instance(), true);
+}
+
+void Thread::UnwrapCurrent() {
+  // Clears the platform-specific thread-specific storage.
+  ThreadManager::Instance()->SetCurrentThread(nullptr);
+#if defined(WEBRTC_WIN)
+  if (thread_ != nullptr) {
+    if (!CloseHandle(thread_)) {
+      RTC_LOG_GLE(LS_ERROR)
+          << "When unwrapping thread, failed to close handle.";
+    }
+    thread_ = nullptr;
+    thread_id_ = 0;
+  }
+#elif defined(WEBRTC_POSIX)
+  thread_ = 0;
+#endif
+}
+
+void Thread::SafeWrapCurrent() {
+  WrapCurrentWithThreadManager(ThreadManager::Instance(), false);
+}
+
+void Thread::Join() {
+  if (!IsRunning())
+    return;
+
+  RTC_DCHECK(!IsCurrent());
+  if (Current() && !Current()->blocking_calls_allowed_) {
+    RTC_LOG(LS_WARNING) << "Waiting for the thread to join, "
+                           "but blocking calls have been disallowed";
+  }
+
+#if defined(WEBRTC_WIN)
+  RTC_DCHECK(thread_ != nullptr);
+  WaitForSingleObject(thread_, INFINITE);
+  CloseHandle(thread_);
+  thread_ = nullptr;
+  thread_id_ = 0;
+#elif defined(WEBRTC_POSIX)
+  pthread_join(thread_, nullptr);
+  thread_ = 0;
+#endif
+}
+
+bool Thread::SetAllowBlockingCalls(bool allow) {
+  RTC_DCHECK(IsCurrent());
+  bool previous = blocking_calls_allowed_;
+  blocking_calls_allowed_ = allow;
+  return previous;
+}
+
+// static
+void Thread::AssertBlockingIsAllowedOnCurrentThread() {
+#if !defined(NDEBUG)
+  Thread* current = Thread::Current();
+  RTC_DCHECK(!current || current->blocking_calls_allowed_);
+#endif
+}
+
+// static
+#if defined(WEBRTC_WIN)
+DWORD WINAPI Thread::PreRun(LPVOID pv) {
+#else
+void* Thread::PreRun(void* pv) {
+#endif
+  Thread* thread = static_cast<Thread*>(pv);
+  ThreadManager::Instance()->SetCurrentThread(thread);
+  rtc::SetCurrentThreadName(thread->name_.c_str());
+#if defined(WEBRTC_MAC)
+  ScopedAutoReleasePool pool;
+#endif
+  thread->Run();
+
+  ThreadManager::Instance()->SetCurrentThread(nullptr);
+#ifdef WEBRTC_WIN
+  return 0;
+#else
+  return nullptr;
+#endif
+}  // namespace rtc
+
+void Thread::Run() {
+  ProcessMessages(kForever);
+}
+
+bool Thread::IsOwned() {
+  RTC_DCHECK(IsRunning());
+  return owned_;
+}
+
+void Thread::Stop() {
+  Thread::Quit();
+  Join();
+}
+
+void Thread::BlockingCall(rtc::FunctionView<void()> functor) {
+  TRACE_EVENT0("webrtc", "Thread::BlockingCall");
+
+  RTC_DCHECK(!IsQuitting());
+  if (IsQuitting())
+    return;
+
+  if (IsCurrent()) {
+#if RTC_DCHECK_IS_ON
+    RTC_DCHECK(this->IsInvokeToThreadAllowed(this));
+    RTC_DCHECK_RUN_ON(this);
+    could_be_blocking_call_count_++;
+#endif
+    functor();
+    return;
+  }
+
+  AssertBlockingIsAllowedOnCurrentThread();
+
+  Thread* current_thread = Thread::Current();
+
+#if RTC_DCHECK_IS_ON
+  if (current_thread) {
+    RTC_DCHECK_RUN_ON(current_thread);
+    current_thread->blocking_call_count_++;
+    RTC_DCHECK(current_thread->IsInvokeToThreadAllowed(this));
+    ThreadManager::Instance()->RegisterSendAndCheckForCycles(current_thread,
+                                                             this);
+  }
+#endif
+
+  // Perhaps down the line we can get rid of this workaround and always require
+  // current_thread to be valid when BlockingCall() is called.
+  std::unique_ptr<rtc::Event> done_event;
+  if (!current_thread)
+    done_event.reset(new rtc::Event());
+
+  bool ready = false;
+  absl::Cleanup cleanup = [this, &ready, current_thread,
+                           done = done_event.get()] {
+    if (current_thread) {
+      {
+        MutexLock lock(&mutex_);
+        ready = true;
+      }
+      current_thread->socketserver()->WakeUp();
+    } else {
+      done->Set();
+    }
+  };
+  PostTask([functor, cleanup = std::move(cleanup)] { functor(); });
+  if (current_thread) {
+    bool waited = false;
+    mutex_.Lock();
+    while (!ready) {
+      mutex_.Unlock();
+      current_thread->socketserver()->Wait(SocketServer::kForever, false);
+      waited = true;
+      mutex_.Lock();
+    }
+    mutex_.Unlock();
+
+    // Our Wait loop above may have consumed some WakeUp events for this
+    // Thread, 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();
+    }
+  } else {
+    done_event->Wait(rtc::Event::kForever);
+  }
+}
+
+// Called by the ThreadManager when being set as the current thread.
+void Thread::EnsureIsCurrentTaskQueue() {
+  task_queue_registration_ =
+      std::make_unique<TaskQueueBase::CurrentTaskQueueSetter>(this);
+}
+
+// Called by the ThreadManager when being set as the current thread.
+void Thread::ClearCurrentTaskQueue() {
+  task_queue_registration_.reset();
+}
+
+void Thread::AllowInvokesToThread(Thread* thread) {
+#if (!defined(NDEBUG) || RTC_DCHECK_IS_ON)
+  if (!IsCurrent()) {
+    PostTask([thread, this]() { AllowInvokesToThread(thread); });
+    return;
+  }
+  RTC_DCHECK_RUN_ON(this);
+  allowed_threads_.push_back(thread);
+  invoke_policy_enabled_ = true;
+#endif
+}
+
+void Thread::DisallowAllInvokes() {
+#if (!defined(NDEBUG) || RTC_DCHECK_IS_ON)
+  if (!IsCurrent()) {
+    PostTask([this]() { DisallowAllInvokes(); });
+    return;
+  }
+  RTC_DCHECK_RUN_ON(this);
+  allowed_threads_.clear();
+  invoke_policy_enabled_ = true;
+#endif
+}
+
+#if RTC_DCHECK_IS_ON
+uint32_t Thread::GetBlockingCallCount() const {
+  RTC_DCHECK_RUN_ON(this);
+  return blocking_call_count_;
+}
+uint32_t Thread::GetCouldBeBlockingCallCount() const {
+  RTC_DCHECK_RUN_ON(this);
+  return could_be_blocking_call_count_;
+}
+#endif
+
+// Returns true if no policies added or if there is at least one policy
+// that permits invocation to `target` thread.
+bool Thread::IsInvokeToThreadAllowed(rtc::Thread* target) {
+#if (!defined(NDEBUG) || RTC_DCHECK_IS_ON)
+  RTC_DCHECK_RUN_ON(this);
+  if (!invoke_policy_enabled_) {
+    return true;
+  }
+  for (const auto* thread : allowed_threads_) {
+    if (thread == target) {
+      return true;
+    }
+  }
+  return false;
+#else
+  return true;
+#endif
+}
+
+void Thread::Delete() {
+  Stop();
+  delete this;
+}
+
+void Thread::PostDelayedTask(absl::AnyInvocable<void() &&> task,
+                             webrtc::TimeDelta delay) {
+  // This implementation does not support low precision yet.
+  PostDelayedHighPrecisionTask(std::move(task), delay);
+}
+
+bool Thread::IsProcessingMessagesForTesting() {
+  return (owned_ || IsCurrent()) && !IsQuitting();
+}
+
+bool Thread::ProcessMessages(int cmsLoop) {
+  // Using ProcessMessages with a custom clock for testing and a time greater
+  // than 0 doesn't work, since it's not guaranteed to advance the custom
+  // clock's time, and may get stuck in an infinite loop.
+  RTC_DCHECK(GetClockForTesting() == nullptr || cmsLoop == 0 ||
+             cmsLoop == kForever);
+  int64_t msEnd = (kForever == cmsLoop) ? 0 : TimeAfter(cmsLoop);
+  int cmsNext = cmsLoop;
+
+  while (true) {
+#if defined(WEBRTC_MAC)
+    ScopedAutoReleasePool pool;
+#endif
+    absl::AnyInvocable<void()&&> task = Get(cmsNext);
+    if (!task)
+      return !IsQuitting();
+    Dispatch(std::move(task));
+
+    if (cmsLoop != kForever) {
+      cmsNext = static_cast<int>(TimeUntil(msEnd));
+      if (cmsNext < 0)
+        return true;
+    }
+  }
+}
+
+bool Thread::WrapCurrentWithThreadManager(ThreadManager* thread_manager,
+                                          bool need_synchronize_access) {
+  RTC_DCHECK(!IsRunning());
+
+#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_) {
+      RTC_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;
+  thread_manager->SetCurrentThread(this);
+  return true;
+}
+
+bool Thread::IsRunning() {
+#if defined(WEBRTC_WIN)
+  return thread_ != nullptr;
+#elif defined(WEBRTC_POSIX)
+  return thread_ != 0;
+#endif
+}
+
+AutoThread::AutoThread()
+    : Thread(CreateDefaultSocketServer(), /*do_init=*/false) {
+  if (!ThreadManager::Instance()->CurrentThread()) {
+    // DoInit registers with ThreadManager. Do that only if we intend to
+    // be rtc::Thread::Current(), otherwise ProcessAllMessageQueuesInternal will
+    // post a message to a queue that no running thread is serving.
+    DoInit();
+    ThreadManager::Instance()->SetCurrentThread(this);
+  }
+}
+
+AutoThread::~AutoThread() {
+  Stop();
+  DoDestroy();
+  if (ThreadManager::Instance()->CurrentThread() == this) {
+    ThreadManager::Instance()->SetCurrentThread(nullptr);
+  }
+}
+
+AutoSocketServerThread::AutoSocketServerThread(SocketServer* ss)
+    : Thread(ss, /*do_init=*/false) {
+  DoInit();
+  old_thread_ = ThreadManager::Instance()->CurrentThread();
+  // Temporarily set the current thread to nullptr so that we can keep checks
+  // around that catch unintentional pointer overwrites.
+  rtc::ThreadManager::Instance()->SetCurrentThread(nullptr);
+  rtc::ThreadManager::Instance()->SetCurrentThread(this);
+  if (old_thread_) {
+    ThreadManager::Remove(old_thread_);
+  }
+}
+
+AutoSocketServerThread::~AutoSocketServerThread() {
+  RTC_DCHECK(ThreadManager::Instance()->CurrentThread() == this);
+  // Stop and destroy the thread before clearing it as the current thread.
+  // Sometimes there are messages left in the Thread that will be
+  // destroyed by DoDestroy, and sometimes the destructors of the message and/or
+  // its contents rely on this thread still being set as the current thread.
+  Stop();
+  DoDestroy();
+  rtc::ThreadManager::Instance()->SetCurrentThread(nullptr);
+  rtc::ThreadManager::Instance()->SetCurrentThread(old_thread_);
+  if (old_thread_) {
+    ThreadManager::Add(old_thread_);
+  }
+}
+
+}  // namespace rtc