1 files changed, 81 insertions, 0 deletions
diff --git a/third_party/libwebrtc/api/task_queue/task_queue_base.cc b/third_party/libwebrtc/api/task_queue/task_queue_base.cc
new file mode 100644
index 0000000000..ecdc7f7691
--- /dev/null
+++ b/third_party/libwebrtc/api/task_queue/task_queue_base.cc
@@ -0,0 +1,81 @@
+/*
+ *  Copyright 2019 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 "api/task_queue/task_queue_base.h"
+
+#include "absl/base/attributes.h"
+#include "absl/base/config.h"
+#include "absl/functional/any_invocable.h"
+#include "api/units/time_delta.h"
+#include "rtc_base/checks.h"
+
+#if defined(ABSL_HAVE_THREAD_LOCAL)
+
+namespace webrtc {
+namespace {
+
+ABSL_CONST_INIT thread_local TaskQueueBase* current = nullptr;
+
+}  // namespace
+
+TaskQueueBase* TaskQueueBase::Current() {
+  return current;
+}
+
+TaskQueueBase::CurrentTaskQueueSetter::CurrentTaskQueueSetter(
+    TaskQueueBase* task_queue)
+    : previous_(current) {
+  current = task_queue;
+}
+
+TaskQueueBase::CurrentTaskQueueSetter::~CurrentTaskQueueSetter() {
+  current = previous_;
+}
+}  // namespace webrtc
+
+#elif defined(WEBRTC_POSIX)
+
+#include <pthread.h>
+
+namespace webrtc {
+namespace {
+
+ABSL_CONST_INIT pthread_key_t g_queue_ptr_tls = 0;
+
+void InitializeTls() {
+  RTC_CHECK(pthread_key_create(&g_queue_ptr_tls, nullptr) == 0);
+}
+
+pthread_key_t GetQueuePtrTls() {
+  static pthread_once_t init_once = PTHREAD_ONCE_INIT;
+  RTC_CHECK(pthread_once(&init_once, &InitializeTls) == 0);
+  return g_queue_ptr_tls;
+}
+
+}  // namespace
+
+TaskQueueBase* TaskQueueBase::Current() {
+  return static_cast<TaskQueueBase*>(pthread_getspecific(GetQueuePtrTls()));
+}
+
+TaskQueueBase::CurrentTaskQueueSetter::CurrentTaskQueueSetter(
+    TaskQueueBase* task_queue)
+    : previous_(TaskQueueBase::Current()) {
+  pthread_setspecific(GetQueuePtrTls(), task_queue);
+}
+
+TaskQueueBase::CurrentTaskQueueSetter::~CurrentTaskQueueSetter() {
+  pthread_setspecific(GetQueuePtrTls(), previous_);
+}
+
+}  // namespace webrtc
+
+#else
+#error Unsupported platform
+#endif