1 files changed, 57 insertions, 0 deletions
diff --git a/third_party/libwebrtc/rtc_base/win/scoped_com_initializer.cc b/third_party/libwebrtc/rtc_base/win/scoped_com_initializer.cc
new file mode 100644
index 0000000000..4b56772ebf
--- /dev/null
+++ b/third_party/libwebrtc/rtc_base/win/scoped_com_initializer.cc
@@ -0,0 +1,57 @@
+/*
+ *  Copyright (c) 2020 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/win/scoped_com_initializer.h"
+
+#include "rtc_base/checks.h"
+#include "rtc_base/logging.h"
+
+namespace webrtc {
+
+ScopedCOMInitializer::ScopedCOMInitializer() {
+  RTC_DLOG(LS_INFO) << "Single-Threaded Apartment (STA) COM thread";
+  Initialize(COINIT_APARTMENTTHREADED);
+}
+
+// Constructor for MTA initialization.
+ScopedCOMInitializer::ScopedCOMInitializer(SelectMTA mta) {
+  RTC_DLOG(LS_INFO) << "Multi-Threaded Apartment (MTA) COM thread";
+  Initialize(COINIT_MULTITHREADED);
+}
+
+ScopedCOMInitializer::~ScopedCOMInitializer() {
+  if (Succeeded()) {
+    CoUninitialize();
+  }
+}
+
+void ScopedCOMInitializer::Initialize(COINIT init) {
+  // Initializes the COM library for use by the calling thread, sets the
+  // thread's concurrency model, and creates a new apartment for the thread
+  // if one is required. CoInitializeEx must be called at least once, and is
+  // usually called only once, for each thread that uses the COM library.
+  hr_ = CoInitializeEx(NULL, init);
+  RTC_CHECK_NE(RPC_E_CHANGED_MODE, hr_)
+      << "Invalid COM thread model change (MTA->STA)";
+  // Multiple calls to CoInitializeEx by the same thread are allowed as long
+  // as they pass the same concurrency flag, but subsequent valid calls
+  // return S_FALSE. To close the COM library gracefully on a thread, each
+  // successful call to CoInitializeEx, including any call that returns
+  // S_FALSE, must be balanced by a corresponding call to CoUninitialize.
+  if (hr_ == S_OK) {
+    RTC_DLOG(LS_INFO)
+        << "The COM library was initialized successfully on this thread";
+  } else if (hr_ == S_FALSE) {
+    RTC_DLOG(LS_WARNING)
+        << "The COM library is already initialized on this thread";
+  }
+}
+
+}  // namespace webrtc