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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
commit26a029d407be480d791972afb5975cf62c9360a6 (patch)
treef435a8308119effd964b339f76abb83a57c29483 /ipc/mscom/EnsureMTA.h
parentInitial commit. (diff)
downloadfirefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz
firefox-26a029d407be480d791972afb5975cf62c9360a6.zip
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'ipc/mscom/EnsureMTA.h')
-rw-r--r--ipc/mscom/EnsureMTA.h129
1 files changed, 129 insertions, 0 deletions
diff --git a/ipc/mscom/EnsureMTA.h b/ipc/mscom/EnsureMTA.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_mscom_EnsureMTA_h
+#define mozilla_mscom_EnsureMTA_h
+
+#include "MainThreadUtils.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/MozPromise.h"
+#include "mozilla/Unused.h"
+#include "mozilla/mscom/AgileReference.h"
+#include "mozilla/mscom/Utils.h"
+#include "mozilla/RefPtr.h"
+#include "nsCOMPtr.h"
+#include "nsIThread.h"
+#include "nsThreadUtils.h"
+#include "nsWindowsHelpers.h"
+
+#include <windows.h>
+
+namespace mozilla {
+namespace mscom {
+namespace detail {
+
+// Forward declarations
+template <typename T>
+struct MTADelete;
+
+template <typename T>
+struct MTARelease;
+
+template <typename T>
+struct MTAReleaseInChildProcess;
+
+struct PreservedStreamDeleter;
+
+} // namespace detail
+
+class ProcessRuntime;
+
+// This class is OK to use as a temporary on the stack.
+class MOZ_STACK_CLASS EnsureMTA final {
+ public:
+ enum class Option {
+ Default,
+ // Forcibly dispatch to the thread returned by GetPersistentMTAThread(),
+ // even if the current thread is already inside a MTA.
+ ForceDispatchToPersistentThread,
+ };
+
+ /**
+ * Synchronously run |aClosure| on a thread living in the COM multithreaded
+ * apartment. If the current thread lives inside the COM MTA, then it runs
+ * |aClosure| immediately unless |aOpt| ==
+ * Option::ForceDispatchToPersistentThread.
+ */
+ template <typename FuncT>
+ explicit EnsureMTA(FuncT&& aClosure, Option aOpt = Option::Default) {
+ if (aOpt != Option::ForceDispatchToPersistentThread &&
+ IsCurrentThreadMTA()) {
+ // We're already on the MTA, we can run aClosure directly
+ aClosure();
+ return;
+ }
+
+ // In this case we need to run aClosure on a background thread in the MTA
+ nsCOMPtr<nsIRunnable> runnable(
+ NS_NewRunnableFunction("EnsureMTA::EnsureMTA", std::move(aClosure)));
+ SyncDispatch(std::move(runnable), aOpt);
+ }
+
+ private:
+ static nsCOMPtr<nsIThread> GetPersistentMTAThread();
+
+ static void SyncDispatch(nsCOMPtr<nsIRunnable>&& aRunnable, Option aOpt);
+ static void SyncDispatchToPersistentThread(nsIRunnable* aRunnable);
+
+ // The following function is private in order to force any consumers to be
+ // declared as friends of EnsureMTA. The intention is to prevent
+ // AsyncOperation from becoming some kind of free-for-all mechanism for
+ // asynchronously executing work on a background thread.
+ template <typename FuncT>
+ static void AsyncOperation(FuncT&& aClosure) {
+ if (IsCurrentThreadMTA()) {
+ aClosure();
+ return;
+ }
+
+ nsCOMPtr<nsIThread> thread(GetPersistentMTAThread());
+ MOZ_ASSERT(thread);
+ if (!thread) {
+ return;
+ }
+
+ DebugOnly<nsresult> rv = thread->Dispatch(
+ NS_NewRunnableFunction("mscom::EnsureMTA::AsyncOperation",
+ std::move(aClosure)),
+ NS_DISPATCH_NORMAL);
+ MOZ_ASSERT(NS_SUCCEEDED(rv));
+ }
+
+ /**
+ * This constructor just ensures that the MTA is up and running. This should
+ * only be called by ProcessRuntime.
+ */
+ EnsureMTA();
+
+ friend class mozilla::mscom::ProcessRuntime;
+
+ template <typename T>
+ friend struct mozilla::mscom::detail::MTADelete;
+
+ template <typename T>
+ friend struct mozilla::mscom::detail::MTARelease;
+
+ template <typename T>
+ friend struct mozilla::mscom::detail::MTAReleaseInChildProcess;
+
+ friend struct mozilla::mscom::detail::PreservedStreamDeleter;
+};
+
+} // namespace mscom
+} // namespace mozilla
+
+#endif // mozilla_mscom_EnsureMTA_h