1 files changed, 178 insertions, 0 deletions
diff --git a/dom/messagechannel/MessagePortParent.cpp b/dom/messagechannel/MessagePortParent.cpp
new file mode 100644
index 0000000000..846f1c2cda
--- /dev/null
+++ b/dom/messagechannel/MessagePortParent.cpp
@@ -0,0 +1,178 @@
+/* -*- 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/. */
+
+#include "MessagePortParent.h"
+#include "MessagePortService.h"
+#include "mozilla/dom/RefMessageBodyService.h"
+#include "mozilla/dom/SharedMessageBody.h"
+#include "mozilla/Unused.h"
+
+namespace mozilla::dom {
+
+MessagePortParent::MessagePortParent(const nsID& aUUID)
+    : mService(MessagePortService::GetOrCreate()),
+      mUUID(aUUID),
+      mEntangled(false),
+      mCanSendData(true) {
+  MOZ_ASSERT(mService);
+}
+
+MessagePortParent::~MessagePortParent() {
+  MOZ_ASSERT(!mService);
+  MOZ_ASSERT(!mEntangled);
+}
+
+bool MessagePortParent::Entangle(const nsID& aDestinationUUID,
+                                 const uint32_t& aSequenceID) {
+  if (!mService) {
+    NS_WARNING("Entangle is called after a shutdown!");
+    return false;
+  }
+
+  MOZ_ASSERT(!mEntangled);
+
+  return mService->RequestEntangling(this, aDestinationUUID, aSequenceID);
+}
+
+mozilla::ipc::IPCResult MessagePortParent::RecvPostMessages(
+    nsTArray<MessageData>&& aMessages) {
+  if (!mService) {
+    NS_WARNING("PostMessages is called after a shutdown!");
+    // This implies most probably that CloseAndDelete() has been already called
+    // such that we have no better option than to silently ignore this call.
+    return IPC_OK();
+  }
+
+  if (!mEntangled) {
+    // If we were shut down, the above condition already bailed out. So this
+    // should actually never happen and returning a failure is fine.
+    return IPC_FAIL(this, "RecvPostMessages not entangled");
+  }
+
+  // This converts the object in a data struct where we have BlobImpls.
+  FallibleTArray<RefPtr<SharedMessageBody>> messages;
+  if (NS_WARN_IF(!SharedMessageBody::FromMessagesToSharedParent(aMessages,
+                                                                messages))) {
+    // FromMessagesToSharedParent() returns false only if the array allocation
+    // failed.
+    // See bug 1750497 for further discussion if this is the wanted behavior.
+    return IPC_FAIL(this, "SharedMessageBody::FromMessagesToSharedParent");
+  }
+
+  if (messages.IsEmpty()) {
+    // An empty payload can be safely ignored.
+    return IPC_OK();
+  }
+
+  if (!mService->PostMessages(this, std::move(messages))) {
+    // TODO: Verify if all failure conditions of PostMessages() merit an
+    // IPC_FAIL. See bug 1750499.
+    return IPC_FAIL(this, "RecvPostMessages->PostMessages");
+  }
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult MessagePortParent::RecvDisentangle(
+    nsTArray<MessageData>&& aMessages) {
+  if (!mService) {
+    NS_WARNING("Entangle is called after a shutdown!");
+    // This implies most probably that CloseAndDelete() has been already called
+    // such that we can silently ignore this call.
+    return IPC_OK();
+  }
+
+  if (!mEntangled) {
+    // If we were shut down, the above condition already bailed out. So this
+    // should actually never happen and returning a failure is fine.
+    return IPC_FAIL(this, "RecvDisentangle not entangled");
+  }
+
+  // This converts the object in a data struct where we have BlobImpls.
+  FallibleTArray<RefPtr<SharedMessageBody>> messages;
+  if (NS_WARN_IF(!SharedMessageBody::FromMessagesToSharedParent(aMessages,
+                                                                messages))) {
+    // TODO: Verify if failed allocations merit an IPC_FAIL. See bug 1750497.
+    return IPC_FAIL(this, "SharedMessageBody::FromMessagesToSharedParent");
+  }
+
+  if (!mService->DisentanglePort(this, std::move(messages))) {
+    // TODO: Verify if all failure conditions of DisentanglePort() merit an
+    // IPC_FAIL. See bug 1750501.
+    return IPC_FAIL(this, "RecvDisentangle->DisentanglePort");
+  }
+
+  CloseAndDelete();
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult MessagePortParent::RecvStopSendingData() {
+  if (!mEntangled) {
+    return IPC_OK();
+  }
+
+  mCanSendData = false;
+  Unused << SendStopSendingDataConfirmed();
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult MessagePortParent::RecvClose() {
+  if (mService) {
+    MOZ_ASSERT(mEntangled);
+
+    if (!mService->ClosePort(this)) {
+      return IPC_FAIL(this, "RecvClose->ClosePort");
+    }
+
+    Close();
+  }
+
+  MOZ_ASSERT(!mEntangled);
+
+  Unused << Send__delete__(this);
+  return IPC_OK();
+}
+
+void MessagePortParent::ActorDestroy(ActorDestroyReason aWhy) {
+  if (mService && mEntangled) {
+    // When the last parent is deleted, this service is freed but this cannot
+    // be done when the hashtables are written by CloseAll.
+    RefPtr<MessagePortService> kungFuDeathGrip = mService;
+    kungFuDeathGrip->ParentDestroy(this);
+  }
+}
+
+bool MessagePortParent::Entangled(nsTArray<MessageData>&& aMessages) {
+  MOZ_ASSERT(!mEntangled);
+  mEntangled = true;
+  return SendEntangled(aMessages);
+}
+
+void MessagePortParent::CloseAndDelete() {
+  Close();
+  Unused << Send__delete__(this);
+}
+
+void MessagePortParent::Close() {
+  mService = nullptr;
+  mEntangled = false;
+}
+
+/* static */
+bool MessagePortParent::ForceClose(const nsID& aUUID,
+                                   const nsID& aDestinationUUID,
+                                   const uint32_t& aSequenceID) {
+  MessagePortService* service = MessagePortService::Get();
+  if (!service) {
+    NS_WARNING(
+        "The service must exist if we want to close an existing MessagePort.");
+    // There is nothing to close so we are ok.
+    return true;
+  }
+
+  return service->ForceClose(aUUID, aDestinationUUID, aSequenceID);
+}
+
+}  // namespace mozilla::dom