dom/clients/manager/ClientSourceOpChild.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "ClientSourceOpChild.h"
   8
   9 #include "ClientSource.h"
  10 #include "ClientSourceChild.h"
  11 #include "mozilla/Assertions.h"
  12 #include "mozilla/Unused.h"
  13
  14 namespace mozilla::dom {
  15
  16 ClientSource* ClientSourceOpChild::GetSource() const {
  17   auto actor = static_cast<ClientSourceChild*>(Manager());
  18   return actor->GetSource();
  19 }
  20
  21 template <typename Method, typename... Args>
  22 void ClientSourceOpChild::DoSourceOp(Method aMethod, Args&&... aArgs) {
  23   RefPtr<ClientOpPromise> promise;
  24   nsCOMPtr<nsISerialEventTarget> target;
  25
  26   // Some ClientSource operations can cause the ClientSource to be destroyed.
  27   // This means we should reference the ClientSource pointer for the minimum
  28   // possible to start the operation.  Use an extra block scope here to help
  29   // enforce this and prevent accidental usage later in the method.
  30   {
  31     ClientSource* source = GetSource();
  32     if (!source) {
  33       CopyableErrorResult rv;
  34       rv.ThrowAbortError("Unknown Client");
  35       Unused << PClientSourceOpChild::Send__delete__(this, rv);
  36       return;
  37     }
  38
  39     target = source->EventTarget();
  40
  41     // This may cause the ClientSource object to be destroyed.  Do not
  42     // use the source variable after this call.
  43     promise = (source->*aMethod)(std::forward<Args>(aArgs)...);
  44   }
  45
  46   // The ClientSource methods are required to always return a promise.  If
  47   // they encounter an error they should just immediately resolve or reject
  48   // the promise as appropriate.
  49   MOZ_DIAGNOSTIC_ASSERT(promise);
  50
  51   // Capture 'this' is safe here because we disconnect the promise
  52   // ActorDestroy() which ensures neither lambda is called if the
  53   // actor is destroyed before the source operation completes.
  54   //
  55   // Also capture the promise to ensure it lives until we get a reaction
  56   // or the actor starts shutting down and we disconnect our Thenable.
  57   // If the ClientSource is doing something async it may throw away the
  58   // promise on its side if the global is closed.
  59   promise
  60       ->Then(
  61           target, __func__,
  62           [this, promise](const mozilla::dom::ClientOpResult& aResult) {
  63             mPromiseRequestHolder.Complete();
  64             Unused << PClientSourceOpChild::Send__delete__(this, aResult);
  65           },
  66           [this, promise](const CopyableErrorResult& aRv) {
  67             mPromiseRequestHolder.Complete();
  68             Unused << PClientSourceOpChild::Send__delete__(this, aRv);
  69           })
  70       ->Track(mPromiseRequestHolder);
  71 }
  72
  73 void ClientSourceOpChild::ActorDestroy(ActorDestroyReason aReason) {
  74   Cleanup();
  75 }
  76
  77 void ClientSourceOpChild::Init(const ClientOpConstructorArgs& aArgs) {
  78   switch (aArgs.type()) {
  79     case ClientOpConstructorArgs::TClientControlledArgs: {
  80       DoSourceOp(&ClientSource::Control, aArgs.get_ClientControlledArgs());
  81       break;
  82     }
  83     case ClientOpConstructorArgs::TClientFocusArgs: {
  84       DoSourceOp(&ClientSource::Focus, aArgs.get_ClientFocusArgs());
  85       break;
  86     }
  87     case ClientOpConstructorArgs::TClientPostMessageArgs: {
  88       DoSourceOp(&ClientSource::PostMessage, aArgs.get_ClientPostMessageArgs());
  89       break;
  90     }
  91     case ClientOpConstructorArgs::TClientClaimArgs: {
  92       MOZ_ASSERT_UNREACHABLE("shouldn't happen with parent intercept");
  93       break;
  94     }
  95     case ClientOpConstructorArgs::TClientGetInfoAndStateArgs: {
  96       DoSourceOp(&ClientSource::GetInfoAndState,
  97                  aArgs.get_ClientGetInfoAndStateArgs());
  98       break;
  99     }
 100     case ClientOpConstructorArgs::TClientEvictBFCacheArgs: {
 101       DoSourceOp(&ClientSource::EvictFromBFCacheOp);
 102       break;
 103     }
 104     default: {
 105       MOZ_ASSERT_UNREACHABLE("unknown client operation!");
 106       break;
 107     }
 108   }
 109
 110   mInitialized.Flip();
 111
 112   if (mDeletionRequested) {
 113     Cleanup();
 114     delete this;
 115   }
 116 }
 117
 118 void ClientSourceOpChild::ScheduleDeletion() {
 119   if (mInitialized) {
 120     Cleanup();
 121     delete this;
 122     return;
 123   }
 124
 125   mDeletionRequested.Flip();
 126 }
 127
 128 ClientSourceOpChild::~ClientSourceOpChild() {
 129   MOZ_DIAGNOSTIC_ASSERT(mInitialized);
 130 }
 131
 132 void ClientSourceOpChild::Cleanup() {
 133   mPromiseRequestHolder.DisconnectIfExists();
 134 }
 135
 136 }  // namespace mozilla::dom