2535 lines
78 KiB
C++
2535 lines
78 KiB
C++
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
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* vim: sw=4 ts=4 et :
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*/
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#include "mozilla/ipc/MessageChannel.h"
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#include "mozilla/ipc/ProtocolUtils.h"
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#include "mozilla/dom/ScriptSettings.h"
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#include "mozilla/Assertions.h"
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#include "mozilla/DebugOnly.h"
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#include "mozilla/Move.h"
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#include "mozilla/SizePrintfMacros.h"
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#include "mozilla/Sprintf.h"
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#include "mozilla/Logging.h"
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#include "nsAutoPtr.h"
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#include "nsDebug.h"
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#include "nsISupportsImpl.h"
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#include "nsContentUtils.h"
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using mozilla::Move;
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// Undo the damage done by mozzconf.h
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#undef compress
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static mozilla::LazyLogModule sLogModule("ipc");
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#define IPC_LOG(...) MOZ_LOG(sLogModule, LogLevel::Debug, (__VA_ARGS__))
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/*
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* IPC design:
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*
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* There are three kinds of messages: async, sync, and intr. Sync and intr
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* messages are blocking.
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*
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* Terminology: To dispatch a message Foo is to run the RecvFoo code for
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* it. This is also called "handling" the message.
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*
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* Sync and async messages can sometimes "nest" inside other sync messages
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* (i.e., while waiting for the sync reply, we can dispatch the inner
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* message). Intr messages cannot nest. The three possible nesting levels are
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* NOT_NESTED, NESTED_INSIDE_SYNC, and NESTED_INSIDE_CPOW. The intended uses
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* are:
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* NOT_NESTED - most messages.
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* NESTED_INSIDE_SYNC - CPOW-related messages, which are always sync
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* and can go in either direction.
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* NESTED_INSIDE_CPOW - messages where we don't want to dispatch
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* incoming CPOWs while waiting for the response.
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* These nesting levels are ordered: NOT_NESTED, NESTED_INSIDE_SYNC,
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* NESTED_INSIDE_CPOW. Async messages cannot be NESTED_INSIDE_SYNC but they can
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* be NESTED_INSIDE_CPOW.
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*
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* To avoid jank, the parent process is not allowed to send NOT_NESTED sync messages.
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* When a process is waiting for a response to a sync message
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* M0, it will dispatch an incoming message M if:
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* 1. M has a higher nesting level than M0, or
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* 2. if M has the same nesting level as M0 and we're in the child, or
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* 3. if M has the same nesting level as M0 and it was sent by the other side
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* while dispatching M0.
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* The idea is that messages with higher nesting should take precendence. The
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* purpose of rule 2 is to handle a race where both processes send to each other
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* simultaneously. In this case, we resolve the race in favor of the parent (so
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* the child dispatches first).
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*
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* Messages satisfy the following properties:
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* A. When waiting for a response to a sync message, we won't dispatch any
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* messages of nesting level.
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* B. Messages of the same nesting level will be dispatched roughly in the
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* order they were sent. The exception is when the parent and child send
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* sync messages to each other simulataneously. In this case, the parent's
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* message is dispatched first. While it is dispatched, the child may send
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* further nested messages, and these messages may be dispatched before the
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* child's original message. We can consider ordering to be preserved here
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* because we pretend that the child's original message wasn't sent until
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* after the parent's message is finished being dispatched.
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*
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* When waiting for a sync message reply, we dispatch an async message only if
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* it is NESTED_INSIDE_CPOW. Normally NESTED_INSIDE_CPOW async
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* messages are sent only from the child. However, the parent can send
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* NESTED_INSIDE_CPOW async messages when it is creating a bridged protocol.
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*
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* Intr messages are blocking and can nest, but they don't participate in the
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* nesting levels. While waiting for an intr response, all incoming messages are
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* dispatched until a response is received. When two intr messages race with
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* each other, a similar scheme is used to ensure that one side wins. The
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* winning side is chosen based on the message type.
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*
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* Intr messages differ from sync messages in that, while sending an intr
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* message, we may dispatch an async message. This causes some additional
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* complexity. One issue is that replies can be received out of order. It's also
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* more difficult to determine whether one message is nested inside
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* another. Consequently, intr handling uses mOutOfTurnReplies and
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* mRemoteStackDepthGuess, which are not needed for sync messages.
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*/
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using namespace mozilla;
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using namespace mozilla::ipc;
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using namespace std;
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using mozilla::dom::AutoNoJSAPI;
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using mozilla::dom::ScriptSettingsInitialized;
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using mozilla::MonitorAutoLock;
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using mozilla::MonitorAutoUnlock;
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#define IPC_ASSERT(_cond, ...) \
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do { \
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if (!(_cond)) \
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DebugAbort(__FILE__, __LINE__, #_cond,## __VA_ARGS__); \
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} while (0)
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static MessageChannel* gParentProcessBlocker;
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namespace mozilla {
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namespace ipc {
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const int32_t MessageChannel::kNoTimeout = INT32_MIN;
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// static
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bool MessageChannel::sIsPumpingMessages = false;
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enum Direction
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{
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IN_MESSAGE,
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OUT_MESSAGE
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};
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class MessageChannel::InterruptFrame
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{
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private:
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enum Semantics
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{
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INTR_SEMS,
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SYNC_SEMS,
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ASYNC_SEMS
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};
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public:
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InterruptFrame(Direction direction, const Message* msg)
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: mMessageName(msg->name()),
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mMessageRoutingId(msg->routing_id()),
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mMesageSemantics(msg->is_interrupt() ? INTR_SEMS :
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msg->is_sync() ? SYNC_SEMS :
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ASYNC_SEMS),
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mDirection(direction),
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mMoved(false)
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{
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MOZ_RELEASE_ASSERT(mMessageName);
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}
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InterruptFrame(InterruptFrame&& aOther)
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{
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MOZ_RELEASE_ASSERT(aOther.mMessageName);
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mMessageName = aOther.mMessageName;
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aOther.mMessageName = nullptr;
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mMoved = aOther.mMoved;
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aOther.mMoved = true;
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mMessageRoutingId = aOther.mMessageRoutingId;
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mMesageSemantics = aOther.mMesageSemantics;
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mDirection = aOther.mDirection;
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}
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~InterruptFrame()
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{
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MOZ_RELEASE_ASSERT(mMessageName || mMoved);
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}
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InterruptFrame& operator=(InterruptFrame&& aOther)
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{
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MOZ_RELEASE_ASSERT(&aOther != this);
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this->~InterruptFrame();
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new (this) InterruptFrame(Move(aOther));
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return *this;
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}
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bool IsInterruptIncall() const
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{
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return INTR_SEMS == mMesageSemantics && IN_MESSAGE == mDirection;
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}
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bool IsInterruptOutcall() const
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{
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return INTR_SEMS == mMesageSemantics && OUT_MESSAGE == mDirection;
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}
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bool IsOutgoingSync() const {
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return (mMesageSemantics == INTR_SEMS || mMesageSemantics == SYNC_SEMS) &&
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mDirection == OUT_MESSAGE;
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}
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void Describe(int32_t* id, const char** dir, const char** sems,
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const char** name) const
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{
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*id = mMessageRoutingId;
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*dir = (IN_MESSAGE == mDirection) ? "in" : "out";
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*sems = (INTR_SEMS == mMesageSemantics) ? "intr" :
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(SYNC_SEMS == mMesageSemantics) ? "sync" :
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"async";
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*name = mMessageName;
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}
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int32_t GetRoutingId() const
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{
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return mMessageRoutingId;
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}
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private:
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const char* mMessageName;
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int32_t mMessageRoutingId;
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Semantics mMesageSemantics;
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Direction mDirection;
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bool mMoved;
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// Disable harmful methods.
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InterruptFrame(const InterruptFrame& aOther) = delete;
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InterruptFrame& operator=(const InterruptFrame&) = delete;
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};
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class MOZ_STACK_CLASS MessageChannel::CxxStackFrame
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{
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public:
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CxxStackFrame(MessageChannel& that, Direction direction, const Message* msg)
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: mThat(that)
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{
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mThat.AssertWorkerThread();
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if (mThat.mCxxStackFrames.empty())
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mThat.EnteredCxxStack();
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if (!mThat.mCxxStackFrames.append(InterruptFrame(direction, msg)))
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MOZ_CRASH();
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const InterruptFrame& frame = mThat.mCxxStackFrames.back();
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if (frame.IsInterruptIncall())
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mThat.EnteredCall();
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if (frame.IsOutgoingSync())
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mThat.EnteredSyncSend();
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mThat.mSawInterruptOutMsg |= frame.IsInterruptOutcall();
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}
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~CxxStackFrame() {
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mThat.AssertWorkerThread();
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MOZ_RELEASE_ASSERT(!mThat.mCxxStackFrames.empty());
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const InterruptFrame& frame = mThat.mCxxStackFrames.back();
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bool exitingSync = frame.IsOutgoingSync();
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bool exitingCall = frame.IsInterruptIncall();
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mThat.mCxxStackFrames.shrinkBy(1);
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bool exitingStack = mThat.mCxxStackFrames.empty();
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// According how lifetime is declared, mListener on MessageChannel
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// lives longer than MessageChannel itself. Hence is expected to
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// be alive. There is nothing to even assert here, there is no place
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// we would be nullifying mListener on MessageChannel.
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if (exitingCall)
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mThat.ExitedCall();
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if (exitingSync)
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mThat.ExitedSyncSend();
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if (exitingStack)
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mThat.ExitedCxxStack();
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}
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private:
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MessageChannel& mThat;
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// Disable harmful methods.
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CxxStackFrame() = delete;
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CxxStackFrame(const CxxStackFrame&) = delete;
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CxxStackFrame& operator=(const CxxStackFrame&) = delete;
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};
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class AutoEnterTransaction
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{
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public:
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explicit AutoEnterTransaction(MessageChannel *aChan,
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int32_t aMsgSeqno,
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int32_t aTransactionID,
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int aNestedLevel)
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: mChan(aChan),
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mActive(true),
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mOutgoing(true),
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mNestedLevel(aNestedLevel),
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mSeqno(aMsgSeqno),
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mTransaction(aTransactionID),
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mNext(mChan->mTransactionStack)
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{
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mChan->mMonitor->AssertCurrentThreadOwns();
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mChan->mTransactionStack = this;
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}
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explicit AutoEnterTransaction(MessageChannel *aChan, const IPC::Message &aMessage)
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: mChan(aChan),
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mActive(true),
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mOutgoing(false),
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mNestedLevel(aMessage.nested_level()),
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mSeqno(aMessage.seqno()),
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mTransaction(aMessage.transaction_id()),
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mNext(mChan->mTransactionStack)
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{
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mChan->mMonitor->AssertCurrentThreadOwns();
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if (!aMessage.is_sync()) {
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mActive = false;
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return;
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}
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mChan->mTransactionStack = this;
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}
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~AutoEnterTransaction() {
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mChan->mMonitor->AssertCurrentThreadOwns();
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if (mActive) {
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mChan->mTransactionStack = mNext;
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}
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}
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void Cancel() {
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AutoEnterTransaction *cur = mChan->mTransactionStack;
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MOZ_RELEASE_ASSERT(cur == this);
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while (cur && cur->mNestedLevel != IPC::Message::NOT_NESTED) {
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// Note that, in the following situation, we will cancel multiple
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// transactions:
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// 1. Parent sends NESTED_INSIDE_SYNC message P1 to child.
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// 2. Child sends NESTED_INSIDE_SYNC message C1 to child.
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// 3. Child dispatches P1, parent blocks.
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// 4. Child cancels.
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// In this case, both P1 and C1 are cancelled. The parent will
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// remove C1 from its queue when it gets the cancellation message.
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MOZ_RELEASE_ASSERT(cur->mActive);
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cur->mActive = false;
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cur = cur->mNext;
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}
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mChan->mTransactionStack = cur;
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MOZ_RELEASE_ASSERT(IsComplete());
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}
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bool AwaitingSyncReply() const {
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MOZ_RELEASE_ASSERT(mActive);
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if (mOutgoing) {
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return true;
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}
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return mNext ? mNext->AwaitingSyncReply() : false;
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}
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int AwaitingSyncReplyNestedLevel() const {
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MOZ_RELEASE_ASSERT(mActive);
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if (mOutgoing) {
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return mNestedLevel;
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}
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return mNext ? mNext->AwaitingSyncReplyNestedLevel() : 0;
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}
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bool DispatchingSyncMessage() const {
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MOZ_RELEASE_ASSERT(mActive);
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if (!mOutgoing) {
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return true;
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}
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return mNext ? mNext->DispatchingSyncMessage() : false;
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}
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int DispatchingSyncMessageNestedLevel() const {
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MOZ_RELEASE_ASSERT(mActive);
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if (!mOutgoing) {
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return mNestedLevel;
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}
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return mNext ? mNext->DispatchingSyncMessageNestedLevel() : 0;
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}
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int NestedLevel() const {
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MOZ_RELEASE_ASSERT(mActive);
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return mNestedLevel;
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}
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int32_t SequenceNumber() const {
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MOZ_RELEASE_ASSERT(mActive);
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return mSeqno;
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}
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int32_t TransactionID() const {
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MOZ_RELEASE_ASSERT(mActive);
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return mTransaction;
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}
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void ReceivedReply(IPC::Message&& aMessage) {
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MOZ_RELEASE_ASSERT(aMessage.seqno() == mSeqno);
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MOZ_RELEASE_ASSERT(aMessage.transaction_id() == mTransaction);
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MOZ_RELEASE_ASSERT(!mReply);
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IPC_LOG("Reply received on worker thread: seqno=%d", mSeqno);
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mReply = new IPC::Message(Move(aMessage));
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MOZ_RELEASE_ASSERT(IsComplete());
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}
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void HandleReply(IPC::Message&& aMessage) {
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AutoEnterTransaction *cur = mChan->mTransactionStack;
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MOZ_RELEASE_ASSERT(cur == this);
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while (cur) {
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MOZ_RELEASE_ASSERT(cur->mActive);
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if (aMessage.seqno() == cur->mSeqno) {
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cur->ReceivedReply(Move(aMessage));
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break;
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}
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cur = cur->mNext;
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MOZ_RELEASE_ASSERT(cur);
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}
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}
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bool IsComplete() {
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return !mActive || mReply;
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}
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bool IsOutgoing() {
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return mOutgoing;
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}
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bool IsCanceled() {
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return !mActive;
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}
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bool IsBottom() const {
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return !mNext;
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}
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bool IsError() {
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MOZ_RELEASE_ASSERT(mReply);
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return mReply->is_reply_error();
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}
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nsAutoPtr<IPC::Message> GetReply() {
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return Move(mReply);
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}
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private:
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MessageChannel *mChan;
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// Active is true if this transaction is on the mChan->mTransactionStack
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// stack. Generally we're not on the stack if the transaction was canceled
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// or if it was for a message that doesn't require transactions (an async
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// message).
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bool mActive;
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// Is this stack frame for an outgoing message?
|
|
bool mOutgoing;
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// Properties of the message being sent/received.
|
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int mNestedLevel;
|
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int32_t mSeqno;
|
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int32_t mTransaction;
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|
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// Next item in mChan->mTransactionStack.
|
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AutoEnterTransaction *mNext;
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|
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// Pointer the a reply received for this message, if one was received.
|
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nsAutoPtr<IPC::Message> mReply;
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};
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MessageChannel::MessageChannel(IToplevelProtocol *aListener)
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: mListener(aListener),
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mChannelState(ChannelClosed),
|
|
mSide(UnknownSide),
|
|
mLink(nullptr),
|
|
mWorkerLoop(nullptr),
|
|
mChannelErrorTask(nullptr),
|
|
mWorkerLoopID(-1),
|
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mTimeoutMs(kNoTimeout),
|
|
mInTimeoutSecondHalf(false),
|
|
mNextSeqno(0),
|
|
mLastSendError(SyncSendError::SendSuccess),
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|
mDispatchingAsyncMessage(false),
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|
mDispatchingAsyncMessageNestedLevel(0),
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mTransactionStack(nullptr),
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|
mTimedOutMessageSeqno(0),
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mTimedOutMessageNestedLevel(0),
|
|
mRemoteStackDepthGuess(0),
|
|
mSawInterruptOutMsg(false),
|
|
mIsWaitingForIncoming(false),
|
|
mAbortOnError(false),
|
|
mNotifiedChannelDone(false),
|
|
mFlags(REQUIRE_DEFAULT),
|
|
mPeerPidSet(false),
|
|
mPeerPid(-1)
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|
{
|
|
MOZ_COUNT_CTOR(ipc::MessageChannel);
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|
|
#ifdef OS_WIN
|
|
mTopFrame = nullptr;
|
|
mIsSyncWaitingOnNonMainThread = false;
|
|
#endif
|
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|
|
mOnChannelConnectedTask =
|
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NewNonOwningCancelableRunnableMethod(this, &MessageChannel::DispatchOnChannelConnected);
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|
|
#ifdef OS_WIN
|
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mEvent = CreateEventW(nullptr, TRUE, FALSE, nullptr);
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MOZ_RELEASE_ASSERT(mEvent, "CreateEvent failed! Nothing is going to work!");
|
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#endif
|
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}
|
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|
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MessageChannel::~MessageChannel()
|
|
{
|
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MOZ_COUNT_DTOR(ipc::MessageChannel);
|
|
IPC_ASSERT(mCxxStackFrames.empty(), "mismatched CxxStackFrame ctor/dtors");
|
|
#ifdef OS_WIN
|
|
if (mEvent) {
|
|
BOOL ok = CloseHandle(mEvent);
|
|
mEvent = nullptr;
|
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|
|
if (!ok) {
|
|
gfxDevCrash(mozilla::gfx::LogReason::MessageChannelCloseFailure) <<
|
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"MessageChannel failed to close. GetLastError: " <<
|
|
GetLastError();
|
|
}
|
|
MOZ_RELEASE_ASSERT(ok);
|
|
} else {
|
|
gfxDevCrash(mozilla::gfx::LogReason::MessageChannelCloseFailure) <<
|
|
"MessageChannel destructor ran without an mEvent Handle";
|
|
}
|
|
#endif
|
|
Clear();
|
|
}
|
|
|
|
// This function returns the current transaction ID. Since the notion of a
|
|
// "current transaction" can be hard to define when messages race with each
|
|
// other and one gets canceled and the other doesn't, we require that this
|
|
// function is only called when the current transaction is known to be for a
|
|
// NESTED_INSIDE_SYNC message. In that case, we know for sure what the caller is
|
|
// looking for.
|
|
int32_t
|
|
MessageChannel::CurrentNestedInsideSyncTransaction() const
|
|
{
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
if (!mTransactionStack) {
|
|
return 0;
|
|
}
|
|
MOZ_RELEASE_ASSERT(mTransactionStack->NestedLevel() == IPC::Message::NESTED_INSIDE_SYNC);
|
|
return mTransactionStack->TransactionID();
|
|
}
|
|
|
|
bool
|
|
MessageChannel::AwaitingSyncReply() const
|
|
{
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
return mTransactionStack ? mTransactionStack->AwaitingSyncReply() : false;
|
|
}
|
|
|
|
int
|
|
MessageChannel::AwaitingSyncReplyNestedLevel() const
|
|
{
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
return mTransactionStack ? mTransactionStack->AwaitingSyncReplyNestedLevel() : 0;
|
|
}
|
|
|
|
bool
|
|
MessageChannel::DispatchingSyncMessage() const
|
|
{
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
return mTransactionStack ? mTransactionStack->DispatchingSyncMessage() : false;
|
|
}
|
|
|
|
int
|
|
MessageChannel::DispatchingSyncMessageNestedLevel() const
|
|
{
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
return mTransactionStack ? mTransactionStack->DispatchingSyncMessageNestedLevel() : 0;
|
|
}
|
|
|
|
static void
|
|
PrintErrorMessage(Side side, const char* channelName, const char* msg)
|
|
{
|
|
const char *from = (side == ChildSide)
|
|
? "Child"
|
|
: ((side == ParentSide) ? "Parent" : "Unknown");
|
|
printf_stderr("\n###!!! [%s][%s] Error: %s\n\n", from, channelName, msg);
|
|
}
|
|
|
|
bool
|
|
MessageChannel::Connected() const
|
|
{
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
|
|
// The transport layer allows us to send messages before
|
|
// receiving the "connected" ack from the remote side.
|
|
return (ChannelOpening == mChannelState || ChannelConnected == mChannelState);
|
|
}
|
|
|
|
bool
|
|
MessageChannel::CanSend() const
|
|
{
|
|
if (!mMonitor) {
|
|
return false;
|
|
}
|
|
MonitorAutoLock lock(*mMonitor);
|
|
return Connected();
|
|
}
|
|
|
|
void
|
|
MessageChannel::Clear()
|
|
{
|
|
// Don't clear mWorkerLoopID; we use it in AssertLinkThread() and
|
|
// AssertWorkerThread().
|
|
//
|
|
// Also don't clear mListener. If we clear it, then sending a message
|
|
// through this channel after it's Clear()'ed can cause this process to
|
|
// crash.
|
|
//
|
|
// In practice, mListener owns the channel, so the channel gets deleted
|
|
// before mListener. But just to be safe, mListener is a weak pointer.
|
|
|
|
if (gParentProcessBlocker == this) {
|
|
gParentProcessBlocker = nullptr;
|
|
}
|
|
|
|
mWorkerLoop = nullptr;
|
|
delete mLink;
|
|
mLink = nullptr;
|
|
|
|
mOnChannelConnectedTask->Cancel();
|
|
|
|
if (mChannelErrorTask) {
|
|
mChannelErrorTask->Cancel();
|
|
mChannelErrorTask = nullptr;
|
|
}
|
|
|
|
// Free up any memory used by pending messages.
|
|
for (RefPtr<MessageTask> task : mPending) {
|
|
task->Clear();
|
|
}
|
|
mPending.clear();
|
|
|
|
mOutOfTurnReplies.clear();
|
|
while (!mDeferred.empty()) {
|
|
mDeferred.pop();
|
|
}
|
|
}
|
|
|
|
bool
|
|
MessageChannel::Open(Transport* aTransport, MessageLoop* aIOLoop, Side aSide)
|
|
{
|
|
NS_PRECONDITION(!mLink, "Open() called > once");
|
|
|
|
mMonitor = new RefCountedMonitor();
|
|
mWorkerLoop = MessageLoop::current();
|
|
mWorkerLoopID = mWorkerLoop->id();
|
|
|
|
ProcessLink *link = new ProcessLink(this);
|
|
link->Open(aTransport, aIOLoop, aSide); // :TODO: n.b.: sets mChild
|
|
mLink = link;
|
|
return true;
|
|
}
|
|
|
|
bool
|
|
MessageChannel::Open(MessageChannel *aTargetChan, MessageLoop *aTargetLoop, Side aSide)
|
|
{
|
|
// Opens a connection to another thread in the same process.
|
|
|
|
// This handshake proceeds as follows:
|
|
// - Let A be the thread initiating the process (either child or parent)
|
|
// and B be the other thread.
|
|
// - A spawns thread for B, obtaining B's message loop
|
|
// - A creates ProtocolChild and ProtocolParent instances.
|
|
// Let PA be the one appropriate to A and PB the side for B.
|
|
// - A invokes PA->Open(PB, ...):
|
|
// - set state to mChannelOpening
|
|
// - this will place a work item in B's worker loop (see next bullet)
|
|
// and then spins until PB->mChannelState becomes mChannelConnected
|
|
// - meanwhile, on PB's worker loop, the work item is removed and:
|
|
// - invokes PB->SlaveOpen(PA, ...):
|
|
// - sets its state and that of PA to Connected
|
|
NS_PRECONDITION(aTargetChan, "Need a target channel");
|
|
NS_PRECONDITION(ChannelClosed == mChannelState, "Not currently closed");
|
|
|
|
CommonThreadOpenInit(aTargetChan, aSide);
|
|
|
|
Side oppSide = UnknownSide;
|
|
switch(aSide) {
|
|
case ChildSide: oppSide = ParentSide; break;
|
|
case ParentSide: oppSide = ChildSide; break;
|
|
case UnknownSide: break;
|
|
}
|
|
|
|
mMonitor = new RefCountedMonitor();
|
|
|
|
MonitorAutoLock lock(*mMonitor);
|
|
mChannelState = ChannelOpening;
|
|
aTargetLoop->PostTask(NewNonOwningRunnableMethod
|
|
<MessageChannel*, Side>(aTargetChan,
|
|
&MessageChannel::OnOpenAsSlave,
|
|
this, oppSide));
|
|
|
|
while (ChannelOpening == mChannelState)
|
|
mMonitor->Wait();
|
|
MOZ_RELEASE_ASSERT(ChannelConnected == mChannelState, "not connected when awoken");
|
|
return (ChannelConnected == mChannelState);
|
|
}
|
|
|
|
void
|
|
MessageChannel::OnOpenAsSlave(MessageChannel *aTargetChan, Side aSide)
|
|
{
|
|
// Invoked when the other side has begun the open.
|
|
NS_PRECONDITION(ChannelClosed == mChannelState,
|
|
"Not currently closed");
|
|
NS_PRECONDITION(ChannelOpening == aTargetChan->mChannelState,
|
|
"Target channel not in the process of opening");
|
|
|
|
CommonThreadOpenInit(aTargetChan, aSide);
|
|
mMonitor = aTargetChan->mMonitor;
|
|
|
|
MonitorAutoLock lock(*mMonitor);
|
|
MOZ_RELEASE_ASSERT(ChannelOpening == aTargetChan->mChannelState,
|
|
"Target channel not in the process of opening");
|
|
mChannelState = ChannelConnected;
|
|
aTargetChan->mChannelState = ChannelConnected;
|
|
aTargetChan->mMonitor->Notify();
|
|
}
|
|
|
|
void
|
|
MessageChannel::CommonThreadOpenInit(MessageChannel *aTargetChan, Side aSide)
|
|
{
|
|
mWorkerLoop = MessageLoop::current();
|
|
mWorkerLoopID = mWorkerLoop->id();
|
|
mLink = new ThreadLink(this, aTargetChan);
|
|
mSide = aSide;
|
|
}
|
|
|
|
bool
|
|
MessageChannel::Echo(Message* aMsg)
|
|
{
|
|
nsAutoPtr<Message> msg(aMsg);
|
|
AssertWorkerThread();
|
|
mMonitor->AssertNotCurrentThreadOwns();
|
|
if (MSG_ROUTING_NONE == msg->routing_id()) {
|
|
ReportMessageRouteError("MessageChannel::Echo");
|
|
return false;
|
|
}
|
|
|
|
MonitorAutoLock lock(*mMonitor);
|
|
|
|
if (!Connected()) {
|
|
ReportConnectionError("MessageChannel", msg);
|
|
return false;
|
|
}
|
|
|
|
mLink->EchoMessage(msg.forget());
|
|
return true;
|
|
}
|
|
|
|
bool
|
|
MessageChannel::Send(Message* aMsg)
|
|
{
|
|
MOZ_RELEASE_ASSERT(!aMsg->is_sync());
|
|
MOZ_RELEASE_ASSERT(aMsg->nested_level() != IPC::Message::NESTED_INSIDE_SYNC);
|
|
|
|
CxxStackFrame frame(*this, OUT_MESSAGE, aMsg);
|
|
|
|
nsAutoPtr<Message> msg(aMsg);
|
|
AssertWorkerThread();
|
|
mMonitor->AssertNotCurrentThreadOwns();
|
|
if (MSG_ROUTING_NONE == msg->routing_id()) {
|
|
ReportMessageRouteError("MessageChannel::Send");
|
|
return false;
|
|
}
|
|
|
|
MonitorAutoLock lock(*mMonitor);
|
|
if (!Connected()) {
|
|
ReportConnectionError("MessageChannel", msg);
|
|
return false;
|
|
}
|
|
mLink->SendMessage(msg.forget());
|
|
return true;
|
|
}
|
|
|
|
class CancelMessage : public IPC::Message
|
|
{
|
|
public:
|
|
explicit CancelMessage(int transaction) :
|
|
IPC::Message(MSG_ROUTING_NONE, CANCEL_MESSAGE_TYPE)
|
|
{
|
|
set_transaction_id(transaction);
|
|
}
|
|
static bool Read(const Message* msg) {
|
|
return true;
|
|
}
|
|
void Log(const std::string& aPrefix, FILE* aOutf) const {
|
|
fputs("(special `Cancel' message)", aOutf);
|
|
}
|
|
};
|
|
|
|
bool
|
|
MessageChannel::MaybeInterceptSpecialIOMessage(const Message& aMsg)
|
|
{
|
|
AssertLinkThread();
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
|
|
if (MSG_ROUTING_NONE == aMsg.routing_id()) {
|
|
if (GOODBYE_MESSAGE_TYPE == aMsg.type()) {
|
|
// :TODO: Sort out Close() on this side racing with Close() on the
|
|
// other side
|
|
mChannelState = ChannelClosing;
|
|
if (LoggingEnabled()) {
|
|
printf("NOTE: %s process received `Goodbye', closing down\n",
|
|
(mSide == ChildSide) ? "child" : "parent");
|
|
}
|
|
return true;
|
|
} else if (CANCEL_MESSAGE_TYPE == aMsg.type()) {
|
|
IPC_LOG("Cancel from message");
|
|
CancelTransaction(aMsg.transaction_id());
|
|
NotifyWorkerThread();
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool
|
|
MessageChannel::ShouldDeferMessage(const Message& aMsg)
|
|
{
|
|
// Never defer messages that have the highest nested level, even async
|
|
// ones. This is safe because only the child can send these messages, so
|
|
// they can never nest.
|
|
if (aMsg.nested_level() == IPC::Message::NESTED_INSIDE_CPOW)
|
|
return false;
|
|
|
|
// Unless they're NESTED_INSIDE_CPOW, we always defer async messages.
|
|
// Note that we never send an async NESTED_INSIDE_SYNC message.
|
|
if (!aMsg.is_sync()) {
|
|
MOZ_RELEASE_ASSERT(aMsg.nested_level() == IPC::Message::NOT_NESTED);
|
|
return true;
|
|
}
|
|
|
|
int msgNestedLevel = aMsg.nested_level();
|
|
int waitingNestedLevel = AwaitingSyncReplyNestedLevel();
|
|
|
|
// Always defer if the nested level of the incoming message is less than the
|
|
// nested level of the message we're awaiting.
|
|
if (msgNestedLevel < waitingNestedLevel)
|
|
return true;
|
|
|
|
// Never defer if the message has strictly greater nested level.
|
|
if (msgNestedLevel > waitingNestedLevel)
|
|
return false;
|
|
|
|
// When both sides send sync messages of the same nested level, we resolve the
|
|
// race by dispatching in the child and deferring the incoming message in
|
|
// the parent. However, the parent still needs to dispatch nested sync
|
|
// messages.
|
|
//
|
|
// Deferring in the parent only sort of breaks message ordering. When the
|
|
// child's message comes in, we can pretend the child hasn't quite
|
|
// finished sending it yet. Since the message is sync, we know that the
|
|
// child hasn't moved on yet.
|
|
return mSide == ParentSide && aMsg.transaction_id() != CurrentNestedInsideSyncTransaction();
|
|
}
|
|
|
|
void
|
|
MessageChannel::OnMessageReceivedFromLink(Message&& aMsg)
|
|
{
|
|
AssertLinkThread();
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
|
|
if (MaybeInterceptSpecialIOMessage(aMsg))
|
|
return;
|
|
|
|
// Regardless of the Interrupt stack, if we're awaiting a sync reply,
|
|
// we know that it needs to be immediately handled to unblock us.
|
|
if (aMsg.is_sync() && aMsg.is_reply()) {
|
|
IPC_LOG("Received reply seqno=%d xid=%d", aMsg.seqno(), aMsg.transaction_id());
|
|
|
|
if (aMsg.seqno() == mTimedOutMessageSeqno) {
|
|
// Drop the message, but allow future sync messages to be sent.
|
|
IPC_LOG("Received reply to timedout message; igoring; xid=%d", mTimedOutMessageSeqno);
|
|
EndTimeout();
|
|
return;
|
|
}
|
|
|
|
MOZ_RELEASE_ASSERT(AwaitingSyncReply());
|
|
MOZ_RELEASE_ASSERT(!mTimedOutMessageSeqno);
|
|
|
|
mTransactionStack->HandleReply(Move(aMsg));
|
|
NotifyWorkerThread();
|
|
return;
|
|
}
|
|
|
|
// Nested messages cannot be compressed.
|
|
MOZ_RELEASE_ASSERT(aMsg.compress_type() == IPC::Message::COMPRESSION_NONE ||
|
|
aMsg.nested_level() == IPC::Message::NOT_NESTED);
|
|
|
|
bool reuseTask = false;
|
|
if (aMsg.compress_type() == IPC::Message::COMPRESSION_ENABLED) {
|
|
bool compress = (!mPending.isEmpty() &&
|
|
mPending.getLast()->Msg().type() == aMsg.type() &&
|
|
mPending.getLast()->Msg().routing_id() == aMsg.routing_id());
|
|
if (compress) {
|
|
// This message type has compression enabled, and the back of the
|
|
// queue was the same message type and routed to the same destination.
|
|
// Replace it with the newer message.
|
|
MOZ_RELEASE_ASSERT(mPending.getLast()->Msg().compress_type() ==
|
|
IPC::Message::COMPRESSION_ENABLED);
|
|
mPending.getLast()->Msg() = Move(aMsg);
|
|
|
|
reuseTask = true;
|
|
}
|
|
} else if (aMsg.compress_type() == IPC::Message::COMPRESSION_ALL && !mPending.isEmpty()) {
|
|
for (RefPtr<MessageTask> p = mPending.getLast(); p; p = p->getPrevious()) {
|
|
if (p->Msg().type() == aMsg.type() &&
|
|
p->Msg().routing_id() == aMsg.routing_id())
|
|
{
|
|
// This message type has compression enabled, and the queue
|
|
// holds a message with the same message type and routed to the
|
|
// same destination. Erase it. Note that, since we always
|
|
// compress these redundancies, There Can Be Only One.
|
|
MOZ_RELEASE_ASSERT(p->Msg().compress_type() == IPC::Message::COMPRESSION_ALL);
|
|
p->remove();
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
bool wakeUpSyncSend = AwaitingSyncReply() && !ShouldDeferMessage(aMsg);
|
|
|
|
bool shouldWakeUp = AwaitingInterruptReply() ||
|
|
wakeUpSyncSend ||
|
|
AwaitingIncomingMessage();
|
|
|
|
// Although we usually don't need to post a message task if
|
|
// shouldWakeUp is true, it's easier to post anyway than to have to
|
|
// guarantee that every Send call processes everything it's supposed to
|
|
// before returning.
|
|
bool shouldPostTask = !shouldWakeUp || wakeUpSyncSend;
|
|
|
|
IPC_LOG("Receive on link thread; seqno=%d, xid=%d, shouldWakeUp=%d",
|
|
aMsg.seqno(), aMsg.transaction_id(), shouldWakeUp);
|
|
|
|
if (reuseTask) {
|
|
return;
|
|
}
|
|
|
|
// There are three cases we're concerned about, relating to the state of the
|
|
// main thread:
|
|
//
|
|
// (1) We are waiting on a sync reply - main thread is blocked on the
|
|
// IPC monitor.
|
|
// - If the message is NESTED_INSIDE_SYNC, we wake up the main thread to
|
|
// deliver the message depending on ShouldDeferMessage. Otherwise, we
|
|
// leave it in the mPending queue, posting a task to the main event
|
|
// loop, where it will be processed once the synchronous reply has been
|
|
// received.
|
|
//
|
|
// (2) We are waiting on an Interrupt reply - main thread is blocked on the
|
|
// IPC monitor.
|
|
// - Always notify and wake up the main thread.
|
|
//
|
|
// (3) We are not waiting on a reply.
|
|
// - We post a task to the main event loop.
|
|
//
|
|
// Note that, we may notify the main thread even though the monitor is not
|
|
// blocked. This is okay, since we always check for pending events before
|
|
// blocking again.
|
|
|
|
RefPtr<MessageTask> task = new MessageTask(this, Move(aMsg));
|
|
mPending.insertBack(task);
|
|
|
|
if (shouldWakeUp) {
|
|
NotifyWorkerThread();
|
|
}
|
|
|
|
if (shouldPostTask) {
|
|
task->Post();
|
|
}
|
|
}
|
|
|
|
void
|
|
MessageChannel::PeekMessages(mozilla::function<bool(const Message& aMsg)> aInvoke)
|
|
{
|
|
// FIXME: We shouldn't be holding the lock for aInvoke!
|
|
MonitorAutoLock lock(*mMonitor);
|
|
|
|
for (RefPtr<MessageTask> it : mPending) {
|
|
const Message &msg = it->Msg();
|
|
if (!aInvoke(msg)) {
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
void
|
|
MessageChannel::ProcessPendingRequests(AutoEnterTransaction& aTransaction)
|
|
{
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
|
|
IPC_LOG("ProcessPendingRequests for seqno=%d, xid=%d",
|
|
aTransaction.SequenceNumber(), aTransaction.TransactionID());
|
|
|
|
// Loop until there aren't any more nested messages to process.
|
|
for (;;) {
|
|
// If we canceled during ProcessPendingRequest, then we need to leave
|
|
// immediately because the results of ShouldDeferMessage will be
|
|
// operating with weird state (as if no Send is in progress). That could
|
|
// cause even NOT_NESTED sync messages to be processed (but not
|
|
// NOT_NESTED async messages), which would break message ordering.
|
|
if (aTransaction.IsCanceled()) {
|
|
return;
|
|
}
|
|
|
|
mozilla::Vector<Message> toProcess;
|
|
|
|
for (RefPtr<MessageTask> p = mPending.getFirst(); p; ) {
|
|
Message &msg = p->Msg();
|
|
|
|
MOZ_RELEASE_ASSERT(!aTransaction.IsCanceled(),
|
|
"Calling ShouldDeferMessage when cancelled");
|
|
bool defer = ShouldDeferMessage(msg);
|
|
|
|
// Only log the interesting messages.
|
|
if (msg.is_sync() || msg.nested_level() == IPC::Message::NESTED_INSIDE_CPOW) {
|
|
IPC_LOG("ShouldDeferMessage(seqno=%d) = %d", msg.seqno(), defer);
|
|
}
|
|
|
|
if (!defer) {
|
|
if (!toProcess.append(Move(msg)))
|
|
MOZ_CRASH();
|
|
|
|
p = p->removeAndGetNext();
|
|
continue;
|
|
}
|
|
p = p->getNext();
|
|
}
|
|
|
|
if (toProcess.empty()) {
|
|
break;
|
|
}
|
|
|
|
// Processing these messages could result in more messages, so we
|
|
// loop around to check for more afterwards.
|
|
|
|
for (auto it = toProcess.begin(); it != toProcess.end(); it++) {
|
|
ProcessPendingRequest(Move(*it));
|
|
}
|
|
}
|
|
}
|
|
|
|
bool
|
|
MessageChannel::Send(Message* aMsg, Message* aReply)
|
|
{
|
|
nsAutoPtr<Message> msg(aMsg);
|
|
|
|
// Sanity checks.
|
|
AssertWorkerThread();
|
|
mMonitor->AssertNotCurrentThreadOwns();
|
|
|
|
#ifdef OS_WIN
|
|
SyncStackFrame frame(this, false);
|
|
NeuteredWindowRegion neuteredRgn(mFlags & REQUIRE_DEFERRED_MESSAGE_PROTECTION);
|
|
#endif
|
|
|
|
CxxStackFrame f(*this, OUT_MESSAGE, msg);
|
|
|
|
MonitorAutoLock lock(*mMonitor);
|
|
|
|
if (mTimedOutMessageSeqno) {
|
|
// Don't bother sending another sync message if a previous one timed out
|
|
// and we haven't received a reply for it. Once the original timed-out
|
|
// message receives a reply, we'll be able to send more sync messages
|
|
// again.
|
|
IPC_LOG("Send() failed due to previous timeout");
|
|
mLastSendError = SyncSendError::PreviousTimeout;
|
|
return false;
|
|
}
|
|
|
|
if (DispatchingSyncMessageNestedLevel() == IPC::Message::NOT_NESTED &&
|
|
msg->nested_level() > IPC::Message::NOT_NESTED)
|
|
{
|
|
// Don't allow sending CPOWs while we're dispatching a sync message.
|
|
// If you want to do that, use sendRpcMessage instead.
|
|
IPC_LOG("Nested level forbids send");
|
|
mLastSendError = SyncSendError::SendingCPOWWhileDispatchingSync;
|
|
return false;
|
|
}
|
|
|
|
if (DispatchingSyncMessageNestedLevel() == IPC::Message::NESTED_INSIDE_CPOW ||
|
|
DispatchingAsyncMessageNestedLevel() == IPC::Message::NESTED_INSIDE_CPOW)
|
|
{
|
|
// Generally only the parent dispatches urgent messages. And the only
|
|
// sync messages it can send are NESTED_INSIDE_SYNC. Mainly we want to ensure
|
|
// here that we don't return false for non-CPOW messages.
|
|
MOZ_RELEASE_ASSERT(msg->nested_level() == IPC::Message::NESTED_INSIDE_SYNC);
|
|
IPC_LOG("Sending while dispatching urgent message");
|
|
mLastSendError = SyncSendError::SendingCPOWWhileDispatchingUrgent;
|
|
return false;
|
|
}
|
|
|
|
if (msg->nested_level() < DispatchingSyncMessageNestedLevel() ||
|
|
msg->nested_level() < AwaitingSyncReplyNestedLevel())
|
|
{
|
|
MOZ_RELEASE_ASSERT(DispatchingSyncMessage() || DispatchingAsyncMessage());
|
|
IPC_LOG("Cancel from Send");
|
|
CancelMessage *cancel = new CancelMessage(CurrentNestedInsideSyncTransaction());
|
|
CancelTransaction(CurrentNestedInsideSyncTransaction());
|
|
mLink->SendMessage(cancel);
|
|
}
|
|
|
|
IPC_ASSERT(msg->is_sync(), "can only Send() sync messages here");
|
|
|
|
IPC_ASSERT(msg->nested_level() >= DispatchingSyncMessageNestedLevel(),
|
|
"can't send sync message of a lesser nested level than what's being dispatched");
|
|
IPC_ASSERT(AwaitingSyncReplyNestedLevel() <= msg->nested_level(),
|
|
"nested sync message sends must be of increasing nested level");
|
|
IPC_ASSERT(DispatchingSyncMessageNestedLevel() != IPC::Message::NESTED_INSIDE_CPOW,
|
|
"not allowed to send messages while dispatching urgent messages");
|
|
|
|
IPC_ASSERT(DispatchingAsyncMessageNestedLevel() != IPC::Message::NESTED_INSIDE_CPOW,
|
|
"not allowed to send messages while dispatching urgent messages");
|
|
|
|
if (!Connected()) {
|
|
ReportConnectionError("MessageChannel::SendAndWait", msg);
|
|
mLastSendError = SyncSendError::NotConnectedBeforeSend;
|
|
return false;
|
|
}
|
|
|
|
msg->set_seqno(NextSeqno());
|
|
|
|
int32_t seqno = msg->seqno();
|
|
int nestedLevel = msg->nested_level();
|
|
msgid_t replyType = msg->type() + 1;
|
|
|
|
AutoEnterTransaction *stackTop = mTransactionStack;
|
|
|
|
// If the most recent message on the stack is NESTED_INSIDE_SYNC, then our
|
|
// message should nest inside that and we use the same transaction
|
|
// ID. Otherwise we need a new transaction ID (so we use the seqno of the
|
|
// message we're sending).
|
|
bool nest = stackTop && stackTop->NestedLevel() == IPC::Message::NESTED_INSIDE_SYNC;
|
|
int32_t transaction = nest ? stackTop->TransactionID() : seqno;
|
|
msg->set_transaction_id(transaction);
|
|
|
|
bool handleWindowsMessages = mListener->HandleWindowsMessages(*aMsg);
|
|
AutoEnterTransaction transact(this, seqno, transaction, nestedLevel);
|
|
|
|
IPC_LOG("Send seqno=%d, xid=%d", seqno, transaction);
|
|
|
|
mLink->SendMessage(msg.forget());
|
|
|
|
while (true) {
|
|
MOZ_RELEASE_ASSERT(!transact.IsCanceled());
|
|
ProcessPendingRequests(transact);
|
|
if (transact.IsComplete()) {
|
|
break;
|
|
}
|
|
if (!Connected()) {
|
|
ReportConnectionError("MessageChannel::Send");
|
|
mLastSendError = SyncSendError::DisconnectedDuringSend;
|
|
return false;
|
|
}
|
|
|
|
MOZ_RELEASE_ASSERT(!mTimedOutMessageSeqno);
|
|
MOZ_RELEASE_ASSERT(!transact.IsComplete());
|
|
MOZ_RELEASE_ASSERT(mTransactionStack == &transact);
|
|
|
|
bool maybeTimedOut = !WaitForSyncNotify(handleWindowsMessages);
|
|
|
|
if (mListener->NeedArtificialSleep()) {
|
|
MonitorAutoUnlock unlock(*mMonitor);
|
|
mListener->ArtificialSleep();
|
|
}
|
|
|
|
if (!Connected()) {
|
|
ReportConnectionError("MessageChannel::SendAndWait");
|
|
mLastSendError = SyncSendError::DisconnectedDuringSend;
|
|
return false;
|
|
}
|
|
|
|
if (transact.IsCanceled()) {
|
|
break;
|
|
}
|
|
|
|
MOZ_RELEASE_ASSERT(mTransactionStack == &transact);
|
|
|
|
// We only time out a message if it initiated a new transaction (i.e.,
|
|
// if neither side has any other message Sends on the stack).
|
|
bool canTimeOut = transact.IsBottom();
|
|
if (maybeTimedOut && canTimeOut && !ShouldContinueFromTimeout()) {
|
|
// Since ShouldContinueFromTimeout drops the lock, we need to
|
|
// re-check all our conditions here. We shouldn't time out if any of
|
|
// these things happen because there won't be a reply to the timed
|
|
// out message in these cases.
|
|
if (transact.IsComplete()) {
|
|
break;
|
|
}
|
|
|
|
IPC_LOG("Timing out Send: xid=%d", transaction);
|
|
|
|
mTimedOutMessageSeqno = seqno;
|
|
mTimedOutMessageNestedLevel = nestedLevel;
|
|
mLastSendError = SyncSendError::TimedOut;
|
|
return false;
|
|
}
|
|
|
|
if (transact.IsCanceled()) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (transact.IsCanceled()) {
|
|
IPC_LOG("Other side canceled seqno=%d, xid=%d", seqno, transaction);
|
|
mLastSendError = SyncSendError::CancelledAfterSend;
|
|
return false;
|
|
}
|
|
|
|
if (transact.IsError()) {
|
|
IPC_LOG("Error: seqno=%d, xid=%d", seqno, transaction);
|
|
mLastSendError = SyncSendError::ReplyError;
|
|
return false;
|
|
}
|
|
|
|
IPC_LOG("Got reply: seqno=%d, xid=%d", seqno, transaction);
|
|
|
|
nsAutoPtr<Message> reply = transact.GetReply();
|
|
|
|
MOZ_RELEASE_ASSERT(reply);
|
|
MOZ_RELEASE_ASSERT(reply->is_reply(), "expected reply");
|
|
MOZ_RELEASE_ASSERT(!reply->is_reply_error());
|
|
MOZ_RELEASE_ASSERT(reply->seqno() == seqno);
|
|
MOZ_RELEASE_ASSERT(reply->type() == replyType, "wrong reply type");
|
|
MOZ_RELEASE_ASSERT(reply->is_sync());
|
|
|
|
*aReply = Move(*reply);
|
|
return true;
|
|
}
|
|
|
|
bool
|
|
MessageChannel::Call(Message* aMsg, Message* aReply)
|
|
{
|
|
nsAutoPtr<Message> msg(aMsg);
|
|
AssertWorkerThread();
|
|
mMonitor->AssertNotCurrentThreadOwns();
|
|
|
|
#ifdef OS_WIN
|
|
SyncStackFrame frame(this, true);
|
|
#endif
|
|
|
|
// This must come before MonitorAutoLock, as its destructor acquires the
|
|
// monitor lock.
|
|
CxxStackFrame cxxframe(*this, OUT_MESSAGE, msg);
|
|
|
|
MonitorAutoLock lock(*mMonitor);
|
|
if (!Connected()) {
|
|
ReportConnectionError("MessageChannel::Call", msg);
|
|
return false;
|
|
}
|
|
|
|
// Sanity checks.
|
|
IPC_ASSERT(!AwaitingSyncReply(),
|
|
"cannot issue Interrupt call while blocked on sync request");
|
|
IPC_ASSERT(!DispatchingSyncMessage(),
|
|
"violation of sync handler invariant");
|
|
IPC_ASSERT(msg->is_interrupt(), "can only Call() Interrupt messages here");
|
|
|
|
msg->set_seqno(NextSeqno());
|
|
msg->set_interrupt_remote_stack_depth_guess(mRemoteStackDepthGuess);
|
|
msg->set_interrupt_local_stack_depth(1 + InterruptStackDepth());
|
|
mInterruptStack.push(MessageInfo(*msg));
|
|
mLink->SendMessage(msg.forget());
|
|
|
|
while (true) {
|
|
// if a handler invoked by *Dispatch*() spun a nested event
|
|
// loop, and the connection was broken during that loop, we
|
|
// might have already processed the OnError event. if so,
|
|
// trying another loop iteration will be futile because
|
|
// channel state will have been cleared
|
|
if (!Connected()) {
|
|
ReportConnectionError("MessageChannel::Call");
|
|
return false;
|
|
}
|
|
|
|
#ifdef OS_WIN
|
|
// We need to limit the scoped of neuteredRgn to this spot in the code.
|
|
// Window neutering can't be enabled during some plugin calls because
|
|
// we then risk the neutered window procedure being subclassed by a
|
|
// plugin.
|
|
{
|
|
NeuteredWindowRegion neuteredRgn(mFlags & REQUIRE_DEFERRED_MESSAGE_PROTECTION);
|
|
/* We should pump messages at this point to ensure that the IPC peer
|
|
does not become deadlocked on a pending inter-thread SendMessage() */
|
|
neuteredRgn.PumpOnce();
|
|
}
|
|
#endif
|
|
|
|
// Now might be the time to process a message deferred because of race
|
|
// resolution.
|
|
MaybeUndeferIncall();
|
|
|
|
// Wait for an event to occur.
|
|
while (!InterruptEventOccurred()) {
|
|
bool maybeTimedOut = !WaitForInterruptNotify();
|
|
|
|
// We might have received a "subtly deferred" message in a nested
|
|
// loop that it's now time to process.
|
|
if (InterruptEventOccurred() ||
|
|
(!maybeTimedOut && (!mDeferred.empty() || !mOutOfTurnReplies.empty())))
|
|
{
|
|
break;
|
|
}
|
|
|
|
if (maybeTimedOut && !ShouldContinueFromTimeout())
|
|
return false;
|
|
}
|
|
|
|
Message recvd;
|
|
MessageMap::iterator it;
|
|
|
|
if ((it = mOutOfTurnReplies.find(mInterruptStack.top().seqno()))
|
|
!= mOutOfTurnReplies.end())
|
|
{
|
|
recvd = Move(it->second);
|
|
mOutOfTurnReplies.erase(it);
|
|
} else if (!mPending.isEmpty()) {
|
|
RefPtr<MessageTask> task = mPending.popFirst();
|
|
recvd = Move(task->Msg());
|
|
} else {
|
|
// because of subtleties with nested event loops, it's possible
|
|
// that we got here and nothing happened. or, we might have a
|
|
// deferred in-call that needs to be processed. either way, we
|
|
// won't break the inner while loop again until something new
|
|
// happens.
|
|
continue;
|
|
}
|
|
|
|
// If the message is not Interrupt, we can dispatch it as normal.
|
|
if (!recvd.is_interrupt()) {
|
|
DispatchMessage(Move(recvd));
|
|
if (!Connected()) {
|
|
ReportConnectionError("MessageChannel::DispatchMessage");
|
|
return false;
|
|
}
|
|
continue;
|
|
}
|
|
|
|
// If the message is an Interrupt reply, either process it as a reply to our
|
|
// call, or add it to the list of out-of-turn replies we've received.
|
|
if (recvd.is_reply()) {
|
|
IPC_ASSERT(!mInterruptStack.empty(), "invalid Interrupt stack");
|
|
|
|
// If this is not a reply the call we've initiated, add it to our
|
|
// out-of-turn replies and keep polling for events.
|
|
{
|
|
const MessageInfo &outcall = mInterruptStack.top();
|
|
|
|
// Note, In the parent, sequence numbers increase from 0, and
|
|
// in the child, they decrease from 0.
|
|
if ((mSide == ChildSide && recvd.seqno() > outcall.seqno()) ||
|
|
(mSide != ChildSide && recvd.seqno() < outcall.seqno()))
|
|
{
|
|
mOutOfTurnReplies[recvd.seqno()] = Move(recvd);
|
|
continue;
|
|
}
|
|
|
|
IPC_ASSERT(recvd.is_reply_error() ||
|
|
(recvd.type() == (outcall.type() + 1) &&
|
|
recvd.seqno() == outcall.seqno()),
|
|
"somebody's misbehavin'", true);
|
|
}
|
|
|
|
// We received a reply to our most recent outstanding call. Pop
|
|
// this frame and return the reply.
|
|
mInterruptStack.pop();
|
|
|
|
bool is_reply_error = recvd.is_reply_error();
|
|
if (!is_reply_error) {
|
|
*aReply = Move(recvd);
|
|
}
|
|
|
|
// If we have no more pending out calls waiting on replies, then
|
|
// the reply queue should be empty.
|
|
IPC_ASSERT(!mInterruptStack.empty() || mOutOfTurnReplies.empty(),
|
|
"still have pending replies with no pending out-calls",
|
|
true);
|
|
|
|
return !is_reply_error;
|
|
}
|
|
|
|
// Dispatch an Interrupt in-call. Snapshot the current stack depth while we
|
|
// own the monitor.
|
|
size_t stackDepth = InterruptStackDepth();
|
|
{
|
|
MonitorAutoUnlock unlock(*mMonitor);
|
|
|
|
CxxStackFrame frame(*this, IN_MESSAGE, &recvd);
|
|
DispatchInterruptMessage(Move(recvd), stackDepth);
|
|
}
|
|
if (!Connected()) {
|
|
ReportConnectionError("MessageChannel::DispatchInterruptMessage");
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool
|
|
MessageChannel::WaitForIncomingMessage()
|
|
{
|
|
#ifdef OS_WIN
|
|
SyncStackFrame frame(this, true);
|
|
NeuteredWindowRegion neuteredRgn(mFlags & REQUIRE_DEFERRED_MESSAGE_PROTECTION);
|
|
#endif
|
|
|
|
MonitorAutoLock lock(*mMonitor);
|
|
AutoEnterWaitForIncoming waitingForIncoming(*this);
|
|
if (mChannelState != ChannelConnected) {
|
|
return false;
|
|
}
|
|
if (!HasPendingEvents()) {
|
|
return WaitForInterruptNotify();
|
|
}
|
|
|
|
MOZ_RELEASE_ASSERT(!mPending.isEmpty());
|
|
RefPtr<MessageTask> task = mPending.getFirst();
|
|
RunMessage(*task);
|
|
return true;
|
|
}
|
|
|
|
bool
|
|
MessageChannel::HasPendingEvents()
|
|
{
|
|
AssertWorkerThread();
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
return Connected() && !mPending.isEmpty();
|
|
}
|
|
|
|
bool
|
|
MessageChannel::InterruptEventOccurred()
|
|
{
|
|
AssertWorkerThread();
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
IPC_ASSERT(InterruptStackDepth() > 0, "not in wait loop");
|
|
|
|
return (!Connected() ||
|
|
!mPending.isEmpty() ||
|
|
(!mOutOfTurnReplies.empty() &&
|
|
mOutOfTurnReplies.find(mInterruptStack.top().seqno()) !=
|
|
mOutOfTurnReplies.end()));
|
|
}
|
|
|
|
bool
|
|
MessageChannel::ProcessPendingRequest(Message &&aUrgent)
|
|
{
|
|
AssertWorkerThread();
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
|
|
IPC_LOG("Process pending: seqno=%d, xid=%d", aUrgent.seqno(), aUrgent.transaction_id());
|
|
|
|
DispatchMessage(Move(aUrgent));
|
|
if (!Connected()) {
|
|
ReportConnectionError("MessageChannel::ProcessPendingRequest");
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool
|
|
MessageChannel::ShouldRunMessage(const Message& aMsg)
|
|
{
|
|
if (!mTimedOutMessageSeqno) {
|
|
return true;
|
|
}
|
|
|
|
// If we've timed out a message and we're awaiting the reply to the timed
|
|
// out message, we have to be careful what messages we process. Here's what
|
|
// can go wrong:
|
|
// 1. child sends a NOT_NESTED sync message S
|
|
// 2. parent sends a NESTED_INSIDE_SYNC sync message H at the same time
|
|
// 3. parent times out H
|
|
// 4. child starts processing H and sends a NESTED_INSIDE_SYNC message H' nested
|
|
// within the same transaction
|
|
// 5. parent dispatches S and sends reply
|
|
// 6. child asserts because it instead expected a reply to H'.
|
|
//
|
|
// To solve this, we refuse to process S in the parent until we get a reply
|
|
// to H. More generally, let the timed out message be M. We don't process a
|
|
// message unless the child would need the response to that message in order
|
|
// to process M. Those messages are the ones that have a higher nested level
|
|
// than M or that are part of the same transaction as M.
|
|
if (aMsg.nested_level() < mTimedOutMessageNestedLevel ||
|
|
(aMsg.nested_level() == mTimedOutMessageNestedLevel
|
|
&& aMsg.transaction_id() != mTimedOutMessageSeqno))
|
|
{
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
void
|
|
MessageChannel::RunMessage(MessageTask& aTask)
|
|
{
|
|
AssertWorkerThread();
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
|
|
Message& msg = aTask.Msg();
|
|
|
|
if (!Connected()) {
|
|
ReportConnectionError("RunMessage");
|
|
return;
|
|
}
|
|
|
|
// Check that we're going to run the first message that's valid to run.
|
|
#ifdef DEBUG
|
|
for (RefPtr<MessageTask> task : mPending) {
|
|
if (task == &aTask) {
|
|
break;
|
|
}
|
|
|
|
MOZ_ASSERT(!ShouldRunMessage(task->Msg()) ||
|
|
aTask.Msg().priority() != task->Msg().priority());
|
|
|
|
}
|
|
#endif
|
|
|
|
if (!mDeferred.empty()) {
|
|
MaybeUndeferIncall();
|
|
}
|
|
|
|
if (!ShouldRunMessage(msg)) {
|
|
return;
|
|
}
|
|
|
|
MOZ_RELEASE_ASSERT(aTask.isInList());
|
|
aTask.remove();
|
|
|
|
if (IsOnCxxStack() && msg.is_interrupt() && msg.is_reply()) {
|
|
// We probably just received a reply in a nested loop for an
|
|
// Interrupt call sent before entering that loop.
|
|
mOutOfTurnReplies[msg.seqno()] = Move(msg);
|
|
return;
|
|
}
|
|
|
|
DispatchMessage(Move(msg));
|
|
}
|
|
|
|
NS_IMPL_ISUPPORTS_INHERITED(MessageChannel::MessageTask, CancelableRunnable, nsIRunnablePriority)
|
|
|
|
nsresult
|
|
MessageChannel::MessageTask::Run()
|
|
{
|
|
if (!mChannel) {
|
|
return NS_OK;
|
|
}
|
|
|
|
mChannel->AssertWorkerThread();
|
|
mChannel->mMonitor->AssertNotCurrentThreadOwns();
|
|
|
|
MonitorAutoLock lock(*mChannel->mMonitor);
|
|
|
|
// In case we choose not to run this message, we may need to be able to Post
|
|
// it again.
|
|
mScheduled = false;
|
|
|
|
if (!isInList()) {
|
|
return NS_OK;
|
|
}
|
|
|
|
mChannel->RunMessage(*this);
|
|
return NS_OK;
|
|
}
|
|
|
|
// Warning: This method removes the receiver from whatever list it might be in.
|
|
nsresult
|
|
MessageChannel::MessageTask::Cancel()
|
|
{
|
|
if (!mChannel) {
|
|
return NS_OK;
|
|
}
|
|
|
|
mChannel->AssertWorkerThread();
|
|
mChannel->mMonitor->AssertNotCurrentThreadOwns();
|
|
|
|
MonitorAutoLock lock(*mChannel->mMonitor);
|
|
|
|
if (!isInList()) {
|
|
return NS_OK;
|
|
}
|
|
remove();
|
|
|
|
return NS_OK;
|
|
}
|
|
|
|
void
|
|
MessageChannel::MessageTask::Post()
|
|
{
|
|
MOZ_RELEASE_ASSERT(!mScheduled);
|
|
MOZ_RELEASE_ASSERT(isInList());
|
|
|
|
mScheduled = true;
|
|
|
|
RefPtr<MessageTask> self = this;
|
|
mChannel->mWorkerLoop->PostTask(self.forget());
|
|
}
|
|
|
|
void
|
|
MessageChannel::MessageTask::Clear()
|
|
{
|
|
mChannel->AssertWorkerThread();
|
|
|
|
mChannel = nullptr;
|
|
}
|
|
|
|
NS_IMETHODIMP
|
|
MessageChannel::MessageTask::GetPriority(uint32_t* aPriority)
|
|
{
|
|
*aPriority = mMessage.priority() == Message::HIGH_PRIORITY ?
|
|
PRIORITY_HIGH : PRIORITY_NORMAL;
|
|
return NS_OK;
|
|
}
|
|
|
|
void
|
|
MessageChannel::DispatchMessage(Message &&aMsg)
|
|
{
|
|
AssertWorkerThread();
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
|
|
Maybe<AutoNoJSAPI> nojsapi;
|
|
if (ScriptSettingsInitialized() && NS_IsMainThread())
|
|
nojsapi.emplace();
|
|
|
|
nsAutoPtr<Message> reply;
|
|
|
|
IPC_LOG("DispatchMessage: seqno=%d, xid=%d", aMsg.seqno(), aMsg.transaction_id());
|
|
|
|
{
|
|
AutoEnterTransaction transaction(this, aMsg);
|
|
|
|
int id = aMsg.transaction_id();
|
|
MOZ_RELEASE_ASSERT(!aMsg.is_sync() || id == transaction.TransactionID());
|
|
|
|
{
|
|
MonitorAutoUnlock unlock(*mMonitor);
|
|
CxxStackFrame frame(*this, IN_MESSAGE, &aMsg);
|
|
|
|
mListener->ArtificialSleep();
|
|
|
|
if (aMsg.is_sync())
|
|
DispatchSyncMessage(aMsg, *getter_Transfers(reply));
|
|
else if (aMsg.is_interrupt())
|
|
DispatchInterruptMessage(Move(aMsg), 0);
|
|
else
|
|
DispatchAsyncMessage(aMsg);
|
|
|
|
mListener->ArtificialSleep();
|
|
}
|
|
|
|
if (reply && transaction.IsCanceled()) {
|
|
// The transaction has been canceled. Don't send a reply.
|
|
IPC_LOG("Nulling out reply due to cancellation, seqno=%d, xid=%d", aMsg.seqno(), id);
|
|
reply = nullptr;
|
|
}
|
|
}
|
|
|
|
if (reply && ChannelConnected == mChannelState) {
|
|
IPC_LOG("Sending reply seqno=%d, xid=%d", aMsg.seqno(), aMsg.transaction_id());
|
|
mLink->SendMessage(reply.forget());
|
|
}
|
|
}
|
|
|
|
void
|
|
MessageChannel::DispatchSyncMessage(const Message& aMsg, Message*& aReply)
|
|
{
|
|
AssertWorkerThread();
|
|
|
|
int nestedLevel = aMsg.nested_level();
|
|
|
|
MOZ_RELEASE_ASSERT(nestedLevel == IPC::Message::NOT_NESTED || NS_IsMainThread());
|
|
|
|
MessageChannel* dummy;
|
|
MessageChannel*& blockingVar = mSide == ChildSide && NS_IsMainThread() ? gParentProcessBlocker : dummy;
|
|
|
|
Result rv;
|
|
{
|
|
AutoSetValue<MessageChannel*> blocked(blockingVar, this);
|
|
rv = mListener->OnMessageReceived(aMsg, aReply);
|
|
}
|
|
|
|
if (!MaybeHandleError(rv, aMsg, "DispatchSyncMessage")) {
|
|
aReply = new Message();
|
|
aReply->set_sync();
|
|
aReply->set_nested_level(aMsg.nested_level());
|
|
aReply->set_reply();
|
|
aReply->set_reply_error();
|
|
}
|
|
aReply->set_seqno(aMsg.seqno());
|
|
aReply->set_transaction_id(aMsg.transaction_id());
|
|
}
|
|
|
|
void
|
|
MessageChannel::DispatchAsyncMessage(const Message& aMsg)
|
|
{
|
|
AssertWorkerThread();
|
|
MOZ_RELEASE_ASSERT(!aMsg.is_interrupt() && !aMsg.is_sync());
|
|
|
|
if (aMsg.routing_id() == MSG_ROUTING_NONE) {
|
|
NS_RUNTIMEABORT("unhandled special message!");
|
|
}
|
|
|
|
Result rv;
|
|
{
|
|
int nestedLevel = aMsg.nested_level();
|
|
AutoSetValue<bool> async(mDispatchingAsyncMessage, true);
|
|
AutoSetValue<int> nestedLevelSet(mDispatchingAsyncMessageNestedLevel, nestedLevel);
|
|
rv = mListener->OnMessageReceived(aMsg);
|
|
}
|
|
MaybeHandleError(rv, aMsg, "DispatchAsyncMessage");
|
|
}
|
|
|
|
bool
|
|
MessageChannel::ShouldDeferInterruptMessage(const Message& aMsg, size_t aStackDepth)
|
|
{
|
|
AssertWorkerThread();
|
|
|
|
// We may or may not own the lock in this function, so don't access any
|
|
// channel state.
|
|
|
|
IPC_ASSERT(aMsg.is_interrupt() && !aMsg.is_reply(), "wrong message type");
|
|
|
|
// Race detection: see the long comment near mRemoteStackDepthGuess in
|
|
// MessageChannel.h. "Remote" stack depth means our side, and "local" means
|
|
// the other side.
|
|
if (aMsg.interrupt_remote_stack_depth_guess() == RemoteViewOfStackDepth(aStackDepth)) {
|
|
return false;
|
|
}
|
|
|
|
// Interrupt in-calls have raced. The winner, if there is one, gets to defer
|
|
// processing of the other side's in-call.
|
|
bool defer;
|
|
const MessageInfo parentMsgInfo =
|
|
(mSide == ChildSide) ? MessageInfo(aMsg) : mInterruptStack.top();
|
|
const MessageInfo childMsgInfo =
|
|
(mSide == ChildSide) ? mInterruptStack.top() : MessageInfo(aMsg);
|
|
switch (mListener->MediateInterruptRace(parentMsgInfo, childMsgInfo))
|
|
{
|
|
case RIPChildWins:
|
|
defer = (mSide == ChildSide);
|
|
break;
|
|
case RIPParentWins:
|
|
defer = (mSide != ChildSide);
|
|
break;
|
|
case RIPError:
|
|
MOZ_CRASH("NYI: 'Error' Interrupt race policy");
|
|
default:
|
|
MOZ_CRASH("not reached");
|
|
}
|
|
|
|
return defer;
|
|
}
|
|
|
|
void
|
|
MessageChannel::DispatchInterruptMessage(Message&& aMsg, size_t stackDepth)
|
|
{
|
|
AssertWorkerThread();
|
|
mMonitor->AssertNotCurrentThreadOwns();
|
|
|
|
IPC_ASSERT(aMsg.is_interrupt() && !aMsg.is_reply(), "wrong message type");
|
|
|
|
if (ShouldDeferInterruptMessage(aMsg, stackDepth)) {
|
|
// We now know the other side's stack has one more frame
|
|
// than we thought.
|
|
++mRemoteStackDepthGuess; // decremented in MaybeProcessDeferred()
|
|
mDeferred.push(Move(aMsg));
|
|
return;
|
|
}
|
|
|
|
// If we "lost" a race and need to process the other side's in-call, we
|
|
// don't need to fix up the mRemoteStackDepthGuess here, because we're just
|
|
// about to increment it, which will make it correct again.
|
|
|
|
#ifdef OS_WIN
|
|
SyncStackFrame frame(this, true);
|
|
#endif
|
|
|
|
nsAutoPtr<Message> reply;
|
|
|
|
++mRemoteStackDepthGuess;
|
|
Result rv = mListener->OnCallReceived(aMsg, *getter_Transfers(reply));
|
|
--mRemoteStackDepthGuess;
|
|
|
|
if (!MaybeHandleError(rv, aMsg, "DispatchInterruptMessage")) {
|
|
reply = new Message();
|
|
reply->set_interrupt();
|
|
reply->set_reply();
|
|
reply->set_reply_error();
|
|
}
|
|
reply->set_seqno(aMsg.seqno());
|
|
|
|
MonitorAutoLock lock(*mMonitor);
|
|
if (ChannelConnected == mChannelState) {
|
|
mLink->SendMessage(reply.forget());
|
|
}
|
|
}
|
|
|
|
void
|
|
MessageChannel::MaybeUndeferIncall()
|
|
{
|
|
AssertWorkerThread();
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
|
|
if (mDeferred.empty())
|
|
return;
|
|
|
|
size_t stackDepth = InterruptStackDepth();
|
|
|
|
Message& deferred = mDeferred.top();
|
|
|
|
// the other side can only *under*-estimate our actual stack depth
|
|
IPC_ASSERT(deferred.interrupt_remote_stack_depth_guess() <= stackDepth,
|
|
"fatal logic error");
|
|
|
|
if (ShouldDeferInterruptMessage(deferred, stackDepth)) {
|
|
return;
|
|
}
|
|
|
|
// maybe time to process this message
|
|
Message call(Move(deferred));
|
|
mDeferred.pop();
|
|
|
|
// fix up fudge factor we added to account for race
|
|
IPC_ASSERT(0 < mRemoteStackDepthGuess, "fatal logic error");
|
|
--mRemoteStackDepthGuess;
|
|
|
|
MOZ_RELEASE_ASSERT(call.nested_level() == IPC::Message::NOT_NESTED);
|
|
RefPtr<MessageTask> task = new MessageTask(this, Move(call));
|
|
mPending.insertBack(task);
|
|
task->Post();
|
|
}
|
|
|
|
void
|
|
MessageChannel::EnteredCxxStack()
|
|
{
|
|
mListener->EnteredCxxStack();
|
|
}
|
|
|
|
void
|
|
MessageChannel::ExitedCxxStack()
|
|
{
|
|
mListener->ExitedCxxStack();
|
|
if (mSawInterruptOutMsg) {
|
|
MonitorAutoLock lock(*mMonitor);
|
|
// see long comment in OnMaybeDequeueOne()
|
|
EnqueuePendingMessages();
|
|
mSawInterruptOutMsg = false;
|
|
}
|
|
}
|
|
|
|
void
|
|
MessageChannel::EnteredCall()
|
|
{
|
|
mListener->EnteredCall();
|
|
}
|
|
|
|
void
|
|
MessageChannel::ExitedCall()
|
|
{
|
|
mListener->ExitedCall();
|
|
}
|
|
|
|
void
|
|
MessageChannel::EnteredSyncSend()
|
|
{
|
|
mListener->OnEnteredSyncSend();
|
|
}
|
|
|
|
void
|
|
MessageChannel::ExitedSyncSend()
|
|
{
|
|
mListener->OnExitedSyncSend();
|
|
}
|
|
|
|
void
|
|
MessageChannel::EnqueuePendingMessages()
|
|
{
|
|
AssertWorkerThread();
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
|
|
MaybeUndeferIncall();
|
|
|
|
// XXX performance tuning knob: could process all or k pending
|
|
// messages here, rather than enqueuing for later processing
|
|
|
|
RepostAllMessages();
|
|
}
|
|
|
|
static inline bool
|
|
IsTimeoutExpired(PRIntervalTime aStart, PRIntervalTime aTimeout)
|
|
{
|
|
return (aTimeout != PR_INTERVAL_NO_TIMEOUT) &&
|
|
(aTimeout <= (PR_IntervalNow() - aStart));
|
|
}
|
|
|
|
bool
|
|
MessageChannel::WaitResponse(bool aWaitTimedOut)
|
|
{
|
|
if (aWaitTimedOut) {
|
|
if (mInTimeoutSecondHalf) {
|
|
// We've really timed out this time.
|
|
return false;
|
|
}
|
|
// Try a second time.
|
|
mInTimeoutSecondHalf = true;
|
|
} else {
|
|
mInTimeoutSecondHalf = false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
#ifndef OS_WIN
|
|
bool
|
|
MessageChannel::WaitForSyncNotify(bool /* aHandleWindowsMessages */)
|
|
{
|
|
#ifdef DEBUG
|
|
// WARNING: We don't release the lock here. We can't because the link thread
|
|
// could signal at this time and we would miss it. Instead we require
|
|
// ArtificialTimeout() to be extremely simple.
|
|
if (mListener->ArtificialTimeout()) {
|
|
return false;
|
|
}
|
|
#endif
|
|
|
|
PRIntervalTime timeout = (kNoTimeout == mTimeoutMs) ?
|
|
PR_INTERVAL_NO_TIMEOUT :
|
|
PR_MillisecondsToInterval(mTimeoutMs);
|
|
// XXX could optimize away this syscall for "no timeout" case if desired
|
|
PRIntervalTime waitStart = PR_IntervalNow();
|
|
|
|
mMonitor->Wait(timeout);
|
|
|
|
// If the timeout didn't expire, we know we received an event. The
|
|
// converse is not true.
|
|
return WaitResponse(IsTimeoutExpired(waitStart, timeout));
|
|
}
|
|
|
|
bool
|
|
MessageChannel::WaitForInterruptNotify()
|
|
{
|
|
return WaitForSyncNotify(true);
|
|
}
|
|
|
|
void
|
|
MessageChannel::NotifyWorkerThread()
|
|
{
|
|
mMonitor->Notify();
|
|
}
|
|
#endif
|
|
|
|
bool
|
|
MessageChannel::ShouldContinueFromTimeout()
|
|
{
|
|
AssertWorkerThread();
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
|
|
bool cont;
|
|
{
|
|
MonitorAutoUnlock unlock(*mMonitor);
|
|
cont = mListener->ShouldContinueFromReplyTimeout();
|
|
mListener->ArtificialSleep();
|
|
}
|
|
|
|
static enum { UNKNOWN, NOT_DEBUGGING, DEBUGGING } sDebuggingChildren = UNKNOWN;
|
|
|
|
if (sDebuggingChildren == UNKNOWN) {
|
|
sDebuggingChildren = getenv("MOZ_DEBUG_CHILD_PROCESS") ? DEBUGGING : NOT_DEBUGGING;
|
|
}
|
|
if (sDebuggingChildren == DEBUGGING) {
|
|
return true;
|
|
}
|
|
|
|
return cont;
|
|
}
|
|
|
|
void
|
|
MessageChannel::SetReplyTimeoutMs(int32_t aTimeoutMs)
|
|
{
|
|
// Set channel timeout value. Since this is broken up into
|
|
// two period, the minimum timeout value is 2ms.
|
|
AssertWorkerThread();
|
|
mTimeoutMs = (aTimeoutMs <= 0)
|
|
? kNoTimeout
|
|
: (int32_t)ceil((double)aTimeoutMs / 2.0);
|
|
}
|
|
|
|
void
|
|
MessageChannel::OnChannelConnected(int32_t peer_id)
|
|
{
|
|
MOZ_RELEASE_ASSERT(!mPeerPidSet);
|
|
mPeerPidSet = true;
|
|
mPeerPid = peer_id;
|
|
RefPtr<CancelableRunnable> task = mOnChannelConnectedTask;
|
|
mWorkerLoop->PostTask(task.forget());
|
|
}
|
|
|
|
void
|
|
MessageChannel::DispatchOnChannelConnected()
|
|
{
|
|
AssertWorkerThread();
|
|
MOZ_RELEASE_ASSERT(mPeerPidSet);
|
|
mListener->OnChannelConnected(mPeerPid);
|
|
}
|
|
|
|
void
|
|
MessageChannel::ReportMessageRouteError(const char* channelName) const
|
|
{
|
|
PrintErrorMessage(mSide, channelName, "Need a route");
|
|
mListener->ProcessingError(MsgRouteError, "MsgRouteError");
|
|
}
|
|
|
|
void
|
|
MessageChannel::ReportConnectionError(const char* aChannelName, Message* aMsg) const
|
|
{
|
|
AssertWorkerThread();
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
|
|
const char* errorMsg = nullptr;
|
|
switch (mChannelState) {
|
|
case ChannelClosed:
|
|
errorMsg = "Closed channel: cannot send/recv";
|
|
break;
|
|
case ChannelOpening:
|
|
errorMsg = "Opening channel: not yet ready for send/recv";
|
|
break;
|
|
case ChannelTimeout:
|
|
errorMsg = "Channel timeout: cannot send/recv";
|
|
break;
|
|
case ChannelClosing:
|
|
errorMsg = "Channel closing: too late to send/recv, messages will be lost";
|
|
break;
|
|
case ChannelError:
|
|
errorMsg = "Channel error: cannot send/recv";
|
|
break;
|
|
|
|
default:
|
|
NS_RUNTIMEABORT("unreached");
|
|
}
|
|
|
|
if (aMsg) {
|
|
char reason[512];
|
|
SprintfLiteral(reason,"(msgtype=0x%X,name=%s) %s",
|
|
aMsg->type(), aMsg->name(), errorMsg);
|
|
|
|
PrintErrorMessage(mSide, aChannelName, reason);
|
|
} else {
|
|
PrintErrorMessage(mSide, aChannelName, errorMsg);
|
|
}
|
|
|
|
MonitorAutoUnlock unlock(*mMonitor);
|
|
mListener->ProcessingError(MsgDropped, errorMsg);
|
|
}
|
|
|
|
bool
|
|
MessageChannel::MaybeHandleError(Result code, const Message& aMsg, const char* channelName)
|
|
{
|
|
if (MsgProcessed == code)
|
|
return true;
|
|
|
|
const char* errorMsg = nullptr;
|
|
switch (code) {
|
|
case MsgNotKnown:
|
|
errorMsg = "Unknown message: not processed";
|
|
break;
|
|
case MsgNotAllowed:
|
|
errorMsg = "Message not allowed: cannot be sent/recvd in this state";
|
|
break;
|
|
case MsgPayloadError:
|
|
errorMsg = "Payload error: message could not be deserialized";
|
|
break;
|
|
case MsgProcessingError:
|
|
errorMsg = "Processing error: message was deserialized, but the handler returned false (indicating failure)";
|
|
break;
|
|
case MsgRouteError:
|
|
errorMsg = "Route error: message sent to unknown actor ID";
|
|
break;
|
|
case MsgValueError:
|
|
errorMsg = "Value error: message was deserialized, but contained an illegal value";
|
|
break;
|
|
|
|
default:
|
|
NS_RUNTIMEABORT("unknown Result code");
|
|
return false;
|
|
}
|
|
|
|
char reason[512];
|
|
const char* msgname = StringFromIPCMessageType(aMsg.type());
|
|
if (msgname[0] == '?') {
|
|
SprintfLiteral(reason,"(msgtype=0x%X) %s", aMsg.type(), errorMsg);
|
|
} else {
|
|
SprintfLiteral(reason,"%s %s", msgname, errorMsg);
|
|
}
|
|
|
|
PrintErrorMessage(mSide, channelName, reason);
|
|
|
|
mListener->ProcessingError(code, reason);
|
|
|
|
return false;
|
|
}
|
|
|
|
void
|
|
MessageChannel::OnChannelErrorFromLink()
|
|
{
|
|
AssertLinkThread();
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
|
|
IPC_LOG("OnChannelErrorFromLink");
|
|
|
|
if (InterruptStackDepth() > 0)
|
|
NotifyWorkerThread();
|
|
|
|
if (AwaitingSyncReply() || AwaitingIncomingMessage())
|
|
NotifyWorkerThread();
|
|
|
|
if (ChannelClosing != mChannelState) {
|
|
if (mAbortOnError) {
|
|
NS_RUNTIMEABORT("Aborting on channel error.");
|
|
}
|
|
mChannelState = ChannelError;
|
|
mMonitor->Notify();
|
|
}
|
|
|
|
PostErrorNotifyTask();
|
|
}
|
|
|
|
void
|
|
MessageChannel::NotifyMaybeChannelError()
|
|
{
|
|
mMonitor->AssertNotCurrentThreadOwns();
|
|
|
|
// TODO sort out Close() on this side racing with Close() on the other side
|
|
if (ChannelClosing == mChannelState) {
|
|
// the channel closed, but we received a "Goodbye" message warning us
|
|
// about it. no worries
|
|
mChannelState = ChannelClosed;
|
|
NotifyChannelClosed();
|
|
return;
|
|
}
|
|
|
|
Clear();
|
|
|
|
// Oops, error! Let the listener know about it.
|
|
mChannelState = ChannelError;
|
|
|
|
// IPDL assumes these notifications do not fire twice, so we do not let
|
|
// that happen.
|
|
if (mNotifiedChannelDone) {
|
|
return;
|
|
}
|
|
mNotifiedChannelDone = true;
|
|
|
|
// After this, the channel may be deleted. Based on the premise that
|
|
// mListener owns this channel, any calls back to this class that may
|
|
// work with mListener should still work on living objects.
|
|
mListener->OnChannelError();
|
|
}
|
|
|
|
void
|
|
MessageChannel::OnNotifyMaybeChannelError()
|
|
{
|
|
AssertWorkerThread();
|
|
mMonitor->AssertNotCurrentThreadOwns();
|
|
|
|
mChannelErrorTask = nullptr;
|
|
|
|
// OnChannelError holds mMonitor when it posts this task and this
|
|
// task cannot be allowed to run until OnChannelError has
|
|
// exited. We enforce that order by grabbing the mutex here which
|
|
// should only continue once OnChannelError has completed.
|
|
{
|
|
MonitorAutoLock lock(*mMonitor);
|
|
// nothing to do here
|
|
}
|
|
|
|
if (IsOnCxxStack()) {
|
|
mChannelErrorTask =
|
|
NewNonOwningCancelableRunnableMethod(this, &MessageChannel::OnNotifyMaybeChannelError);
|
|
RefPtr<Runnable> task = mChannelErrorTask;
|
|
// 10 ms delay is completely arbitrary
|
|
mWorkerLoop->PostDelayedTask(task.forget(), 10);
|
|
return;
|
|
}
|
|
|
|
NotifyMaybeChannelError();
|
|
}
|
|
|
|
void
|
|
MessageChannel::PostErrorNotifyTask()
|
|
{
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
|
|
if (mChannelErrorTask)
|
|
return;
|
|
|
|
// This must be the last code that runs on this thread!
|
|
mChannelErrorTask =
|
|
NewNonOwningCancelableRunnableMethod(this, &MessageChannel::OnNotifyMaybeChannelError);
|
|
RefPtr<Runnable> task = mChannelErrorTask;
|
|
mWorkerLoop->PostTask(task.forget());
|
|
}
|
|
|
|
// Special async message.
|
|
class GoodbyeMessage : public IPC::Message
|
|
{
|
|
public:
|
|
GoodbyeMessage() :
|
|
IPC::Message(MSG_ROUTING_NONE, GOODBYE_MESSAGE_TYPE)
|
|
{
|
|
}
|
|
static bool Read(const Message* msg) {
|
|
return true;
|
|
}
|
|
void Log(const std::string& aPrefix, FILE* aOutf) const {
|
|
fputs("(special `Goodbye' message)", aOutf);
|
|
}
|
|
};
|
|
|
|
void
|
|
MessageChannel::SynchronouslyClose()
|
|
{
|
|
AssertWorkerThread();
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
mLink->SendClose();
|
|
while (ChannelClosed != mChannelState)
|
|
mMonitor->Wait();
|
|
}
|
|
|
|
void
|
|
MessageChannel::CloseWithError()
|
|
{
|
|
AssertWorkerThread();
|
|
|
|
MonitorAutoLock lock(*mMonitor);
|
|
if (ChannelConnected != mChannelState) {
|
|
return;
|
|
}
|
|
SynchronouslyClose();
|
|
mChannelState = ChannelError;
|
|
PostErrorNotifyTask();
|
|
}
|
|
|
|
void
|
|
MessageChannel::CloseWithTimeout()
|
|
{
|
|
AssertWorkerThread();
|
|
|
|
MonitorAutoLock lock(*mMonitor);
|
|
if (ChannelConnected != mChannelState) {
|
|
return;
|
|
}
|
|
SynchronouslyClose();
|
|
mChannelState = ChannelTimeout;
|
|
}
|
|
|
|
void
|
|
MessageChannel::Close()
|
|
{
|
|
AssertWorkerThread();
|
|
|
|
{
|
|
MonitorAutoLock lock(*mMonitor);
|
|
|
|
if (ChannelError == mChannelState || ChannelTimeout == mChannelState) {
|
|
// See bug 538586: if the listener gets deleted while the
|
|
// IO thread's NotifyChannelError event is still enqueued
|
|
// and subsequently deletes us, then the error event will
|
|
// also be deleted and the listener will never be notified
|
|
// of the channel error.
|
|
if (mListener) {
|
|
MonitorAutoUnlock unlock(*mMonitor);
|
|
NotifyMaybeChannelError();
|
|
}
|
|
return;
|
|
}
|
|
|
|
if (ChannelOpening == mChannelState) {
|
|
// SynchronouslyClose() waits for an ack from the other side, so
|
|
// the opening sequence should complete before this returns.
|
|
SynchronouslyClose();
|
|
mChannelState = ChannelError;
|
|
NotifyMaybeChannelError();
|
|
return;
|
|
}
|
|
|
|
if (ChannelClosed == mChannelState) {
|
|
// XXX be strict about this until there's a compelling reason
|
|
// to relax
|
|
NS_RUNTIMEABORT("Close() called on closed channel!");
|
|
}
|
|
|
|
// Notify the other side that we're about to close our socket. If we've
|
|
// already received a Goodbye from the other side (and our state is
|
|
// ChannelClosing), there's no reason to send one.
|
|
if (ChannelConnected == mChannelState) {
|
|
mLink->SendMessage(new GoodbyeMessage());
|
|
}
|
|
SynchronouslyClose();
|
|
}
|
|
|
|
NotifyChannelClosed();
|
|
}
|
|
|
|
void
|
|
MessageChannel::NotifyChannelClosed()
|
|
{
|
|
mMonitor->AssertNotCurrentThreadOwns();
|
|
|
|
if (ChannelClosed != mChannelState)
|
|
NS_RUNTIMEABORT("channel should have been closed!");
|
|
|
|
Clear();
|
|
|
|
// IPDL assumes these notifications do not fire twice, so we do not let
|
|
// that happen.
|
|
if (mNotifiedChannelDone) {
|
|
return;
|
|
}
|
|
mNotifiedChannelDone = true;
|
|
|
|
// OK, the IO thread just closed the channel normally. Let the
|
|
// listener know about it. After this point the channel may be
|
|
// deleted.
|
|
mListener->OnChannelClose();
|
|
}
|
|
|
|
void
|
|
MessageChannel::DebugAbort(const char* file, int line, const char* cond,
|
|
const char* why,
|
|
bool reply)
|
|
{
|
|
printf_stderr("###!!! [MessageChannel][%s][%s:%d] "
|
|
"Assertion (%s) failed. %s %s\n",
|
|
mSide == ChildSide ? "Child" : "Parent",
|
|
file, line, cond,
|
|
why,
|
|
reply ? "(reply)" : "");
|
|
// technically we need the mutex for this, but we're dying anyway
|
|
DumpInterruptStack(" ");
|
|
printf_stderr(" remote Interrupt stack guess: %" PRIuSIZE "\n",
|
|
mRemoteStackDepthGuess);
|
|
printf_stderr(" deferred stack size: %" PRIuSIZE "\n",
|
|
mDeferred.size());
|
|
printf_stderr(" out-of-turn Interrupt replies stack size: %" PRIuSIZE "\n",
|
|
mOutOfTurnReplies.size());
|
|
|
|
MessageQueue pending = Move(mPending);
|
|
while (!pending.isEmpty()) {
|
|
printf_stderr(" [ %s%s ]\n",
|
|
pending.getFirst()->Msg().is_interrupt() ? "intr" :
|
|
(pending.getFirst()->Msg().is_sync() ? "sync" : "async"),
|
|
pending.getFirst()->Msg().is_reply() ? "reply" : "");
|
|
pending.popFirst();
|
|
}
|
|
|
|
NS_RUNTIMEABORT(why);
|
|
}
|
|
|
|
void
|
|
MessageChannel::DumpInterruptStack(const char* const pfx) const
|
|
{
|
|
NS_WARNING_ASSERTION(
|
|
MessageLoop::current() != mWorkerLoop,
|
|
"The worker thread had better be paused in a debugger!");
|
|
|
|
printf_stderr("%sMessageChannel 'backtrace':\n", pfx);
|
|
|
|
// print a python-style backtrace, first frame to last
|
|
for (uint32_t i = 0; i < mCxxStackFrames.length(); ++i) {
|
|
int32_t id;
|
|
const char* dir;
|
|
const char* sems;
|
|
const char* name;
|
|
mCxxStackFrames[i].Describe(&id, &dir, &sems, &name);
|
|
|
|
printf_stderr("%s[(%u) %s %s %s(actor=%d) ]\n", pfx,
|
|
i, dir, sems, name, id);
|
|
}
|
|
}
|
|
|
|
int32_t
|
|
MessageChannel::GetTopmostMessageRoutingId() const
|
|
{
|
|
MOZ_RELEASE_ASSERT(MessageLoop::current() == mWorkerLoop);
|
|
if (mCxxStackFrames.empty()) {
|
|
return MSG_ROUTING_NONE;
|
|
}
|
|
const InterruptFrame& frame = mCxxStackFrames.back();
|
|
return frame.GetRoutingId();
|
|
}
|
|
|
|
void
|
|
MessageChannel::EndTimeout()
|
|
{
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
|
|
IPC_LOG("Ending timeout of seqno=%d", mTimedOutMessageSeqno);
|
|
mTimedOutMessageSeqno = 0;
|
|
mTimedOutMessageNestedLevel = 0;
|
|
|
|
RepostAllMessages();
|
|
}
|
|
|
|
void
|
|
MessageChannel::RepostAllMessages()
|
|
{
|
|
bool needRepost = false;
|
|
for (RefPtr<MessageTask> task : mPending) {
|
|
if (!task->IsScheduled()) {
|
|
needRepost = true;
|
|
}
|
|
}
|
|
if (!needRepost) {
|
|
// If everything is already scheduled to run, do nothing.
|
|
return;
|
|
}
|
|
|
|
// In some cases we may have deferred dispatch of some messages in the
|
|
// queue. Now we want to run them again. However, we can't just re-post
|
|
// those messages since the messages after them in mPending would then be
|
|
// before them in the event queue. So instead we cancel everything and
|
|
// re-post all messages in the correct order.
|
|
MessageQueue queue = Move(mPending);
|
|
while (RefPtr<MessageTask> task = queue.popFirst()) {
|
|
RefPtr<MessageTask> newTask = new MessageTask(this, Move(task->Msg()));
|
|
mPending.insertBack(newTask);
|
|
newTask->Post();
|
|
}
|
|
}
|
|
|
|
void
|
|
MessageChannel::CancelTransaction(int transaction)
|
|
{
|
|
mMonitor->AssertCurrentThreadOwns();
|
|
|
|
// When we cancel a transaction, we need to behave as if there's no longer
|
|
// any IPC on the stack. Anything we were dispatching or sending will get
|
|
// canceled. Consequently, we have to update the state variables below.
|
|
//
|
|
// We also need to ensure that when any IPC functions on the stack return,
|
|
// they don't reset these values using an RAII class like AutoSetValue. To
|
|
// avoid that, these RAII classes check if the variable they set has been
|
|
// tampered with (by us). If so, they don't reset the variable to the old
|
|
// value.
|
|
|
|
IPC_LOG("CancelTransaction: xid=%d", transaction);
|
|
|
|
// An unusual case: We timed out a transaction which the other side then
|
|
// cancelled. In this case we just leave the timedout state and try to
|
|
// forget this ever happened.
|
|
if (transaction == mTimedOutMessageSeqno) {
|
|
IPC_LOG("Cancelled timed out message %d", mTimedOutMessageSeqno);
|
|
EndTimeout();
|
|
|
|
// Normally mCurrentTransaction == 0 here. But it can be non-zero if:
|
|
// 1. Parent sends NESTED_INSIDE_SYNC message H.
|
|
// 2. Parent times out H.
|
|
// 3. Child dispatches H and sends nested message H' (same transaction).
|
|
// 4. Parent dispatches H' and cancels.
|
|
MOZ_RELEASE_ASSERT(!mTransactionStack || mTransactionStack->TransactionID() == transaction);
|
|
if (mTransactionStack) {
|
|
mTransactionStack->Cancel();
|
|
}
|
|
} else {
|
|
MOZ_RELEASE_ASSERT(mTransactionStack->TransactionID() == transaction);
|
|
mTransactionStack->Cancel();
|
|
}
|
|
|
|
bool foundSync = false;
|
|
for (RefPtr<MessageTask> p = mPending.getFirst(); p; ) {
|
|
Message &msg = p->Msg();
|
|
|
|
// If there was a race between the parent and the child, then we may
|
|
// have a queued sync message. We want to drop this message from the
|
|
// queue since if will get cancelled along with the transaction being
|
|
// cancelled. This happens if the message in the queue is NESTED_INSIDE_SYNC.
|
|
if (msg.is_sync() && msg.nested_level() != IPC::Message::NOT_NESTED) {
|
|
MOZ_RELEASE_ASSERT(!foundSync);
|
|
MOZ_RELEASE_ASSERT(msg.transaction_id() != transaction);
|
|
IPC_LOG("Removing msg from queue seqno=%d xid=%d", msg.seqno(), msg.transaction_id());
|
|
foundSync = true;
|
|
p = p->removeAndGetNext();
|
|
continue;
|
|
}
|
|
|
|
p = p->getNext();
|
|
}
|
|
}
|
|
|
|
bool
|
|
MessageChannel::IsInTransaction() const
|
|
{
|
|
MonitorAutoLock lock(*mMonitor);
|
|
return !!mTransactionStack;
|
|
}
|
|
|
|
void
|
|
MessageChannel::CancelCurrentTransaction()
|
|
{
|
|
MonitorAutoLock lock(*mMonitor);
|
|
if (DispatchingSyncMessageNestedLevel() >= IPC::Message::NESTED_INSIDE_SYNC) {
|
|
if (DispatchingSyncMessageNestedLevel() == IPC::Message::NESTED_INSIDE_CPOW ||
|
|
DispatchingAsyncMessageNestedLevel() == IPC::Message::NESTED_INSIDE_CPOW)
|
|
{
|
|
mListener->IntentionalCrash();
|
|
}
|
|
|
|
IPC_LOG("Cancel requested: current xid=%d", CurrentNestedInsideSyncTransaction());
|
|
MOZ_RELEASE_ASSERT(DispatchingSyncMessage());
|
|
CancelMessage *cancel = new CancelMessage(CurrentNestedInsideSyncTransaction());
|
|
CancelTransaction(CurrentNestedInsideSyncTransaction());
|
|
mLink->SendMessage(cancel);
|
|
}
|
|
}
|
|
|
|
void
|
|
CancelCPOWs()
|
|
{
|
|
if (gParentProcessBlocker) {
|
|
gParentProcessBlocker->CancelCurrentTransaction();
|
|
}
|
|
}
|
|
|
|
} // namespace ipc
|
|
} // namespace mozilla
|