gecko/ipc/glue/AsyncChannel.cpp

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 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
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 *
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 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Plugin App.
 *
 * The Initial Developer of the Original Code is
 *   Chris Jones <jones.chris.g@gmail.com>
 * Portions created by the Initial Developer are Copyright (C) 2009
 * the Initial Developer. All Rights Reserved.
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 *
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#include "mozilla/ipc/AsyncChannel.h"
#include "mozilla/ipc/GeckoThread.h"

#include "nsDebug.h"
#include "nsXULAppAPI.h"

using mozilla::MutexAutoLock;

template<>
struct RunnableMethodTraits<mozilla::ipc::AsyncChannel>
{
    static void RetainCallee(mozilla::ipc::AsyncChannel* obj) { }
    static void ReleaseCallee(mozilla::ipc::AsyncChannel* obj) { }
};

namespace mozilla {
namespace ipc {

bool
AsyncChannel::Open(Transport* aTransport, MessageLoop* aIOLoop)
{
    NS_PRECONDITION(!mTransport, "Open() called > once");
    NS_PRECONDITION(aTransport, "need transport layer");

    // FIXME need to check for valid channel

    mTransport = aTransport;
    mTransport->set_listener(this);

    // FIXME figure out whether we're in parent or child, grab IO loop
    // appropriately
    bool needOpen = true;
    if(!aIOLoop) {
        // parent
        needOpen = false;
        aIOLoop = BrowserProcessSubThread
                  ::GetMessageLoop(BrowserProcessSubThread::IO);
        // FIXME assuming that the parent waits for the OnConnected event.
        // FIXME see GeckoChildProcessHost.cpp.  bad assumption!
        mChannelState = ChannelConnected;
    }

    mChild = needOpen;

    mIOLoop = aIOLoop;
    mWorkerLoop = MessageLoop::current();

    NS_ASSERTION(mIOLoop, "need an IO loop");
    NS_ASSERTION(mWorkerLoop, "need a worker loop");

    if (needOpen) {             // child process
        MutexAutoLock lock(mMutex);

        mIOLoop->PostTask(FROM_HERE, 
                          NewRunnableMethod(this,
                                            &AsyncChannel::OnChannelOpened));

        // FIXME/cjones: handle errors
        while (mChannelState != ChannelConnected) {
            mCvar.Wait();
        }
    }

    return true;
}

void
AsyncChannel::Close()
{
    // FIXME impl

    mChannelState = ChannelClosed;
}

bool
AsyncChannel::Send(Message* msg)
{
    AssertWorkerThread();
    mMutex.AssertNotCurrentThreadOwns();
    NS_ABORT_IF_FALSE(MSG_ROUTING_NONE != msg->routing_id(), "need a route");

    {
        MutexAutoLock lock(mMutex);

        if (!Connected())
            // trying to Send() to a closed or error'd channel
            return false;

        mIOLoop->PostTask(FROM_HERE,
                          NewRunnableMethod(this, &AsyncChannel::OnSend, msg));
    }

    return true;
}

void
AsyncChannel::OnDispatchMessage(const Message& msg)
{
    AssertWorkerThread();
    NS_ASSERTION(!msg.is_reply(), "can't process replies here");
    NS_ASSERTION(!(msg.is_sync() || msg.is_rpc()), "async dispatch only");

    switch (mListener->OnMessageReceived(msg)) {
    case MsgProcessed:
        return;

    case MsgNotKnown:
    case MsgNotAllowed:
    case MsgPayloadError:
    case MsgRouteError:
    case MsgValueError:
        // FIXME/cjones: error handling; OnError()?
        return;

    default:
        NOTREACHED();
        return;
    }
}

//
// The methods below run in the context of the IO thread, and can proxy
// back to the methods above
//

void
AsyncChannel::OnMessageReceived(const Message& msg)
{
    AssertIOThread();
    NS_ASSERTION(mChannelState != ChannelError, "Shouldn't get here!");

    // wake up the worker, there's work to do
    mWorkerLoop->PostTask(
        FROM_HERE,
        NewRunnableMethod(this, &AsyncChannel::OnDispatchMessage, msg));
}

void
AsyncChannel::OnChannelConnected(int32 peer_pid)
{
    AssertIOThread();

    MutexAutoLock lock(mMutex);
    mChannelState = ChannelConnected;
    mCvar.Notify();
}

void
AsyncChannel::OnChannelError()
{
    AssertIOThread();

    {
        MutexAutoLock lock(mMutex);
        mChannelState = ChannelError;
    }

    if (XRE_GetProcessType() == GeckoProcessType_Default) {
        // Parent process, one of our children died. Notify?
    }
    else {
        // Child process, initiate quit sequence.
#ifdef DEBUG
        // XXXbent this is totally out of place, but works for now.
        XRE_ShutdownChildProcess(mWorkerLoop);

        // Must exit the IO loop, which will then join with the UI loop.
        MessageLoop::current()->Quit();
#else
        // Go ahead and abort here.
        NS_DebugBreak(NS_DEBUG_ABORT, nsnull, nsnull, nsnull, 0);
#endif
    }
}

void
AsyncChannel::OnChannelOpened()
{
    AssertIOThread();
    mChannelState = ChannelOpening;
    /*assert*/mTransport->Connect();
}

void
AsyncChannel::OnSend(Message* aMsg)
{
    AssertIOThread();
    mTransport->Send(aMsg);
    // mTransport deletes aMsg
}


} // namespace ipc
} // namespace mozilla