serverChannelImpl.cpp

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#include <pv/reftrack.h>

#define epicsExportSharedSymbols
#include <pv/serverChannelImpl.h>

using namespace epics::pvData;

namespace epics {
namespace pvAccess {

size_t ServerChannel::num_instances;

ServerChannel::ServerChannel(Channel::shared_pointer const & channel,
                             const ChannelRequester::shared_pointer &requester,
                             pvAccessID cid, pvAccessID sid):
    _channel(channel),
    _requester(requester),
    _cid(cid),
    _sid(sid),
    _destroyed(false)
{
    REFTRACE_INCREMENT(num_instances);
    if (!channel.get())
    {
        THROW_BASE_EXCEPTION("non-null channel required");
    }
}

void ServerChannel::registerRequest(const pvAccessID id, const std::tr1::shared_ptr<BaseChannelRequester> & request)
{
    Lock guard(_mutex);
    if(_destroyed) throw std::logic_error("Can't registerRequest() for destory'd server channel");
    _requests[id] = request;
}

void ServerChannel::unregisterRequest(const pvAccessID id)
{
    Lock guard(_mutex);
    _requests_t::iterator iter = _requests.find(id);
    if(iter != _requests.end())
    {
        _requests.erase(iter);
    }
}

std::tr1::shared_ptr<BaseChannelRequester> ServerChannel::getRequest(const pvAccessID id)
{
    Lock guard(_mutex);
    _requests_t::iterator iter = _requests.find(id);
    if(iter != _requests.end())
    {
        return iter->second;
    }
    return BaseChannelRequester::shared_pointer();
}

void ServerChannel::destroy()
{
    _requests_t reqs;
    {
        Lock guard(_mutex);

        if (_destroyed) return;
        _destroyed = true;

        // destroy all requests
        // take ownership of _requests locally to prevent
        // removal via unregisterRequest() during iteration
        _requests.swap(reqs);

        // ... and the channel
        // TODO try catch
        _channel->destroy();
    }
    // unlock our before destroy.
    // our mutex is subordinate to operation mutex

    for(_requests_t::const_iterator it=reqs.begin(), end=reqs.end(); it!=end; ++it)
    {
        const _requests_t::mapped_type& req = it->second;
        // will call unregisterRequest() which is now a no-op
        req->destroy();
        // May still be in the send queue
    }
}

ServerChannel::~ServerChannel()
{
    destroy();
    REFTRACE_DECREMENT(num_instances);
}

void ServerChannel::printInfo() const
{
    printInfo(stdout);
}

void ServerChannel::printInfo(FILE *fd) const
{
    fprintf(fd,"CLASS        : %s\n", typeid(*this).name());
    fprintf(fd,"CHANNEL      : %s\n", typeid(*_channel).name());
}

void ServerChannel::installGetField(const GetFieldRequester::shared_pointer& gf)
{
    GetFieldRequester::shared_pointer prev;
    {
        epicsGuard<epicsMutex> G(_mutex);
        prev.swap(_active_requester);
        _active_requester = gf;
    }
    if(prev) {
        prev->getDone(Status::error("Aborted"), FieldConstPtr());
    }
}

void ServerChannel::completeGetField(GetFieldRequester *req)
{
    GetFieldRequester::shared_pointer prev;
    {
        epicsGuard<epicsMutex> G(_mutex);
        if(_active_requester.get()==req)
            prev.swap(_active_requester);
    }
}

}
}