Files
pvAccess/src/rpcClient/rpcClient.cpp
2017-07-03 19:24:01 +02:00

284 lines
8.3 KiB
C++

/**
* Copyright - See the COPYRIGHT that is included with this distribution.
* EPICS pvAccessCPP is distributed subject to a Software License Agreement
* found in file LICENSE that is included with this distribution.
*/
#include <iostream>
#include <string>
#include <epicsEvent.h>
#include <pv/pvData.h>
#include <pv/event.h>
#include <pv/current_function.h>
#define epicsExportSharedSymbols
#include <pv/pvAccess.h>
#include <pv/clientFactory.h>
#include <pv/logger.h>
#include <pv/rpcService.h>
#include "pv/rpcClient.h"
#if 0
# define TRACE(msg) std::cerr<<"TRACE: "<<CURRENT_FUNCTION<<" : "<< msg <<"\n"
#else
# define TRACE(msg)
#endif
namespace pvd = epics::pvData;
namespace pva = epics::pvAccess;
namespace epics{namespace pvAccess{
struct RPCClient::RPCRequester : public pva::ChannelRPCRequester
{
POINTER_DEFINITIONS(RPCRequester);
pvd::Mutex mutex;
ChannelRPC::weak_pointer op;
pvd::Status conn_status, resp_status;
epics::pvData::PVStructure::shared_pointer next_args, last_data;
epicsEvent event;
bool inprogress, last;
RPCRequester()
:conn_status(pvd::Status::error("Never connected"))
,resp_status(pvd::Status::error("Never connected"))
,inprogress(false)
,last(false)
{}
virtual ~RPCRequester() {}
virtual std::string getRequesterName() { return "RPCClient::RPCRequester"; }
virtual void channelRPCConnect(
const pvd::Status& status,
ChannelRPC::shared_pointer const & operation)
{
bool lastreq, inprog;
pvd::PVStructure::shared_pointer args;
{
pvd::Lock L(mutex);
TRACE("status="<<status);
op = operation;
conn_status = status;
args.swap(next_args);
lastreq = last;
inprog = inprogress;
if(inprog && args)
TRACE("request deferred: "<<args);
}
if(inprog && args) {
TRACE("request deferred: "<<args);
if(lastreq)
operation->lastRequest();
operation->request(args);
}
event.signal();
}
virtual void requestDone(
const pvd::Status& status,
ChannelRPC::shared_pointer const & operation,
pvd::PVStructure::shared_pointer const & pvResponse)
{
TRACE("status="<<status<<" response:\n"<<pvResponse<<"\n");
{
pvd::Lock L(mutex);
if(!inprogress) {
std::cerr<<"pva provider give RPC requestDone() when no request in progress\n";
} else {
resp_status = status;
last_data = pvResponse;
if(resp_status.isSuccess() && !last_data) {
resp_status = pvd::Status::error("No reply data");
}
inprogress = false;
}
}
event.signal();
}
virtual void channelDisconnect(bool destroy)
{
TRACE("destroy="<<destroy);
{
pvd::Lock L(mutex);
resp_status = conn_status = pvd::Status::error("Connection lost");
last_data.reset();
next_args.reset();
inprogress = false;
}
event.signal();
}
};
RPCClient::RPCClient(const std::string & serviceName,
pvd::PVStructure::shared_pointer const & pvRequest,
const ChannelProvider::shared_pointer &provider,
const std::string &address)
: m_serviceName(serviceName)
, m_provider(provider)
, m_pvRequest(pvRequest ? pvRequest : pvd::createRequest(""))
{
ClientFactory::start();
if(!m_provider)
m_provider = ChannelProviderRegistry::clients()->getProvider("pva");
if(!m_provider)
throw std::logic_error("Unknown Provider");
m_channel = m_provider->createChannel(serviceName, DefaultChannelRequester::build(),
ChannelProvider::PRIORITY_DEFAULT,
address);
if(!m_channel)
throw std::logic_error("provider createChannel() succeeds w/ NULL Channel");
m_rpc_requester.reset(new RPCRequester);
m_rpc = m_channel->createChannelRPC(m_rpc_requester, m_pvRequest);
if(!m_rpc)
throw std::logic_error("channel createChannelRPC() NULL");
}
void RPCClient::destroy()
{
if (m_channel)
{
m_channel->destroy();
m_channel.reset();
}
if (m_rpc)
{
m_rpc->destroy();
m_rpc.reset();
}
}
bool RPCClient::connect(double timeout)
{
issueConnect();
return waitConnect(timeout);
}
void RPCClient::issueConnect()
{
}
bool RPCClient::waitConnect(double timeout)
{
pvd::Lock L(m_rpc_requester->mutex);
TRACE("timeout="<<timeout);
while(!m_rpc_requester->conn_status.isSuccess()) {
L.unlock();
if(!m_rpc_requester->event.wait(timeout)) {
TRACE("TIMEOUT");
return false;
}
L.lock();
}
TRACE("Connected");
return true;
}
pvd::PVStructure::shared_pointer RPCClient::request(
pvd::PVStructure::shared_pointer const & pvArgument,
double timeout,
bool lastRequest)
{
if (connect(timeout))
{
issueRequest(pvArgument, lastRequest);
return waitResponse(timeout); // TODO reduce timeout for a time spent on connect
}
else
throw epics::pvAccess::RPCRequestException(pvd::Status::STATUSTYPE_ERROR, "connection timeout");
}
void RPCClient::issueRequest(
pvd::PVStructure::shared_pointer const & pvArgument,
bool lastRequest)
{
{
pvd::Lock L(m_rpc_requester->mutex);
TRACE("conn_status="<<m_rpc_requester->conn_status
<<" resp_status="<<m_rpc_requester->resp_status
<<" args:\n"<<pvArgument);
if(m_rpc_requester->inprogress)
throw std::logic_error("Request already in progress");
m_rpc_requester->inprogress = true;
m_rpc_requester->resp_status = pvd::Status::error("No Data");
if(!m_rpc_requester->conn_status.isSuccess()) {
TRACE("defer");
m_rpc_requester->last = lastRequest;
m_rpc_requester->next_args = pvArgument;
return;
}
TRACE("request args: "<<pvArgument);
}
if(lastRequest)
m_rpc->lastRequest();
m_rpc->request(pvArgument);
}
pvd::PVStructure::shared_pointer RPCClient::waitResponse(double timeout)
{
pvd::Lock L(m_rpc_requester->mutex);
TRACE("timeout="<<timeout);
if(!m_rpc_requester->inprogress)
throw std::logic_error("No request in progress");
while(m_rpc_requester->inprogress)
{
L.unlock();
if(!m_rpc_requester->event.wait(timeout)) {
TRACE("TIMEOUT");
throw RPCRequestException(pvd::Status::STATUSTYPE_ERROR, "RPC timeout");
}
L.lock();
}
TRACE("Complete: conn_status="<<m_rpc_requester->conn_status
<<" resp_status="<<m_rpc_requester->resp_status
<<" data:\n"<<m_rpc_requester->last_data);
if(!m_rpc_requester->conn_status.isSuccess())
throw RPCRequestException(pvd::Status::STATUSTYPE_ERROR, m_rpc_requester->conn_status.getMessage());
if(!m_rpc_requester->resp_status.isSuccess())
throw RPCRequestException(pvd::Status::STATUSTYPE_ERROR, m_rpc_requester->resp_status.getMessage());
// consume last_data so that we can't possibly return it twice
pvd::PVStructure::shared_pointer data;
data.swap(m_rpc_requester->last_data);
if(!data)
throw std::logic_error("No reply data?!?");
// copy it so that the caller need not worry about whether it will overwritten
// when the next request is issued
pvd::PVStructure::shared_pointer ret(pvd::getPVDataCreate()->createPVStructure(data->getStructure()));
ret->copyUnchecked(*data);
return ret;
}
RPCClient::shared_pointer RPCClient::create(const std::string & serviceName,
pvd::PVStructure::shared_pointer const & pvRequest)
{
return RPCClient::shared_pointer(new RPCClient(serviceName, pvRequest));
}
pvd::PVStructure::shared_pointer RPCClient::sendRequest(const std::string & serviceName,
pvd::PVStructure::shared_pointer const & queryRequest,
double timeOut)
{
RPCClient client(serviceName, queryRequest);
return client.request(queryRequest, timeOut);
}
}}// namespace epics::pvAccess