more work on EasyGet and conneection management; still work in progress

documentation/easyPVA.html

@@ -28,7 +28,7 @@
 <h1>EPICS easyPVA</h1>
 <!-- Maturity: Working Draft or Request for Comments, or Recommendation, and date.  -->
 <h2 class="nocount">EPICS V4 Working Group, Working Draft,
-19-Feb-2015</h2>
+02-Mar-2015</h2>
 <dl>
   <dt>This version:</dt>
     <dd><a
@@ -104,20 +104,20 @@ an interface to many of the features provided by pvData and pvAccess.</p>
   <li>Allows efficient client side programs.</li>
 </ol>
 
-<p>The following describes the CPP version of EasyPVA.</p>
-
-<p>This is the overview for EasyPVACPP. JavaDoc documentation is available at <a
+<p>This document briefly describes the CPP version of EasyPVA.
+Doxygen documentation is available at <a
 href="./html/index.html">doxygenDoc</a></p>
 
 
 <h3>Initialization</h3>
 
 <p>A client obtains the interface to EasyPVA via the call:</p>
-<pre>EasyPVA easy = EasyPVAFactory.get();</pre>
+<pre>EasyPVAPtr easyPVA = EasyPVAFactorys-&gt;create();</pre>
 
-<p>The client can make this call many times, but an instance of the EastPVA interface object is
-only created in the first call. This first call also
-starts the PVAccess client factory.</p>
+<p>The client can call this an arbitrary number of times.
+On the first call the PVAccess client factory is started.
+When the last EasyPVA is destroyed the PVAccess client factory is stopped.
+</p>
 
 <h3>EasyPVA Overview</h3>
 
@@ -139,13 +139,6 @@ starts the PVAccess client factory.</p>
     </dd>
 </dl>
 
-
-<p>There are additional methods that allows the client to:</p>
-<ol>
-  <li>Control how error messages are handled.</li>
-  <li>Control when get/put commands are sent the channel or channels.</li>
-</ol>
-
 <h3>EasyChannel Overview</h3>
 
 <p>This interface creates Easy support for each PVAccess::Channel create
@@ -208,15 +201,17 @@ The only requirement of the channels is that each must have a top level field na
      </dd>
 </dl>
 
-<h2>shell</h2>
-<p>Directory <b>shell</b> has the following files:</p>
-<dl>
-  <dt>exampleDatabaseEasyPVA.zip</dt>
-     <dd>
-       When unzipped this is used to create an example IOC database.
-      The database has the record used by the examples are tests that come with easyPVAJava.
-      It uses pvDatabaseCPP to build the database.
-      After unzipping the file:
+<h2>example source code</h2>
+<h3>Example Database</h3>
+<p>The examples require that an example pvAccess server is runnimg.
+This distribution has a file <b>exampleDatabaseEasyPVA.zip</b>.
+When unzipped this is used to create an example IOC database.
+The database has the record used by the examples are tests that come with easyPVAJava.
+It uses pvDatabaseCPP to build the database.
+</p>
+<p>
+After unzipping the file:
+</p>
 <pre>
 cd configure
 cp ExampleRELEASE.local RELEASE.local
@@ -226,68 +221,16 @@ make
 cd iocBoot/exampleDatabase
 ../../bin/&lt;arch:&gt;/exampleDatabase st.cmd
 </pre>
-     You now have a running database.
-     </dd>
-  <dt>source</dt>
-     <dd>
-      This file creates the <b>CLASSPATH</b> required
-      to run the examples and tests.
-     You have to edit it for your environment.
-     </dd>
-  <dt>rpcServiceExample</dt>
-     <dd>
-       This starts the RPCServiceExample.
-       This is required by ExampleEasyRPC.
-     </dd>
-  <dt>exampleGet</dt>
-     <dd>
-       This runs ExampleGet.
-     </dd>
-  <dt>exampleGetDouble</dt>
-     <dd>
-       This runs ExampleGetDouble
-     </dd>
-  <dt>doublePut</dt>
-     <dd>
-       This runs DoublePut.
-     </dd>
-  <dt>doubleArrayPut</dt>
-     <dd>
-       This runs DoubleArrayPut
-     </dd>
-  <dt>exampleMonitor</dt>
-     <dd>
-       This runs ExampleMonitor
-     </dd>
-  <dt>exampleMonitorCallback</dt>
-     <dd>
-       This runs ExampleMonitorCallback
-     </dd>
-  <dt>exampleMultiMonitor</dt>
-     <dd>
-       This runs ExampleMultiMonitor.
-       It and polls every few seconds for monitor events.
-      It gets data as NTMultiChannel.
-     </dd>
-  <dt>exampleMultiMonitorDouble</dt>
-     <dd>
-       This runs ExampleMultiMonitorDouble.
-       It has an event listener for new events.
-      It gets data as an array of doubles.
-     </dd>
-</dl>
 <h3>Examples</h3>
-<p>These are examples in package <b>org.epics.pvaccess.easyPVA.example</b>
+<p>These are examples in directory <b>example/src</b>.
+An example of how to run them is:</p>
+<pre>
+mrk&gt; pwd
+/home/hg/easyPVACPP/example
+mrk&gt; bin/linux-x86_64/exampleEasyGet 
+</pre>
+<p>
 See the source code for each example.
-In order to run the examples exampleDatabaseEasyPVA must be running.
-</p>
-<p>There is a shell command to run each example,</p>
-<h3>Tests</h3>
-<p>A test directory has a number of tests for easyPVAJava.
-In order to run the tests both exampleDatabaseEasyPVA and rpcServiceExample
-must be running.
-For now these tests are being run as eclipse unit tests.
-The tests also provide examples of using EasyPVA.
 </p>
 
 </div> <!-- class="contents" -->

example/src/exampleEasyGet.cpp

@@ -13,18 +13,17 @@
 #include <iostream>
 
 #include <pv/easyPVA.h>
-#include <pv/clientFactory.h>
 
 using namespace std;
 using namespace epics::pvData;
 using namespace epics::pvAccess;
 using namespace epics::easyPVA;
 
-int main(int argc,char *argv[])
-{
-    ClientFactory::start();
-    EasyPVAPtr easyPVA = EasyPVA::create();
+static EasyPVAPtr easyPVA;
 
+static void exampleDouble()
+{
+    cout << "example double scalar\n";
     double value;
     try {
         cout << "short way\n";
@@ -43,7 +42,52 @@ int main(int argc,char *argv[])
     } catch (std::runtime_error e) {
         cout << "exception " << e.what() << endl;
     }
+}
+
+static void exampleDoubleArray()
+{
+    cout << "example double array\n";
+    shared_vector<double> value;
+    try {
+        cout << "short way\n";
+        value =  easyPVA->createChannel("exampleDoubleArray")->createGet()->getDoubleArray();
+        cout << "as doubleArray " << value << endl;
+    } catch (std::runtime_error e) {
+        cout << "exception " << e.what() << endl;
+    }
+    try {
+        cout << "long way\n";
+        EasyChannelPtr easyChannel = easyPVA->createChannel("exampleDoubleArray");
+        easyChannel->connect(2.0);
+        EasyGetPtr easyGet = easyChannel->createGet();
+        value = easyGet->getDoubleArray();
+        cout << "as doubleArray " << value << endl;
+    } catch (std::runtime_error e) {
+        cout << "exception " << e.what() << endl;
+    }
+}
+
+static void examplePowerSupply()
+{
+    cout << "example powerSupply\n";
+    PVStructurePtr pvStructure;
+    try {
+        cout << "short way\n";
+        pvStructure =  easyPVA->createChannel("examplePowerSupply")->createGet("field()")->getPVStructure();
+        cout << pvStructure << endl;
+    } catch (std::runtime_error e) {
+        cout << "exception " << e.what() << endl;
+    }
+     
+}
+
+int main(int argc,char *argv[])
+{
+    easyPVA = EasyPVA::create();
+    exampleDouble();
+    exampleDoubleArray();
+    examplePowerSupply();
     cout << "done\n";
-    ClientFactory::stop();
+    easyPVA->destroy();
     return 0;
 }

src/easyChannel.cpp

@@ -143,19 +143,23 @@ EasyChannelImpl::~EasyChannelImpl()
 void EasyChannelImpl::channelCreated(const Status& status, Channel::shared_pointer const & channel)
 {
     if(isDestroyed) throw std::runtime_error("easyChannel was destroyed");
-    channelConnectStatus = status;
-    this->channel = channel;
+    if(status.isOK()) {
+        this->channel = channel;
+        return;
+    }
+    cout << "EasyChannelImpl::channelCreated status " << status.getMessage() << " why??\n";
 }
 
 void EasyChannelImpl::channelStateChange(
     Channel::shared_pointer const & channel,
     Channel::ConnectionState connectionState)
 {
-    if(isDestroyed) throw std::runtime_error("easyChannel was destroyed");
+    if(isDestroyed) return;
     bool waitingForConnect = false;
     if(connectState==connectActive) waitingForConnect = true;
     if(connectionState!=Channel::CONNECTED) {
-         string mess(channelName + " connection state " + Channel::ConnectionStateNames[connectionState]);
+         string mess(channelName +
+             " connection state " + Channel::ConnectionStateNames[connectionState]);
          message(mess,errorMessage);
          channelConnectStatus = Status(Status::STATUSTYPE_ERROR,mess);
          connectState = notConnected;
@@ -220,10 +224,14 @@ void EasyChannelImpl::issueConnect()
     }
     channelRequester = ChannelRequester::shared_pointer(new ChannelRequesterImpl(this));
 
+    channelConnectStatus = Status(Status::STATUSTYPE_ERROR,"createChannel failed");
     connectState = connectActive;
     ChannelProviderRegistry::shared_pointer reg = getChannelProviderRegistry();
     ChannelProvider::shared_pointer provider = reg->getProvider(providerName);
     channel = provider->createChannel(channelName,channelRequester,ChannelProvider::PRIORITY_DEFAULT);
+    if(!channel) {
+         throw std::runtime_error(channelConnectStatus.getMessage());
+    }
 }
 
 Status EasyChannelImpl::waitConnect(double timeout)
@@ -268,7 +276,7 @@ EasyProcessPtr EasyChannelImpl::createProcess(PVStructurePtr const &  pvRequest)
 
 EasyGetPtr EasyChannelImpl::createGet()
 {
-    return EasyChannelImpl::createGet("value,alarm.timeStamp");
+    return EasyChannelImpl::createGet("value,alarm,timeStamp");
 }
 
 EasyGetPtr EasyChannelImpl::createGet(string const & request)

src/easyGet.cpp

@@ -101,6 +101,7 @@ public:
         return shared_from_this();
     }
 private:
+    void checkGetState();
     enum GetConnectState {connectIdle,connectActive,connected};
 
     EasyPVAPtr easyPVA;
@@ -176,6 +177,12 @@ EasyGetImpl::~EasyGetImpl()
     destroy();
 }
 
+void EasyGetImpl::checkGetState()
+{
+    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    if(connectState==connectIdle) connect();
+    if(getState==getIdle) get();
+}
 
 // from ChannelGetRequester
 string EasyGetImpl::getRequesterName()
@@ -257,7 +264,6 @@ void EasyGetImpl::issueConnect()
         throw std::runtime_error(ss.str());
     }
     getRequester = ChannelGetRequester::shared_pointer(new ChannelGetRequesterImpl(this));
-
     connectState = connectActive;
     channelGet = channel->createChannelGet(getRequester,pvRequest);
 }
@@ -335,206 +341,206 @@ void EasyGetImpl::setPVStructure(epics::pvData::PVStructurePtr const & pvStructu
 
 Alarm EasyGetImpl::getAlarm()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getAlarm();
 }
 
 TimeStamp EasyGetImpl::getTimeStamp()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getTimeStamp();
 }
 
 bool EasyGetImpl::hasValue()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->hasValue();
 }
 
 bool EasyGetImpl::isValueScalar()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->isValueScalar();
 }
 
 bool EasyGetImpl::isValueScalarArray()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->isValueScalarArray();
 }
 
 PVFieldPtr EasyGetImpl::getValue()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getValue();
 }
 
 PVScalarPtr EasyGetImpl::getScalarValue()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getScalarValue();
 }
 
 std::tr1::shared_ptr<PVArray> EasyGetImpl::getArrayValue()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getArrayValue();
 }
 
 std::tr1::shared_ptr<PVScalarArray> EasyGetImpl::getScalarArrayValue()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getScalarArrayValue();
 }
 
 bool EasyGetImpl::getBoolean()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getBoolean();
 }
 
 int8 EasyGetImpl::getByte()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getByte();
 }
 
 int16 EasyGetImpl::getShort()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getShort();
 }
 
 int32 EasyGetImpl::getInt()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getInt();
 }
 
 int64 EasyGetImpl::getLong()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getLong();
 }
 
 uint8 EasyGetImpl::getUByte()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getUByte();
 }
 
 uint16 EasyGetImpl::getUShort()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getUShort();
 }
 
 uint32 EasyGetImpl::getUInt()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getUInt();
 }
 
 uint64 EasyGetImpl::getULong()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getULong();
 }
 
 float EasyGetImpl::getFloat()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getFloat();
 }
 
 double EasyGetImpl::getDouble()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
-    return easyPVStructure->isValueScalar();
+    checkGetState();
+    return easyPVStructure->getDouble();
 }
 
 std::string EasyGetImpl::getString()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getString();
 }
 
 
 shared_vector<boolean>  EasyGetImpl::getBooleanArray()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getBooleanArray();
 }
 
 shared_vector<int8>  EasyGetImpl::getByteArray()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getByteArray();
 }
 
 shared_vector<int16>  EasyGetImpl::getShortArray()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getShortArray();
 }
 
 shared_vector<int32>  EasyGetImpl::getIntArray()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getIntArray();
 }
 
 shared_vector<int64>  EasyGetImpl::getLongArray()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getLongArray();
 }
 
 shared_vector<uint8>  EasyGetImpl::getUByteArray()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getUByteArray();
 }
 
 shared_vector<uint16>  EasyGetImpl::getUShortArray()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getUShortArray();
 }
 
 shared_vector<uint32>  EasyGetImpl::getUIntArray()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getUIntArray();
 }
 
 shared_vector<uint64>  EasyGetImpl::getULongArray()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getULongArray();
 }
 
 shared_vector<float>  EasyGetImpl::getFloatArray()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getFloatArray();
 }
 
 shared_vector<double>  EasyGetImpl::getDoubleArray()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getDoubleArray();
 }
 
 shared_vector<std::string>  EasyGetImpl::getStringArray()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getStringArray();
 }
 
 PVStructurePtr EasyGetImpl::getPVStructure()
 {
-    if(isDestroyed) throw std::runtime_error("easyGet was destroyed");
+    checkGetState();
     return easyPVStructure->getPVStructure();
 }
 

src/easyPVA.cpp

@@ -11,6 +11,7 @@
  #define epicsExportSharedSymbols
 #include <pv/easyPVA.h>
 #include <pv/createRequest.h>
+#include <pv/clientFactory.h>
 
 using std::tr1::static_pointer_cast;
 using namespace epics::pvData;
@@ -24,9 +25,46 @@ static const string easyPVAName = "easyPVA";
 static const string defaultProvider = "pva";
 static UnionConstPtr variantUnion = fieldCreate->createVariantUnion();
 
+namespace easyPVAPvt {
+
+static size_t numberEasyPVA = 0;
+static bool firstTime = true;
+static Mutex mutex;
+
+class StartStopClientFactory {
+
+public:
+    static void EasyPVABeingConstructed()
+    {
+        bool saveFirst = false;
+        { 
+             Lock xx(mutex);
+             ++numberEasyPVA;
+             saveFirst = firstTime;
+             firstTime = false;
+        }
+        if(saveFirst) ClientFactory::start();
+    }
+
+    static void EasyPVABeingDestroyed() {
+        size_t numLeft = 0;
+        {
+             Lock xx(mutex);
+             --numberEasyPVA;
+              numLeft = numberEasyPVA;
+        }
+        if(numLeft<=0) ClientFactory::stop();
+    }
+};
+}
+
+using namespace epics::easyPVA::easyPVAPvt;
+
+
 EasyPVAPtr EasyPVA::create()
 {
     EasyPVAPtr xx(new EasyPVA());
+    StartStopClientFactory::EasyPVABeingConstructed();
     return xx;
 }
 
@@ -45,7 +83,9 @@ EasyPVA::EasyPVA()
 {
 }
 
-EasyPVA::~EasyPVA() {destroy();}
+EasyPVA::~EasyPVA() {
+    destroy();
+}
 
 void EasyPVA::destroy()
 {
@@ -61,8 +101,8 @@ void EasyPVA::destroy()
         channelList.erase(channelIter);
         (*channelIter)->destroy();
     }
-    std::list<EasyMultiChannelPtr>::iterator multiChannelIter;
 #ifdef NOTDONE
+    std::list<EasyMultiChannelPtr>::iterator multiChannelIter;
     while(true) {
         multiChannelIter = multiChannelList.begin();
         if(multiChannelIter==multiChannelList.end()) break;
@@ -70,7 +110,7 @@ void EasyPVA::destroy()
         (*multiChannelIter)->destroy();
     }
 #endif
-
+    StartStopClientFactory::EasyPVABeingDestroyed();
 }
 
 string EasyPVA:: getRequesterName()