TriggeredPollDistributor.h

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// SPDX-FileCopyrightText: Deutsches Elektronen-Synchrotron DESY, MSK, ChimeraTK Project <chimeratk-support@desy.de>
// SPDX-License-Identifier: LGPL-3.0-or-later
#pragma once
 
#include "../TransferGroup.h"
#include "AsyncAccessorManager.h"
#include "MuxedInterruptDistributor.h"
 
#include <memory>
 
namespace ChimeraTK::async {
  class TriggeredPollDistributor : public SourceTypedAsyncAccessorManager<std::nullptr_t> {
   public:
    TriggeredPollDistributor(boost::shared_ptr<DeviceBackend> backend,
        boost::shared_ptr<SubDomain<std::nullptr_t>> parent, boost::shared_ptr<Domain> asyncDomain);
 
    bool prepareIntermediateBuffers() override;
 
    template<typename UserType>
    std::unique_ptr<AsyncVariable> createAsyncVariable(AccessorInstanceDescriptor const& descriptor);
 
   protected:
    TransferGroup _transferGroup;
    boost::shared_ptr<SubDomain<std::nullptr_t>> _parent;
  };
 
  /********************************************************************************************************************/
 
  template<typename UserType>
  struct PolledAsyncVariable : public AsyncVariableImpl<UserType> {
    void fillSendBuffer() final;
 
    explicit PolledAsyncVariable(boost::shared_ptr<NDRegisterAccessor<UserType>> syncAccessor_, VersionNumber& v);
 
    boost::shared_ptr<NDRegisterAccessor<UserType>> syncAccessor;
    VersionNumber& _version;
 
    unsigned int getNumberOfChannels() override { return syncAccessor->getNumberOfChannels(); }
    unsigned int getNumberOfSamples() override { return syncAccessor->getNumberOfSamples(); }
    const std::string& getUnit() override { return syncAccessor->getUnit(); }
    const std::string& getDescription() override { return syncAccessor->getDescription(); }
  };
 
  /********************************************************************************************************************/
  // Implementations
  /********************************************************************************************************************/
 
  template<typename UserType>
  std::unique_ptr<AsyncVariable> TriggeredPollDistributor::createAsyncVariable(
      AccessorInstanceDescriptor const& descriptor) {
    auto synchronousFlags = descriptor.flags;
    synchronousFlags.remove(AccessMode::wait_for_new_data);
    // Don't call backend->getSyncRegisterAccessor() here. It might skip the overriding of a backend.
    auto syncAccessor = _backend->getRegisterAccessor<UserType>(
        descriptor.name, descriptor.numberOfWords, descriptor.wordOffsetInRegister, synchronousFlags);
    // read the initial value before adding it to the transfer group
    if(_asyncDomain->unsafeGetIsActive()) {
      try {
        syncAccessor->read();
      }
      catch(ChimeraTK::runtime_error&) {
        // Nothing to do here. The backend's setException() has already been called by the syncAccessor.
      }
    }
 
    _transferGroup.addAccessor(syncAccessor);
    return std::make_unique<PolledAsyncVariable<UserType>>(syncAccessor, _version);
  }
 
  /********************************************************************************************************************/
  template<typename UserType>
  void PolledAsyncVariable<UserType>::fillSendBuffer() {
    this->_sendBuffer.versionNumber = _version;
    this->_sendBuffer.dataValidity = syncAccessor->dataValidity();
    this->_sendBuffer.value.swap(syncAccessor->accessChannels());
  }
 
  /********************************************************************************************************************/
  template<typename UserType>
  PolledAsyncVariable<UserType>::PolledAsyncVariable(
      boost::shared_ptr<NDRegisterAccessor<UserType>> syncAccessor_, VersionNumber& v)
  : AsyncVariableImpl<UserType>(syncAccessor_->getNumberOfChannels(), syncAccessor_->getNumberOfSamples()),
    syncAccessor(syncAccessor_), _version(v) {}
 
} // namespace ChimeraTK::async