DeviceBackendImpl.cc

Go to the documentation of this file.

// SPDX-FileCopyrightText: Deutsches Elektronen-Synchrotron DESY, MSK, ChimeraTK Project <chimeratk-support@desy.de>
// SPDX-License-Identifier: LGPL-3.0-or-later
 
#include "DeviceBackendImpl.h"
 
#include <unistd.h>
 
namespace ChimeraTK {
 
  /********************************************************************************************************************/
 
  void DeviceBackendImpl::setOpenedAndClearException() noexcept {
    // busy-wait until all exceptions have been distributed to the AsyncAccessors
    while(_asyncDomainsContainer.isSendingExceptions()) {
      usleep(10000);
    }
 
    _opened = true;
    _hasActiveException = false;
    std::lock_guard<std::mutex> lk(_mx_activeExceptionMessage);
    _activeExceptionMessage = "(exception cleared)";
  }
 
  /********************************************************************************************************************/
 
  void DeviceBackendImpl::setException(const std::string& message) noexcept {
    // set exception flag and atomically get the previous state
    bool hadExceptionBefore = _hasActiveException.exchange(true);
 
    // if previously backend was already in exception state, don't continue here
    if(hadExceptionBefore) {
      return;
    }
 
    // set exception message
    {
      std::lock_guard<std::mutex> lk(_mx_activeExceptionMessage);
      _activeExceptionMessage = message;
    }
 
    // execute backend-specific code
    setExceptionImpl();
 
    // finally turn off all async accessors and distribute the exception to them
    _asyncDomainsContainer.sendExceptions(message);
  }
 
  /********************************************************************************************************************/
 
  std::string DeviceBackendImpl::getActiveExceptionMessage() noexcept {
    std::lock_guard<std::mutex> lk(_mx_activeExceptionMessage);
    return _activeExceptionMessage;
  }
 
  /********************************************************************************************************************/
 
} // namespace ChimeraTK