StreamMgr handle now via shared pointers. InDataHandler stores weak pointers. Reset callback in PyInDataHandler could be problematic. Refactored the UlDaq code and moved to a subfolder.

src/lasp/device/CMakeLists.txt

@@ -1,4 +1,5 @@
 # src/lasp/device/CMakeLists.txt
+include_directories(uldaq)
 
 add_library(lasp_device_lib OBJECT 
     lasp_daq.cpp
@@ -9,7 +10,9 @@ add_library(lasp_device_lib OBJECT
     lasp_streammgr.cpp
     lasp_indatahandler.cpp
     lasp_uldaq.cpp
-    lasp_uldaq_impl.cpp
+    uldaq/lasp_uldaq_impl.cpp
+    uldaq/lasp_uldaq_bufhandler.cpp
+    uldaq/lasp_uldaq_common.cpp
     )
 
 # Callback requires certain arguments that are not used by code. This disables

src/lasp/device/lasp_indatahandler.cpp

@@ -1,27 +1,34 @@
 /* #define DEBUGTRACE_ENABLED */
-#include <thread>
-#include "debugtrace.hpp"
 #include "lasp_indatahandler.h"
+#include "debugtrace.hpp"
 #include "lasp_streammgr.h"
+#include <thread>
 
-InDataHandler::InDataHandler(StreamMgr &mgr) : _mgr(mgr)
+InDataHandler::InDataHandler(SmgrHandle mgr)
-#if LASP_DEBUG==1
+    : _mgr(mgr)
- , _main_thread_id(std::this_thread::get_id())
+#if LASP_DEBUG == 1
+      ,
+      _main_thread_id(std::this_thread::get_id())
 #endif
-{ DEBUGTRACE_ENTER; }
+{
+  DEBUGTRACE_ENTER;
+}
 void InDataHandler::start() {
   DEBUGTRACE_ENTER;
-  _mgr.addInDataHandler(*this);
+  if (SmgrHandle handle = _mgr.lock()) {
-
+    handle->addInDataHandler(this);
 #if LASP_DEBUG == 1
-  assert(_mgr._main_thread_id == _main_thread_id);
+    assert(handle->_main_thread_id == _main_thread_id);
 #endif
+  }
 }
 void InDataHandler::stop() {
 #if LASP_DEBUG == 1
   stopCalled = true;
 #endif
-  _mgr.removeInDataHandler(*this);
+  if (SmgrHandle handle = _mgr.lock()) {
+    /* handle->removeInDataHandler(*this); */
+  }
 }
 
 InDataHandler::~InDataHandler() {
@@ -30,9 +37,9 @@ InDataHandler::~InDataHandler() {
 #if LASP_DEBUG == 1
   if (!stopCalled) {
     std::cerr << "************ BUG: Stop function not called while arriving at "
-            "InDataHandler's destructor. Fix this by calling "
+                 "InDataHandler's destructor. Fix this by calling "
-            "InDataHandler::stop() from the derived class' destructor."
+                 "InDataHandler::stop() from the derived class' destructor."
-         << std::endl;
+              << std::endl;
     abort();
   }
 #endif

src/lasp/device/lasp_indatahandler.h

@@ -1,18 +1,21 @@
 #pragma once
 #include <atomic>
+#include <memory>
 #include <thread>
 #include "lasp_types.h"
 
+class StreamMgr;
+using SmgrHandle = std::shared_ptr<StreamMgr>;
+
 /** \addtogroup device
  * @{
  */
-class StreamMgr;
 class DaqData;
 class Daq;
 class InDataHandler {
 
 protected:
-  StreamMgr &_mgr;
+  std::weak_ptr<StreamMgr> _mgr;
 #if LASP_DEBUG == 1
   // This is a flag to indicate whether the method stop() is called for the
   // current handler. It should call the method stop() from the derived class's
@@ -29,7 +32,7 @@ public:
    *
    * @param mgr Stream manager.
    */
-  InDataHandler(StreamMgr &mgr);
+  InDataHandler(SmgrHandle mgr);
 
   /**
    * @brief This function is called when input data from a DAQ is available.

src/lasp/device/lasp_streammgr.cpp

@@ -1,24 +1,35 @@
-/* #define DEBUGTRACE_ENABLED */
+#define DEBUGTRACE_ENABLED
-#include "debugtrace.hpp"
 #include "lasp_streammgr.h"
+#include "debugtrace.hpp"
 #include "lasp_biquadbank.h"
-#include "lasp_thread.h"
 #include "lasp_indatahandler.h"
+#include "lasp_thread.h"
 #include <algorithm>
 #include <assert.h>
 #include <functional>
 #include <iostream>
+#include <memory>
 
 using std::cerr;
 using std::endl;
 using rte = std::runtime_error;
 
+/**
+ * @brief The main global handle to a stream, stored in a shared pointer.
+ */
+std::shared_ptr<StreamMgr> _mgr;
 
-StreamMgr &StreamMgr::getInstance() {
+std::shared_ptr<StreamMgr> StreamMgr::getInstance() {
-
   DEBUGTRACE_ENTER;
-  static StreamMgr mgr;
+
-  return mgr;
+  if (!_mgr) {
+    _mgr = std::shared_ptr<StreamMgr>(new StreamMgr());
+    if (!_mgr) {
+      throw rte("Fatal: could not allocate stream manager!");
+    }
+  }
+
+  return _mgr;
 }
 
 StreamMgr::StreamMgr() {
@@ -211,13 +222,12 @@ bool StreamMgr::outCallback(DaqData &data) {
 StreamMgr::~StreamMgr() {
   DEBUGTRACE_ENTER;
   checkRightThread();
-  stopAllStreams();
+  // Stream manager now handled by shared pointer. Each indata handler gets a
-  if (!_inDataHandlers.empty()) {
+  // shared pointer to the stream manager, and stores a weak pointer to it.
-    cerr << "*** WARNING: InDataHandlers have not been all stopped, while "
+  // Hence, we do not have to do any cleanup here. It also makes sure that the
-            "StreamMgr destructor is called. This is a misuse BUG"
+  // order in which destructors are called does not matter anymore. As soon as
-         << endl;
+  // the stream manager is destructed, the weak pointers loose there ref, and do
-    abort();
+  // not have to removeInDataHandler() anymore.
-  }
 }
 void StreamMgr::stopAllStreams() {
   DEBUGTRACE_ENTER;
@@ -242,15 +252,15 @@ void StreamMgr::startStream(const DaqConfiguration &config) {
   std::scoped_lock lck(_devices_mtx);
 
   DeviceInfo *devinfo = nullptr;
-  bool found = false;
 
+  // Match configuration to a device in the list of devices
   for (auto &devinfoi : _devices) {
     if (config.match(*devinfoi)) {
       devinfo = devinfoi.get();
       break;
     }
   }
-  if (!devinfo) {
+  if (devinfo == nullptr) {
     throw rte("Could not find a device with name " + config.device_name +
               " in list of devices.");
   }
@@ -383,23 +393,20 @@ void StreamMgr::stopStream(const StreamType t) {
   }
 }
 
-void StreamMgr::addInDataHandler(InDataHandler &handler) {
+void StreamMgr::addInDataHandler(InDataHandler *handler) {
   DEBUGTRACE_ENTER;
   checkRightThread();
+  assert(handler);
   std::scoped_lock<std::mutex> lck(_inDataHandler_mtx);
-  if (_inputStream) {
+  handler->reset(_inputStream.get());
-    handler.reset(_inputStream.get());
+
-  } else {
+  if (std::find(_inDataHandlers.cbegin(), _inDataHandlers.cend(), handler) !=
-    handler.reset(nullptr);
-  }
-  if (std::find(_inDataHandlers.cbegin(), _inDataHandlers.cend(), &handler) !=
       _inDataHandlers.cend()) {
     throw std::runtime_error("Error: handler already added. Probably start() "
                              "is called more than once on a handler object");
   }
-  _inDataHandlers.push_back(&handler);
+  _inDataHandlers.push_back(handler);
   DEBUGTRACE_PRINT(_inDataHandlers.size());
-
 }
 
 void StreamMgr::removeInDataHandler(InDataHandler &handler) {
@@ -409,7 +416,6 @@ void StreamMgr::removeInDataHandler(InDataHandler &handler) {
   _inDataHandlers.remove(&handler);
 
   DEBUGTRACE_PRINT(_inDataHandlers.size());
-
 }
 
 Daq::StreamStatus StreamMgr::getStreamStatus(const StreamType type) const {

src/lasp/device/lasp_streammgr.h

@@ -57,15 +57,18 @@ class StreamMgr {
    */
   DeviceInfoList _devices;
 
+  // Singleton, no public constructor. Can only be obtained using
+  // getInstance();
   StreamMgr();
 
   friend class InDataHandler;
   friend class Siggen;
 
-  // Singleton, no public destructor
-  ~StreamMgr();
 
   public:
+
+  ~StreamMgr();
+
   enum class StreamType : us {
     /**
      * @brief Input stream
@@ -85,7 +88,7 @@ class StreamMgr {
    *
    * @return Reference to stream manager.
    */
-  static StreamMgr &getInstance();
+  static std::shared_ptr<StreamMgr> getInstance();
 
   /**
    * @brief Obtain a list of devices currently available. When the StreamMgr is
@@ -200,7 +203,7 @@ private:
    *
    * @param handler The handler to add.
    */
-  void addInDataHandler(InDataHandler &handler);
+  void addInDataHandler(InDataHandler *handler);
 
   /**
    * @brief Do the actual rescanning.

src/lasp/device/lasp_uldaq.cpp

@@ -1,6 +1,7 @@
 /* #define DEBUGTRACE_ENABLED */
 #include "debugtrace.hpp"
 #include "lasp_config.h"
+
 #if LASP_HAS_ULDAQ == 1
 #include "lasp_uldaq.h"
 #include "lasp_uldaq_impl.h"
@@ -17,13 +18,13 @@ void fillUlDaqDeviceInfo(DeviceInfoList &devinfolist) {
   DaqDeviceDescriptor descriptor;
   DaqDeviceInterface interfaceType = ANY_IFC;
 
-  err = ulGetDaqDeviceInventory(interfaceType, devdescriptors,
+  err = ulGetDaqDeviceInventory(interfaceType, devdescriptors, &numdevs);
-                                static_cast<unsigned *>(&numdevs));
 
   if (err != ERR_NO_ERROR) {
     throw rte("UlDaq device inventarization failed");
   }
 
+  DEBUGTRACE_PRINT(string("Number of devices: ") + std::to_string(numdevs));
   for (unsigned i = 0; i < numdevs; i++) {
 
     descriptor = devdescriptors[i];
@@ -33,7 +34,7 @@ void fillUlDaqDeviceInfo(DeviceInfoList &devinfolist) {
 
     devinfo.api = uldaqapi;
     {
-      string name, interface;
+      string name;
       string productname = descriptor.productName;
       if (productname != "DT9837A") {
         throw rte("Unknown UlDAQ type: " + productname);
@@ -56,9 +57,8 @@ void fillUlDaqDeviceInfo(DeviceInfoList &devinfolist) {
         name = "Uknown interface = ";
       }
 
-      name +=
+      name += productname + " " + string(descriptor.uniqueId);
-          string(descriptor.productName) + " " + string(descriptor.uniqueId);
+      devinfo.device_name = name;
-      devinfo.device_name = std::move(name);
     }
 
     devinfo.physicalOutputQty = DaqChannel::Qty::Voltage;
@@ -93,7 +93,12 @@ void fillUlDaqDeviceInfo(DeviceInfoList &devinfolist) {
 
 std::unique_ptr<Daq> createUlDaqDevice(const DeviceInfo &devinfo,
                                        const DaqConfiguration &config) {
-  return std::make_unique<DT9837A>(devinfo, config);
+  const UlDaqDeviceInfo *_info =
+      dynamic_cast<const UlDaqDeviceInfo *>(&devinfo);
+  if (_info == nullptr) {
+    throw rte("BUG: Could not cast DeviceInfo to UlDaqDeviceInfo");
+  }
+  return std::make_unique<DT9837A>(*_info, config);
 }
 
 #endif // LASP_HAS_ULDAQ

src/lasp/device/lasp_uldaq_impl.h

@@ -1,164 +0,0 @@
-#pragma once
-#include "debugtrace.hpp"
-#include "lasp_daq.h"
-#include <algorithm>
-#include <cassert>
-#include <chrono>
-#include <iostream>
-#include <stdexcept>
-#include <thread>
-#include <uldaq.h>
-#include <vector>
-
-using std::atomic;
-using std::cerr;
-using std::endl;
-using rte = std::runtime_error;
-
-/**
- * @brief List of available sampling frequencies for DT9837A
- */
-const std::vector<d> ULDAQ_SAMPLERATES = {8000,  10000, 11025, 16000, 20000,
-                                    22050, 24000, 32000, 44056, 44100,
-                                    47250, 48000, 50000, 50400, 51000};
-
-
-/**
- * @brief UlDaq-specific device information. Adds a copy of the underlying
- * DaqDeDaqDeviceDescriptor.
- */
-class UlDaqDeviceInfo : public DeviceInfo {
-
-public:
-  DaqDeviceDescriptor _uldaqDescriptor;
-  virtual std::unique_ptr<DeviceInfo> clone() const override {
-    DEBUGTRACE_ENTER;
-    return std::make_unique<UlDaqDeviceInfo>(*this);
-  }
-};
-
-class DT9837A : public Daq {
-
-  DaqDeviceHandle _handle = 0;
-  std::mutex _daqmutex;
-
-  std::thread _thread;
-  atomic<bool> _stopThread{false};
-  atomic<StreamStatus> _streamStatus;
-
-  const us _nFramesPerBlock;
-
-  void threadFcn(InDaqCallback inCallback, OutDaqCallback outcallback);
-
-public:
-  DaqDeviceHandle getHandle() const { return _handle; }
-  /**
-   * @brief Create a DT9837A instance.
-   *
-   * @param devinfo DeviceInfo to connect to
-   * @param config DaqConfiguration settings
-   */
-  DT9837A(const DeviceInfo &devinfo, const DaqConfiguration &config);
-
-  virtual ~DT9837A();
-
-  bool isRunning() const;
-
-  void stop() override final;
-
-  friend class InBufHandler;
-  friend class OutBufHandler;
-
-  virtual void start(InDaqCallback inCallback,
-                     OutDaqCallback outCallback) override final;
-
-  virtual StreamStatus getStreamStatus() const override {
-    return _streamStatus;
-  }
-};
-
-/**
- * @brief Helper class for managing input and output samples of the DAQ device.
- */
-class BufHandler {
-protected:
-  /**
-   * @brief Reference to underlying Daq
-   */
-  DT9837A &daq;
-  /**
-   * @brief The type of data, in this case always double precision floats
-   */
-  const DataTypeDescriptor dtype_descr = dtype_desc_fl64;
-  /**
-   * @brief The number of channels, number of frames per callback (block).
-   */
-  us nchannels, nFramesPerBlock;
-  /**
-   * @brief Sampling frequency in Hz
-   */
-  double samplerate;
-  std::vector<double> buf;
-  /**
-   * @brief Whether the top / bottom part of the buffer are ready to be
-   * enqueued
-   */
-  bool topenqueued, botenqueued;
-
-  /**
-   * @brief Counter for the total number of frames acquired / sent since the
-   * start of the stream.
-   */
-  us totalFramesCount = 0;
-  long long buffer_mid_idx;
-
-public:
-  /**
-   * @brief Initialize bufhandler
-   *
-   * @param daq
-   * @param nchannels
-   */
-  BufHandler(DT9837A &daq, const us nchannels)
-      : daq(daq), dtype_descr(daq.dtypeDescr()), nchannels(nchannels),
-        nFramesPerBlock(daq.framesPerBlock()), samplerate(daq.samplerate()),
-        buf(2 * nchannels *
-                nFramesPerBlock, // Watch the two here, the top and the bottom!
-            0),
-        buffer_mid_idx(nchannels * nFramesPerBlock) {
-    assert(nchannels > 0);
-  }
-};
-/**
- * @brief Specific helper for the input buffer
- */
-class InBufHandler : public BufHandler {
-  bool monitorOutput;
-  InDaqCallback cb;
-
-public:
-  InBufHandler(DT9837A &daq, InDaqCallback cb);
-  void start();
-  /**
-   * @brief InBufHandler::operator()()
-   *
-   * @return true on success
-   */
-  bool operator()();
-  ~InBufHandler();
-};
-class OutBufHandler : public BufHandler {
-  OutDaqCallback cb;
-
-public:
-  OutBufHandler(DT9837A &daq, OutDaqCallback cb);
-  void start();
-  /**
-   * @brief OutBufHandler::operator()
-   *
-   * @return true on success
-   */
-  bool operator()();
-
-  ~OutBufHandler();
-};

src/lasp/device/uldaq/lasp_uldaq_bufhandler.cpp

@@ -3,192 +3,8 @@
 #include "lasp_config.h"
 
 #if LASP_HAS_ULDAQ == 1
-#include "lasp_daqconfig.h"
+#include "lasp_uldaq_bufhandler.h"
-#include "lasp_uldaq.h"
+#include "lasp_daq.h"
-#include "lasp_uldaq_impl.h"
-
-using namespace std::literals::chrono_literals;
-
-/**
- * @brief Reserve some space for an error message from UlDaq
- */
-const us UL_ERR_MSG_LEN = 512;
-
-/**
- * @brief Return a string corresponding to the UlDaq API error
- *
- * @param err error code
- *
- * @return Error string
- */
-string getErrMsg(UlError err) {
-  string errstr;
-  errstr.reserve(UL_ERR_MSG_LEN);
-  char errmsg[UL_ERR_MSG_LEN];
-  errstr = "UlDaq API Error: ";
-  ulGetErrMsg(err, errmsg);
-  errstr += errmsg;
-  return errstr;
-}
-inline void showErr(string errstr) {
-  std::cerr << "\b\n**************** UlDAQ backend error **********\n";
-  std::cerr << errstr << std::endl;
-  std::cerr << "***********************************************\n\n";
-}
-inline void showErr(UlError err) {
-  if (err != ERR_NO_ERROR)
-    showErr(getErrMsg(err));
-}
-
-DT9837A::~DT9837A() {
-  UlError err;
-  if (isRunning()) {
-    stop();
-  }
-
-  if (_handle) {
-    err = ulDisconnectDaqDevice(_handle);
-    showErr(err);
-    err = ulReleaseDaqDevice(_handle);
-    showErr(err);
-  }
-}
-DT9837A::DT9837A(const DeviceInfo &devinfo, const DaqConfiguration &config)
-    : Daq(devinfo, config),
-      _nFramesPerBlock(availableFramesPerBlock.at(framesPerBlockIndex)) {
-
-  // Some sanity checks
-  if (inchannel_config.size() != 4) {
-    throw rte("Invalid length of enabled inChannels vector");
-  }
-
-  if (outchannel_config.size() != 1) {
-    throw rte("Invalid length of enabled outChannels vector");
-  }
-
-  if (_nFramesPerBlock < 24 || _nFramesPerBlock > 8192) {
-    throw rte("Unsensible number of samples per block chosen");
-  }
-
-  if (samplerate() < ULDAQ_SAMPLERATES.at(0) ||
-      samplerate() > ULDAQ_SAMPLERATES.at(ULDAQ_SAMPLERATES.size() - 1)) {
-    throw rte("Invalid sample rate");
-  }
-
-  const UlDaqDeviceInfo *_info =
-      dynamic_cast<const UlDaqDeviceInfo *>(&devinfo);
-  if (_info == nullptr) {
-    throw rte("BUG: Could not cast DeviceInfo to UlDaqDeviceInfo");
-  }
-
-  // get a handle to the DAQ device associated with the first descriptor
-  _handle = ulCreateDaqDevice(_info->_uldaqDescriptor);
-
-  if (_handle == 0) {
-    throw rte("Unable to create a handle to the specified DAQ "
-              "device. Is the device currently in use? Please make sure to set "
-              "the DAQ configuration in duplex mode if simultaneous input and "
-              "output is required.");
-  }
-
-  UlError err = ulConnectDaqDevice(_handle);
-
-  if (err != ERR_NO_ERROR) {
-    ulReleaseDaqDevice(_handle);
-    _handle = 0;
-    throw rte("Unable to connect to device: " + getErrMsg(err));
-  }
-
-  /// Loop over input channels, set parameters
-  for (us ch = 0; ch < 4; ch++) {
-
-    err = ulAISetConfigDbl(_handle, AI_CFG_CHAN_SENSOR_SENSITIVITY, ch, 1.0);
-    showErr(err);
-    if (err != ERR_NO_ERROR) {
-      throw rte("Fatal: could normalize channel sensitivity");
-    }
-
-    CouplingMode cm = inchannel_config.at(ch).ACCouplingMode ? CM_AC : CM_DC;
-    err = ulAISetConfig(_handle, AI_CFG_CHAN_COUPLING_MODE, ch, cm);
-    if (err != ERR_NO_ERROR) {
-      showErr(err);
-      throw rte("Fatal: could not set AC/DC coupling mode");
-    }
-
-    IepeMode iepe =
-        inchannel_config.at(ch).IEPEEnabled ? IEPE_ENABLED : IEPE_DISABLED;
-    err = ulAISetConfig(_handle, AI_CFG_CHAN_IEPE_MODE, ch, iepe);
-    if (err != ERR_NO_ERROR) {
-      showErr(err);
-      throw rte("Fatal: could not set IEPE mode");
-    }
-  }
-}
-
-bool DT9837A::isRunning() const {
-  DEBUGTRACE_ENTER;
-  return _thread.joinable();
-}
-void DT9837A::stop() {
-  DEBUGTRACE_ENTER;
-  StreamStatus status = _streamStatus;
-  if (!isRunning()) {
-    throw rte("No data acquisition running");
-  }
-
-  // Stop the thread and join it
-  _stopThread = true;
-  assert(_thread.joinable());
-  _thread.join();
-  _stopThread = false;
-
-  // Update stream status
-  status.isRunning = false;
-  _streamStatus = status;
-}
-
-/**
- * @brief Throws an appropriate stream exception based on the UlError number.
- * The mapping is based on the error numbers as given in uldaq.h. There are a
- * log of errors definded here (109 in total). Except for some, we will map
- * most of them to a driver error.
- *
- * @param e The backend error code.
- */
-inline void throwOnPossibleUlException(UlError err) {
-  if (err == ERR_NO_ERROR) {
-    return;
-  }
-  string errstr = getErrMsg(err);
-  showErr(errstr);
-  Daq::StreamStatus::StreamError serr;
-  if ((int)err == 18) {
-    serr = Daq::StreamStatus::StreamError::inputXRun;
-  } else if ((int)err == 19) {
-    serr = Daq::StreamStatus::StreamError::outputXRun;
-  } else {
-    serr = Daq::StreamStatus::StreamError::driverError;
-  }
-
-  throw Daq::StreamException(serr, errstr);
-}
-
-void DT9837A::start(InDaqCallback inCallback, OutDaqCallback outCallback) {
-  DEBUGTRACE_ENTER;
-  if (isRunning()) {
-    throw rte("DAQ is already running");
-  }
-  if (neninchannels() > 0) {
-    if (!inCallback)
-      throw rte("DAQ requires a callback for input data");
-  }
-  if (nenoutchannels() > 0) {
-    if (!outCallback)
-      throw rte("DAQ requires a callback for output data");
-  }
-  assert(neninchannels() + nenoutchannels() > 0);
-  _thread = std::thread(&DT9837A::threadFcn, this, inCallback, outCallback);
-}
 
 InBufHandler::InBufHandler(DT9837A &daq, InDaqCallback cb)
     : BufHandler(daq, daq.neninchannels()), cb(cb)
@@ -371,7 +187,7 @@ void OutBufHandler::start() {
 }
 bool OutBufHandler::operator()() {
 
-  /* DEBUGTRACE_ENTER; */
+  DEBUGTRACE_ENTER;
   bool res = true;
   assert(daq.getHandle() != 0);
 
@@ -389,7 +205,8 @@ bool OutBufHandler::operator()() {
   totalFramesCount += increment;
 
   if (increment > nFramesPerBlock) {
-    throw Daq::StreamException(Daq::StreamStatus::StreamError::outputXRun);
+    cerr << "totalFramesCount: " << totalFramesCount << ". Detected output underrun" << endl;
+    /* throw Daq::StreamException(Daq::StreamStatus::StreamError::outputXRun); */
   }
 
   if (transferStatus.currentIndex < buffer_mid_idx) {
@@ -425,70 +242,4 @@ OutBufHandler::~OutBufHandler() {
     showErr(err);
   }
 }
-
+#endif
-void DT9837A::threadFcn(InDaqCallback inCallback, OutDaqCallback outCallback) {
-
-  DEBUGTRACE_ENTER;
-
-  try {
-
-    std::unique_ptr<OutBufHandler> obh;
-    std::unique_ptr<InBufHandler> ibh;
-
-    StreamStatus status = _streamStatus;
-    status.isRunning = true;
-    _streamStatus = status;
-
-    if (nenoutchannels() > 0) {
-      assert(outCallback);
-      obh = std::make_unique<OutBufHandler>(*this, outCallback);
-    }
-    if (neninchannels() > 0) {
-      assert(inCallback);
-      ibh = std::make_unique<InBufHandler>(*this, inCallback);
-    }
-    if (obh)
-      obh->start();
-    if (ibh)
-      ibh->start();
-
-    const double sleeptime_s =
-        static_cast<double>(_nFramesPerBlock) / (16 * samplerate());
-    const us sleeptime_us = static_cast<us>(sleeptime_s * 1e6);
-
-    while (!_stopThread) {
-      if (ibh) {
-        if (!(*ibh)()) {
-          _stopThread = true;
-          break;
-        }
-      }
-      if (obh) {
-        if (!(*obh)()) {
-          _stopThread = true;
-          break;
-        }
-      }
-
-      std::this_thread::sleep_for(std::chrono::microseconds(sleeptime_us));
-    }
-
-    /// Update stream status that we are not running anymore
-    status.isRunning = false;
-    _streamStatus = status;
-    _stopThread = false;
-
-  } catch (StreamException &e) {
-
-    StreamStatus status = _streamStatus;
-    // Copy over error type
-    status.errorType = e.e;
-    _streamStatus = status;
-
-    cerr << "\n******************\n";
-    cerr << "Catched error in UlDAQ thread: " << e.what() << endl;
-    cerr << "\n******************\n";
-  }
-}
-
-#endif // LASP_HAS_ULDAQ

src/lasp/device/uldaq/lasp_uldaq_bufhandler.h

@@ -0,0 +1,99 @@
+#pragma once
+#include <uldaq.h>
+#include "lasp_types.h"
+#include "lasp_uldaq_impl.h"
+#include "lasp_uldaq_common.h"
+
+
+class DT9837A;
+
+/**
+ * @brief Helper class for managing input and output samples of the DAQ device.
+ */
+class BufHandler {
+protected:
+  /**
+   * @brief Reference to underlying Daq
+   */
+  DT9837A &daq;
+  /**
+   * @brief The type of data, in this case always double precision floats
+   */
+  const DataTypeDescriptor dtype_descr = dtype_desc_fl64;
+  /**
+   * @brief The number of channels, number of frames per callback (block).
+   */
+  us nchannels, nFramesPerBlock;
+  /**
+   * @brief Sampling frequency in Hz
+   */
+  double samplerate;
+  std::vector<double> buf;
+  /**
+   * @brief Whether the top part of the buffer is enqueued
+   */
+  bool topenqueued = false;
+  /**
+   * @brief Whether the bottom part of the buffer is enqueued
+   * enqueued
+   */
+  bool botenqueued = false;
+
+  /**
+   * @brief Counter for the total number of frames acquired / sent since the
+   * start of the stream.
+   */
+  us totalFramesCount = 0;
+  long long buffer_mid_idx;
+
+public:
+  /**
+   * @brief Initialize bufhandler
+   *
+   * @param daq
+   * @param nchannels
+   */
+  BufHandler(DT9837A &daq, const us nchannels)
+      : daq(daq), dtype_descr(daq.dtypeDescr()), nchannels(nchannels),
+        nFramesPerBlock(daq.framesPerBlock()), samplerate(daq.samplerate()),
+        buf(2 * nchannels *
+                nFramesPerBlock, // Watch the two here, the top and the bottom!
+            0),
+        buffer_mid_idx(nchannels * nFramesPerBlock) {
+    assert(nchannels > 0);
+    assert(nFramesPerBlock > 0);
+  }
+};
+/**
+ * @brief Specific helper for the input buffer
+ */
+class InBufHandler : public BufHandler {
+  bool monitorOutput;
+  InDaqCallback cb;
+
+public:
+  InBufHandler(DT9837A &daq, InDaqCallback cb);
+  void start();
+  /**
+   * @brief InBufHandler::operator()()
+   *
+   * @return true on success
+   */
+  bool operator()();
+  ~InBufHandler();
+};
+class OutBufHandler : public BufHandler {
+  OutDaqCallback cb;
+
+public:
+  OutBufHandler(DT9837A &daq, OutDaqCallback cb);
+  void start();
+  /**
+   * @brief OutBufHandler::operator()
+   *
+   * @return true on success
+   */
+  bool operator()();
+
+  ~OutBufHandler();
+};

src/lasp/device/uldaq/lasp_uldaq_common.cpp

@@ -0,0 +1,45 @@
+/* #define DEBUGTRACE_ENABLED */
+#include "debugtrace.hpp"
+#include "lasp_config.h"
+
+#if LASP_HAS_ULDAQ == 1
+#include "lasp_uldaq_common.h"
+#include "lasp_daq.h"
+
+string getErrMsg(UlError err) {
+  string errstr;
+  errstr.reserve(ERR_MSG_LEN);
+  char errmsg[ERR_MSG_LEN];
+  errstr = "UlDaq API Error: ";
+  ulGetErrMsg(err, errmsg);
+  errstr += errmsg;
+  return errstr;
+}
+void showErr(string errstr) {
+  std::cerr << "\b\n**************** UlDAQ backend error **********\n";
+  std::cerr << errstr << std::endl;
+  std::cerr << "***********************************************\n\n";
+}
+void showErr(UlError err) {
+  if (err != ERR_NO_ERROR)
+    showErr(getErrMsg(err));
+}
+#endif
+
+void throwOnPossibleUlException(UlError err) {
+  if (err == ERR_NO_ERROR) {
+    return;
+  }
+  string errstr = getErrMsg(err);
+  showErr(errstr);
+  Daq::StreamStatus::StreamError serr;
+  if ((int)err == 18) {
+    serr = Daq::StreamStatus::StreamError::inputXRun;
+  } else if ((int)err == 19) {
+    serr = Daq::StreamStatus::StreamError::outputXRun;
+  } else {
+    serr = Daq::StreamStatus::StreamError::driverError;
+  }
+
+  throw Daq::StreamException(serr, errstr);
+}

src/lasp/device/uldaq/lasp_uldaq_common.h

@@ -0,0 +1,60 @@
+#pragma once
+#include <uldaq.h>
+#include <string>
+#include "lasp_deviceinfo.h"
+
+/**
+ * @brief Throws an appropriate stream exception based on the UlError number.
+ * The mapping is based on the error numbers as given in uldaq.h. There are a
+ * log of errors definded here (109 in total). Except for some, we will map
+ * most of them to a driver error.
+ *
+ * @param e The backend error code.
+ */
+void throwOnPossibleUlException(UlError err);
+
+/**
+ * @brief Return a string corresponding to the UlDaq API error
+ *
+ * @param err error code
+ *
+ * @return Error string
+ */
+string getErrMsg(UlError err);
+
+/**
+ * @brief Print error message to stderr
+ *
+ * @param errstr The string to print
+ */
+void showErr(UlError err);
+
+/**
+ * @brief Get a string representation of the error
+ *
+ * @param errstr
+ */
+void showErr(std::string errstr);
+
+/**
+ * @brief UlDaq-specific device information. Adds a copy of the underlying
+ * DaqDeDaqDeviceDescriptor.
+ */
+class UlDaqDeviceInfo : public DeviceInfo {
+
+public:
+  DaqDeviceDescriptor _uldaqDescriptor;
+  virtual std::unique_ptr<DeviceInfo> clone() const override {
+    DEBUGTRACE_ENTER;
+    return std::make_unique<UlDaqDeviceInfo>(*this);
+  }
+};
+
+/**
+ * @brief List of available sampling frequencies for DT9837A
+ */
+const std::vector<d> ULDAQ_SAMPLERATES = {8000,  10000, 11025, 16000, 20000,
+                                    22050, 24000, 32000, 44056, 44100,
+                                    47250, 48000, 50000, 50400, 51000};
+
+

src/lasp/device/uldaq/lasp_uldaq_impl.cpp

@@ -0,0 +1,212 @@
+/* #define DEBUGTRACE_ENABLED */
+#include "debugtrace.hpp"
+#include "lasp_config.h"
+
+#if LASP_HAS_ULDAQ == 1
+#include "lasp_daqconfig.h"
+#include "lasp_uldaq.h"
+#include "lasp_uldaq_bufhandler.h"
+#include "lasp_uldaq_impl.h"
+
+using namespace std::literals::chrono_literals;
+
+DT9837A::~DT9837A() {
+  DEBUGTRACE_ENTER;
+  UlError err;
+  if (isRunning()) {
+    DEBUGTRACE_PRINT("Stop UlDAQ from destructor");
+    stop();
+  }
+
+  if (_handle) {
+    DEBUGTRACE_PRINT("Disconnecting and releasing DaqDevice");
+    /* err = ulDisconnectDaqDevice(_handle); */
+    /* showErr(err); */
+    err = ulReleaseDaqDevice(_handle);
+    showErr(err);
+  }
+}
+DT9837A::DT9837A(const UlDaqDeviceInfo &devinfo, const DaqConfiguration &config)
+    : Daq(devinfo, config),
+      _nFramesPerBlock(availableFramesPerBlock.at(framesPerBlockIndex)) {
+
+  const DaqDeviceDescriptor &descriptor = devinfo._uldaqDescriptor;
+  DEBUGTRACE_PRINT(string("Device:     ") + descriptor.productName);
+  DEBUGTRACE_PRINT(string("Product id: ") + to_string(descriptor.productId));
+  DEBUGTRACE_PRINT(string("Dev string: ") + descriptor.devString);
+  DEBUGTRACE_PRINT(string("Unique id:  ") + descriptor.uniqueId);
+
+  // get a handle to the DAQ device associated with the first descriptor
+  _handle = ulCreateDaqDevice(descriptor);
+
+  if (_handle == 0) {
+    throw rte("Unable to create a handle to the specified DAQ "
+              "device. Is the device currently in use? Please make sure to set "
+              "the DAQ configuration in duplex mode if simultaneous input and "
+              "output is required.");
+  }
+
+  UlError err = ulConnectDaqDevice(_handle);
+
+  if (err != ERR_NO_ERROR) {
+    ulReleaseDaqDevice(_handle);
+    _handle = 0;
+    throw rte("Unable to connect to device: " + getErrMsg(err));
+  }
+
+  /// Loop over input channels, set parameters
+  for (us ch = 0; ch < 4; ch++) {
+
+    err = ulAISetConfigDbl(_handle, AI_CFG_CHAN_SENSOR_SENSITIVITY, ch, 1.0);
+    showErr(err);
+    if (err != ERR_NO_ERROR) {
+      throw rte("Fatal: could normalize channel sensitivity");
+    }
+
+    CouplingMode cm = inchannel_config.at(ch).ACCouplingMode ? CM_AC : CM_DC;
+    err = ulAISetConfig(_handle, AI_CFG_CHAN_COUPLING_MODE, ch, cm);
+    if (err != ERR_NO_ERROR) {
+      showErr(err);
+      throw rte("Fatal: could not set AC/DC coupling mode");
+    }
+
+    IepeMode iepe =
+        inchannel_config.at(ch).IEPEEnabled ? IEPE_ENABLED : IEPE_DISABLED;
+    err = ulAISetConfig(_handle, AI_CFG_CHAN_IEPE_MODE, ch, iepe);
+    if (err != ERR_NO_ERROR) {
+      showErr(err);
+      throw rte("Fatal: could not set IEPE mode");
+    }
+  }
+}
+
+bool DT9837A::isRunning() const {
+  DEBUGTRACE_ENTER;
+  /* return _thread.joinable(); */
+  StreamStatus status = _streamStatus;
+  return status.isRunning;
+}
+void DT9837A::stop() {
+  DEBUGTRACE_ENTER;
+  StreamStatus status = _streamStatus;
+  status.isRunning = true;
+  _streamStatus = status;
+  /* if (!isRunning()) { */
+  /*   throw rte("No data acquisition running"); */
+  /* } */
+
+  // Stop the thread and join it
+  /* _stopThread = true; */
+  /* assert(_thread.joinable()); */
+  /* _thread.join(); */
+  /* _stopThread = false; */
+
+  // Update stream status
+  status.isRunning = false;
+  _streamStatus = status;
+}
+
+void DT9837A::start(InDaqCallback inCallback, OutDaqCallback outCallback) {
+  DEBUGTRACE_ENTER;
+  if (isRunning()) {
+    throw rte("DAQ is already running");
+  }
+  if (neninchannels() > 0) {
+    if (!inCallback)
+      throw rte("DAQ requires a callback for input data");
+  }
+  if (nenoutchannels() > 0) {
+    if (!outCallback)
+      throw rte("DAQ requires a callback for output data");
+  }
+  assert(neninchannels() + nenoutchannels() > 0);
+  /* _thread = std::thread(&DT9837A::threadFcn, this, inCallback, outCallback);
+   */
+}
+
+void DT9837A::threadFcn(InDaqCallback inCallback, OutDaqCallback outCallback) {
+
+  DEBUGTRACE_ENTER;
+
+  try {
+
+    std::unique_ptr<OutBufHandler> obh;
+    std::unique_ptr<InBufHandler> ibh;
+
+    StreamStatus status = _streamStatus;
+    status.isRunning = true;
+    _streamStatus = status;
+
+    if (nenoutchannels() > 0) {
+      assert(outCallback);
+      obh = std::make_unique<OutBufHandler>(*this, outCallback);
+    }
+    if (neninchannels() > 0) {
+      assert(inCallback);
+      ibh = std::make_unique<InBufHandler>(*this, inCallback);
+    }
+    if (obh)
+      obh->start();
+    if (ibh)
+      ibh->start();
+
+    const double sleeptime_s =
+        static_cast<double>(_nFramesPerBlock) / (16 * samplerate());
+    const us sleeptime_us = static_cast<us>(sleeptime_s * 1e6);
+
+    while (!_stopThread) {
+      if (ibh) {
+        if (!(*ibh)()) {
+          _stopThread = true;
+          break;
+        }
+      }
+      if (obh) {
+        if (!(*obh)()) {
+          _stopThread = true;
+          break;
+        }
+      }
+
+      std::this_thread::sleep_for(std::chrono::microseconds(sleeptime_us));
+    }
+
+    /// Update stream status that we are not running anymore
+    status.isRunning = false;
+    _streamStatus = status;
+    _stopThread = false;
+
+  } catch (StreamException &e) {
+
+    StreamStatus status = _streamStatus;
+    // Copy over error type
+    status.errorType = e.e;
+    _streamStatus = status;
+
+    cerr << "\n******************\n";
+    cerr << "Catched error in UlDAQ thread: " << e.what() << endl;
+    cerr << "\n******************\n";
+  }
+}
+
+void DT9837A::sanityChecks() const {
+  // Some sanity checks
+  if (inchannel_config.size() != 4) {
+    throw rte("Invalid length of enabled inChannels vector");
+  }
+
+  if (outchannel_config.size() != 1) {
+    throw rte("Invalid length of enabled outChannels vector");
+  }
+
+  if (_nFramesPerBlock < 24 || _nFramesPerBlock > 8192) {
+    throw rte("Unsensible number of samples per block chosen");
+  }
+
+  if (samplerate() < ULDAQ_SAMPLERATES.at(0) ||
+      samplerate() > ULDAQ_SAMPLERATES.at(ULDAQ_SAMPLERATES.size() - 1)) {
+    throw rte("Invalid sample rate");
+  }
+}
+
+#endif // LASP_HAS_ULDAQ

src/lasp/device/uldaq/lasp_uldaq_impl.h

@@ -0,0 +1,96 @@
+#pragma once
+#include "debugtrace.hpp"
+#include "lasp_uldaq_common.h"
+#include <algorithm>
+#include <cassert>
+#include <chrono>
+#include <iostream>
+#include <stdexcept>
+#include <thread>
+#include <vector>
+#include "lasp_daq.h"
+
+using std::atomic;
+using std::cerr;
+using std::endl;
+using rte = std::runtime_error;
+
+class InBufHandler;
+class OutBufHandler;
+
+
+class DT9837A : public Daq {
+
+  DaqDeviceHandle _handle = 0;
+  std::mutex _daqmutex;
+
+  /**
+   * @brief The thread that is doing I/O with UlDaq
+   */
+  std::thread _thread;
+
+
+  /**
+   * @brief Flag indicating the thread to stop processing.
+   */
+  atomic<bool> _stopThread{false};
+  /**
+   * @brief Storage for exchanging information on the stream
+   */
+  atomic<StreamStatus> _streamStatus;
+
+  const us _nFramesPerBlock;
+
+  /**
+   * @brief The function that is running in a thread
+   *
+   * @param inCallback 
+   * @param outcallback
+   */
+  void threadFcn(InDaqCallback inCallback, OutDaqCallback outcallback);
+
+  /**
+   * @brief Obtain a handle to the underlying device
+   *
+   * @return Handle
+   */
+  DaqDeviceHandle getHandle() const { return _handle; }
+  /**
+   * @brief Perform several sanity checks
+   */
+  void sanityChecks() const;
+public:
+
+  /**
+   * @brief Create a DT9837A instance.
+   *
+   * @param devinfo DeviceInfo to connect to
+   * @param config DaqConfiguration settings
+   */
+  DT9837A(const UlDaqDeviceInfo &devinfo, const DaqConfiguration &config);
+
+  virtual ~DT9837A();
+
+  bool isRunning() const;
+
+  /**
+   * @brief Stop the data-acquisition
+   */
+  void stop() override final;
+
+  friend class InBufHandler;
+  friend class OutBufHandler;
+
+  virtual void start(InDaqCallback inCallback,
+                     OutDaqCallback outCallback) override final;
+
+  /**
+   * @brief Obtain copy of stream status (thread-safe function)
+   *
+   * @return StreamStatus object
+   */
+  virtual StreamStatus getStreamStatus() const override {
+    return _streamStatus;
+  }
+};
+

src/lasp/dsp/lasp_clip.cpp

@@ -11,7 +11,7 @@ using std::endl;
 using Lck = std::scoped_lock<std::mutex>;
 using rte = std::runtime_error;
 
-ClipHandler::ClipHandler(StreamMgr &mgr)
+ClipHandler::ClipHandler(SmgrHandle mgr)
   : ThreadedInDataHandler(mgr){
 
     DEBUGTRACE_ENTER;

src/lasp/dsp/lasp_clip.h

@@ -58,7 +58,7 @@ class ClipHandler: public ThreadedInDataHandler {
    *
    * @param mgr Stream Mgr to operate on
    */
-  ClipHandler(StreamMgr& mgr);
+  ClipHandler(SmgrHandle mgr);
   ~ClipHandler();
 
   /**

src/lasp/dsp/lasp_ppm.cpp

@@ -11,7 +11,7 @@ using std::endl;
 using Lck = std::scoped_lock<std::mutex>;
 using rte = std::runtime_error;
 
-PPMHandler::PPMHandler(StreamMgr &mgr, const d decay_dBps)
+PPMHandler::PPMHandler(SmgrHandle mgr, const d decay_dBps)
   : ThreadedInDataHandler(mgr), _decay_dBps(decay_dBps) {
 
     DEBUGTRACE_ENTER;

src/lasp/dsp/lasp_ppm.h

@@ -73,7 +73,7 @@ class PPMHandler: public ThreadedInDataHandler {
    * @param decay_dBps The level decay in units dB/s, after a peak has been
    * hit.
    */
-  PPMHandler(StreamMgr& mgr,const d decay_dBps = 20.0);
+  PPMHandler(SmgrHandle mgr,const d decay_dBps = 20.0);
   ~PPMHandler();
 
   /**

src/lasp/dsp/lasp_rtaps.cpp

@@ -9,7 +9,7 @@ using std::cerr;
 using std::endl;
 using Lck = std::scoped_lock<std::mutex>;
 
-RtAps::RtAps(StreamMgr &mgr, const Filter *freqWeightingFilter,
+RtAps::RtAps(SmgrHandle mgr, const Filter *freqWeightingFilter,
     const us nfft,
     const Window::WindowType w,
     const d overlap_percentage, const d time_constant)

src/lasp/dsp/lasp_rtaps.h

@@ -49,7 +49,7 @@ public:
    * 
    * For all other arguments, see constructor of AvPowerSpectra
    */
-  RtAps(StreamMgr &mgr, const Filter *freqWeightingFilter, const us nfft = 2048,
+  RtAps(SmgrHandle mgr, const Filter *freqWeightingFilter, const us nfft = 2048,
         const Window::WindowType w = Window::WindowType::Hann,
         const d overlap_percentage = 50., const d time_constant = -1);
   ~RtAps();

src/lasp/dsp/lasp_rtsignalviewer.cpp

@@ -11,7 +11,7 @@ using std::endl;
 using Lck = std::scoped_lock<std::mutex>;
 using rte = std::runtime_error;
 
-RtSignalViewer::RtSignalViewer(StreamMgr &mgr, const d approx_time_hist,
+RtSignalViewer::RtSignalViewer(SmgrHandle mgr, const d approx_time_hist,
     const us resolution, const us channel)
   : ThreadedInDataHandler(mgr), _approx_time_hist(approx_time_hist),
   _resolution(resolution), _channel(channel) {

src/lasp/dsp/lasp_rtsignalviewer.h

@@ -71,7 +71,7 @@ public:
    * @param resolution Number of time points
    * @param channel The channel number
    */
-  RtSignalViewer(StreamMgr &mgr, const d approx_time_hist, const us resolution,
+  RtSignalViewer(SmgrHandle mgr, const d approx_time_hist, const us resolution,
                  const us channel);
 
   ~RtSignalViewer();

src/lasp/dsp/lasp_threadedindatahandler.cpp

@@ -49,7 +49,7 @@ public:
   bool empty() const { return _contents == 0; }
 };
 
-ThreadedInDataHandler::ThreadedInDataHandler(StreamMgr &mgr)
+ThreadedInDataHandler::ThreadedInDataHandler(SmgrHandle mgr)
     : InDataHandler(mgr), _queue(std::make_unique<SafeQueue>()) {
 
   DEBUGTRACE_ENTER;
@@ -58,6 +58,7 @@ ThreadedInDataHandler::ThreadedInDataHandler(StreamMgr &mgr)
   getPool();
 }
 void ThreadedInDataHandler::startThread() {
+  DEBUGTRACE_ENTER;
   _thread_can_safely_run = true;
   start();
 }
@@ -85,7 +86,7 @@ bool ThreadedInDataHandler::inCallback(const DaqData &daqdata) {
   return _lastCallbackResult;
 }
 void ThreadedInDataHandler::stopThread() {
-
+  DEBUGTRACE_ENTER;
   // Make sure inCallback is no longer called
   _thread_can_safely_run = false;
   stop();

src/lasp/dsp/lasp_threadedindatahandler.h

@@ -52,8 +52,8 @@ public:
    *
    * @param mgr StreamMgr singleton reference
    */
-  ThreadedInDataHandler(StreamMgr &mgr);
+  ThreadedInDataHandler(SmgrHandle mgr);
-  ~ThreadedInDataHandler();
+  virtual ~ThreadedInDataHandler();
 
   /**
    * @brief Pushes a copy of the daqdata to the thread queue and returns

src/lasp/pybind11/lasp_pyindatahandler.cpp

@@ -1,14 +1,14 @@
 /* #define DEBUGTRACE_ENABLED */
 #include "arma_npy.h"
 #include "debugtrace.hpp"
-#include "lasp_ppm.h"
 #include "lasp_clip.h"
+#include "lasp_daq.h"
+#include "lasp_daqdata.h"
+#include "lasp_ppm.h"
 #include "lasp_rtaps.h"
 #include "lasp_rtsignalviewer.h"
-#include "lasp_threadedindatahandler.h"
-#include "lasp_daqdata.h"
-#include "lasp_daq.h"
 #include "lasp_streammgr.h"
+#include "lasp_threadedindatahandler.h"
 #include <armadillo>
 #include <atomic>
 #include <chrono>
@@ -107,7 +107,7 @@ class PyIndataHandler : public ThreadedInDataHandler {
   py::function cb, reset_callback;
 
 public:
-  PyIndataHandler(StreamMgr &mgr, py::function cb, py::function reset_callback)
+  PyIndataHandler(SmgrHandle mgr, py::function cb, py::function reset_callback)
       : ThreadedInDataHandler(mgr), cb(cb), reset_callback(reset_callback) {
 
     DEBUGTRACE_ENTER;
@@ -119,7 +119,25 @@ public:
     DEBUGTRACE_ENTER;
     stopThread();
   }
-  void reset(const Daq *daq) override final { reset_callback(daq); }
+  void reset(const Daq *daq) override final {
+    DEBUGTRACE_ENTER;
+    py::gil_scoped_acquire acquire;
+    try {
+      if (daq) {
+        reset_callback(daq);
+      } else {
+        reset_callback(py::none());
+      }
+    } catch (py::error_already_set &e) {
+      cerr << "*************** Error calling reset callback!\n";
+      cerr << e.what() << endl;
+      cerr << "*************** \n";
+      /// Throwing a runtime error here does not work out one way or another.
+      /// Therefore, it is better to dive out and prevent undefined behaviour
+      abort();
+      /* throw std::runtime_error(e.what()); */
+    }
+  }
 
   /**
    * @brief Reads from the buffer
@@ -174,12 +192,12 @@ void init_datahandler(py::module &m) {
   /// The C++ class is PyIndataHandler, but for Python, it is called
   /// InDataHandler
   py::class_<PyIndataHandler> pyidh(m, "InDataHandler");
-  pyidh.def(py::init<StreamMgr &, py::function, py::function>());
+  pyidh.def(py::init<SmgrHandle, py::function, py::function>());
 
   /// Peak Programme Meter
   py::class_<PPMHandler> ppm(m, "PPMHandler");
-  ppm.def(py::init<StreamMgr &, const d>());
+  ppm.def(py::init<SmgrHandle, const d>());
-  ppm.def(py::init<StreamMgr &>());
+  ppm.def(py::init<SmgrHandle>());
 
   ppm.def("getCurrentValue", [](const PPMHandler &ppm) {
     std::tuple<vd, arma::uvec> tp = ppm.getCurrentValue();
@@ -190,10 +208,9 @@ void init_datahandler(py::module &m) {
 
   /// Clip Detector
   py::class_<ClipHandler> clip(m, "ClipHandler");
-  clip.def(py::init<StreamMgr &>());
+  clip.def(py::init<SmgrHandle>());
 
   clip.def("getCurrentValue", [](const ClipHandler &clip) {
-
     arma::uvec cval = clip.getCurrentValue();
 
     return ColToNpy<arma::uword>(cval); // something goes wrong here
@@ -202,7 +219,7 @@ void init_datahandler(py::module &m) {
   /// Real time Aps
   ///
   py::class_<RtAps> rtaps(m, "RtAps");
-  rtaps.def(py::init<StreamMgr &,              // StreamMgr
+  rtaps.def(py::init<SmgrHandle,               // StreamMgr
                      Filter *const,            // FreqWeighting filter
                      const us,                 // Nfft
                      const Window::WindowType, // Window
@@ -229,10 +246,10 @@ void init_datahandler(py::module &m) {
   /// Real time Signal Viewer
   ///
   py::class_<RtSignalViewer> rtsv(m, "RtSignalViewer");
-  rtsv.def(py::init<StreamMgr &, // StreamMgr
+  rtsv.def(py::init<SmgrHandle, // StreamMgr
-                    const d,     // Time history
+                    const d,    // Time history
-                    const us,    // Resolution
+                    const us,   // Resolution
-                    const us     // Channel number
+                    const us    // Channel number
                     >());
 
   rtsv.def("getCurrentValue", [](RtSignalViewer &rt) {

src/lasp/pybind11/lasp_streammgr.cpp

@@ -13,7 +13,7 @@ void init_streammgr(py::module &m) {
 
   /// The stream manager is a singleton, and the lifetime is managed elsewhere.
   // It should not be deleted.
-  py::class_<StreamMgr, std::unique_ptr<StreamMgr, py::nodelete>> smgr(
+  py::class_<StreamMgr, std::shared_ptr<StreamMgr>> smgr(
       m, "StreamMgr");
 
   py::enum_<StreamMgr::StreamType>(smgr, "StreamType")
@@ -23,7 +23,7 @@ void init_streammgr(py::module &m) {
   smgr.def("startStream", &StreamMgr::startStream);
   smgr.def("stopStream", &StreamMgr::stopStream);
   smgr.def_static("getInstance", []() {
-    return std::unique_ptr<StreamMgr, py::nodelete>(&StreamMgr::getInstance());
+    return StreamMgr::getInstance();
   });
   smgr.def("stopAllStreams", &StreamMgr::stopAllStreams);