Incallbacks should not return anything anymore. From inheritance to composition for InDataHandler code. StreamMgr singleton only weak ptr stored, this makes sure destruction from Python is more often done. UlDAQ code back to working.

src/lasp/device/lasp_daq.h

@@ -15,12 +15,12 @@
  * @brief Callback of DAQ for input data. Callback should return
  * false for a stop request.
  */
-using InDaqCallback = std::function<bool(const DaqData &)>;
+using InDaqCallback = std::function<void(const DaqData &)>;
 
 /**
  * @brief
  */
-using OutDaqCallback = std::function<bool(DaqData &)>;
+using OutDaqCallback = std::function<void(DaqData &)>;
 
 /**
  * @brief Base cass for all DAQ (Data Acquisition) interfaces. A DAQ can be a

src/lasp/device/lasp_indatahandler.cpp

@@ -4,43 +4,56 @@
 #include "lasp_streammgr.h"
 #include <thread>
 
-InDataHandler::InDataHandler(SmgrHandle mgr)
+InDataHandler::InDataHandler(SmgrHandle mgr, const InCallbackType cb,
-    : _mgr(mgr)
+                             const InResetType resetfcn)
+    : _mgr(mgr), inCallback(cb), reset(resetfcn)
 #if LASP_DEBUG == 1
       ,
-      _main_thread_id(std::this_thread::get_id())
+      main_thread_id(std::this_thread::get_id())
 #endif
 {
   DEBUGTRACE_ENTER;
+#if LASP_DEBUG == 1
+  assert(mgr->main_thread_id == main_thread_id);
+#endif
 }
 void InDataHandler::start() {
   DEBUGTRACE_ENTER;
+  checkRightThread();
   if (SmgrHandle handle = _mgr.lock()) {
     handle->addInDataHandler(this);
 #if LASP_DEBUG == 1
-    assert(handle->_main_thread_id == _main_thread_id);
+    assert(handle->main_thread_id == main_thread_id);
 #endif
   }
 }
 void InDataHandler::stop() {
+  DEBUGTRACE_ENTER;
+  checkRightThread();
 #if LASP_DEBUG == 1
   stopCalled = true;
 #endif
   if (SmgrHandle handle = _mgr.lock()) {
-    /* handle->removeInDataHandler(*this); */
+    handle->removeInDataHandler(*this);
   }
 }
 
 InDataHandler::~InDataHandler() {
 
   DEBUGTRACE_ENTER;
+  checkRightThread();
 #if LASP_DEBUG == 1
   if (!stopCalled) {
     std::cerr << "************ BUG: Stop function not called while arriving at "
                  "InDataHandler's destructor. Fix this by calling "
-                 "InDataHandler::stop() from the derived class' destructor."
+                 "InDataHandler::stop()."
               << std::endl;
     abort();
   }
 #endif
 }
+#if LASP_DEBUG == 1
+void InDataHandler::checkRightThread() const {
+  assert(std::this_thread::get_id() == main_thread_id);
+}
+#endif

src/lasp/device/lasp_indatahandler.h

@@ -1,17 +1,29 @@
 #pragma once
+#include "lasp_types.h"
 #include <atomic>
+#include <functional>
 #include <memory>
 #include <thread>
-#include "lasp_types.h"
 
 class StreamMgr;
 using SmgrHandle = std::shared_ptr<StreamMgr>;
 
+class DaqData;
+class Daq;
+
 /** \addtogroup device
  * @{
  */
-class DaqData;
+
-class Daq;
+/**
+ * @brief The function definition of callbacks with incoming DAQ data
+ */
+using InCallbackType = std::function<void(const DaqData &)>;
+/**
+ * @brief Function definition for the reset callback.
+ */
+using InResetType = std::function<void(const Daq *)>;
+
 class InDataHandler {
 
 protected:
@@ -24,53 +36,41 @@ protected:
 #endif
 
 public:
-  virtual ~InDataHandler();
+  ~InDataHandler();
+  const InCallbackType inCallback;
+  const InResetType reset;
 
   /**
    * @brief When constructed, the handler is added to the stream manager, which
    * will call the handlers's inCallback() until stop() is called.
    *
    * @param mgr Stream manager.
+   * @param cb The callback that is stored, and called on new DAQ data
+   * @param resetfcn The callback that is stored, and called when the DAQ
+   * changes state.
    */
-  InDataHandler(SmgrHandle mgr);
+  InDataHandler(SmgrHandle mgr, InCallbackType cb,
+                InResetType resetfcn);
 
   /**
-   * @brief This function is called when input data from a DAQ is available.
+   * @brief Adds the current InDataHandler to the list of handlers in the
-   *
+   * StreamMgr. After this happens, the reset() method stored in this
-   * @param daqdata Input data from DAQ
+   * object is called back. When the stream is running, right after this,
-   *
+   * inCallback() is called with DaqData.
-   * @return true if no error. False to stop the stream from running.
-   */
-  virtual bool inCallback(const DaqData &daqdata) = 0;
-
-  /**
-   * @brief Reset in-data handler.
-   *
-   * @param daq New DAQ configuration of inCallback(). If nullptr is given,
-   * it means that the stream is stopped.
-   */
-  virtual void reset(const Daq *daq = nullptr) = 0;
-
-  /**
-   * @brief This function should be called from the constructor of the
-   * implementation of InDataHandler, that one than also implements
-   * `inCallback`. It will start the stream's calling of inCallback().
    */
   void start();
 
   /**
-   * @brief This function should be called from the destructor of derived
+   * @brief Removes the currend InDataHandler from the list of handlers in the
-   * classes, to disable the calls to inCallback(), such that proper
+   * StreamMgr. From that point on, the object can be safely destroyed. Not
-   * destruction of the object is allowed and no other threads call methods
+   * calling stop() before destruction of this object is considered a BUG. I.e.
-   * from the object. It removes the inCallback() from the callback list of the
+   * a class which *uses* an InDataHandler should always call stop() in its
-   * StreamMgr(). **Failing to call this function results in deadlocks, errors
+   * destructor.
-   * like "pure virtual function called", or other**.
    */
   void stop();
 
-private:
 #if LASP_DEBUG == 1
-  const std::thread::id _main_thread_id;
+  const std::thread::id main_thread_id;
   void checkRightThread() const;
 #else
   void checkRightThread() const {}

src/lasp/device/lasp_rtaudiodaq.cpp

@@ -368,11 +368,7 @@ public:
       DaqData d{nFramesPerBlock, neninchannels, dtype};
       d.copyInFromRaw(ptrs);
 
-      bool ret = _incallback(d);
+       _incallback(d);
-      if (!ret) {
-        stopWithError(se::noError);
-        return 1;
-      }
     }
 
     if (outputBuffer) {
@@ -395,11 +391,8 @@ public:
       }
       DaqData d{nFramesPerBlock, nenoutchannels, dtype};
 
-      bool ret = _outcallback(d);
+      _outcallback(d);
-      if (!ret) {
+      // Copy over the buffer
-        stopWithError(se::noError);
-        return 1;
-      }
       us j = 0;
       for (auto ptr : ptrs) {
         d.copyToRaw(j, ptr);

src/lasp/device/lasp_rtaudiodaq.h

@@ -2,6 +2,25 @@
 #include "lasp_daq.h"
 #include <memory>
 
+/** \addtogroup device
+ * @{
+ * \defgroup rtaudio RtAudio backend
+ * This code is used to interface with the RtAudio cross-platform audio
+ * interface.
+ *
+ * \addtogroup rtaudio
+ * @{
+ */
+
+
+/**
+ * @brief Method called from Daq::createDaq.
+ *
+ * @param devinfo Device info
+ * @param config DAQ Configuration settings
+ *
+ * @return Pointer to Daq instance. Throws Runtime errors on error.
+ */
 std::unique_ptr<Daq> createRtAudioDevice(const DeviceInfo& devinfo,
         const DaqConfiguration& config);
 
@@ -12,3 +31,5 @@ std::unique_ptr<Daq> createRtAudioDevice(const DeviceInfo& devinfo,
  */
 void fillRtAudioDeviceInfo(DeviceInfoList &devinfolist);
 
+/** @} */
+/** @} */

src/lasp/device/lasp_streammgr.cpp

@@ -15,34 +15,55 @@ using std::endl;
 using rte = std::runtime_error;
 
 /**
- * @brief The main global handle to a stream, stored in a shared pointer.
+ * @brief The main global handle to a stream, stored in a weak pointer, if it
+ * does not yet exist, via StreamMgr::getInstance, a new stream mgr is created.
+ * It also makes sure that the stream manager is deleted once the latest handle
+ * to it has been destroyed (no global stuff left).
  */
-std::shared_ptr<StreamMgr> _mgr;
+std::weak_ptr<StreamMgr> _mgr;
 
-std::shared_ptr<StreamMgr> StreamMgr::getInstance() {
+
+
+/**
+ * @brief The only way to obtain a stream manager, can only be called from the
+ * thread that does it the first time.
+ *
+ * @return Stream manager handle
+ */
+SmgrHandle StreamMgr::getInstance() {
   DEBUGTRACE_ENTER;
 
-  if (!_mgr) {
+  auto mgr = _mgr.lock();
-    _mgr = std::shared_ptr<StreamMgr>(new StreamMgr());
+  if (!mgr) {
-    if (!_mgr) {
+
+    mgr = SmgrHandle(new StreamMgr());
+    if (!mgr) {
       throw rte("Fatal: could not allocate stream manager!");
     }
+    // Update global weak pointer
+    _mgr = mgr;
+    return mgr;
   }
+#if LASP_DEBUG == 1
+  // Make sure we never ask for a new SmgrHandle from a different thread.
+  assert(std::this_thread::get_id() == mgr->main_thread_id);
+#endif
 
-  return _mgr;
+  return mgr;
 }
 
-StreamMgr::StreamMgr() {
+StreamMgr::StreamMgr()
-  DEBUGTRACE_ENTER;
 #if LASP_DEBUG == 1
-  _main_thread_id = std::this_thread::get_id();
+  : main_thread_id(std::this_thread::get_id())
 #endif
+{
+  DEBUGTRACE_ENTER;
   // Trigger a scan for the available devices, in the background.
   rescanDAQDevices(true);
 }
 #if LASP_DEBUG == 1
 void StreamMgr::checkRightThread() const {
-  assert(std::this_thread::get_id() == _main_thread_id);
+  assert(std::this_thread::get_id() == main_thread_id);
 }
 #endif
 
@@ -65,6 +86,7 @@ void StreamMgr::rescanDAQDevices(bool background,
   if (!background) {
     rescanDAQDevices_impl(callback);
   } else {
+    DEBUGTRACE_PRINT("Rescanning DAQ devices on different thread...");
     pool.push_task(&StreamMgr::rescanDAQDevices_impl, this, callback);
   }
 }
@@ -76,7 +98,7 @@ void StreamMgr::rescanDAQDevices_impl(std::function<void()> callback) {
     callback();
   }
 }
-bool StreamMgr::inCallback(const DaqData &data) {
+void StreamMgr::inCallback(const DaqData &data) {
 
   DEBUGTRACE_ENTER;
 
@@ -107,23 +129,15 @@ bool StreamMgr::inCallback(const DaqData &data) {
     }
 
     for (auto &handler : _inDataHandlers) {
-      bool res = handler->inCallback(input_filtered);
+      handler->inCallback(input_filtered);
-      if (!res) {
-        return false;
-      }
     }
 
   } else {
     /// No input filters
     for (auto &handler : _inDataHandlers) {
-
+      handler->inCallback(data);
-      bool res = handler->inCallback(data);
-      if (!res) {
-        return false;
     }
   }
-  }
-  return true;
 }
 
 void StreamMgr::setSiggen(std::shared_ptr<Siggen> siggen) {
@@ -187,7 +201,7 @@ template <typename T> bool fillData(DaqData &data, const vd &signal) {
 
   return true;
 }
-bool StreamMgr::outCallback(DaqData &data) {
+void StreamMgr::outCallback(DaqData &data) {
 
   /* DEBUGTRACE_ENTER; */
 
@@ -216,7 +230,6 @@ bool StreamMgr::outCallback(DaqData &data) {
     // Set all values to 0.
     std::fill(data.raw_ptr(), data.raw_ptr() + data.size_bytes(), 0);
   }
-  return true;
 }
 
 StreamMgr::~StreamMgr() {

src/lasp/device/lasp_streammgr.h

@@ -183,17 +183,17 @@ class StreamMgr {
   /**
    * @brief Set active signal generator for output streams. Only one `Siggen'
    * is active at the same time. Siggen controls its own data race protection
-   * using a mutex.
+   * using a mutex. If no Siggen is there, and an output stream is running, it
+   * will send a default signal of 0.
    *
    * @param s New Siggen pointer
    */
   void setSiggen(std::shared_ptr<Siggen> s);
 
 private:
-  bool inCallback(const DaqData &data);
+  void inCallback(const DaqData &data);
-  bool outCallback(DaqData &data);
+  void outCallback(DaqData &data);
 
-  void removeInDataHandler(InDataHandler &handler);
 
   /**
    * @brief Add an input data handler. The handler's inCallback() function is
@@ -205,6 +205,12 @@ private:
    */
   void addInDataHandler(InDataHandler *handler);
 
+  /**
+   * @brief Remove InDataHandler from the list.
+   *
+   * @param handler
+   */
+  void removeInDataHandler(InDataHandler &handler);
   /**
    * @brief Do the actual rescanning.
    *
@@ -213,7 +219,7 @@ private:
   void rescanDAQDevices_impl(std::function<void()> callback);
 
 #if LASP_DEBUG == 1
-  std::thread::id _main_thread_id;
+  const std::thread::id main_thread_id;
   void checkRightThread() const;
 #else
   void checkRightThread() const {}

src/lasp/device/lasp_uldaq.cpp

@@ -7,6 +7,12 @@
 #include "lasp_uldaq_impl.h"
 #include <uldaq.h>
 
+/**
+ * @brief The maximum number of devices that can be enumerated when calling
+ * ulGetDaqDeviceInventory()
+ */
+const us MAX_ULDAQ_DEV_COUNT_PER_API = 100;
+
 void fillUlDaqDeviceInfo(DeviceInfoList &devinfolist) {
 
   DEBUGTRACE_ENTER;

src/lasp/device/lasp_uldaq.h

@@ -1,18 +1,24 @@
 #pragma once
 #include "lasp_daq.h"
 
-/**
+/** \addtogroup device
- * @brief The maximum number of devices that can be enumerated when calling
+ * \defgroup uldaq UlDAQ specific code
- * ulGetDaqDeviceInventory()
+ * This code is used to interface with UlDAQ compatible devices. It is only
+ * tested on Linux.
+ * @{
+ * \addtogroup uldaq
+ * @{
  */
-const us MAX_ULDAQ_DEV_COUNT_PER_API = 100;
 
 std::unique_ptr<Daq> createUlDaqDevice(const DeviceInfo &devinfo,
                                        const DaqConfiguration &config);
 
 /**
- * @brief Fill device info list with UlDaq specific devices, if any.
+ * @brief Append device info list with UlDaq specific devices, if any.
  *
  * @param devinfolist Info list to append to.
  */
 void fillUlDaqDeviceInfo(DeviceInfoList& devinfolist);
+
+/** @} */
+/** @} */

src/lasp/device/uldaq/lasp_uldaq_bufhandler.cpp

@@ -134,13 +134,13 @@ bool InBufHandler::operator()() {
   if (transferStatus.currentIndex < (long long)buffer_mid_idx) {
     topenqueued = false;
     if (!botenqueued) {
-      ret = runCallback(nchannels * nFramesPerBlock);
+      runCallback(nchannels * nFramesPerBlock);
       botenqueued = true;
     }
   } else {
     botenqueued = false;
     if (!topenqueued) {
-      ret = runCallback(0);
+      runCallback(0);
       topenqueued = true;
     }
   }
@@ -214,8 +214,8 @@ bool OutBufHandler::operator()() {
     if (!botenqueued) {
       DaqData d(nFramesPerBlock, 1,// Only one output channel
                                   dtype_descr.dtype);
-      // Receive data
+      // Receive data, run callback
-      res = cb(d);
+      cb(d);
       d.copyToRaw(0, reinterpret_cast<byte_t *>(&(buf[buffer_mid_idx])));
 
       botenqueued = true;
@@ -226,7 +226,7 @@ bool OutBufHandler::operator()() {
       DaqData d(nFramesPerBlock, 1,// Only one output channel
                                   dtype_descr.dtype);
       // Receive
-      res = cb(d);
+      cb(d);
       d.copyToRaw(0, reinterpret_cast<byte_t *>(&(buf[0])));
 
       topenqueued = true;

src/lasp/device/uldaq/lasp_uldaq_bufhandler.h

@@ -5,11 +5,16 @@
 #include "lasp_uldaq_common.h"
 
 
-class DT9837A;
 
+/** \addtogroup device
+ * @{
+ * \addtogroup uldaq
+ */
 /**
  * @brief Helper class for managing input and output samples of the DAQ device.
  */
+
+class DT9837A;
 class BufHandler {
 protected:
   /**
@@ -28,6 +33,9 @@ protected:
    * @brief Sampling frequency in Hz
    */
   double samplerate;
+  /**
+   * @brief Storage capacity for the DAQ I/O.
+   */
   std::vector<double> buf;
   /**
    * @brief Whether the top part of the buffer is enqueued
@@ -97,3 +105,5 @@ public:
 
   ~OutBufHandler();
 };
+/** @} */
+/** @} */

src/lasp/device/uldaq/lasp_uldaq_common.h

@@ -3,6 +3,10 @@
 #include <string>
 #include "lasp_deviceinfo.h"
 
+/** \addtogroup device
+ * @{
+ * \addtogroup uldaq
+ */
 /**
  * @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
@@ -58,3 +62,5 @@ const std::vector<d> ULDAQ_SAMPLERATES = {8000,  10000, 11025, 16000, 20000,
                                     47250, 48000, 50000, 50400, 51000};
 
 
+/** @} */
+/** @} */

src/lasp/device/uldaq/lasp_uldaq_impl.cpp

@@ -91,15 +91,15 @@ void DT9837A::stop() {
   StreamStatus status = _streamStatus;
   status.isRunning = true;
   _streamStatus = status;
-  /* if (!isRunning()) { */
+  if (!isRunning()) {
-  /*   throw rte("No data acquisition running"); */
+    throw rte("No data acquisition running");
-  /* } */
+  }
 
   // Stop the thread and join it
-  /* _stopThread = true; */
+  _stopThread = true;
-  /* assert(_thread.joinable()); */
+  assert(_thread.joinable());
-  /* _thread.join(); */
+  _thread.join();
-  /* _stopThread = false; */
+  _stopThread = false;
 
   // Update stream status
   status.isRunning = false;
@@ -120,8 +120,8 @@ void DT9837A::start(InDaqCallback inCallback, OutDaqCallback outCallback) {
       throw rte("DAQ requires a callback for output data");
   }
   assert(neninchannels() + nenoutchannels() > 0);
-  /* _thread = std::thread(&DT9837A::threadFcn, this, inCallback, outCallback);
+  _thread = std::thread(&DT9837A::threadFcn, this, inCallback, outCallback);
-   */
+  
 }
 
 void DT9837A::threadFcn(InDaqCallback inCallback, OutDaqCallback outCallback) {

src/lasp/device/uldaq/lasp_uldaq_impl.h

@@ -18,7 +18,14 @@ using rte = std::runtime_error;
 class InBufHandler;
 class OutBufHandler;
 
+/** \addtogroup device
+ * @{
+ * \addtogroup uldaq
+ */
 
+/**
+ * @brief Data translation DT9837A Daq device.
+ */
 class DT9837A : public Daq {
 
   DaqDeviceHandle _handle = 0;
@@ -71,6 +78,11 @@ public:
 
   virtual ~DT9837A();
 
+  /**
+   * @brief Returns true when the stream is running
+   *
+   * @return as above stated
+   */
   bool isRunning() const;
 
   /**
@@ -94,3 +106,5 @@ public:
   }
 };
 
+/** @} */
+/** @} */

src/lasp/dsp/lasp_clip.cpp

@@ -18,7 +18,7 @@ ClipHandler::ClipHandler(SmgrHandle mgr)
     startThread();
   }
 
-bool ClipHandler::inCallback_threaded(const DaqData &d) {
+void ClipHandler::inCallback(const DaqData &d) {
 
   DEBUGTRACE_ENTER;
   Lck lck(_mtx);
@@ -52,7 +52,6 @@ bool ClipHandler::inCallback_threaded(const DaqData &d) {
       _clip_time(i) += _dt;
     }
   }
-  return true;
 }
 
 arma::uvec ClipHandler::getCurrentValue() const {

src/lasp/dsp/lasp_clip.h

@@ -21,7 +21,7 @@
 /**
  * @brief Clipping detector (Clip). Detects when a signal overdrives the input
  * */
-class ClipHandler: public ThreadedInDataHandler {
+class ClipHandler: public ThreadedInDataHandler<ClipHandler> {
 
   /**
    * @brief Assuming full scale of a signal is +/- 1.0. If a value is found 
@@ -68,8 +68,8 @@ class ClipHandler: public ThreadedInDataHandler {
    */
   arma::uvec getCurrentValue() const;
 
-  bool inCallback_threaded(const DaqData& ) override final;
+  void inCallback(const DaqData& );
-  void reset(const Daq*) override final;
+  void reset(const Daq*);
 
 };
 

src/lasp/dsp/lasp_ppm.cpp

@@ -12,13 +12,13 @@ using Lck = std::scoped_lock<std::mutex>;
 using rte = std::runtime_error;
 
 PPMHandler::PPMHandler(SmgrHandle mgr, const d decay_dBps)
-  : ThreadedInDataHandler(mgr), _decay_dBps(decay_dBps) {
+  : ThreadedInDataHandler<PPMHandler>(mgr), _decay_dBps(decay_dBps) {
 
     DEBUGTRACE_ENTER;
     startThread();
   }
 
-bool PPMHandler::inCallback_threaded(const DaqData &d) {
+void PPMHandler::inCallback(const DaqData &d) {
 
   DEBUGTRACE_ENTER;
   Lck lck(_mtx);
@@ -64,12 +64,11 @@ bool PPMHandler::inCallback_threaded(const DaqData &d) {
       _cur_max(i) *= _alpha;
     }
   }
-  return true;
 }
 
 std::tuple<vd, arma::uvec> PPMHandler::getCurrentValue() const {
 
-  DEBUGTRACE_ENTER;
+  /* DEBUGTRACE_ENTER; */
   Lck lck(_mtx);
 
   arma::uvec clips(_clip_time.size(), arma::fill::zeros);
@@ -85,9 +84,11 @@ void PPMHandler::reset(const Daq *daq) {
 
   if (daq) {
 
+    DEBUGTRACE_PRINT("New daq found");
     _cur_max.fill(1e-80);
 
     const us nchannels = daq->neninchannels();
+    DEBUGTRACE_PRINT(nchannels);
     _max_range.resize(nchannels);
 
     dvec ranges = daq->inputRangeForEnabledChannels();

src/lasp/dsp/lasp_ppm.h

@@ -4,7 +4,6 @@
 //
 // Description: Peak Programme Meter
 #pragma once
-#include <memory>
 #include "lasp_filter.h"
 #include "lasp_mathtypes.h"
 #include "lasp_threadedindatahandler.h"
@@ -23,7 +22,7 @@
  * with a certain amount of dB/s. If a new peak is found, it goes up again.
  * Also detects clipping.
  * */
-class PPMHandler: public ThreadedInDataHandler {
+class PPMHandler : public ThreadedInDataHandler<PPMHandler> {
 
   /**
    * @brief Assuming full scale of a signal is +/- 1.0. If a value is found 
@@ -69,7 +68,7 @@ class PPMHandler: public ThreadedInDataHandler {
   /**
    * @brief Constructs Peak Programme Meter
    *
-   * @param mgr Stream Mgr to operate on
+   * @param mgr Stream Mgr to install callbacks for
    * @param decay_dBps The level decay in units dB/s, after a peak has been
    * hit.
    */
@@ -91,8 +90,8 @@ class PPMHandler: public ThreadedInDataHandler {
    *
    * @return true when stream should continue.
    */
-  bool inCallback_threaded(const DaqData& d) override final;
+  void inCallback(const DaqData& d);
-  void reset(const Daq*) override final;
+  void reset(const Daq*);
 
 };
 

src/lasp/dsp/lasp_rtaps.cpp

@@ -25,7 +25,7 @@ RtAps::RtAps(SmgrHandle mgr, const Filter *freqWeightingFilter,
 RtAps::~RtAps() {
   stopThread();
 }
-bool RtAps::inCallback_threaded(const DaqData &data) {
+void RtAps::inCallback(const DaqData &data) {
 
   DEBUGTRACE_ENTER;
 
@@ -35,7 +35,7 @@ bool RtAps::inCallback_threaded(const DaqData &data) {
   const us nchannels = fltdata.n_cols;
   if(nchannels != _sens.size()) {
     cerr << "**** Error: sensitivity size does not match! *****" << endl;
-    return false;
+    return;
   }
   fltdata.each_row() %= _sens.as_row();
 
@@ -63,7 +63,6 @@ bool RtAps::inCallback_threaded(const DaqData &data) {
 
   _ps.compute(fltdata);
 
-  return true;
 }
 void RtAps::reset(const Daq *daq) {
 

src/lasp/dsp/lasp_rtaps.h

@@ -23,7 +23,7 @@
  * @brief Real time spectral estimator using Welch method of spectral
  * estimation.
  */
-class RtAps : public ThreadedInDataHandler {
+class RtAps : public ThreadedInDataHandler<RtAps> {
 
   std::unique_ptr<Filter> _filterPrototype;
   std::vector<std::unique_ptr<Filter>> _freqWeightingFilters;
@@ -69,8 +69,8 @@ public:
    *
    * @return true if stream should continue.
    */
-  bool inCallback_threaded(const DaqData & d) override final;
+  void inCallback(const DaqData & d);
-  void reset(const Daq *) override final;
+  void reset(const Daq *);
 };
 
 /** @} */

src/lasp/dsp/lasp_rtsignalviewer.cpp

@@ -27,7 +27,7 @@ RtSignalViewer::RtSignalViewer(SmgrHandle mgr, const d approx_time_hist,
     startThread();
   }
 
-bool RtSignalViewer::inCallback_threaded(const DaqData &data) {
+void RtSignalViewer::inCallback(const DaqData &data) {
 
   DEBUGTRACE_ENTER;
 
@@ -52,8 +52,6 @@ bool RtSignalViewer::inCallback_threaded(const DaqData &data) {
     _dat(_resolution-1, 1) = newmin;
     _dat(_resolution-1, 2) = newmax;
   }
-
-  return true;
 }
 
 RtSignalViewer::~RtSignalViewer() {

src/lasp/dsp/lasp_rtsignalviewer.h

@@ -24,7 +24,7 @@
  * @brief Real time signal viewer. Shows envelope of the signal based on amount
  * of history shown.
  */
-class RtSignalViewer : public ThreadedInDataHandler {
+class RtSignalViewer : public ThreadedInDataHandler<RtSignalViewer> {
 
   /**
    * @brief Storage for sensitivity values
@@ -85,8 +85,8 @@ public:
    */
   dmat getCurrentValue() const;
 
-  bool inCallback_threaded(const DaqData &) override final;
+  void inCallback(const DaqData &);
-  void reset(const Daq *) override final;
+  void reset(const Daq *);
 };
 
 /** @} */

src/lasp/dsp/lasp_threadedindatahandler.cpp

@@ -13,6 +13,7 @@ using lck = std::scoped_lock<std::mutex>;
 using rte = std::runtime_error;
 using std::cerr;
 using std::endl;
+using std::placeholders::_1;
 
 class SafeQueue {
   std::queue<DaqData> _queue;
@@ -49,47 +50,50 @@ public:
   bool empty() const { return _contents == 0; }
 };
 
-ThreadedInDataHandler::ThreadedInDataHandler(SmgrHandle mgr)
+ThreadedInDataHandlerBase::ThreadedInDataHandlerBase(SmgrHandle mgr,
-    : InDataHandler(mgr), _queue(std::make_unique<SafeQueue>()) {
+                                             InCallbackType cb,
+                                             InResetType reset)
+    : _indatahandler(
+          mgr,
+          std::bind(&ThreadedInDataHandlerBase::_inCallbackFromInDataHandler, this,
+                    _1),
+          reset),
+      _queue(std::make_unique<SafeQueue>()), inCallback(cb) {
 
   DEBUGTRACE_ENTER;
 
   // Initialize thread pool, if not already done
   getPool();
 }
-void ThreadedInDataHandler::startThread() {
+void ThreadedInDataHandlerBase::startThread() {
   DEBUGTRACE_ENTER;
   _thread_can_safely_run = true;
-  start();
+  _indatahandler.start();
 }
 
-bool ThreadedInDataHandler::inCallback(const DaqData &daqdata) {
+void ThreadedInDataHandlerBase::_inCallbackFromInDataHandler(
+    const DaqData &daqdata) {
   DEBUGTRACE_ENTER;
   std::scoped_lock lck(_mtx);
 
   // Early return in case object is under DESTRUCTION
   if (!_thread_can_safely_run)
-    return true;
+    return;
-
-  if (!_lastCallbackResult) {
-    return false;
-  }
 
   _queue->push(daqdata);
-  if (!_thread_running && _lastCallbackResult) {
+  if (!_thread_running) {
     auto &pool = getPool();
     DEBUGTRACE_PRINT("Pushing new thread in pool");
     _thread_running = true;
-    pool.push_task(&ThreadedInDataHandler::threadFcn, this);
+    pool.push_task(&ThreadedInDataHandlerBase::threadFcn, this);
   }
-
-  return _lastCallbackResult;
 }
-void ThreadedInDataHandler::stopThread() {
+
+void ThreadedInDataHandlerBase::stopThread() {
   DEBUGTRACE_ENTER;
   // Make sure inCallback is no longer called
   _thread_can_safely_run = false;
-  stop();
+  _indatahandler.stop();
 
   std::scoped_lock lck(_mtx);
 
@@ -99,7 +103,7 @@ void ThreadedInDataHandler::stopThread() {
   }
 }
 
-ThreadedInDataHandler::~ThreadedInDataHandler() {
+ThreadedInDataHandlerBase::~ThreadedInDataHandlerBase() {
 
   DEBUGTRACE_ENTER;
   if (_thread_can_safely_run) {
@@ -111,18 +115,14 @@ ThreadedInDataHandler::~ThreadedInDataHandler() {
   }
 }
 
-void ThreadedInDataHandler::threadFcn() {
+void ThreadedInDataHandlerBase::threadFcn() {
 
   DEBUGTRACE_ENTER;
 
   while (!_queue->empty() && _thread_can_safely_run) {
 
     // Call inCallback_threaded
-    if (!inCallback_threaded(_queue->pop())) {
+    inCallback(_queue->pop());
-      cerr << "*********** Callback result returned false! *************"
-           << endl;
-      _lastCallbackResult = false;
-    }
   }
   _thread_running = false;
 }

src/lasp/dsp/lasp_threadedindatahandler.h

@@ -1,9 +1,11 @@
 #pragma once
+#include "debugtrace.hpp"
 #include "lasp_indatahandler.h"
 #include <atomic>
 #include <memory>
 #include <mutex>
 
+using std::placeholders::_1;
 const us RINGBUFFER_SIZE = 1024;
 
 /**
@@ -16,23 +18,45 @@ const us RINGBUFFER_SIZE = 1024;
 
 class SafeQueue;
 /**
- * @brief Threaded in data handler. Buffers inCallback data and calls a
+ * @brief Threaded in data handler base. Buffers inCallback data and calls a
- * callback with the same signature on a different thread.
+ * callback with the same signature on a different thread. The main function of
+ * this is to offload the thread that handles the stream, such that expensive
+ * computations do not result in stream buffer xruns.
  */
-class ThreadedInDataHandler : protected InDataHandler {
+class ThreadedInDataHandlerBase {
   /**
    * @brief The queue used to push elements to the handling thread.
    */
+
+  InDataHandler _indatahandler;
   std::unique_ptr<SafeQueue> _queue;
+
   mutable std::recursive_mutex _mtx;
 
   std::atomic<bool> _thread_running{false};
-  std::atomic<bool> _lastCallbackResult{true};
   std::atomic<bool> _thread_can_safely_run{false};
 
+  /**
+   * @brief Function pointer that is called when new DaqData arrives.
+   */
+  const InCallbackType inCallback;
+
   void threadFcn();
 
-protected:
+
+  /**
+   * @brief Pushes a copy of the daqdata to the thread queue and returns.
+   * Adds a thread to handle the queue, whihc will call inCallback();
+   *
+   * @param daqdata the daq info to push
+   *
+   * @return true, to continue with sampling.
+   */
+  void _inCallbackFromInDataHandler(const DaqData &daqdata);
+
+  public:
+  ThreadedInDataHandlerBase(SmgrHandle mgr, InCallbackType cb, InResetType reset);
+  ~ThreadedInDataHandlerBase();
   /**
    * @brief This method should be called from the derived class' constructor,
    * to start the thread and data is incoming.
@@ -46,33 +70,44 @@ protected:
    */
   void stopThread();
 
-public:
+};
-  /**
-   * @brief Initialize a ThreadedInDataHandler
-   *
-   * @param mgr StreamMgr singleton reference
-   */
-  ThreadedInDataHandler(SmgrHandle mgr);
-  virtual ~ThreadedInDataHandler();
 
-  /**
+/**
-   * @brief Pushes a copy of the daqdata to the thread queue and returns
+ * @brief A bit of curiously recurring template pattern, to connect the
+ * specific handlers and connect the proper callbacks in a type-agnostic way.
+ * Using this class, each threaded handler should just implement its reset()
+ * and inCallback() method. Ellides the virtual method calls.
  *
-   * @param daqdata the daq info to push
+ * Usage: class XHandler: public ThreadedInDataHandler<XHandler> {
+ * public:
+ * XHandler(streammgr) : ThreadedInDataHandler(streammgr) {}
+ * void inCallback(const DaqData& d) { ... do something with d }
+ * void reset(const Daq* daq) { ... do something with daq }
+ * };
  *
-   * @return true, to continue with sampling.
+ * For examples, see PPMHandler, etc.
+ *
+ * @tparam Derived The
  */
-  virtual bool inCallback(const DaqData &daqdata) override final;
+template <typename Derived>
+class ThreadedInDataHandler : public ThreadedInDataHandlerBase {
+  public:
+  ThreadedInDataHandler(SmgrHandle mgr):
+    ThreadedInDataHandlerBase(mgr, 
+        std::bind(&ThreadedInDataHandler::_inCallback, this, _1),
+        std::bind(&ThreadedInDataHandler::_reset, this, _1))
+  {
 
-  /**
+  }
-   * @brief This function should be overridden with an actual implementation,
+
-   * of what should happen on a different thread.
+  void _reset(const Daq* daq) {
-   *
+    DEBUGTRACE_ENTER;
-   * @param d Input daq data
+    return static_cast<Derived*>(this)->reset(daq);
-   *
+  }
-   * @return true on succes. False when an error occured.
+  void _inCallback(const DaqData& data) {
-   */
+    DEBUGTRACE_ENTER;
-  virtual bool inCallback_threaded(const DaqData &d) = 0;
+    return static_cast<Derived*>(this)->inCallback(data);
+  }
 };
 
 /** @} */

src/lasp/pybind11/lasp_pyindatahandler.cpp

@@ -96,17 +96,26 @@ py::array_t<d> dmat_to_ndarray(const DaqData &d) {
 }
 
 /**
- * @brief Wraps the InDataHandler such that it calls a Python callback with a
+ * @brief Wraps the ThreadedInDataHandler such that it calls a Python callback with a
- * buffer of sample data. The Python callback is called from a different
+ * buffer of sample data. Converts DaqData objects to Numpy arrays and calls
- * thread, using a Numpy array as argument.
+ * Python given as argument to the constructor
  */
-class PyIndataHandler : public ThreadedInDataHandler {
+class PyIndataHandler : public ThreadedInDataHandler<PyIndataHandler> {
   /**
    * @brief The callback functions that is called.
    */
   py::function cb, reset_callback;
 
 public:
+  /**
+   * @brief Initialize PyIndataHandler
+   *
+   * @param mgr StreamMgr handle
+   * @param cb Python callback that is called with Numpy input data from device
+   * @param reset_callback Python callback that is called with a Daq pointer.
+   * Careful: do not store this handle, as it is only valid as long as reset()
+   * is called, when a stream stops, this pointer / handle will dangle.
+   */
   PyIndataHandler(SmgrHandle mgr, py::function cb, py::function reset_callback)
       : ThreadedInDataHandler(mgr), cb(cb), reset_callback(reset_callback) {
 
@@ -119,7 +128,12 @@ public:
     DEBUGTRACE_ENTER;
     stopThread();
   }
-  void reset(const Daq *daq) override final {
+  /**
+   * @brief Calls the reset callback in Python.
+   *
+   * @param daq Daq device, or nullptr in case no input stream is running.
+   */
+  void reset(const Daq *daq) {
     DEBUGTRACE_ENTER;
     py::gil_scoped_acquire acquire;
     try {
@@ -140,9 +154,10 @@ public:
   }
 
   /**
-   * @brief Reads from the buffer
+   * @brief Calls the Python callback method / function with a Numpy array of
+   * stream data.
    */
-  bool inCallback_threaded(const DaqData &d) override final {
+  void inCallback(const DaqData &d) {
 
     /* DEBUGTRACE_ENTER; */
 
@@ -172,18 +187,15 @@ public:
       } // End of switch
 
       bool res = bool_val.cast<bool>();
-      if (!res)
-        return false;
     } catch (py::error_already_set &e) {
       cerr << "ERROR: Python raised exception from callback function: ";
       cerr << e.what() << endl;
-      return false;
+      abort();
     } catch (py::cast_error &e) {
       cerr << e.what() << endl;
       cerr << "ERROR: Python callback does not return boolean value." << endl;
-      return false;
+      abort();
     }
-    return true;
   }
 };