DATV: enhancement and fixes to DVBS2 external LDPC tool process. Implements #804

plugins/channelrx/demoddatv/datvdemodsettings.cpp

@@ -197,7 +197,7 @@ bool DATVDemodSettings::deserialize(const QByteArray& data)
         d.readS32(33, &m_maxBitflips, 0);
         d.readString(34, &m_softLDPCToolPath, "/opt/install/sdrangel/bin/ldpctool");
         d.readS32(35, &tmp, 8);
-        m_softLDPCMaxTrials = tmp < 1 ? 1 : tmp > 8 ? 8 : tmp;
+        m_softLDPCMaxTrials = tmp < 1 ? 1 : tmp > m_softLDPCMaxMaxTrials ? m_softLDPCMaxMaxTrials : tmp;
 
         validateSystemConfiguration();
 

plugins/channelrx/demoddatv/datvdemodsettings.h

@@ -106,6 +106,7 @@ struct DATVDemodSettings
     uint16_t m_reverseAPIPort;
     uint16_t m_reverseAPIDeviceIndex;
     uint16_t m_reverseAPIChannelIndex;
+    static const int m_softLDPCMaxMaxTrials = 25;
 
     DATVDemodSettings();
     void resetToDefaults();

plugins/channelrx/demoddatv/datvdemodsink.cpp

@@ -431,6 +431,10 @@ void DATVDemodSink::CleanUpDATVFramework(bool blnRelease)
         {
             delete (leansdr::s2_fecdec_soft<leansdr::llr_t,leansdr::llr_sb>*) r_fecdecsoft;
         }
+        if(r_fecdechelper != nullptr)
+        {
+            delete (leansdr::s2_fecdec_helper<leansdr::llr_t,leansdr::llr_sb>*) r_fecdechelper;
+        }
 #endif
 
         if(p_deframer != nullptr)
@@ -442,7 +446,7 @@ void DATVDemodSink::CleanUpDATVFramework(bool blnRelease)
         {
             delete r_scope_symbols_dvbs2;
         }
-    }
+    } // blnRelease
 
     m_objScheduler=nullptr;
 
@@ -547,6 +551,7 @@ void DATVDemodSink::CleanUpDATVFramework(bool blnRelease)
     p_s2_deinterleaver = nullptr;
     r_fecdec = nullptr;
     r_fecdecsoft = nullptr;
+    r_fecdechelper = nullptr;
     p_deframer = nullptr;
     r_scope_symbols_dvbs2 = nullptr;
 }
@@ -893,7 +898,7 @@ void DATVDemodSink::InitDATVS2Framework()
 
     m_blnDVBInitialized = false;
     m_lngReadIQ = 0;
-    CleanUpDATVFramework(false);
+    CleanUpDATVFramework(true);
 
     qDebug()  << "DATVDemodSink::InitDATVS2Framework:"
         <<  " Standard: " << m_settings.m_standard
@@ -1185,7 +1190,7 @@ void DATVDemodSink::InitDATVS2Framework()
             *(leansdr::pipebuf< leansdr::fecframe<leansdr::llr_sb> > *) p_fecframes
         );
         // Decode FEC-protected frames into plain BB frames.
-        r_fecdec = new leansdr::s2_fecdec_helper<leansdr::llr_t, leansdr::llr_sb>(
+        r_fecdechelper = new leansdr::s2_fecdec_helper<leansdr::llr_t, leansdr::llr_sb>(
             m_objScheduler,
             *(leansdr::pipebuf< leansdr::fecframe<leansdr::llr_sb> > *) p_fecframes,
             *(leansdr::pipebuf<leansdr::bbframe> *) p_bbframes,
@@ -1193,8 +1198,8 @@ void DATVDemodSink::InitDATVS2Framework()
             p_vbitcount,
             p_verrcount)
         ;
-        leansdr::s2_fecdec_helper<leansdr::llr_t, leansdr::llr_sb> *fecdec = (leansdr::s2_fecdec_helper<leansdr::llr_t, leansdr::llr_sb> *) r_fecdec;
+        leansdr::s2_fecdec_helper<leansdr::llr_t, leansdr::llr_sb> *fecdec = (leansdr::s2_fecdec_helper<leansdr::llr_t, leansdr::llr_sb> *) r_fecdechelper;
-        const int nhelpers = 2;
+        const int nhelpers = 4;
         fecdec->nhelpers = nhelpers;
         fecdec->must_buffer = false;
         fecdec->max_trials = m_settings.m_softLDPCMaxTrials;

plugins/channelrx/demoddatv/datvdemodsink.h

@@ -225,6 +225,7 @@ private:
     void *p_s2_deinterleaver;
     void *r_fecdec;
     void *r_fecdecsoft;
+    void *r_fecdechelper;
     void *p_deframer;
 
     //DECIMATION

plugins/channelrx/demoddatv/datvdvbs2ldpcdialog.cpp

@@ -19,6 +19,7 @@
 #include <QFileDialog>
 
 #include "datvdvbs2ldpcdialog.h"
+#include "datvdemodsettings.h"
 #include "ui_datvdvbs2ldpcdialog.h"
 
 DatvDvbS2LdpcDialog::DatvDvbS2LdpcDialog(QWidget* parent) :
@@ -46,7 +47,8 @@ void DatvDvbS2LdpcDialog::setFileName(const QString& fileName)
 
 void DatvDvbS2LdpcDialog::setMaxTrials(int maxTrials)
 {
-    m_maxTrials = maxTrials < 1 ? 1 : maxTrials > 8 ? 8 : maxTrials;
+    m_maxTrials = maxTrials < 1 ? 1 :
+        maxTrials > DATVDemodSettings::m_softLDPCMaxMaxTrials ? DATVDemodSettings::m_softLDPCMaxMaxTrials : maxTrials;
     ui->maxTrials->setValue(m_maxTrials);
 }
 

plugins/channelrx/demoddatv/datvdvbs2ldpcdialog.ui

@@ -31,11 +31,17 @@
      </item>
      <item>
       <widget class="QSpinBox" name="maxTrials">
+       <property name="minimumSize">
+        <size>
+         <width>55</width>
+         <height>0</height>
+        </size>
+       </property>
        <property name="minimum">
         <number>1</number>
        </property>
        <property name="maximum">
-        <number>8</number>
+        <number>25</number>
        </property>
        <property name="displayIntegerBase">
         <number>10</number>

plugins/channelrx/demoddatv/ldpctool/ldpc_tool.cpp

@@ -136,6 +136,10 @@ int main(int argc, char **argv)
 	if (sizeof(ldpctool::code_type) != 1)
 		fail("Bug: Unsupported code_type");
 
+	int trials_count = 0;
+	int max_count = 0;
+	int num_decodes = 0;
+
 	while (true)
 	{
 		ssize_t iosize = BLOCKS * CODE_LEN * sizeof(*code);
@@ -153,8 +157,6 @@ int main(int argc, char **argv)
 			pos += nr;
 		}
 
-		int iterations = 0;
-		int num_decodes = 0;
 
 		for (int j = 0; j < BLOCKS; j += ldpctool::SIMD_WIDTH)
 		{
@@ -164,24 +166,31 @@ int main(int argc, char **argv)
 				for (int i = 0; i < CODE_LEN; ++i)
 					reinterpret_cast<ldpctool::code_type *>(simd + i)[n] = code[(j + n) * CODE_LEN + i];
 
-			int trials = max_trials;
+			int count = decode(simd, simd + DATA_LEN, max_trials, blocks);
-			int count = decode(simd, simd + DATA_LEN, trials, blocks);
+			num_decodes++;
-			++num_decodes;
+
+			if (count < 0)
+			{
+				trials_count += max_trials;
+				max_count++;
+			}
+			else
+			{
+				trials_count += max_trials - count;
+			}
+
+			if (num_decodes == 20)
+			{
+				fprintf(stderr, "ldpc_tool: trials: %d%% max: %d%% at converging to a code word\n",
+					(trials_count*100)/(num_decodes*max_trials), (max_count*100)/num_decodes);
+				trials_count = 0;
+				max_count = 0;
+				num_decodes = 0;
+			}
 
 			for (int n = 0; n < blocks; ++n)
 				for (int i = 0; i < CODE_LEN; ++i)
 					code[(j + n) * CODE_LEN + i] = reinterpret_cast<ldpctool::code_type *>(simd + i)[n];
-
-			if (count < 0)
-			{
-				iterations += blocks * trials;
-				std::cerr << "ldpc_tool: decoder failed at converging to a code word in " << trials << " trials" << std::endl;
-				break;
-			}
-			else
-			{
-				iterations += blocks * (trials - count);
-			}
 		}
 
 		for (int i = 0; i < BLOCKS * CODE_LEN; ++i)

plugins/channelrx/demoddatv/leansdr/dvbs2.h

@@ -37,6 +37,8 @@
 #include "sdr.h"
 
 #ifdef LINUX
+#include <signal.h>
+#include <sys/wait.h>
 #include "ldpctool/layered_decoder.h"
 #include "ldpctool/testbench.h"
 #include "ldpctool/algorithms.h"
@@ -2379,6 +2381,7 @@ struct s2_fecdec_helper : runnable
     ~s2_fecdec_helper()
     {
         free(command);
+        killall();
     }
 
     void run()
@@ -2424,6 +2427,7 @@ struct s2_fecdec_helper : runnable
         int batch_size; // Latency
         int b_in;       // Jobs in input queue
         int b_out;      // Jobs in output queue
+        int pid;        // PID of the child
     };
     struct pool
     {
@@ -2451,10 +2455,13 @@ struct s2_fecdec_helper : runnable
             int nw = write(h->fd_tx, pin->bytes, iosize);
 
             if (nw < 0 && errno == EWOULDBLOCK)
+            {
+                lseek(h->fd_tx, 0, SEEK_SET); // allow new writes on this worker
                 continue; // next worker
+            }
             if (nw < 0)
                 fatal("write(LDPC helper");
-            if (nw != iosize)
+            else if (nw != iosize)
                 fatal("partial write(LDPC helper)");
 
             helper_job *job = jobs.put();
@@ -2471,9 +2478,9 @@ struct s2_fecdec_helper : runnable
             return true; // done sent to worker
         }
 
-        fprintf(stderr, "s2_fecdec_helper::send_frame: WARNING: all %d workers are busy: modcod=%d sf=%d)\n",
+        fprintf(stderr, "s2_fecdec_helper::send_frame: WARNING: all %d workers were busy: modcod=%d sf=%d)\n",
             p->nprocs, pin->pls.modcod, pin->pls.sf);
-        return false; // all workers are busy
+        return false; // all workers were busy
     }
 
     // Return a pool of running helpers for a given modcod.
@@ -2494,6 +2501,42 @@ struct s2_fecdec_helper : runnable
         return p;
     }
 
+    void killall()
+    {
+        fprintf(stderr, "s2_fecdec_helper::killall\n");
+
+        for (int i = 0; i < 32; i++) // all MODCODs
+        {
+            for (int j = 0; j < 2; j++) // long and short frames
+            {
+                pool *p = &pools[i][j];
+
+                if (p->procs)
+                {
+                    for (int i = 0; i < p->nprocs; ++i)
+                    {
+                        helper_instance *h = &p->procs[i];
+                        fprintf(stderr, "s2_fecdec_helper::killall: killing %d\n", h->pid);
+                        int rc = kill(h->pid, SIGKILL);
+                        if (rc < 0) {
+                            fatal("s2_fecdec_helper::killall");
+                        } else {
+                            int cs;
+                            waitpid(h->pid, &cs, 0);
+                        }
+                        // reset pipes
+                        lseek(h->fd_tx, 0, SEEK_SET);
+                        lseek(h->fd_rx, 0, SEEK_SET);
+                    }
+
+                    delete p->procs;
+                    p->procs = nullptr;
+                    p->nprocs = 0;
+                }
+            } // long and short frames
+        } // all MODCODs
+    }
+
     // Spawn a helper process.
     void spawn_helper(helper_instance *h, const s2_pls *pls)
     {
@@ -2507,19 +2550,31 @@ struct s2_fecdec_helper : runnable
 // macOS does not have F_SETPIPE_SZ and there
 // is no way to change the buffer size
 #ifndef __APPLE__
-        if (fcntl(tx[0], F_SETPIPE_SZ, pipesize) < 0 ||
+        long min_pipe_size = (long) fcntl(tx[0], F_GETPIPE_SZ);
-            fcntl(rx[0], F_SETPIPE_SZ, pipesize) < 0 ||
+        long pipe_size = (long) fcntl(rx[0], F_GETPIPE_SZ);
-            fcntl(tx[1], F_SETPIPE_SZ, pipesize) < 0 ||
+        min_pipe_size = std::min(min_pipe_size, pipe_size);
-            fcntl(rx[1], F_SETPIPE_SZ, pipesize) < 0)
+        pipe_size = (long) fcntl(tx[1], F_GETPIPE_SZ);
+        min_pipe_size = std::min(min_pipe_size, pipe_size);
+        pipe_size = (long) fcntl(rx[1], F_GETPIPE_SZ);
+        min_pipe_size = std::min(min_pipe_size, pipe_size);
+
+        if (min_pipe_size < pipesize)
         {
-            fprintf(stderr,
+            if (fcntl(tx[0], F_SETPIPE_SZ, pipesize) < 0 ||
-                    "*** Failed to increase pipe size.\n"
+                fcntl(rx[0], F_SETPIPE_SZ, pipesize) < 0 ||
-                    "*** Try echo %d > /proc/sys/fs/pipe-max-size\n",
+                fcntl(tx[1], F_SETPIPE_SZ, pipesize) < 0 ||
-                    pipesize);
+                fcntl(rx[1], F_SETPIPE_SZ, pipesize) < 0)
-            if (must_buffer)
+            {
-                fatal("F_SETPIPE_SZ");
+                fprintf(stderr,
-            else
+                        "*** Failed to increase pipe size from %ld.\n"
-                fprintf(stderr, "*** Throughput will be suboptimal.\n");
+                        "*** Try echo %d > /proc/sys/fs/pipe-max-size\n",
+                        min_pipe_size,
+                        pipesize);
+                if (must_buffer)
+                    fatal("F_SETPIPE_SZ");
+                else
+                    fprintf(stderr, "*** Throughput will be suboptimal.\n");
+            }
         }
 #endif
         // vfork() differs from fork(2) in that the calling thread is
@@ -2552,15 +2607,19 @@ struct s2_fecdec_helper : runnable
             fatal(command);
         }
 
+        h->pid = child;
         h->fd_tx = tx[1];
         close(tx[0]);
         h->fd_rx = rx[0];
         close(rx[1]);
         h->batch_size = batch_size; // TBD
         h->b_in = h->b_out = 0;
-        int flags = fcntl(h->fd_tx, F_GETFL);
+        int flags_tx = fcntl(h->fd_tx, F_GETFL);
-        if (fcntl(h->fd_tx, F_SETFL, flags | O_NONBLOCK))
+        if (fcntl(h->fd_tx, F_SETFL, flags_tx | O_NONBLOCK))
-            fatal("fcntl(helper)");
+            fatal("fcntl_tx(helper)");
+        int flags_rx = fcntl(h->fd_rx, F_GETFL);
+        if (fcntl(h->fd_rx, F_SETFL, flags_rx | O_NONBLOCK))
+            fatal("fcntl_rx(helper)");
     }
 
     // Receive a finished job.
@@ -2570,10 +2629,18 @@ struct s2_fecdec_helper : runnable
         const s2_pls *pls = &job->pls;
         int iosize = (pls->framebits() / 8) * sizeof(ldpc_buf[0]);
         int nr = read(job->h->fd_rx, ldpc_buf, iosize);
+
         if (nr < 0)
-            fatal("read(LDPC helper)");
+        {
-        if (nr != iosize)
+            if (errno != EAGAIN) { // if no data then try again next time
-            fatal("partial read(LDPC helper)");
+                fatal("s2_fecdec_helper::receive_frame read error");
+            }
+        }
+        else if (nr != iosize)
+        {
+            fprintf(stderr, "s2_fecdec_helper::receive_frame: %d bytes read vs %d", nr, iosize);
+        }
+
         --job->h->b_out;
         // Decode BCH.
         const modcod_info *mcinfo = check_modcod(job->pls.modcod);