From e48df9cb5ec9e48cd836ec227127f42c5cc99aa1 Mon Sep 17 00:00:00 2001
From: "Matthias P. Braendli" <matthias.braendli@mpb.li>
Date: Fri, 17 Jun 2016 11:26:57 +0200
Subject: Set SCHED_RR prio for all data processing threads

This includes Modulator, FIR Filter and UHD worker
---
 src/DabMod.cpp    | 4 ++++
 src/FIRFilter.cpp | 3 +++
 src/OutputUHD.cpp | 6 ++++++
 src/Utils.cpp     | 9 +++++++++
 src/Utils.h       | 2 ++
 5 files changed, 24 insertions(+)

diff --git a/src/DabMod.cpp b/src/DabMod.cpp
index e0e7f8e..b5e3568 100644
--- a/src/DabMod.cpp
+++ b/src/DabMod.cpp
@@ -751,6 +751,10 @@ int launch_modulator(int argc, char* argv[])
     }
 #endif
 
+    // Set thread priority to realtime
+    if (int r = set_realtime_prio(1)) {
+        etiLog.level(error) << "Could not set priority for modulator:" << r;
+    }
 
     while (run_again) {
         Flowgraph flowgraph;
diff --git a/src/FIRFilter.cpp b/src/FIRFilter.cpp
index e217288..ebd4518 100644
--- a/src/FIRFilter.cpp
+++ b/src/FIRFilter.cpp
@@ -29,6 +29,7 @@
 
 #include "FIRFilter.h"
 #include "PcDebug.h"
+#include "Utils.h"
 
 #include <stdio.h>
 #include <stdexcept>
@@ -55,6 +56,8 @@ void FIRFilterWorker::process(struct FIRFilterWorkerData *fwd)
     struct timespec time_start;
     struct timespec time_end;
 
+    set_realtime_prio(1);
+
     // This thread creates the dataOut buffer, and deletes
     // the incoming buffer
 
diff --git a/src/OutputUHD.cpp b/src/OutputUHD.cpp
index a49b659..dff0fd2 100644
--- a/src/OutputUHD.cpp
+++ b/src/OutputUHD.cpp
@@ -45,6 +45,7 @@
 #include <time.h>
 #include <errno.h>
 #include <unistd.h>
+#include <pthread.h>
 
 using namespace std;
 
@@ -595,6 +596,11 @@ void OutputUHD::check_gps()
 
 void UHDWorker::process_errhandler()
 {
+    // Set thread priority to realtime
+    if (int ret = set_realtime_prio(1)) {
+        etiLog.level(error) << "Could not set priority for UHD worker:" << ret;
+    }
+
     process();
     uwd->running = false;
     etiLog.level(warn) << "UHD worker terminated";
diff --git a/src/Utils.cpp b/src/Utils.cpp
index 4805374..ab1866c 100644
--- a/src/Utils.cpp
+++ b/src/Utils.cpp
@@ -114,4 +114,13 @@ void printVersion(void)
 
 }
 
+int set_realtime_prio(int prio)
+{
+    // Set thread priority to realtime
+    const int policy = SCHED_RR;
+    sched_param sp;
+    sp.sched_priority = sched_get_priority_min(policy) + prio;
+    int ret = pthread_setschedparam(pthread_self(), policy, &sp);
+    return ret;
+}
 
diff --git a/src/Utils.h b/src/Utils.h
index f023646..7f65fa3 100644
--- a/src/Utils.h
+++ b/src/Utils.h
@@ -57,6 +57,8 @@ inline long timespecdiff_us(struct timespec& oldTime, struct timespec& time)
     return tv_sec * 1000 + tv_nsec / 1000;
 }
 
+// Set SCHED_RR with priority prio (0=lowest)
+int set_realtime_prio(int prio);
 
 #endif
 
-- 
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