1 files changed, 106 insertions, 0 deletions
diff --git a/host/lib/utils/thread_priority.cpp b/host/lib/utils/thread_priority.cpp
new file mode 100644
index 000000000..6d6ca5630
--- /dev/null
+++ b/host/lib/utils/thread_priority.cpp
@@ -0,0 +1,106 @@
+//
+// Copyright 2010-2011 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <uhd/utils/thread_priority.hpp>
+#include <uhd/utils/msg.hpp>
+#include <uhd/exception.hpp>
+#include <boost/format.hpp>
+#include <iostream>
+
+bool uhd::set_thread_priority_safe(float priority, bool realtime){
+    try{
+        set_thread_priority(priority, realtime);
+        return true;
+    }catch(const std::exception &e){
+        UHD_MSG(warning) << boost::format(
+            "Unable to set the thread priority. Performance may be negatively affected.\n"
+            "Please see the general application notes in the manual for instructions.\n"
+            "%s\n"
+        ) % e.what();
+        return false;
+    }
+}
+
+static void check_priority_range(float priority){
+    if (priority > +1.0 or priority < -1.0)
+        throw uhd::value_error("priority out of range [-1.0, +1.0]");
+}
+
+/***********************************************************************
+ * Pthread API to set priority
+ **********************************************************************/
+#ifdef HAVE_PTHREAD_SETSCHEDPARAM
+    #include <pthread.h>
+
+    void uhd::set_thread_priority(float priority, bool realtime){
+        check_priority_range(priority);
+
+        //when realtime is not enabled, use sched other
+        int policy = (realtime)? SCHED_RR : SCHED_OTHER;
+
+        //we cannot have below normal priority, set to zero
+        if (priority < 0) priority = 0;
+
+        //get the priority bounds for the selected policy
+        int min_pri = sched_get_priority_min(policy);
+        int max_pri = sched_get_priority_max(policy);
+        if (min_pri == -1 or max_pri == -1) throw uhd::os_error("error in sched_get_priority_min/max");
+
+        //set the new priority and policy
+        sched_param sp;
+        sp.sched_priority = int(priority*(max_pri - min_pri)) + min_pri;
+        int ret = pthread_setschedparam(pthread_self(), policy, &sp);
+        if (ret != 0) throw uhd::os_error("error in pthread_setschedparam");
+    }
+#endif /* HAVE_PTHREAD_SETSCHEDPARAM */
+
+/***********************************************************************
+ * Windows API to set priority
+ **********************************************************************/
+#ifdef HAVE_WIN_SETTHREADPRIORITY
+    #include <windows.h>
+
+    void uhd::set_thread_priority(float priority, bool realtime){
+        check_priority_range(priority);
+
+        //set the priority class on the process
+        int pri_class = (realtime)? REALTIME_PRIORITY_CLASS : NORMAL_PRIORITY_CLASS;
+        if (SetPriorityClass(GetCurrentProcess(), pri_class) == 0)
+            throw uhd::os_error("error in SetPriorityClass");
+
+        //scale the priority value to the constants
+        int priorities[] = {
+            THREAD_PRIORITY_IDLE, THREAD_PRIORITY_LOWEST, THREAD_PRIORITY_BELOW_NORMAL, THREAD_PRIORITY_NORMAL,
+            THREAD_PRIORITY_ABOVE_NORMAL, THREAD_PRIORITY_HIGHEST, THREAD_PRIORITY_TIME_CRITICAL
+        };
+        size_t pri_index = size_t((priority+1.0)*6/2.0); // -1 -> 0, +1 -> 6
+
+        //set the thread priority on the thread
+        if (SetThreadPriority(GetCurrentThread(), priorities[pri_index]) == 0)
+            throw uhd::os_error("error in SetThreadPriority");
+    }
+#endif /* HAVE_WIN_SETTHREADPRIORITY */
+
+/***********************************************************************
+ * Unimplemented API to set priority
+ **********************************************************************/
+#ifdef HAVE_LOAD_MODULES_DUMMY
+    void uhd::set_thread_priority(float, bool){
+        throw uhd::not_implemented_error("set thread priority not implemented");
+    }
+
+#endif /* HAVE_LOAD_MODULES_DUMMY */