extend gruel:enable_realtime_scheduling interface to allow pri/policy

[debian/gnuradio] / gruel / src / include / gruel / realtime.h

diff --git a/gruel/src/include/gruel/realtime.h b/gruel/src/include/gruel/realtime.h
index ded70ed0d7b7c99cdf8b7408c169e0d82de6ca70..8beec26d646e28836865380ac9e34af1609cca0d 100644 (file)
--- a/gruel/src/include/gruel/realtime.h
+++ b/gruel/src/include/gruel/realtime.h
@@ -1,6 +1,6 @@
 /* -*- c++ -*- */
 /*
- * Copyright 2006 Free Software Foundation, Inc.
+ * Copyright 2006,2008 Free Software Foundation, Inc.
  * 
  * This file is part of GNU Radio
  * 
@@ -20,8 +20,16 @@
  * Boston, MA 02110-1301, USA.
  */
 
-#ifndef INCLUDED_REALTIME_H
-#define INCLUDED_REALTIME_H
+#ifndef INCLUDED_GRUEL_REALTIME_H
+#define INCLUDED_GRUEL_REALTIME_H
+
+#include <stdexcept>
+
+/*!
+ * \brief System independent way to ask for realtime scheduling
+ *
+ * \sa sys_pri.h
+ */
 
 namespace gruel {
 
@@ -32,13 +40,53 @@ namespace gruel {
     RT_OTHER_ERROR
   } rt_status_t;
 
+
+  enum rt_sched_policy {
+    RT_SCHED_RR   = 0,         // round robin
+    RT_SCHED_FIFO = 1,         // first in first out
+  };
+
+  /*
+   * Define the range for our virtual priorities (don't change these)
+   *
+   * Processes (or threads) with numerically higher priority values
+   * are scheduled before processes with numerically lower priority
+   * values.  Thus, the value returned by rt_priority_max() will be
+   * greater than the value returned by rt_priority_min().
+   */
+  static inline int rt_priority_min() { return  0; }
+  static inline int rt_priority_max() { return 15; }
+  static inline int rt_priority_default() { return 1; }
+
+  struct rt_sched_param {
+    int                        priority;
+    rt_sched_policy    policy;
+
+    rt_sched_param()
+      : priority(rt_priority_default()), policy(RT_SCHED_RR){}
+
+    rt_sched_param(int priority_, rt_sched_policy policy_ = RT_SCHED_RR)
+    {
+      if (priority_ < rt_priority_min() || priority_ > rt_priority_max())
+       throw std::invalid_argument("rt_sched_param: priority out of range");
+
+      priority = priority_;
+      policy = policy_;
+    }
+  };
+
   /*!
-   * \brief If possible, enable high-priority "real time" scheduling.
+   * \brief If possible, enable "realtime" scheduling.
    * \ingroup misc
+   *
+   * In general, this means that the code will be scheduled before any
+   * non-realtime (normal) processes.  Note that if your code contains
+   * an non-blocking infinite loop and you enable realtime scheduling,
+   * it's possible to hang the system.
    */
   rt_status_t
-  enable_realtime_scheduling();
+  enable_realtime_scheduling(rt_sched_param = rt_sched_param());
 
 } // namespace gruel
 
-#endif /* INCLUDED_GR_REALTIME_H */
+#endif /* INCLUDED_GRUEL_REALTIME_H */