gruel: support for windows API set realtime scheduling

1 files changed, 32 insertions, 0 deletions

diff --git a/gruel/src/lib/realtime.cc b/gruel/src/lib/realtime.cc
index 7397cf3d3..96351f812 100644
--- a/gruel/src/lib/realtime.cc
+++ b/gruel/src/lib/realtime.cc
@@ -132,6 +132,38 @@ namespace gruel {
 
 } // namespace gruel
 
+#elif defined(_WIN32) || defined(__WIN32__) || defined(WIN32)
+
+#include <windows.h>
+
+namespace gruel {
+
+    rt_status_t enable_realtime_scheduling(rt_sched_param p){
+
+        //set the priority class on the process
+        int pri_class = (true)? REALTIME_PRIORITY_CLASS : NORMAL_PRIORITY_CLASS;
+        if (SetPriorityClass(GetCurrentProcess(), pri_class) == 0)
+            return RT_OTHER_ERROR;
+
+        //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
+        };
+        const double priority = double(p.priority)/(rt_priority_max() - rt_priority_min());
+        size_t pri_index = size_t((priority+1.0)*6/2.0); // -1 -> 0, +1 -> 6
+        pri_index %= sizeof(priorities)/sizeof(*priorities); //range check
+
+        //set the thread priority on the thread
+        if (SetThreadPriority(GetCurrentThread(), priorities[pri_index]) == 0)
+            return RT_OTHER_ERROR;
+
+        //printf("SetPriorityClass + SetThreadPriority\n");
+        return RT_OK;
+    }
+
+} // namespace gruel
+
 #else
 
 namespace gruel {