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| author | Joel Sherrill <joel.sherrill@OARcorp.com> | 2011-09-11 20:52:37 +0000 |
|---|---|---|
| committer | Joel Sherrill <joel.sherrill@OARcorp.com> | 2011-09-11 20:52:37 +0000 |
| commit | 5472ad414f5eec7aba13f3d03ee8e35dfdfa406a (patch) | |
| tree | 48cbdd803d647379298e1596dcaaf0a68598cc54 /cpukit/score/src/scheduleredfprioritycompare.c | |
| parent | 2011-09-09 Sebastian Huber <sebastian.huber@embedded-brains.de> (diff) | |
| download | rtems-5472ad414f5eec7aba13f3d03ee8e35dfdfa406a.tar.bz2 | |
2011-09-11 Petr Benes <benesp16@fel.cvut.cz>
PR 1896/cpukit
* sapi/include/confdefs.h, score/Makefile.am, score/preinstall.am: Add
Earliest Deadline First (EDF) Scheduling Algorithm implementation.
* score/include/rtems/score/scheduleredf.h, score/src/scheduleredf.c,
score/src/scheduleredfallocate.c, score/src/scheduleredfblock.c,
score/src/scheduleredfenqueue.c,
score/src/scheduleredfenqueuefirst.c,
score/src/scheduleredfextract.c, score/src/scheduleredffree.c,
score/src/scheduleredfprioritycompare.c,
score/src/scheduleredfreleasejob.c, score/src/scheduleredfschedule.c,
score/src/scheduleredfunblock.c, score/src/scheduleredfupdate.c,
score/src/scheduleredfyield.c: New files.
Diffstat (limited to 'cpukit/score/src/scheduleredfprioritycompare.c')
| -rw-r--r-- | cpukit/score/src/scheduleredfprioritycompare.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/cpukit/score/src/scheduleredfprioritycompare.c b/cpukit/score/src/scheduleredfprioritycompare.c new file mode 100644 index 0000000000..324e44af37 --- /dev/null +++ b/cpukit/score/src/scheduleredfprioritycompare.c @@ -0,0 +1,40 @@ +/* + * Copyright (C) 2011 Petr Benes. + * Copyright (C) 2011 On-Line Applications Research Corporation (OAR). + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.com/license/LICENSE. + * + * $Id$ + */ + +#if HAVE_CONFIG_H +#include "config.h" +#endif + +#include <rtems/system.h> +#include <rtems/config.h> +#include <rtems/score/scheduleredf.h> + +int _Scheduler_EDF_Priority_compare ( + Priority_Control p1, + Priority_Control p2 +) +{ + Watchdog_Interval time = _Watchdog_Ticks_since_boot; + + /* + * Reorder priorities to separate deadline driven and background tasks. + * + * The background tasks have p1 or p2 > SCHEDULER_EDF_PRIO_MSB. + * The deadline driven tasks need to have subtracted current time in order + * to see which deadline is closer wrt. current time. + */ + if (!(p1 & SCHEDULER_EDF_PRIO_MSB)) + p1 = (p1 - time) & ~SCHEDULER_EDF_PRIO_MSB; + if (!(p2 & SCHEDULER_EDF_PRIO_MSB)) + p2 = (p2 - time) & ~SCHEDULER_EDF_PRIO_MSB; + + return ((p1<p2) - (p1>p2)); +} |