From 6881e0cb4be86a4e91cd2f4d95c43b20d7b89de4 Mon Sep 17 00:00:00 2001 From: Joel Sherrill Date: Tue, 15 Apr 1997 18:02:18 +0000 Subject: Reduced number of POSIX thread priorities from 255 to 254 to avoid conflicts of lowest priority with the RTEMS IDLE thread. This was causing the lowest priority GNAT Ada task to never run. --- cpukit/posix/include/rtems/posix/priority.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'cpukit/posix/include/rtems') diff --git a/cpukit/posix/include/rtems/posix/priority.h b/cpukit/posix/include/rtems/posix/priority.h index ce925b6d58..c0253f3bab 100644 --- a/cpukit/posix/include/rtems/posix/priority.h +++ b/cpukit/posix/include/rtems/posix/priority.h @@ -15,9 +15,15 @@ * "Numericallly higher values represent higher priorities." * * Thus, RTEMS Core has priorities run in the opposite sense of the POSIX API. + * + * There are only 254 posix priority levels since a task at priority level + * 255 would never run because of the RTEMS idle task. This is necessary + * because GNAT maps the lowest Ada task priority to the lowest thread + * priority. The lowest priority Ada task should get to run, so there is + * a fundamental conflict with having 255 priorities. */ -#define POSIX_SCHEDULER_MAXIMUM_PRIORITY (255) +#define POSIX_SCHEDULER_MAXIMUM_PRIORITY (254) #define POSIX_SCHEDULER_MINIMUM_PRIORITY (1) -- cgit v1.2.3