Commit Graph

14 Commits

Author SHA1 Message Date
Gregory Nutt
3e13ed2400 Within the OS, when a thread obtains a semaphore count it must call sem_addholder() if CONFIG_PRIORITY_INHERITANCE is enabled. If a count is available, then sem_wait() calls sem_addholder(), otherwise it waited for the semaphore and called sem_addholder() when it eventually received the count.
This caused a problem when the thread calling sem_wait() was very low priority.  When it received the count, there may be higher priority threads "hogging" the CPU that prevent the lower priority task from running and, as a result, the sem_addholder() may be delayed indefinitely.

The fix was to have sem_post() call sem_addholder() just before restarting the thread waiting for the semaphore count.

This problem was noted by Benix Vincent who also suggested the solution.
2016-10-26 07:23:15 -06:00
Gregory Nutt
0c8c7fecf0 Add _ to the beginning of all debug macros to avoid name collisions 2016-06-16 12:33:32 -06:00
Gregory Nutt
13cac3b592 sched/: Change some *err() message to *info() messages if what was a *dbg() message does not indicate and error condition. 2016-06-11 16:42:42 -06:00
Gregory Nutt
a1469a3e95 Add CONFIG_DEBUG_ERROR. Change names of *dbg() * *err() 2016-06-11 15:50:49 -06:00
Gregory Nutt
1cdc746726 Rename CONFIG_DEBUG to CONFIG_DEBUG_FEATURES 2016-06-11 14:14:08 -06:00
Gregory Nutt
74db48202e sched/: Replace explict references to g_readytorun with indirect references via the this_task() macro 2016-02-06 17:44:41 -06:00
Gregory Nutt
b90da3f27b waitpid: CRITICAL BUGFIX. Add a reference counting mechansim to prevent wait from using stale memory that was freed by the exiting task 2015-12-22 11:48:17 -06:00
Gregory Nutt
79d554939e sched/: Fix some spacing issues 2015-10-07 19:59:14 -06:00
Gregory Nutt
0b12dbf95d Fix some spacing problems 2015-10-04 15:04:00 -06:00
Gregory Nutt
cb9e27c3b0 Standardize naming used for public data and function groupings 2015-10-02 16:30:35 -06:00
Gregory Nutt
b4423c1eed Make some file section headers more consistent with standard 2015-04-08 06:47:36 -06:00
Gregory Nutt
38ddbc774f Cosmetic change to comments 2014-10-06 18:03:01 -06:00
Gregory Nutt
d798dd37a7 Replace os_internal.h with sched/sched.h in files that actually reference something in sched.h 2014-08-08 17:53:55 -06:00
Gregory Nutt
e10a23ae50 Move environment files from sched/ to sched/environ 2014-08-08 13:53:29 -06:00