Freddie Chopin
484a1b6104
sem_wait() and sem_trywait() no longer modify the errno value UNLESS an error occurs. This allows these functions to be used internallly without clobbering the errno value.
2016-11-09 07:01:49 -06:00
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
Paul A. Patience
891113dac9
sched/semaphore: Fix setting EINVAL in sem_post() and sem_wait()
2016-06-28 10:15:52 -04:00
Gregory Nutt
6e3107650d
nuttx/sched: Replace irqsave() with enter_critical_section(); replace irqrestore() with leave_critical_section()
2016-02-14 08:17:46 -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
cb9e27c3b0
Standardize naming used for public data and function groupings
2015-10-02 16:30:35 -06:00
Gregory Nutt
093a144934
sem_wait(): Missing comma on debug statement caused compile error with DEBUG on. Why hasn't that been noted before?
2015-04-23 07:15:55 -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
