Commit Graph

18 Commits

Author SHA1 Message Date
Gregory Nutt
74189d84e2 Cancellation points: Fix some backward logic in conditional compilation. 2017-02-02 06:42:41 -06:00
Gregory Nutt
6997cda1b5 Grrr... cloned typos! 2016-12-10 09:45:55 -06:00
Gregory Nutt
842ec7e612 ifdef out some non-reachable code 2016-12-10 09:43:04 -06:00
Gregory Nutt
b52e4e5ecd Move cancellation point definitions to their own header file. 2016-12-10 09:08:26 -06:00
Gregory Nutt
bc3ca25cc7 Cancellation points: Close up some logic to eliminte some race conditions. 2016-12-10 08:36:58 -06:00
Gregory Nutt
c9ca97b4b5 cancellation points are basically function. More tested is needed and additional cancellation points must be implemented before this can be merged back to master. 2016-12-09 12:01:18 -06:00
Gregory Nutt
018db84567 Flesh out more cancellation point logic. 2016-12-09 10:31:40 -06:00
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