Commit Graph

28 Commits

Author SHA1 Message Date
Gregory Nutt
6893843cc5 sched/semaphore: Fix a warning aout an unused variable when priority inheritance is enabled. 2017-03-21 13:47:56 -06:00
Gregory Nutt
e8e3c2f362 sched/semaphore: Convert strange use of DEBUGASSERT to DEBUGPANIC. 2017-03-21 13:34:17 -06:00
David Sidrane
d76157db7b sem_holder:Clean up from Review
Spelling and backward DEBUGASSERT along with one gem

  if (sem->holder[0].htcb != NULL || sem->holder[**1**].htcb != NULL)
2017-03-21 08:03:06 -10:00
David Sidrane
7601a27cee sem_holder:The logic for the list version is unchanged 2017-03-16 14:16:18 -10:00
David Sidrane
3cc2a4f7c9 sem_holder: Fixes improper restoration of base_priority
in the case of CONFIG_SEM_PREALLOCHOLDERS=0

   The call to sem_restorebaseprio_task context switches in the
   sem_foreachholder(sem, sem_restoreholderprioB, stcb); call
   prior to releasing the holder. So the running task is left
   as a holder as is the started task. Leaving both slots filled
   Thus failing to perforem the boost/or restoration on the
   correct tcb.

   This PR fixes this by releasing the running task slot prior
   to reprioritization that can lead to the context switch.
   To faclitate this, the interface to sem_restorebaseprio
   needed to take the tcb from the holder prior to the
   holder being freed. In the failure case where sched_verifytcb
   fails it added the overhead of looking up the holder.

   There is also the adfitinal thunking on the foreach to
   get from holer to holder->tcb.

   An alternate approach could be to leve the interface the same
   and allocate a holder on the stack of sem_restoreholderprioB
   copy the sem's holder to it, free it as is done in this pr
   and and then pass that address sem_restoreholderprio as the
   holder. It could then get the holder's tcb but we would
   keep the same sem_findholder in sched_verifytcb.
2017-03-15 17:12:45 -10:00
David Sidrane
caf8bac7fb missing semi 2017-03-13 22:54:13 +00:00
David Sidrane
d66fd9f965 semaphore:sem_boostholderprio prevent overrun of pend_reprios
The second case rtcb->sched_priority <= htcb->sched_priority
  did not check if there is sufficient space in the pend_reprios
  array.
2017-03-13 12:34:39 -10:00
David Sidrane
3c00651cfe semaphore:sem_holder sem_findholder missing inintalization of pholder
sem_findholder would fail and code optimization coverd this up.
2017-03-13 11:56:31 -10:00
David Sidrane
4d760c5ea4 semaphore:sem_holder add DEBUGASSERT s 2017-03-13 10:46:26 -10:00
Gregory Nutt
399f306744 A few cosmetic changes 2017-03-11 08:58:42 -06:00
David Sidrane
6cc8f9100b Priority Inversion fixes:typo 2017-03-10 06:37:46 -10:00
Gregory Nutt
360539afac Priority inheritance: When CONFIG_SEM_PREALLOCHOLDERS==0, there is only a single, hard-allocated holder structure. This is problem because in sem_wait() the holder is released, but needs to remain in the holder container until sem_restorebaseprio() is called. The call to sem_restorebaseprio() must be one of the last things the sem_wait() does because it can cause the task to be suspended. If in sem_wait(), a new task gets the semaphore count then it will fail to allocate the holder and will not participate in priority inheritance. This fix is to add two hard-allocated holders in the sem_t structure: One of the old holder and one for the new holder. 2017-03-10 09:30:15 -06:00
Gregory Nutt
a93e46d00c Cosmetic 2017-03-10 08:54:50 -06:00
Gregory Nutt
92d3022411 Add pthread_mutexattr_get/set_protocol and non-standard sem_get/set_protocol. These may use to enable or disable priority inheritance on a single semaphore. 2016-11-02 09:05:18 -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
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