diff options
Diffstat (limited to 'nuttx/sched/task_deletecurrent.c')
| -rw-r--r-- | nuttx/sched/task_deletecurrent.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/nuttx/sched/task_deletecurrent.c b/nuttx/sched/task_deletecurrent.c index 77025f5e0..e1e06acf6 100644 --- a/nuttx/sched/task_deletecurrent.c +++ b/nuttx/sched/task_deletecurrent.c @@ -90,6 +90,9 @@ * Return Value: * OK on success; or ERROR on failure * + * Assumeptions: + * Interrupts are disabled. + * ****************************************************************************/ int task_deletecurrent(void) @@ -108,13 +111,16 @@ int task_deletecurrent(void) (void)sched_removereadytorun(dtcb); rtcb = (FAR _TCB*)g_readytorun.head; - /* We are not in a bad state -- the head of the ready to run task list + /* We are now in a bad state -- the head of the ready to run task list * does not correspond to the thread that is running. Disabling pre- * emption on this TCB and marking the new ready-to-run task as not * running (see, for example, get_errno_ptr()). + * + * We disable pre-emption here by directly incrementing the lockcount + * (vs. calling sched_lock()). */ - sched_lock(); + rtcb->lockcount++; rtcb->task_state = TSTATE_TASK_READYTORUN; /* Move the TCB to the specified blocked task list and delete it */ @@ -132,9 +138,15 @@ int task_deletecurrent(void) (void)sched_mergepending(); } - /* Now calling sched_unlock() should have no effect */ + /* We can't use sched_unlock() to decrement the lock count because the + * sched_mergepending() call above might have changed the task at the + * head of the ready-to-run list. Furthermore, we should not need to + * perform the unlock action anyway because we know that the pending + * task list is empty. So all we really need to do is to decrement + * the lockcount on rctb. + */ - sched_unlock(); + rtcb->lockcount--; return OK; } |