Module: xenomai-2.6
Branch: master
Commit: fae534b67cd593974387442d46a4816c3cc113fc
URL:
http://git.xenomai.org/?p=xenomai-2.6.git;a=commit;h=fae534b67cd593974387442d46a4816c3cc113fc
Author: Gilles Chanteperdrix <gilles.chanteperd...@xenomai.org>
Date: Thu Dec 6 00:03:42 2012 +0100
nucleus/sched: allow disabling preemption temporarily
Some constructs require disabling thread preemption temporarily (e.g.
RTDM_EXECUTE_ATOMICALLY). We introduce a lightweight mechanism for this
purpose based on a core scheduler state flag. The per-thread persistent
scheduler lock feature (XNLOCK) is rebased over the new mechanism.
---
include/nucleus/pod.h | 30 +++++++++++++++---------------
include/nucleus/sched.h | 1 +
ksrc/nucleus/pod.c | 23 ++++++++++++++++++-----
3 files changed, 34 insertions(+), 20 deletions(-)
diff --git a/include/nucleus/pod.h b/include/nucleus/pod.h
index 8a7f23e..fd09dd6 100644
--- a/include/nucleus/pod.h
+++ b/include/nucleus/pod.h
@@ -281,54 +281,54 @@ static inline void xnpod_schedule(void)
return;
#else /* !XENO_DEBUG(NUCLEUS) */
if (testbits(sched->status | sched->lflags,
- XNKCOUT|XNINIRQ|XNINSW|XNRESCHED) != XNRESCHED)
+ XNKCOUT|XNINIRQ|XNINSW|XNRESCHED|XNINLOCK) != XNRESCHED)
return;
#endif /* !XENO_DEBUG(NUCLEUS) */
__xnpod_schedule(sched);
}
-void ___xnpod_lock_sched(struct xnthread *curr);
+void ___xnpod_lock_sched(xnsched_t *sched);
-void ___xnpod_unlock_sched(struct xnthread *curr);
+void ___xnpod_unlock_sched(xnsched_t *sched);
static inline void __xnpod_lock_sched(void)
{
- struct xnthread *curr;
+ xnsched_t *sched;
barrier();
- curr = xnpod_current_thread();
- ___xnpod_lock_sched(curr);
+ sched = xnpod_current_sched();
+ ___xnpod_lock_sched(sched);
}
static inline void __xnpod_unlock_sched(void)
{
- struct xnthread *curr;
+ xnsched_t *sched;
barrier();
- curr = xnpod_current_thread();
- ___xnpod_unlock_sched(curr);
+ sched = xnpod_current_sched();
+ ___xnpod_unlock_sched(sched);
}
static inline void xnpod_lock_sched(void)
{
- struct xnthread *curr;
+ xnsched_t *sched;
spl_t s;
xnlock_get_irqsave(&nklock, s);
- curr = xnpod_current_thread();
- ___xnpod_lock_sched(curr);
+ sched = xnpod_current_sched();
+ ___xnpod_lock_sched(sched);
xnlock_put_irqrestore(&nklock, s);
}
static inline void xnpod_unlock_sched(void)
{
- struct xnthread *curr;
+ xnsched_t *sched;
spl_t s;
xnlock_get_irqsave(&nklock, s);
- curr = xnpod_current_thread();
- ___xnpod_unlock_sched(curr);
+ sched = xnpod_current_sched();
+ ___xnpod_unlock_sched(sched);
xnlock_put_irqrestore(&nklock, s);
}
diff --git a/include/nucleus/sched.h b/include/nucleus/sched.h
index 59dece9..b9d0f01 100644
--- a/include/nucleus/sched.h
+++ b/include/nucleus/sched.h
@@ -42,6 +42,7 @@
#define XNINTCK 0x40000000 /* In master tick handler
context */
#define XNINSW 0x20000000 /* In context switch */
#define XNRESCHED 0x10000000 /* Needs rescheduling */
+#define XNINLOCK 0x08000000 /* Scheduler locked */
/* Sched local flags */
#define XNHTICK 0x00008000 /* Host tick pending */
diff --git a/ksrc/nucleus/pod.c b/ksrc/nucleus/pod.c
index af53f6e..cf6c9de 100644
--- a/ksrc/nucleus/pod.c
+++ b/ksrc/nucleus/pod.c
@@ -1200,6 +1200,7 @@ void xnpod_delete_thread(xnthread_t *thread)
* thread zombie state to go through the rescheduling
* procedure then actually destroy the thread object.
*/
+ __clrbits(sched->status, XNINLOCK);
xnsched_set_resched(sched);
xnpod_schedule();
#ifdef CONFIG_XENO_HW_UNLOCKED_SWITCH
@@ -1452,6 +1453,7 @@ void xnpod_suspend_thread(xnthread_t *thread, xnflags_t
mask,
#endif /* __XENO_SIM__ */
if (thread == sched->curr) {
+ __clrbits(sched->status, XNINLOCK);
/*
* If the current thread is being relaxed, we must
* have been called from xnshadow_relax(), in which
@@ -2302,7 +2304,6 @@ reschedule:
xnpod_run_hooks(&nkpod->tswitchq, curr, "SWITCH");
signal_unlock_and_exit:
-
if (xnthread_signaled_p(curr))
xnpod_dispatch_signals();
@@ -2310,6 +2311,9 @@ reschedule:
xnsched_maybe_resched_after_unlocked_switch(sched))
goto reschedule;
+ if (xnthread_lock_count(curr))
+ __setbits(sched->status, XNINLOCK);
+
xnlock_put_irqrestore(&nklock, s);
return;
@@ -2336,18 +2340,27 @@ reschedule:
}
EXPORT_SYMBOL_GPL(__xnpod_schedule);
-void ___xnpod_lock_sched(struct xnthread *curr)
+void ___xnpod_lock_sched(xnsched_t *sched)
{
- if (xnthread_lock_count(curr)++ == 0)
+ struct xnthread *curr = sched->curr;
+
+ if (xnthread_lock_count(curr)++ == 0) {
+ __setbits(sched->status, XNINLOCK);
xnthread_set_state(curr, XNLOCK);
+ }
}
EXPORT_SYMBOL_GPL(___xnpod_lock_sched);
-void ___xnpod_unlock_sched(struct xnthread *curr)
+void ___xnpod_unlock_sched(xnsched_t *sched)
{
+ struct xnthread *curr = sched->curr;
+ XENO_ASSERT(NUCLEUS, xnthread_lock_count(curr) > 0,
+ xnpod_fatal("Unbalanced lock/unlock");
+ );
+
if (--xnthread_lock_count(curr) == 0) {
xnthread_clear_state(curr, XNLOCK);
- xnsched_set_self_resched(curr->sched);
+ __clrbits(sched->status, XNINLOCK);
xnpod_schedule();
}
}
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