Module: xenomai-gch
Branch: u_mode
Commit: 1f14785539e6add86bc583804f0476c56d1ca7f3
URL:
http://git.xenomai.org/?p=xenomai-gch.git;a=commit;h=1f14785539e6add86bc583804f0476c56d1ca7f3
Author: Gilles Chanteperdrix <gilles.chanteperd...@xenomai.org>
Date: Thu Jun 23 22:57:59 2011 +0200
nucleus: add reference counter to sys_ppd
This way, if the main thread is shadowed and the last event is its
taskexit event, the ppd are destroyed at this point and not earlier.
---
include/nucleus/sys_ppd.h | 1 +
ksrc/nucleus/shadow.c | 53 ++++++++++++++++++++++++++++++++------------
2 files changed, 39 insertions(+), 15 deletions(-)
diff --git a/include/nucleus/sys_ppd.h b/include/nucleus/sys_ppd.h
index 3ae8581..665e973 100644
--- a/include/nucleus/sys_ppd.h
+++ b/include/nucleus/sys_ppd.h
@@ -10,6 +10,7 @@ struct xnsys_ppd {
#ifdef XNARCH_HAVE_MAYDAY
unsigned long mayday_addr;
#endif
+ xnarch_atomic_t refcnt;
#define ppd2sys(addr) container_of(addr, struct xnsys_ppd, ppd)
};
diff --git a/ksrc/nucleus/shadow.c b/ksrc/nucleus/shadow.c
index dcda1e7..08ce462 100644
--- a/ksrc/nucleus/shadow.c
+++ b/ksrc/nucleus/shadow.c
@@ -673,6 +673,14 @@ static inline void ppd_remove_mm(struct mm_struct *mm,
xnlock_put_irqrestore(&nklock, s);
}
+static void detach_ppd(xnshadow_ppd_t * ppd)
+{
+ unsigned muxid = xnshadow_ppd_muxid(ppd);
+ muxtable[muxid].props->eventcb(XNSHADOW_CLIENT_DETACH, ppd);
+ if (muxtable[muxid].props->module)
+ module_put(muxtable[muxid].props->module);
+}
+
struct xnvdso *nkvdso;
EXPORT_SYMBOL_GPL(nkvdso);
@@ -1237,9 +1245,11 @@ int xnshadow_map(xnthread_t *thread, xncompletion_t
__user *u_completion,
{
struct xnthread_start_attr attr;
xnarch_cpumask_t affinity;
+ struct xnsys_ppd *sys_ppd;
unsigned int muxid, magic;
unsigned long *u_mode;
xnheap_t *sem_heap;
+ spl_t s;
int ret;
if (!xnthread_test_state(thread, XNSHADOW))
@@ -1278,7 +1288,11 @@ int xnshadow_map(xnthread_t *thread, xncompletion_t
__user *u_completion,
}
}
- sem_heap = &xnsys_ppd_get(0)->sem_heap;
+ xnlock_get_irqsave(&nklock, s);
+ sys_ppd = xnsys_ppd_get(0);
+ xnlock_put_irqrestore(&nklock, s);
+
+ sem_heap = &sys_ppd->sem_heap;
u_mode = xnheap_alloc(sem_heap, sizeof(*u_mode));
if (!u_mode)
return -ENOMEM;
@@ -1317,6 +1331,7 @@ int xnshadow_map(xnthread_t *thread, xncompletion_t
__user *u_completion,
*/
xnshadow_thrptd(current) = thread;
xnshadow_mmptd(current) = current->mm;
+ xnarch_atomic_inc(&sys_ppd->refcnt);
rthal_enable_notifier(current);
@@ -1371,6 +1386,7 @@ EXPORT_SYMBOL_GPL(xnshadow_map);
void xnshadow_unmap(xnthread_t *thread)
{
+ struct xnsys_ppd *sys_ppd;
struct task_struct *p;
if (XENO_DEBUG(NUCLEUS) &&
@@ -1382,6 +1398,12 @@ void xnshadow_unmap(xnthread_t *thread)
xnthread_clear_state(thread, XNMAPPED);
rpi_pop(thread);
+ sys_ppd = xnsys_ppd_get(0);
+ xnheap_free(&sys_ppd->sem_heap, thread->u_mode);
+ thread->u_mode = NULL;
+
+ xnarch_atomic_dec(&sys_ppd->refcnt);
+
trace_mark(xn_nucleus, shadow_unmap,
"thread %p thread_name %s pid %d",
thread, xnthread_name(thread), p ? p->pid : -1);
@@ -1396,9 +1418,6 @@ void xnshadow_unmap(xnthread_t *thread)
xnshadow_thrptd(p) = NULL;
- xnheap_free(&xnsys_ppd_get(0)->sem_heap, thread->u_mode);
- thread->u_mode = NULL;
-
schedule_linux_call(LO_UNMAP_REQ, p, xnthread_get_magic(thread));
}
EXPORT_SYMBOL_GPL(xnshadow_unmap);
@@ -2119,14 +2138,14 @@ static void *xnshadow_sys_event(int event, void *data)
return ERR_PTR(err);
}
#endif /* XNARCH_HAVE_MAYDAY */
-
+ xnarch_atomic_set(&p->refcnt, 1);
xnarch_atomic_inc(&muxtable[0].refcnt);
return &p->ppd;
case XNSHADOW_CLIENT_DETACH:
+ printk("sys detach !\n");
p = ppd2sys(data);
xnheap_destroy_mapped(&p->sem_heap, post_ppd_release, NULL);
- xnarch_atomic_dec(&muxtable[0].refcnt);
return NULL;
}
@@ -2474,6 +2493,7 @@ RTHAL_DECLARE_EVENT(losyscall_event);
static inline void do_taskexit_event(struct task_struct *p)
{
xnthread_t *thread = xnshadow_thread(p); /* p == current */
+ struct xnsys_ppd *sys_ppd;
unsigned magic;
spl_t s;
@@ -2494,9 +2514,13 @@ static inline void do_taskexit_event(struct task_struct
*p)
/* xnpod_delete_thread() -> hook -> xnshadow_unmap(). */
xnsched_set_resched(thread->sched);
xnpod_delete_thread(thread);
+ sys_ppd = xnsys_ppd_get(0);
xnlock_put_irqrestore(&nklock, s);
xnpod_schedule();
+ if (!xnarch_atomic_get(&sys_ppd->refcnt))
+ ppd_remove_mm(xnshadow_mm(p), &detach_ppd);
+
xnshadow_dereference_skin(magic);
trace_mark(xn_nucleus, shadow_exit, "thread %p thread_name %s",
thread, xnthread_name(thread));
@@ -2731,24 +2755,23 @@ static inline void do_setsched_event(struct task_struct
*p, int priority)
RTHAL_DECLARE_SETSCHED_EVENT(setsched_event);
-static void detach_ppd(xnshadow_ppd_t * ppd)
-{
- unsigned muxid = xnshadow_ppd_muxid(ppd);
- muxtable[muxid].props->eventcb(XNSHADOW_CLIENT_DETACH, ppd);
- if (muxtable[muxid].props->module)
- module_put(muxtable[muxid].props->module);
-}
-
static inline void do_cleanup_event(struct mm_struct *mm)
{
struct task_struct *p = current;
+ struct xnsys_ppd *sys_ppd;
struct mm_struct *old;
old = xnshadow_mm(p);
xnshadow_mmptd(p) = mm;
- ppd_remove_mm(mm, &detach_ppd);
+ sys_ppd = xnsys_ppd_get(0);
+ if (sys_ppd == &__xnsys_global_ppd)
+ goto done;
+
+ if (xnarch_atomic_dec_and_test(&sys_ppd->refcnt))
+ ppd_remove_mm(mm, &detach_ppd);
+ done:
xnshadow_mmptd(p) = old;
}
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