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[Qemu-stable] [PATCH 1/4] fifolock: create rfifolock_is_locked helper
From: |
Denis V. Lunev |
Subject: |
[Qemu-stable] [PATCH 1/4] fifolock: create rfifolock_is_locked helper |
Date: |
Wed, 28 Oct 2015 18:01:02 +0300 |
This helper is necessary to ensure locking constraints.
Signed-off-by: Denis V. Lunev <address@hidden>
CC: Stefan Hajnoczi <address@hidden>
CC: Paolo Bonzini <address@hidden>
---
include/qemu/rfifolock.h | 1 +
util/rfifolock.c | 9 +++++++--
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/include/qemu/rfifolock.h b/include/qemu/rfifolock.h
index b23ab53..2c00c4b 100644
--- a/include/qemu/rfifolock.h
+++ b/include/qemu/rfifolock.h
@@ -50,5 +50,6 @@ void rfifolock_init(RFifoLock *r, void (*cb)(void *), void
*opaque);
void rfifolock_destroy(RFifoLock *r);
void rfifolock_lock(RFifoLock *r);
void rfifolock_unlock(RFifoLock *r);
+int rfifolock_is_locked(RFifoLock *r);
#endif /* QEMU_RFIFOLOCK_H */
diff --git a/util/rfifolock.c b/util/rfifolock.c
index afbf748..8ac58cb 100644
--- a/util/rfifolock.c
+++ b/util/rfifolock.c
@@ -48,7 +48,7 @@ void rfifolock_lock(RFifoLock *r)
/* Take a ticket */
unsigned int ticket = r->tail++;
- if (r->nesting > 0 && qemu_thread_is_self(&r->owner_thread)) {
+ if (r->nesting > 0 && rfifolock_is_locked(r)) {
r->tail--; /* put ticket back, we're nesting */
} else {
while (ticket != r->head) {
@@ -69,10 +69,15 @@ void rfifolock_unlock(RFifoLock *r)
{
qemu_mutex_lock(&r->lock);
assert(r->nesting > 0);
- assert(qemu_thread_is_self(&r->owner_thread));
+ assert(rfifolock_is_locked(r));
if (--r->nesting == 0) {
r->head++;
qemu_cond_broadcast(&r->cond);
}
qemu_mutex_unlock(&r->lock);
}
+
+int rfifolock_is_locked(RFifoLock *r)
+{
+ return qemu_thread_is_self(&r->owner_thread);
+}
--
2.1.4