@@ -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);
+bool rfifolock_is_owner(RFifoLock *r);
#endif /* QEMU_RFIFOLOCK_H */
@@ -12,6 +12,7 @@
*/
#include <assert.h>
+#include <string.h>
#include "qemu/rfifolock.h"
void rfifolock_init(RFifoLock *r, void (*cb)(void *), void *opaque)
@@ -48,7 +49,7 @@ 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 (rfifolock_is_owner(r)) {
r->tail--; /* put ticket back, we're nesting */
} else {
while (ticket != r->head) {
@@ -68,11 +69,16 @@ void rfifolock_lock(RFifoLock *r)
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_owner(r));
if (--r->nesting == 0) {
+ memset(&r->owner_thread, 0, sizeof(r->owner_thread));
r->head++;
qemu_cond_broadcast(&r->cond);
}
qemu_mutex_unlock(&r->lock);
}
+
+bool rfifolock_is_owner(RFifoLock *r)
+{
+ return r->nesting > 0 && qemu_thread_is_self(&r->owner_thread);
+}
This helper is necessary to ensure locking constraints. Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Paolo Bonzini <pbonzini@redhat.com> --- include/qemu/rfifolock.h | 1 + util/rfifolock.c | 12 +++++++++--- 2 files changed, 10 insertions(+), 3 deletions(-)