From: Kevin Wolf <kw...@redhat.com>
Some functions require that the caller holds a certain CoMutex for them
to operate correctly. Add a function so that they can assert the lock is
really held.
Cc: qemu-sta...@nongnu.org
Signed-off-by: Kevin Wolf <kw...@redhat.com>
Tested-by: Michael Weiser <michael.wei...@gmx.de>
Reviewed-by: Michael Weiser <michael.wei...@gmx.de>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Reviewed-by: Denis V. Lunev <d...@openvz.org>
Reviewed-by: Max Reitz <mre...@redhat.com>
(cherry picked from commit 944f3d5dd216fcd8cb007eddd4f82dced0a15b3d)
Signed-off-by: Michael Roth <mdr...@linux.vnet.ibm.com>
---
include/qemu/coroutine.h | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/include/qemu/coroutine.h b/include/qemu/coroutine.h
index 9801e7f5a4..f4843b5f59 100644
--- a/include/qemu/coroutine.h
+++ b/include/qemu/coroutine.h
@@ -167,6 +167,21 @@ void coroutine_fn qemu_co_mutex_lock(CoMutex *mutex);
*/
void coroutine_fn qemu_co_mutex_unlock(CoMutex *mutex);
+/**
+ * Assert that the current coroutine holds @mutex.
+ */
+static inline coroutine_fn void qemu_co_mutex_assert_locked(CoMutex *mutex)
+{
+ /*
+ * mutex->holder doesn't need any synchronisation if the assertion holds
+ * true because the mutex protects it. If it doesn't hold true, we still
+ * don't mind if another thread takes or releases mutex behind our back,
+ * because the condition will be false no matter whether we read NULL or
+ * the pointer for any other coroutine.
+ */
+ assert(atomic_read(&mutex->locked) &&
+ mutex->holder == qemu_coroutine_self());
+}
/**
* CoQueues are a mechanism to queue coroutines in order to continue executing
--
2.17.1
