[PATCH 1/3] coroutine: Add qemu_co_mutex_assert_locked()

[Kevin Wolf <kwolf@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-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/qemu/coroutine.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/qemu/coroutine.h b/include/qemu/coroutine.h
index 9801e7f5a4..a36bcfe5c8 100644
--- a/include/qemu/coroutine.h
+++ b/include/qemu/coroutine.h
@@ -167,6 +167,13 @@ 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)
+{
+    assert(mutex->locked && mutex->holder == qemu_coroutine_self());
+}
 
 /**
  * CoQueues are a mechanism to queue coroutines in order to continue executing
-- 
2.20.1