From: Kevin Wolf <[email protected]> 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: [email protected] Signed-off-by: Kevin Wolf <[email protected]> Tested-by: Michael Weiser <[email protected]> Reviewed-by: Michael Weiser <[email protected]> Reviewed-by: Vladimir Sementsov-Ogievskiy <[email protected]> Reviewed-by: Denis V. Lunev <[email protected]> Reviewed-by: Max Reitz <[email protected]> (cherry picked from commit 944f3d5dd216fcd8cb007eddd4f82dced0a15b3d) Signed-off-by: Michael Roth <[email protected]> --- 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
