Re: [libvirt PATCH 06/11] virthread: Introduce WITH_VIR_MUTEX_LOCK_GUARD

Modeled after "WITH_QEMU_LOCK_GUARD" (see qemu's include/qemu/lockable.h). Uses "__LINE__" instead of "__COUNTER__", as the latter is a GNU extension.

See comment for typical usage. Signed-off-by: Tim Wiederhake <twiederh(a)redhat.com&gt; --- src/util/virthread.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/src/util/virthread.h b/src/util/virthread.h index b394dbd226..00a9987a79 100644 --- a/src/util/virthread.h +++ b/src/util/virthread.h @@ -209,3 +209,23 @@ int virThreadLocalSet(virThreadLocal *l, void*) G_GNUC_WARN_UNUSED_RESULT; return 0; \ } \ struct classname ## EatSemicolon + +/** + * WITH_VIR_MUTEX_LOCK_GUARD:

+ * + * This macro defines a lock scope such that entering the scope takes the lock + * and leaving the scope releases the lock. Return statements are allowed + * within the scope and release the lock. Break and continue statements leave + * the scope early and release the lock. + * + * virMutex *mutex = ...; + * + * WITH_VIR_MUTEX_LOCK_GUARD(mutex) { + * // `mutex` is locked, and released automatically on scope exit + * ... + * } + */ +#define WITH_VIR_MUTEX_LOCK_GUARD(m) \ + for (g_autoptr(virLockGuard) CONCAT(var, __LINE__) = virLockGuardNew(m); \ + CONCAT(var, __LINE__); \ + CONCAT(var, __LINE__) = (virLockGuardFree(CONCAT(var, __LINE__)), NULL)) -- 2.31.1