diff options
| -rw-r--r-- | include/qemu/lockable.h | 88 |
1 files changed, 40 insertions, 48 deletions
diff --git a/include/qemu/lockable.h b/include/qemu/lockable.h index b620023..86db7cb 100644 --- a/include/qemu/lockable.h +++ b/include/qemu/lockable.h @@ -24,79 +24,71 @@ struct QemuLockable { QemuLockUnlockFunc *unlock; }; -/* This function gives an error if an invalid, non-NULL pointer type is passed - * to QEMU_MAKE_LOCKABLE. For optimized builds, we can rely on dead-code elimination - * from the compiler, and give the errors already at link time. - */ -#if defined(__OPTIMIZE__) && !defined(__SANITIZE_ADDRESS__) -void unknown_lock_type(void *); -#else -static inline void unknown_lock_type(void *unused) -{ - abort(); -} -#endif - static inline __attribute__((__always_inline__)) QemuLockable * qemu_make_lockable(void *x, QemuLockable *lockable) { - /* We cannot test this in a macro, otherwise we get compiler + /* + * We cannot test this in a macro, otherwise we get compiler * warnings like "the address of 'm' will always evaluate as 'true'". */ return x ? lockable : NULL; } -/* Auxiliary macros to simplify QEMU_MAKE_LOCABLE. */ -#define QEMU_LOCK_FUNC(x) ((QemuLockUnlockFunc *) \ - QEMU_GENERIC(x, \ - (QemuMutex *, qemu_mutex_lock), \ - (QemuRecMutex *, qemu_rec_mutex_lock), \ - (CoMutex *, qemu_co_mutex_lock), \ - (QemuSpin *, qemu_spin_lock), \ - unknown_lock_type)) - -#define QEMU_UNLOCK_FUNC(x) ((QemuLockUnlockFunc *) \ - QEMU_GENERIC(x, \ - (QemuMutex *, qemu_mutex_unlock), \ - (QemuRecMutex *, qemu_rec_mutex_unlock), \ - (CoMutex *, qemu_co_mutex_unlock), \ - (QemuSpin *, qemu_spin_unlock), \ - unknown_lock_type)) - -/* In C, compound literals have the lifetime of an automatic variable. +static inline __attribute__((__always_inline__)) QemuLockable * +qemu_null_lockable(void *x) +{ + if (x != NULL) { + qemu_build_not_reached(); + } + return NULL; +} + +/* + * In C, compound literals have the lifetime of an automatic variable. * In C++ it would be different, but then C++ wouldn't need QemuLockable * either... */ -#define QEMU_MAKE_LOCKABLE_(x) (&(QemuLockable) { \ - .object = (x), \ - .lock = QEMU_LOCK_FUNC(x), \ - .unlock = QEMU_UNLOCK_FUNC(x), \ +#define QML_OBJ_(x, name) (&(QemuLockable) { \ + .object = (x), \ + .lock = (QemuLockUnlockFunc *) qemu_ ## name ## _lock, \ + .unlock = (QemuLockUnlockFunc *) qemu_ ## name ## _unlock \ }) -/* QEMU_MAKE_LOCKABLE - Make a polymorphic QemuLockable +/** + * QEMU_MAKE_LOCKABLE - Make a polymorphic QemuLockable * - * @x: a lock object (currently one of QemuMutex, QemuRecMutex, CoMutex, QemuSpin). + * @x: a lock object (currently one of QemuMutex, QemuRecMutex, + * CoMutex, QemuSpin). * * Returns a QemuLockable object that can be passed around * to a function that can operate with locks of any kind, or * NULL if @x is %NULL. + * + * Note the special case for void *, so that we may pass "NULL". */ -#define QEMU_MAKE_LOCKABLE(x) \ - QEMU_GENERIC(x, \ - (QemuLockable *, (x)), \ - qemu_make_lockable((x), QEMU_MAKE_LOCKABLE_(x))) +#define QEMU_MAKE_LOCKABLE(x) \ + _Generic((x), QemuLockable *: (x), \ + void *: qemu_null_lockable(x), \ + QemuMutex *: qemu_make_lockable(x, QML_OBJ_(x, mutex)), \ + QemuRecMutex *: qemu_make_lockable(x, QML_OBJ_(x, rec_mutex)), \ + CoMutex *: qemu_make_lockable(x, QML_OBJ_(x, co_mutex)), \ + QemuSpin *: qemu_make_lockable(x, QML_OBJ_(x, spin))) -/* QEMU_MAKE_LOCKABLE_NONNULL - Make a polymorphic QemuLockable +/** + * QEMU_MAKE_LOCKABLE_NONNULL - Make a polymorphic QemuLockable * - * @x: a lock object (currently one of QemuMutex, QemuRecMutex, CoMutex, QemuSpin). + * @x: a lock object (currently one of QemuMutex, QemuRecMutex, + * CoMutex, QemuSpin). * * Returns a QemuLockable object that can be passed around * to a function that can operate with locks of any kind. */ -#define QEMU_MAKE_LOCKABLE_NONNULL(x) \ - QEMU_GENERIC(x, \ - (QemuLockable *, (x)), \ - QEMU_MAKE_LOCKABLE_(x)) +#define QEMU_MAKE_LOCKABLE_NONNULL(x) \ + _Generic((x), QemuLockable *: (x), \ + QemuMutex *: QML_OBJ_(x, mutex), \ + QemuRecMutex *: QML_OBJ_(x, rec_mutex), \ + CoMutex *: QML_OBJ_(x, co_mutex), \ + QemuSpin *: QML_OBJ_(x, spin)) static inline void qemu_lockable_lock(QemuLockable *x) { |