diff options
Diffstat (limited to 'include/qemu/coroutine.h')
| -rw-r--r-- | include/qemu/coroutine.h | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/include/qemu/coroutine.h b/include/qemu/coroutine.h index 84eab6e3bf..ce5b9c6851 100644 --- a/include/qemu/coroutine.h +++ b/include/qemu/coroutine.h @@ -237,11 +237,15 @@ bool qemu_co_enter_next_impl(CoQueue *queue, QemuLockable *lock); bool qemu_co_queue_empty(CoQueue *queue); +typedef struct CoRwTicket CoRwTicket; typedef struct CoRwlock { - int pending_writer; - int reader; CoMutex mutex; - CoQueue queue; + + /* Number of readers, or -1 if owned for writing. */ + int owners; + + /* Waiting coroutines. */ + QSIMPLEQ_HEAD(, CoRwTicket) tickets; } CoRwlock; /** @@ -260,10 +264,9 @@ void qemu_co_rwlock_rdlock(CoRwlock *lock); /** * Write Locks the CoRwlock from a reader. This is a bit more efficient than * @qemu_co_rwlock_unlock followed by a separate @qemu_co_rwlock_wrlock. - * However, if the lock cannot be upgraded immediately, control is transferred - * to the caller of the current coroutine. Also, @qemu_co_rwlock_upgrade - * only overrides CoRwlock fairness if there are no concurrent readers, so - * another writer might run while @qemu_co_rwlock_upgrade blocks. + * Note that if the lock cannot be upgraded immediately, control is transferred + * to the caller of the current coroutine; another writer might run while + * @qemu_co_rwlock_upgrade blocks. */ void qemu_co_rwlock_upgrade(CoRwlock *lock); |