diff options
Diffstat (limited to 'include/qemu/coroutine.h')
| -rw-r--r-- | include/qemu/coroutine.h | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/include/qemu/coroutine.h b/include/qemu/coroutine.h index 12584ed1b7..fce228f68a 100644 --- a/include/qemu/coroutine.h +++ b/include/qemu/coroutine.h @@ -160,10 +160,23 @@ bool qemu_co_queue_empty(CoQueue *queue); /** * Provides a mutex that can be used to synchronise coroutines */ +struct CoWaitRecord; typedef struct CoMutex { - bool locked; + /* Count of pending lockers; 0 for a free mutex, 1 for an + * uncontended mutex. + */ + unsigned locked; + + /* A queue of waiters. Elements are added atomically in front of + * from_push. to_pop is only populated, and popped from, by whoever + * is in charge of the next wakeup. This can be an unlocker or, + * through the handoff protocol, a locker that is about to go to sleep. + */ + QSLIST_HEAD(, CoWaitRecord) from_push, to_pop; + + unsigned handoff, sequence; + Coroutine *holder; - CoQueue queue; } CoMutex; /** |