diff options
Diffstat (limited to 'kern/turnstile.h')
| -rw-r--r-- | kern/turnstile.h | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/kern/turnstile.h b/kern/turnstile.h index 0473a4c6..e7b4a5e3 100644 --- a/kern/turnstile.h +++ b/kern/turnstile.h @@ -28,6 +28,7 @@ #include <stdbool.h> #include <stddef.h> +#include <stdint.h> #include <kern/init.h> #include <kern/plist.h> @@ -157,9 +158,17 @@ bool turnstile_empty(const struct turnstile *turnstile); * the associated synchronization object. The priority of the caller * is propagated to the chain of turnstiles and owners as necessary * to prevent unbounded priority inversion. + * + * When bounding the duration of the wait, the caller must pass an absolute + * time in ticks, and ERROR_TIMEDOUT is returned if that time is reached + * before the turnstile is signalled. In addition, if a timeout occurs, + * the calling thread temporarily releases the turnstile before returning, + * causing other threads to consider the turnstile as empty. */ void turnstile_wait(struct turnstile *turnstile, const char *wchan, struct thread *owner); +int turnstile_timedwait(struct turnstile *turnstile, const char *wchan, + struct thread *owner, uint64_t ticks); /* * Wake up a thread waiting on the given turnstile, if any. @@ -175,8 +184,7 @@ void turnstile_signal(struct turnstile *turnstile); * Own/disown a turnstile. * * The turnstile must be lent when taking ownership, acquired when - * releasing it. Owning has no effect on empty turnstiles. - * Conversely, an empty turnstile cannot be disowned. + * releasing it. * * Ownership must be updated atomically with regard to the ownership * of the associated synchronization object. |