~jojo/Carth

d43904b49f898feb4b2e6ebef26d62e5651047bf — JoJo 1 year, 1 month ago 008911c
std: Add Mutex
1 files changed, 30 insertions(+), 0 deletions(-)

A std/sync.carth
A std/sync.carth => std/sync.carth +30 -0
@@ 0,0 1,30 @@
(import io)

;; TODO: Enforce usage invariants with linear types.

;; The size of a pthread_mutex_t can be found in ~pthreadtypes-arch.h~.
(define: sizeof_pthread_mutex_t Nat (cast 40))

(data Mutex (Mutex (Box Unit)))

(extern pthread_mutex_init (Fun Mutex (Box Unit) Int32))
(extern pthread_mutex_destroy (Fun Mutex Int32))
(extern pthread_mutex_lock (Fun Mutex Int32))
(extern pthread_mutex_trylock (Fun Mutex Int32))
(extern pthread_mutex_unlock (Fun Mutex Int32))

(define: mutex/new
    (IO Mutex)
  (io/wrap (let ((mx (Mutex (cast-ptr (id@"GC_malloc" sizeof_pthread_mutex_t))))
                 (attrs (mem/unsafe-null Unit)))
             (seq (pthread_mutex_init mx attrs)
                  mx))))

(define: (mutex/lock mx) (Fun Mutex (IO Unit))
  (io/wrap (seq (pthread_mutex_lock mx) Unit)))

(define: (mutex/try-lock mx) (Fun Mutex (IO Bool))
  (io/wrap (= (pthread_mutex_trylock mx) (cast 0))))

(define: (mutex/release mx) (Fun Mutex (IO Unit))
  (io/wrap (seq (pthread_mutex_unlock mx) Unit)))