19 lines
518 B
Scheme
19 lines
518 B
Scheme
|
(define-record-type resource :resource
|
||
|
|
(make-resource align! lock)
|
||
|
|
resource?
|
||
|
|
(align! resource-align!)
|
||
|
|
(lock resource-lock))
|
||
|
|
|
||
|
|
(define (with-resources-aligned resources thunk)
|
||
|
|
(let ((locks (map resource-lock resources)))
|
||
|
|
(apply obtain-all-or-none locks)
|
||
|
|
(for-each
|
||
|
|
(lambda (align!) (align!))
|
||
|
|
(map resource-align! resources))
|
||
|
|
(let ((val (with-handler
|
||
|
|
(lambda (cond more)
|
||
|
|
(for-each release-lock locks)
|
||
|
|
(more))
|
||
|
|
thunk)))
|
||
|
|
(for-each release-lock locks)
|
||
|
|
val)))
|