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db: fix check for recursive lock acquire

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This commit is contained in:
Ryan Culpepper 2021-03-20 13:54:13 +01:00
parent 815910b419
commit 5f66fad355
1 changed files with 5 additions and 5 deletions
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10
racket/collects/db/private/generic/common.rkt
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@ -133,8 +133,11 @@
(define sema-peek (lock-sema-peek lk)) (define sema-peek (lock-sema-peek lk))
(let loop () (let loop ()
(define result (define result
(cond [enable-break? (sync/enable-break sema-peek (lock-owner lk))] (let ([owner (lock-owner lk)])
[else (sync sema-peek (lock-owner lk))])) (cond [(eq? owner me)
(error 'lock-acquire "attempted to recursively acquire lock")]
[enable-break? (sync/enable-break sema-peek owner)]
[else (sync sema-peek owner)])))
(cond [(eq? result sema-peek) (cond [(eq? result sema-peek)
;; Got past outer stage ;; Got past outer stage
(start-atomic) (start-atomic)
@ -151,9 +154,6 @@
[(eq? result (lock-owner lk)) [(eq? result (lock-owner lk))
;; Thread holding lock is dead ;; Thread holding lock is dead
#f] #f]
[(eq? result me)
;; Attempt to recursively acquire lock
(error 'lock-acquire "attempted to recursively acquire lock")]
[else [else
;; Owner was stale => retry ;; Owner was stale => retry
;; This can happen if the thread holding the lock releases ;; This can happen if the thread holding the lock releases