diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/cuirass/database.scm | 25 | ||||
| -rw-r--r-- | src/cuirass/utils.scm | 19 |
2 files changed, 17 insertions, 27 deletions
diff --git a/src/cuirass/database.scm b/src/cuirass/database.scm index 2468804..c82e306 100644 --- a/src/cuirass/database.scm +++ b/src/cuirass/database.scm @@ -434,24 +434,13 @@ WHERE id = " eval-id ";") (#:in_progress . #f))))) (define-syntax-rule (with-database body ...) - "Run BODY with %DB-CHANNEL being dynamically bound to a channel implementing -a critical section that allows database operations to be serialized." - ;; XXX: We don't install an unwind handler to play well with delimited - ;; continuations and fibers. But as a consequence, we leak DB when BODY - ;; raises an exception. - (let ((db (db-open))) - (unwind-protect - ;; Process database queries sequentially in a thread. We need this - ;; because otherwise we would need to use the SQLite multithreading - ;; feature for which it is required to wait until the database is - ;; available, and the waiting would happen in non-cooperative and - ;; non-resumable code that blocks the fibers scheduler. Now the database - ;; access blocks on PUT-MESSAGE, which allows the scheduler to schedule - ;; another fiber. Also, creating one new handle for each request would - ;; be costly and may defeat statement caching. - (parameterize ((%db-channel (make-worker-thread-channel db))) - body ...) - (db-close db)))) + "Run BODY with %DB-CHANNEL being dynamically bound to a channel providing a +worker thread that allows database operations to run without intefering with +fibers." + (parameterize ((%db-channel (make-worker-thread-channel + (lambda () + (list (db-open)))))) + body ...)) (define* (read-quoted-string #:optional (port (current-input-port))) "Read all of the characters out of PORT and return them as a SQL quoted diff --git a/src/cuirass/utils.scm b/src/cuirass/utils.scm index 514899e..dfed4a9 100644 --- a/src/cuirass/utils.scm +++ b/src/cuirass/utils.scm @@ -99,19 +99,20 @@ delimited continuations and fibers." (define %worker-thread-args (make-parameter #f)) -(define (make-worker-thread-channel . args) +(define (make-worker-thread-channel initializer) "Return a channel used to offload work to a dedicated thread. ARGS are the arguments of the worker thread procedure." (parameterize (((@@ (fibers internal) current-fiber) #f)) (let ((channel (make-channel))) - (call-with-new-thread - (lambda () - (parameterize ((%worker-thread-args args)) - (let loop () - (match (get-message channel) - (((? channel? reply) . (? procedure? proc)) - (put-message reply (apply proc args)))) - (loop))))) + (let ((args (initializer))) + (call-with-new-thread + (lambda () + (parameterize ((%worker-thread-args args)) + (let loop () + (match (get-message channel) + (((? channel? reply) . (? procedure? proc)) + (put-message reply (apply proc args)))) + (loop)))))) channel))) (define (call-with-worker-thread channel proc) |