Megatest

    tmpdb))
		

(define (dbfile:cautious-open-database fname init-proc #!optional (tries-left 50))

  (let* ((busy-file  (conc fname"-journal"))
	 (delay-time (* (- 51 tries-left) 1.1))
	 (write-access (file-write-access? fname))
         (retry      (lambda ()
		       (thread-sleep! delay-time)
		       (if (> tries-left 0)
			   (dbfile:cautious-open-database fname init-proc (- tries-left 1))))))
    (assert (>= tries-left 0) (conc "FATAL: too many attempts in dbfile:cautious-open-database of "fname", giving up."))

    (if (and (file-write-access? fname)
	     (file-exists? busy-file))
	(begin
	  (dbfile:print-err "INFO: dbfile:cautious-open-database: journal file " busy-file " exists, trying again in few seconds.")
	  (thread-sleep! 1)
	  (if (eq? tries-left 2)
	      (begin
		(dbfile:print-err "INFO: forcing journal rollup "busy-file)
		(dbfile:brute-force-salvage-db fname)))
	  (dbfile:cautious-open-database fname init-proc (- tries-left 1)))

	(let* ((result (condition-case
			   (if write-access
                             (dbfile:with-simple-file-lock
			       (conc fname ".lock")
			        (lambda ()
			          (let* ((db-exists (file-exists? fname))
				         (db        (sqlite3:open-database fname)))
				      (if (and init-proc (not db-exists))
				        (init-proc db))
				   db)))
                                (if (file-exists? fname )
                                   (sqlite3:open-database fname)
                                   #f
                                )
                           )
			 (exn (io-error)
			      (dbfile:print-err exn "ERROR: i/o error with " fname ". Check permissions, disk space etc. and try again.")
			      (retry))
			 (exn (corrupt)
			      (dbfile:print-err exn "ERROR: database " fname " is corrupt. Repair it to proceed.")
			      (retry))
			 (exn (busy)