Megatest

;; setting/getting a lock on the db for only one server per db
;;
;;  NOTE:
;;       These operate directly on the disk file, NOT on the inmemory db
;;       The lockname is the filename (can have many to one, run-id to fname 
;;======================================================================

;; only use for main.db - need to re-write some of this :(
;;
(define (db:get-main-lock dbfile)
  (db:with-lock-db dbfile
		(lambda (dbh dbfile)
		  (db:get-iam-server-lock dbh dbfile))))

(define (with-lock-db dbfile proc)
(define (db:with-lock-db dbfile proc)
  (let* ((dbh (db:open-run-db dbfile db:initialize-db))
	 (res (proc dbh dbfile)))
    (sqlite3:finalize! dbh)
    res))

;; called before db is open?
;;
(define (db:get-iam-server-lock dbh dbfname)
  (sqlite3:with-transaction
   dbh
   (lambda ()
     (let* ((locker (db:get-locker dbh dbfname)))
       (if locker
	   #f
	   (db:take-lock dbh dbfname))))))
	     
;; (exn sqlite3) 
(define (db:get-locker dbh dbfname)
  (condition-case
   (sqlite3:first-row dbh "SELECT owner_pid,owner_host,event_time FROM locks WHERE lockname=%;" dbfname)
   (sqlite3:first-row dbh "SELECT owner_pid,owner_host,event_time FROM locks WHERE lockname=?;" dbfname)
   (exn (sqlite3) #f)))

;; should never fail because it is run in a transaction with a test for the lock
;;
(define (db:take-lock dbh dbfname)
  ;; (condition-case
  ;;  (begin

	 (server-dat   (vector iface port api-uri api-url api-req (current-seconds) server-id)))
    server-dat))

;;======================================================================
;; NEW SERVER METHOD
;;======================================================================

;; only use for main.db - need to re-write some of this :(
;;
(define (get-lock-db dbfile)
  (let* ((dbh (db:open-run-db dbfile db:initialize-db))
	 (res (db:get-iam-server-lock dbh dbfile)))
    (sqlite3:finalize! dbh)
    res))

(define *srvpktspec*
  `((server (host    . h)
	    (port    . p)
	    (servkey . k)
	    (pid     . i)
	    (ipaddr  . a)
	    (dbpath  . d))))

				(let* ((all-pkts     (get-all-server-pkts pkts-dir *srvpktspec*))
				       (viables      (get-viable-servers all-pkts db-file))
				       (best-srv     (get-best-candidate viables db-file))
				       (best-srv-key (if best-srv (alist-ref 'servkey best-srv) #f)))
				  (debug:print 0 *default-log-port* "best-srv-key: "best-srv-key", server-key: "server-key)
				  ;; am I the best-srv, compare server-keys to know
				  (if (equal? best-srv-key server-key)
				      (if (get-lock-db db-file) ;; (db:get-iam-server-lock *dbstruct-db* *toppath* run-id)
				      (if (db:get-main-lock db-file)
					  (begin
					    (debug:print 0 *default-log-port* "I'm the server!")
					    (servdat-dbfile-set! sdat db-file))
					  (begin
					    (debug:print 0 *default-log-port* "I'm not the server, exiting.")
					    (bdat-time-to-exit-set! *bdat* #t)
					    (thread-sleep! 0.2)

					(dbfile   (servdat-dbfile *server-info*)))
				    (debug:print-info 0 *default-log-port* "removing pkt "pkt-file)
				    (delete-file* pkt-file)
				    (if (and dbfile
					     (string-match ".*/main.db$" dbfile))
					(begin
					  (debug:print-info 0 *default-log-port* "Releasing lock for "dbfile)
					  (with-lock-db (servdat-dbfile *server-info*)
							(lambda (dbh dbfile)
							  (db:release-lock dbh)))))))
					  (db:with-lock-db (servdat-dbfile *server-info*)
							   (lambda (dbh dbfile)
							     (db:release-lock dbh)))))))
			      (if (bdat-task-db *bdat*)    ;; TODO: Check that this is correct for task db
				  (let ((db (cdr (bdat-task-db *bdat*))))
				    (if (sqlite3:database? db)
					(begin
					  (sqlite3:interrupt! db)
					  (sqlite3:finalize! db #t)
					  (bdat-task-db-set! *bdat* #f)))))