118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
|
-
+
-
-
-
-
+
+
+
+
+
+
+
|
server-id)))
(define (tasks:have-clients? mdb server-id)
(null? (tasks:get-logged-in-clients mdb server-id)))
;; ping each server in the db and return first found that responds.
;; remove any others. will not necessarily remove all!
(define (tasks:get-best-server mdb)
(define (tasks:get-best-server mdb #!key (do-ping #f))
(let ((res '())
(best #f))
(sqlite3:for-each-row
(lambda (id hostname port)
(set! res (cons (list hostname port) res))
(debug:print-info 1 "Found " hostname ":" port))
mdb
"SELECT id,hostname,port FROM servers WHERE state='live' ORDER BY start_time DESC LIMIT 1;")
;; (print "res=" res)
(if (null? res) #f
(let loop ((hed (car res))
(tal (cdr res)))
;; (print "hed=" hed ", tal=" tal)
(let* ((host (car hed))
(port (cadr hed))
(ping-res (server:ping host port)))
(if ping-res hed
(let* ((host (car hed))
(port (cadr hed))
(ping-res (if do-ping (server:ping host port return-socket: #f) '(#t "NO PING" #f)))
(alive (car ping-res))
(reason (cadr ping-res))
(zsocket (caddr ping-res)))
(if alive (list host port zsocket)
;; remove defunct server from table
(begin
(open-run-close tasks:server-deregister tasks:open-db host port: port)
(if (null? tal)
#f
(loop (car tal)(cdr tal))))))))))
|