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(define *send-receive-mutex* (make-mutex)) ;; should have separate mutex per run-id
;; RA => e.g. usage (rmt:send-receive 'get-var #f (list varname))
;;
(define (rmt:send-receive cmd rid params #!key (attemptnum 1)(area-dat #f)) ;; start attemptnum at 1 so the modulo below works as expected
;;DOT digraph megatest_state_status {
;;DOT ranksep=0;
;;DOT // rankdir=LR;
;;DOT node [shape="box"];
;;DOT "rmt:send-receive" -> MUTEXLOCK;
;;DOT { edge [style=invis];"case 1" -> "case 2" -> "case 3" -> "case 4" -> "case 5" -> "case 6" -> "case 7" -> "case 8" -> "case 9" -> "case 10" -> "case 11"; }
;; do all the prep locked under the rmt-mutex
(mutex-lock! *rmt-mutex*)
;; 1. check if server is started IFF cmd is a write OR if we are not on the homehost, store in runremote
;; 2. check the age of the connections. refresh the connection if it is older than timeout-20 seconds.
;; 3. do the query, if on homehost use local access
;;
(let* ((start-time (current-seconds)) ;; snapshot time so all use cases get same value
(areapath *toppath*);; TODO - resolve from dbstruct to be compatible with multiple areas
(runremote (or area-dat
*runremote*))
(readonly-mode (if (and runremote
(remote-ro-mode-checked runremote))
(remote-ro-mode runremote)
(let* ((dbfile (conc *toppath* "/megatest.db"))
(ro-mode (not (file-write-access? dbfile)))) ;; TODO: use dbstruct or runremote to figure this out in future
(if runremote
(begin
(remote-ro-mode-set! runremote ro-mode)
(remote-ro-mode-checked-set! runremote #t)
ro-mode)
ro-mode)))))
;; DOT INIT_RUNREMOTE; // leaving off - doesn't really add to the clarity
;; DOT MUTEXLOCK -> INIT_RUNREMOTE [label="no remote?"];
;; DOT INIT_RUNREMOTE -> MUTEXLOCK;
;; ensure we have a record for our connection for given area
(if (not runremote) ;; can remove this one. should never get here.
(begin
(set! *runremote* (make-remote))
(set! runremote *runremote*))) ;; new runremote will come from this on next iteration
;; ensure we have a homehost record
(if (not (pair? (remote-hh-dat runremote))) ;; not on homehost
(thread-sleep! 0.1) ;; since we shouldn't get here, delay a little
(remote-hh-dat-set! runremote (common:get-homehost)))
;;(print "BB> readonly-mode is "readonly-mode" dbfile is "dbfile)
;; readonly mode, read request- handle it - case 20
;; readonly mode, read request- handle it - case 2
((and readonly-mode
(member cmd api:read-only-queries))
(mutex-unlock! *rmt-mutex*)
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 20")
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 2")
(rmt:open-qry-close-locally cmd 0 params)
)
;;DOT CASE3 [label="write in\nread-only mode"];
;;DOT MUTEXLOCK -> CASE3 [label="readonly\nmode?"]; {rank=same "case 3" CASE3}
;;DOT CASE3 -> "#f";
;; readonly mode, write request. Do nothing, return #f
(readonly-mode
(mutex-unlock! *rmt-mutex*)
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 21")
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 3")
(debug:print 0 *default-log-port* "WARNING: write transaction requested on a readonly area. cmd="cmd" params="params)
#f
)
#f)
;;DOT CASE4 [label="reset\nconnection"];
;;DOT MUTEXLOCK -> CASE4 [label="have connection,\nlast_access > expire_time"]; {rank=same "case 4" CASE4}
;;DOT CASE4 -> "rmt:send-receive";
;; reset the connection if it has been unused too long
((and runremote
(remote-conndat runremote)
(let ((expire-time (+ (- start-time (remote-server-timeout runremote))(random 10)))) ;; Subtract or add the random value? Seems like it should be substract but Neither fixes the "WARNING: failure in with-input-from-request to #<request>.\n message: Server closed connection before sending response"
(< (http-transport:server-dat-get-last-access (remote-conndat runremote)) expire-time)))
(debug:print-info 0 *default-log-port* "Connection to " (remote-server-url runremote) " expired due to no accesses, forcing new connection.")
(let ((old-conn (remote-conndat runremote)))
(handle-exceptions
exn
(begin
(print-call-chain *default-log-port*)
(debug:print-error 0 *default-log-port* " closing connection failed with error: " ((condition-property-accessor 'exn 'message) exn)))
(http-transport:close-connections area-dat: runremote)))
(remote-conndat-set! runremote #f) ;; invalidate the connection, thus forcing a new connection.
(mutex-unlock! *rmt-mutex*)
(rmt:send-receive cmd rid params attemptnum: attemptnum))
;;DOT CASE5 [label="local\nread"];
;;DOT MUTEXLOCK -> CASE5 [label="server not required,\non homehost,\nread-only query"]; {rank=same "case 5" CASE5};
;;DOT CASE5 -> "rmt:open-qry-close-locally";
;; on homehost and this is a read
((and (not (remote-force-server runremote)) ;; honor forced use of server
(cdr (remote-hh-dat runremote)) ;; on homehost
(member cmd api:read-only-queries)) ;; this is a read
((and (not (remote-force-server runremote)) ;; honor forced use of server, i.e. server NOT required
(cdr (remote-hh-dat runremote)) ;; on homehost
(member cmd api:read-only-queries)) ;; this is a read
(mutex-unlock! *rmt-mutex*)
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 3")
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 5")
(rmt:open-qry-close-locally cmd 0 params))
;;DOT CASE6 [label="init\nremote"];
;;DOT MUTEXLOCK -> CASE6 [label="on homehost,\nwrite query,\nhave server,\ncan't reach it"]; {rank=same "case 6" CASE6};
;;DOT CASE6 -> "rmt:send-receive";
;; on homehost and this is a write, we already have a server, but server has died
((and (cdr (remote-hh-dat runremote)) ;; on homehost
(not (member cmd api:read-only-queries)) ;; this is a write
(remote-server-url runremote) ;; have a server
(not (server:ping (remote-server-url runremote)))) ;; server has died. NOTE: this is not a cheap call! Need better approach.
(set! *runremote* (make-remote))
(remote-force-server-set! runremote (common:force-server?))
(mutex-unlock! *rmt-mutex*)
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 4.1")
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 6")
(rmt:send-receive cmd rid params attemptnum: attemptnum))
;;DOT CASE7 [label="homehost\nwrite"];
;;DOT MUTEXLOCK -> CASE7 [label="server not required,\non homehost,\na write,\nhave a server"]; {rank=same "case 7" CASE7};
;;DOT CASE7 -> "rmt:open-qry-close-locally";
;; on homehost and this is a write, we already have a server
((and (not (remote-force-server runremote)) ;; honor forced use of server
((and (not (remote-force-server runremote)) ;; honor forced use of server, i.e. server NOT required
(cdr (remote-hh-dat runremote)) ;; on homehost
(not (member cmd api:read-only-queries)) ;; this is a write
(remote-server-url runremote)) ;; have a server
(mutex-unlock! *rmt-mutex*)
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 4")
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 4.1")
(rmt:open-qry-close-locally cmd 0 params))
;;DOT CASE8 [label="force\nserver"];
;;DOT MUTEXLOCK -> CASE8 [label="server not required,\nhave homehost info,\nno connection yet,\nnot a read-only query"]; {rank=same "case 8" CASE8};
;;DOT CASE8 -> "rmt:open-qry-close-locally";
;; on homehost, no server contact made and this is a write, passively start a server
((and (not (remote-force-server runremote)) ;; honor forced use of server
(cdr (remote-hh-dat runremote)) ;; new
(not (remote-server-url runremote))
(not (member cmd api:read-only-queries)))
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 5")
((and (not (remote-force-server runremote)) ;; honor forced use of server, i.e. server NOT required
(cdr (remote-hh-dat runremote)) ;; have homehost
(not (remote-server-url runremote)) ;; no connection yet
(not (member cmd api:read-only-queries))) ;; not a read-only query
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 8")
(let ((server-url (server:check-if-running *toppath*))) ;; (server:read-dotserver->url *toppath*))) ;; (server:check-if-running *toppath*))) ;; Do NOT want to run server:check-if-running - very expensive to do for every write call
(if server-url
(remote-server-url-set! runremote server-url) ;; the string can be consumed by the client setup if needed
(if (common:force-server?)
(server:start-and-wait *toppath*)
(server:kind-run *toppath*))))
(remote-force-server-set! runremote (common:force-server?))
(mutex-unlock! *rmt-mutex*)
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 5.1")
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 8.1")
(rmt:open-qry-close-locally cmd 0 params))
;;DOT CASE9 [label="force server\nnot on homehost"];
;;DOT MUTEXLOCK -> CASE9 [label="no connection\nand either require server\nor not on homehost"]; {rank=same "case 9" CASE9};
;;DOT CASE9 -> "start\nserver" -> "rmt:send-receive";
((or (and (remote-force-server runremote) ;; we are forcing a server and don't yet have a connection to one
(not (remote-conndat runremote)))
(and (not (cdr (remote-hh-dat runremote))) ;; not on a homehost
(not (remote-conndat runremote)))) ;; and no connection
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 6 hh-dat: " (remote-hh-dat runremote) " conndat: " (remote-conndat runremote))
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 9, hh-dat: " (remote-hh-dat runremote) " conndat: " (remote-conndat runremote))
(mutex-unlock! *rmt-mutex*)
(if (not (server:check-if-running *toppath*)) ;; who knows, maybe one has started up?
(server:start-and-wait *toppath*))
(remote-force-server-set! runremote (common:force-server?))
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 7")
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 10")
(rmt:open-qry-close-locally cmd (if rid rid 0) params))
;;DOT CASE11 [label="send_receive"];
;;DOT MUTEXLOCK -> CASE11 [label="else"]; {rank=same "case 11" CASE11};
;;DOT CASE11 -> "rmt:send-receive" [label="call failed"];
;;DOT CASE11 -> "RESULT" [label="call succeeded"];
;; not on homehost, do server query
(else
(mutex-unlock! *rmt-mutex*)
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 9")
(mutex-lock! *rmt-mutex*)
(let* ((conninfo (remote-conndat runremote))
(dat (case (remote-transport runremote)
|