Handle EPIPE in tcp driver

syndicate/drivers/tcp.rkt

@@ -16,6 +16,8 @@
 (require syndicate/schemas/gen/tcp)
 (require syndicate/schemas/gen/dataspace-patterns)
 
+(require (for-syntax racket/base))
+
 (define-logger syndicate/drivers/tcp)
 
 (define (spawn-tcp-driver ds)
@@ -108,17 +110,33 @@
          (turn! facet (lambda () (send-data target bs)))
          (loop))))))
 
+(define-syntax (EPIPE stx)
+  (local-require ffi/unsafe)
+  (define errno-value (cons (lookup-errno 'EPIPE) 'posix))
+  (syntax-case stx ()
+    [(_) #`'#,errno-value]))
+
+(define (with-stop-current-facet-on-epipe operation thunk)
+  (with-handlers ([(lambda (e)
+                     (and (exn:fail:network:errno? e)
+                          (equal? (exn:fail:network:errno-errno e) (EPIPE))))
+                   (lambda (e)
+                     (log-syndicate/drivers/tcp-debug "epipe while ~a" operation)
+                     (stop-current-facet))])
+    (thunk)))
+
 (define (outbound-relay name o)
   (define flush-pending #f)
   (lambda (payload)
     (log-syndicate/drivers/tcp-debug "outbound data ~v for ~v" payload name)
-    (write-bytes payload o)
+    (with-stop-current-facet-on-epipe 'writing (lambda () (write-bytes payload o)))
     (when (not flush-pending)
       (set! flush-pending #t)
       (facet-on-end-of-turn! this-facet
                              (lambda ()
                                (set! flush-pending #f)
-                               (flush-output o))))))
+                               (with-stop-current-facet-on-epipe 'flushing
+                                 (lambda () (flush-output o))))))))
 
 (define (read-bytes-avail input-port #:limit [limit 65536])
   (define buffer (make-bytes limit))