Add a utility thread pool

And use this to read derivations.

2 files changed, 29 insertions, 6 deletions

diff --git a/guix-build-coordinator/client-communication.scm b/guix-build-coordinator/client-communication.scm
index 3d780c4..354cb31 100644
--- a/guix-build-coordinator/client-communication.scm
+++ b/guix-build-coordinator/client-communication.scm
@@ -65,7 +65,8 @@
 (define (start-client-request-server secret-key-base
                                      host
                                      port
-                                     build-coordinator)
+                                     build-coordinator
+                                     utility-thread-pool-channel)
   (run-server/patched
    (lambda (request body)
      (log-msg (build-coordinator-logger build-coordinator)
@@ -80,7 +81,8 @@
                                (uri-path (request-uri request))))
                         body
                         secret-key-base
-                        build-coordinator)))
+                        build-coordinator
+                        utility-thread-pool-channel)))
    #:host host
    #:port port))
 
@@ -88,7 +90,8 @@
                     method-and-path-components
                     raw-body
                     secret-key-base
-                    build-coordinator)
+                    build-coordinator
+                    utility-thread-pool-channel)
   (define datastore
     (build-coordinator-datastore build-coordinator))
 
@@ -483,7 +486,11 @@
                (substitute-derivation store
                                       derivation-file
                                       #:substitute-urls substitute-urls)))
-           (read-derivation-from-file* derivation-file))
+           ;; Read the derivation in a thread to avoid blocking fibers
+           (call-with-worker-thread
+            utility-thread-pool-channel
+            (lambda ()
+              (read-derivation-from-file* derivation-file))))
 
          (let ((submit-build-result
                 (call-with-delay-logging
diff --git a/guix-build-coordinator/coordinator.scm b/guix-build-coordinator/coordinator.scm
index 2d7f3d9..59891d1 100644
--- a/guix-build-coordinator/coordinator.scm
+++ b/guix-build-coordinator/coordinator.scm
@@ -504,7 +504,22 @@
     ;; to run-fibers being called.
     (let ((output-hash-channel
            (make-output-hash-channel
-            build-coordinator)))
+            build-coordinator))
+
+          (utility-thread-pool-channel
+           (make-worker-thread-channel
+            (const '())
+            #:name "utility"
+            #:parallelism 6
+            #:delay-logger
+            (lambda (seconds-delayed)
+              (log-delay "utility thread channel"
+                         seconds-delayed)
+              (when (> seconds-delayed 0.1)
+                (format
+                 (current-error-port)
+                 "warning: utility thread channel delayed by ~1,2f seconds~%"
+                 seconds-delayed))))))
 
       (let ((finished? (make-condition)))
         (call-with-sigint
@@ -575,7 +590,8 @@
                secret-key-base
                (uri-host client-communication-uri)
                (uri-port client-communication-uri)
-               build-coordinator)
+               build-coordinator
+               utility-thread-pool-channel)
 
               ;; Guile seems to just stop listening on ports, so try to
               ;; monitor that internally and just quit if it happens