From 2b6624568622a409804a52cedcc2f7c15c420112 Mon Sep 17 00:00:00 2001
From: Maxim Cournoyer <maxim.cournoyer@gmail.com>
Date: Wed, 8 Dec 2021 17:25:11 -0500
Subject: [PATCH 4/5] services: telephony: Factorize bus polling logic.

* gnu/services/telephony.scm (jami-shepherd-services): Move bus readiness
polling logic to...
* gnu/build/dbus-service.scm (wait-for-bus-readiness): ... here.
(%dbus-system-bus): New variable.
* gnu/packages/freedesktop.scm (localed): Use it.
---
 gnu/build/dbus-service.scm   | 20 +++++++++++++++++++-
 gnu/packages/freedesktop.scm |  8 ++++----
 gnu/services/telephony.scm   | 10 +---------
 3 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/gnu/build/dbus-service.scm b/gnu/build/dbus-service.scm
index fd56c8dae7..3ffdebc04d 100644
--- a/gnu/build/dbus-service.scm
+++ b/gnu/build/dbus-service.scm
@@ -31,7 +31,9 @@ (define-module (gnu build dbus-service)
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-26)
   #:autoload (shepherd service) (fork+exec-command)
-  #:export (%send-dbus-binary
+  #:export (%dbus-system-bus
+
+            %send-dbus-binary
             %send-dbus-bus
             %send-dbus-user
             %send-dbus-group
@@ -44,11 +46,14 @@ (define-module (gnu build dbus-service)
             dbus-dict->alist
             dbus-array->list
 
+            wait-for-bus-readiness
             dbus-available-services
             dbus-service-available?
 
             with-retries))
 
+(define %dbus-system-bus "/var/run/dbus/system_bus_socket")
+
 ;;;
 ;;; Utilities.
 ;;;
@@ -232,6 +237,19 @@ (define* (send-dbus #:key service path interface method
 ;;; Higher-level, D-Bus-related procedures.
 ;;;
 
+(define* (wait-for-bus-readiness #:key (bus %dbus-system-bus)
+                                 (timeout 25))
+  "Wait until a connection can be opened to BUS.  An error is raised when
+TIMEOUT seconds elapse."
+  (let ((sock (socket PF_UNIX SOCK_STREAM 0)))
+    (with-retries timeout 1 (catch 'system-error
+                              (lambda ()
+                                (connect sock AF_UNIX bus)
+                                (close-port sock)
+                                #t)
+                              (lambda args
+                                #f)))))
+
 (define (dbus-available-services)
   "Return the list of available (acquired) D-Bus services."
   (let ((reply (parse-dbus-reply
diff --git a/gnu/packages/freedesktop.scm b/gnu/packages/freedesktop.scm
index eba06600b2..5f9cbd8438 100644
--- a/gnu/packages/freedesktop.scm
+++ b/gnu/packages/freedesktop.scm
@@ -57,6 +57,7 @@ (define-module (gnu packages freedesktop)
   #:use-module (guix build-system perl)
   #:use-module (guix build-system python)
   #:use-module (guix build-system glib-or-gtk)
+  #:use-module ((gnu build dbus-service) #:select (%dbus-system-bus))
   #:use-module (gnu packages)
   #:use-module (gnu packages acl)
   #:use-module (gnu packages admin)
@@ -730,20 +731,19 @@ (define-public localed
               (file-name (git-file-name name version))
               (modules '((guix build utils)))
               (snippet
-               '(begin
+               `(begin
                   ;; Connect to the right location for our D-Bus daemon.
                   (substitute* '("src/basic/def.h"
                                  "src/libsystemd/sd-bus/sd-bus.c"
                                  "src/stdio-bridge/stdio-bridge.c")
                     (("/run/dbus/system_bus_socket")
-                     "/var/run/dbus/system_bus_socket"))
+                     ,%dbus-system-bus))
 
                   ;; Don't insist on having systemd as PID 1 (otherwise
                   ;; 'localectl' would exit without doing anything.)
                   (substitute* "src/shared/bus-util.c"
                     (("sd_booted\\(\\)")
-                     "(1)"))
-                  #t))
+                     "(1)"))))
               (patches (search-patches "localed-xorg-keyboard.patch"))))
     (build-system meson-build-system)
     (arguments
diff --git a/gnu/services/telephony.scm b/gnu/services/telephony.scm
index f6501b6423..0ceebbc6d6 100644
--- a/gnu/services/telephony.scm
+++ b/gnu/services/telephony.scm
@@ -549,15 +549,7 @@ (define pid
                   ;; needed if we were using a PID file, but providing it via a
                   ;; customized config file with <pidfile> would not override
                   ;; the one inherited from the base config of D-Bus.
-                  (let ((sock (socket PF_UNIX SOCK_STREAM 0)))
-                    (with-retries 20 1 (catch 'system-error
-                                         (lambda ()
-                                           (connect sock AF_UNIX
-                                                    "/var/run/jami/bus")
-                                           (close-port sock)
-                                           #t)
-                                         (lambda args
-                                           #f))))
+                  (wait-for-bus-readiness #:bus "/var/run/jami/bus")
 
                   pid))
              (stop #~(make-kill-destructor)))
-- 
2.34.0