Hi!
Starting to play with Goblins I had some trouble creating a timer.
Thanks to the kind help on IRC, I was able to create this example.
There are two things I had to discover: how to "sleep" in Goblins and
the fact that in some(?) cases you need do to some extra work to keep a
vat alive/running, and how to do that. I tried several kind of loops
and other stuff until I found conditions.
Possibly others can find use for it.
Greetings,
Janneke
>From 3be0f50c30e5b9e8250d5653abd9027c8b8feccc Mon Sep 17 00:00:00 2001
From: Janneke Nieuwenhuizen <jann...@gnu.org>
Date: Thu, 6 Mar 2025 21:51:25 +0100
Subject: [PATCH guile-goblins] examples: Add timer.
---
Makefile.am | 1 +
examples/timer.scm | 60 ++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 61 insertions(+)
create mode 100644 examples/timer.scm
diff --git a/Makefile.am b/Makefile.am
index 330b87d..4ee8de5 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -196,6 +196,7 @@ js/goblins.wasm: js/goblins.scm
js: js/goblins.wasm js/reflect.js js/reflect.wasm js/wtf8.wasm
EXAMPLES = examples/cauldron.scm \
+ examples/timer.scm \
examples/try-captp-onion.scm \
examples/try-base-netlayer.scm \
examples/prelay-server.scm
diff --git a/examples/timer.scm b/examples/timer.scm
new file mode 100644
index 0000000..dd6fd2d
--- /dev/null
+++ b/examples/timer.scm
@@ -0,0 +1,60 @@
+;;; This file is part of Guile Goblins.
+
+;;; Copyright 2025 Jannekxe Nieuwenhuizen <jann...@gnu.org>
+;;;
+;;; Licensed under the Apache License, Version 2.0 (the "License");
+;;; you may not use this file except in compliance with the License.
+;;; You may obtain a copy of the License at
+;;;
+;;; http://www.apache.org/licenses/LICENSE-2.0
+;;;
+;;; Unless required by applicable law or agreed to in writing, software
+;;; distributed under the License is distributed on an "AS IS" BASIS,
+;;; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+;;; See the License for the specific language governing permissions and
+;;; limitations under the License.
+
+(use-modules (srfi srfi-26)
+ ((fibers) #:select ((sleep . fibers:sleep))) ;avoid #:replace warning
+ ((fibers conditions) #:select (make-condition signal-condition! wait))
+ ((goblins) #:select ((spawn . spawn-actor) ;avoid #:replace warning
+ ($ . $$) ;support (ice-9 match) ($ <record-type>)
+ <-
+ define-actor
+ on
+ spawn-vat with-vat))
+ ((goblins actor-lib methods) #:select (methods))
+ ((goblins vat) #:select (spawn-fibrous-vow)))
+
+(define (timeout-vow duration)
+ (spawn-fibrous-vow (lambda _ (fibers:sleep duration) #t)))
+
+(define-actor (^timer bcom #:key canceled?)
+ (methods
+ ((create target timeout)
+ (on (timeout-vow timeout)
+ (lambda _ (unless canceled? (<- target 'timeout target timeout))))
+ (bcom (^timer bcom)))
+ ((cancel)
+ (bcom (^timer bcom #:canceled? #t)))))
+
+(define-actor (^handler bcom thunk #:key timer)
+ (methods
+ ((timeout self timeout)
+ (thunk)
+ (when timer
+ (<- timer 'create self timeout)))))
+
+(let ((vat (spawn-vat))
+ (exit? (make-condition)))
+ (with-vat vat
+ (let* ((timer (spawn-actor ^timer))
+ (boom (spawn-actor ^handler (cute display "boom\n") #:timer timer))
+ (clap (spawn-actor ^handler (cute display "*clap*\n") #:timer timer))
+ (exit (spawn-actor ^handler (cute signal-condition! exit?))))
+ ($$ timer 'create boom 0.29)
+ ($$ timer 'create clap 0.6)
+ (on (timeout-vow 1) (lambda _ ($$ timer 'cancel)))
+ ($$ timer 'create exit 2.5)))
+ (wait exit?)
+ (display "That's all folks!\n"))
--
2.47.1
--
Janneke Nieuwenhuizen <jann...@gnu.org> | GNU LilyPond https://LilyPond.org
Freelance IT https://www.JoyOfSource.com | Avatar® https://AvatarAcademy.com
