From: Andrew Tropin <andrew@trop.in>
To: guile-devel@gnu.org
Cc: Andrew Tropin <andrew@trop.in>
Subject: [PATCH v3] Add atomic-box-update! function to (ice-9 atomic)
Date: Thu, 24 Aug 2023 19:38:39 +0400 [thread overview]
Message-ID: <20230824154213.14514-1-andrew@trop.in> (raw)
In-Reply-To: <87jzvztzi3.fsf@trop.in>
* module/ice-9/atomic.scm (atomic-box-update!): New variable.
---
Changes since v2:
1. Removed unecessary atomic-box-ref.
2. Update docstring to imperative mood.
module/ice-9/atomic.scm | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/module/ice-9/atomic.scm b/module/ice-9/atomic.scm
index 2a8af901d..aaa7238fc 100644
--- a/module/ice-9/atomic.scm
+++ b/module/ice-9/atomic.scm
@@ -25,7 +25,8 @@
atomic-box-ref
atomic-box-set!
atomic-box-swap!
- atomic-box-compare-and-swap!))
+ atomic-box-compare-and-swap!
+ atomic-box-update!))
(eval-when (expand load eval)
(load-extension (string-append "libguile-" (effective-version))
@@ -36,3 +37,14 @@
(add-interesting-primitive! 'atomic-box-set!)
(add-interesting-primitive! 'atomic-box-swap!)
(add-interesting-primitive! 'atomic-box-compare-and-swap!))
+
+(define (atomic-box-update! box proc)
+ "Atomically update the value of BOX to (PROC BOX-VALUE) and return the
+new value. PROC may be called multiple times, and thus PROC should be
+free of side effects."
+ (let loop ((old-value (atomic-box-ref box)))
+ (let* ((new-value (proc old-value proc-args))
+ (cas-value (atomic-box-compare-and-swap! box old-value new-value)))
+ (if (eq? old-value cas-value)
+ new-value
+ (loop cas-value)))))
--
2.41.0
next prev parent reply other threads:[~2023-08-24 15:38 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-19 12:20 [PATCH] Add atomic-box-update! function to (ice-9 atomic) Andrew Tropin
2023-06-21 9:06 ` Jean Abou Samra
2023-06-21 9:06 ` Jean Abou Samra
2023-06-21 16:46 ` Andrew Tropin
2023-06-21 16:54 ` Jean Abou Samra
2023-06-22 3:59 ` Andrew Tropin
2023-06-22 5:21 ` Philip McGrath
2023-06-22 9:02 ` Andrew Tropin
2023-06-22 21:42 ` Philip McGrath
2023-07-13 3:30 ` Andrew Tropin
2023-08-22 10:51 ` Andrew Tropin
2023-08-22 10:59 ` [PATCH v2] " Andrew Tropin
2023-08-22 17:51 ` Maxime Devos
2023-08-24 16:19 ` Andrew Tropin
2023-08-24 15:38 ` Andrew Tropin [this message]
2023-09-20 8:17 ` [PATCH v4] " Andrew Tropin
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