From e8cb1281e76dba0692594491d7e95e3ed85761c3 Mon Sep 17 00:00:00 2001
From: Hannes Mehnert <hannes@mehnert.org>
Date: Thu, 28 Mar 2024 16:22:47 +0100
Subject: [PATCH] Revert "Use backoff to be sure to be in sync when we update
 sources (@reynir)"

This reverts commit 37267b35227ebc7fe9aee19a3375b7b5a7b9d560.
---
 mirage-crypto-rng.opam |  1 -
 rng/dune               |  2 +-
 rng/entropy.ml         | 13 ++++---------
 3 files changed, 5 insertions(+), 11 deletions(-)

diff --git a/mirage-crypto-rng.opam b/mirage-crypto-rng.opam
index 35acbbd7..b8f4471d 100644
--- a/mirage-crypto-rng.opam
+++ b/mirage-crypto-rng.opam
@@ -18,7 +18,6 @@ depends: [
   "dune-configurator" {>= "2.0.0"}
   "duration"
   "logs"
-  "backoff"
   "mirage-crypto" {=version}
   "digestif" {>= "1.1.4"}
   "ounit2" {with-test}
diff --git a/rng/dune b/rng/dune
index 8ae2c924..e70f9743 100644
--- a/rng/dune
+++ b/rng/dune
@@ -1,5 +1,5 @@
 (library
  (name mirage_crypto_rng)
  (public_name mirage-crypto-rng)
- (libraries mirage-crypto backoff digestif)
+ (libraries mirage-crypto digestif)
  (private_modules entropy fortuna hmac_drbg rng))
diff --git a/rng/entropy.ml b/rng/entropy.ml
index 46bf492f..008bdb80 100644
--- a/rng/entropy.ml
+++ b/rng/entropy.ml
@@ -55,15 +55,10 @@ let _sources = Atomic.make S.empty
 type source = Rng.source
 
 let register_source name =
-  let rec go backoff =
-    let seen = Atomic.get _sources in
-    let n = S.cardinal seen in
-    let source = (n, name) in
-    let after = S.add source (Atomic.get _sources) in
-    if Atomic.compare_and_set _sources seen after = false
-    then go (Backoff.once backoff)
-    else source in
-  go Backoff.default
+  let n = S.cardinal (Atomic.get _sources) in
+  let source = (n, name) in
+  Atomic.set _sources (S.add source (Atomic.get _sources));
+  source
 
 let id (idx, _) = idx