From: Taylor R Campbell <campbell@mumble.net>
Date: Wed, 29 May 2019 04:24:40 +0000 (+0000)
Subject: Block interrupts, _then_ lock.
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=4d8be78a84614f58e409e1078f9b0ba1212784a7;p=mit-scheme.git

Block interrupts, _then_ lock.

Otherwise an interrupt might try to acquire the lock while we already
hold it, leading to deadlock.

(cherry picked from commit 9a3417ac7a5f294fbbda397086d890029d45343a)
---

diff --git a/src/runtime/gcfinal.scm b/src/runtime/gcfinal.scm
index 8bee6bc69..344373137 100644
--- a/src/runtime/gcfinal.scm
+++ b/src/runtime/gcfinal.scm
@@ -111,10 +111,10 @@ USA.
 	    (loop (cdr items) items))))))
 
 (define (with-finalizer-lock finalizer thunk)
-  (with-thread-mutex-lock
-      (gc-finalizer-mutex finalizer)
-    (lambda ()
-      (without-interruption thunk))))
+  (without-interruption
+   (lambda ()
+     (with-thread-mutex-lock (gc-finalizer-mutex finalizer)
+       thunk))))
 
 (define (with-gc-finalizer-lock finalizer thunk)
   (guarantee-gc-finalizer finalizer 'with-gc-finalizer-lock)