The man page contains a trivial bug that's discussed here:
https://stackoverflow.com/q/59628958
The patch was against latest master (commit:
f7d3e6aac109528e6f22f7c9cc5439a6ceeaa7de) and tested on Ubuntu
4.15.0-72-generic kernel.
--
Regards,
Ponnuvel P
From 3ab2e9d969c63a4f6cbca415a6a3ac1763449fd3 Mon Sep 17 00:00:00 2001
From: Ponnuvel Palaniyappan <pponnuvel@xxxxxxxxx>
Date: Wed, 8 Jan 2020 09:03:07 +0000
Subject: [PATCH] futex.2: Fix a bug in the example
---
man2/futex.2 | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/man2/futex.2 b/man2/futex.2
index 8a003e2be..01b36cac3 100644
--- a/man2/futex.2
+++ b/man2/futex.2
@@ -1797,8 +1797,8 @@ fwait(int *futexp)
while (1) {
/* Is the futex available? */
- const int zero = 0;
- if (atomic_compare_exchange_strong(futexp, &zero, 1))
+ const int one = 1;
+ if (atomic_compare_exchange_strong(futexp, &one, 0))
break; /* Yes */
/* Futex is not available; wait */
@@ -1820,8 +1820,8 @@ fpost(int *futexp)
/* atomic_compare_exchange_strong() was described in comments above */
- const int one = 1;
- if (atomic_compare_exchange_strong(futexp, &one, 0)) {
+ const int zero = 0;
+ if (atomic_compare_exchange_strong(futexp, &zero, 1)) {
s = futex(futexp, FUTEX_WAKE, 1, NULL, NULL, 0);
if (s == \-1)
errExit("futex\-FUTEX_WAKE");
--
2.17.1
