diff options
| author | Jethro Beekman <jethro@fortanix.com> | 2022-02-14 10:35:56 +0100 |
|---|---|---|
| committer | Florian Westphal <fw@strlen.de> | 2022-02-15 23:42:05 +0100 |
| commit | 07e2107ef0cbc1b81864c3c0f0ef297a9dfff44d (patch) | |
| tree | eba64618054cf690c69159d3f7e95f4429e19912 /iptables/tests/shell/testcases/ipt-restore | |
| parent | a3980769541f6deb8d7b185de488dec6f40092f1 (diff) | |
xshared: Implement xtables lock timeout using signals
Previously, if a lock timeout is specified using `-wN `, flock() is
called using LOCK_NB in a loop with a sleep. This results in two issues.
The first issue is that the process may wait longer than necessary when
the lock becomes available. For this the `-W` option was added, but this
requires fine-tuning.
The second issue is that if lock contention is high, invocations using
`-w` (without a timeout) will always win lock acquisition from
invocations that use `-w N`. This is because invocations using `-w` are
actively waiting on the lock whereas those using `-w N` only check from
time to time whether the lock is free, which will never be the case.
This patch removes the sleep loop and deprecates the `-W` option (making
it non-functional). Instead, flock() is always called in a blocking
fashion, but the alarm() function is used with a non-SA_RESTART signal
handler to cancel the system call.
Signed-off-by: Jethro Beekman <jethro@fortanix.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Diffstat (limited to 'iptables/tests/shell/testcases/ipt-restore')
| -rwxr-xr-x | iptables/tests/shell/testcases/ipt-restore/0002-parameters_0 | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/iptables/tests/shell/testcases/ipt-restore/0002-parameters_0 b/iptables/tests/shell/testcases/ipt-restore/0002-parameters_0 index 5c8748ec..d632cbc0 100755 --- a/iptables/tests/shell/testcases/ipt-restore/0002-parameters_0 +++ b/iptables/tests/shell/testcases/ipt-restore/0002-parameters_0 @@ -2,7 +2,7 @@ set -e -# make sure wait and wait-interval options are accepted +# make sure wait options are accepted clean_tempfile() { @@ -18,4 +18,3 @@ tmpfile=$(mktemp) || exit 1 $XT_MULTI iptables-save -f $tmpfile $XT_MULTI iptables-restore $tmpfile $XT_MULTI iptables-restore -w 5 $tmpfile -$XT_MULTI iptables-restore -w 5 -W 1 $tmpfile |