From: Matthias Kruk <m@m10k.eu>
Date: Mon, 14 Feb 2022 10:52:14 +0000 (+0900)
Subject: include/mutex: Use $$ instead of $BASHPID to identify the owner
X-Git-Url: https://git.corax.cc/?a=commitdiff_plain;h=9a2c3df836641d552e6223fafe623e7e9e95819d;p=toolbox

include/mutex: Use $$ instead of $BASHPID to identify the owner

The mutex module uses $BASHPID to identify the owner of a mutex,
causing scripts to be unable to unlock a mutex that was created in a
subshell (which is what happens when using the ipc module).

This commit changes the mutex module to use $$ to identify the owner
of a mutex, allowing child processes to unlock their parent's mutexes
and vice-versa.
---

diff --git a/include/mutex.sh b/include/mutex.sh
index 1d04ce0..32ee320 100644
--- a/include/mutex.sh
+++ b/include/mutex.sh
@@ -23,7 +23,7 @@ __init() {
 mutex_trylock() {
 	local lock="$1"
 
-	if ! ln -s "$BASHPID" "$lock" &> /dev/null; then
+	if ! ln -s "$$" "$lock" &> /dev/null; then
 		return 1
 	fi
 
@@ -58,7 +58,7 @@ mutex_unlock() {
 		return 1
 	fi
 
-	if (( owner != BASHPID )); then
+	if (( owner != $$ )); then
 		return 2
 	fi