From: Matthias Kruk <matthias.kruk@miraclelinux.com>
Date: Fri, 18 Jun 2021 07:15:24 +0000 (+0900)
Subject: include/{mutex,wmutex,queue,sem}: Fix timeout behavior of blocking calls
X-Git-Url: https://git.corax.cc/?a=commitdiff_plain;h=b94ce8914852facec4ce7df177b9eadf8aea8ec5;p=toolbox

include/{mutex,wmutex,queue,sem}: Fix timeout behavior of blocking calls

Because of a bug in the timeout handling, the mutex_lock(),
wmutex_lock(), queue_get(), and sem_wait() functions wait forever if a
positive timeout is specified.
This commit changes the behavior so that the functions will wait
forever if the timeout is -1 or omitted, return immediately if the
timeout is zero, or otherwise wait for the specified number of seconds.
---

diff --git a/include/mutex.sh b/include/mutex.sh
index eb8de81..1d04ce0 100644
--- a/include/mutex.sh
+++ b/include/mutex.sh
@@ -34,12 +34,12 @@ mutex_lock() {
 	local lock="$1"
 	local -i timeout="$2"
 
-	local -i remaining
-
-	remaining="$timeout"
+	if (( $# < 2 )); then
+		timeout=-1
+	fi
 
 	while ! mutex_trylock "$lock"; do
-		if (( timeout != 0 && --remaining < 0 )); then
+		if (( timeout-- == 0 )); then
 			return 1
 		fi
 
diff --git a/include/queue.sh b/include/queue.sh
index c1c8b9c..fbcb8ff 100644
--- a/include/queue.sh
+++ b/include/queue.sh
@@ -387,6 +387,10 @@ queue_get() {
 	local item
 	local err
 
+	if (( $# < 2 )); then
+		timeout=-1
+	fi
+
 	sem=$(_queue_get_sem "$queue")
 	mutex=$(_queue_get_mutex "$queue")
 	data=$(_queue_get_data "$queue")
diff --git a/include/sem.sh b/include/sem.sh
index 8446901..7189ab7 100644
--- a/include/sem.sh
+++ b/include/sem.sh
@@ -191,6 +191,10 @@ sem_wait() {
 	local counter
 	local err
 
+	if (( $# < 2 )); then
+		timeout=-1
+	fi
+
 	waitlock=$(_sem_get_waitlock "$name")
 	countlock=$(_sem_get_countlock "$name")
 	counter=$(_sem_get_counter "$name")
diff --git a/include/wmutex.sh b/include/wmutex.sh
index 5b8593f..3ce6f2d 100644
--- a/include/wmutex.sh
+++ b/include/wmutex.sh
@@ -34,12 +34,12 @@ wmutex_lock() {
 	local lock="$1"
 	local -i timeout="$2"
 
-	local -i remaining
-
-	remaining="$timeout"
+	if (( $# < 2 )); then
+		timeout=-1
+	fi
 
 	while ! wmutex_trylock "$lock"; do
-		if (( timeout != 0 && --remaining < 0 )); then
+		if (( timeout-- == 0 )); then
 			return 1
 		fi