[jira] [Commented] (ZOOKEEPER-3186) bug in barrier example code
[
https://issues.apache.org/jira/browse/ZOOKEEPER-3186?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16695474#comment-16695474
]
Michael K. Edwards commented on ZOOKEEPER-3186:
---
Appropriate for 3.5.5?
> bug in barrier example code
> ---
>
> Key: ZOOKEEPER-3186
> URL: https://issues.apache.org/jira/browse/ZOOKEEPER-3186
> Project: ZooKeeper
> Issue Type: Bug
> Components: documentation
>Reporter: cheng pan
>Priority: Major
>
> the code given in the documentation
> {code:java}
> while (true) {
> synchronized (mutex) {
> List list = zk.getChildren(root, true);
> if (list.size() < size) {
> mutex.wait();
> } else {
> return true;
> }
> }
> }
> {code}
> When some nodes are not ready, the code calls mutex.wait() and waits for the
> watcher event to call mutex.notify() to wake it up. The problem is, we can't
> guarantee that mutex.notify() will definitely happen after mutex.wait(),
> which will cause client is stuck.
> The solution might be CountDownLatch?
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[jira] [Commented] (ZOOKEEPER-3186) bug in barrier example code
[
https://issues.apache.org/jira/browse/ZOOKEEPER-3186?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16683331#comment-16683331
]
cheng pan commented on ZOOKEEPER-3186:
--
[~maoling] :(Sorry, I forgot to submit it, now you can see it
> bug in barrier example code
> ---
>
> Key: ZOOKEEPER-3186
> URL: https://issues.apache.org/jira/browse/ZOOKEEPER-3186
> Project: ZooKeeper
> Issue Type: Bug
> Components: documentation
>Reporter: cheng pan
>Priority: Major
>
> the code given in the documentation
> {code:java}
> while (true) {
> synchronized (mutex) {
> List list = zk.getChildren(root, true);
> if (list.size() < size) {
> mutex.wait();
> } else {
> return true;
> }
> }
> }
> {code}
> When some nodes are not ready, the code calls mutex.wait() and waits for the
> watcher event to call mutex.notify() to wake it up. The problem is, we can't
> guarantee that mutex.notify() will definitely happen after mutex.wait(),
> which will cause client is stuck.
> The solution might be CountDownLatch?
--
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(v7.6.3#76005)
[jira] [Commented] (ZOOKEEPER-3186) bug in barrier example code
[
https://issues.apache.org/jira/browse/ZOOKEEPER-3186?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16683314#comment-16683314
]
maoling commented on ZOOKEEPER-3186:
[~pancheng]
Pardon me,where can i find your review comments?
> bug in barrier example code
> ---
>
> Key: ZOOKEEPER-3186
> URL: https://issues.apache.org/jira/browse/ZOOKEEPER-3186
> Project: ZooKeeper
> Issue Type: Bug
> Components: documentation
>Reporter: cheng pan
>Priority: Major
>
> the code given in the documentation
> {code:java}
> while (true) {
> synchronized (mutex) {
> List list = zk.getChildren(root, true);
> if (list.size() < size) {
> mutex.wait();
> } else {
> return true;
> }
> }
> }
> {code}
> When some nodes are not ready, the code calls mutex.wait() and waits for the
> watcher event to call mutex.notify() to wake it up. The problem is, we can't
> guarantee that mutex.notify() will definitely happen after mutex.wait(),
> which will cause client is stuck.
> The solution might be CountDownLatch?
--
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[jira] [Commented] (ZOOKEEPER-3186) bug in barrier example code
[
https://issues.apache.org/jira/browse/ZOOKEEPER-3186?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16682266#comment-16682266
]
cheng pan commented on ZOOKEEPER-3186:
--
[~maoling] I have seen your code, it does solve the problem, but I added a
review, please check it on github
> bug in barrier example code
> ---
>
> Key: ZOOKEEPER-3186
> URL: https://issues.apache.org/jira/browse/ZOOKEEPER-3186
> Project: ZooKeeper
> Issue Type: Bug
> Components: documentation
>Reporter: cheng pan
>Priority: Major
>
> the code given in the documentation
> {code:java}
> while (true) {
> synchronized (mutex) {
> List list = zk.getChildren(root, true);
> if (list.size() < size) {
> mutex.wait();
> } else {
> return true;
> }
> }
> }
> {code}
> When some nodes are not ready, the code calls mutex.wait() and waits for the
> watcher event to call mutex.notify() to wake it up. The problem is, we can't
> guarantee that mutex.notify() will definitely happen after mutex.wait(),
> which will cause client is stuck.
> The solution might be CountDownLatch?
--
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(v7.6.3#76005)
[jira] [Commented] (ZOOKEEPER-3186) bug in barrier example code
[
https://issues.apache.org/jira/browse/ZOOKEEPER-3186?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16681125#comment-16681125
]
maoling commented on ZOOKEEPER-3186:
[~pancheng]
Thanks for reporting this issue.I had fixed this bug in the
[ZOOKEEPER-1011|https://github.com/apache/zookeeper/pull/618] which had not
been reviewed and merged.
I will nudge this issue.
h1.
> bug in barrier example code
> ---
>
> Key: ZOOKEEPER-3186
> URL: https://issues.apache.org/jira/browse/ZOOKEEPER-3186
> Project: ZooKeeper
> Issue Type: Bug
> Components: documentation
>Reporter: cheng pan
>Priority: Major
>
> the code given in the documentation
> {code:java}
> while (true) {
> synchronized (mutex) {
> List list = zk.getChildren(root, true);
> if (list.size() < size) {
> mutex.wait();
> } else {
> return true;
> }
> }
> }
> {code}
> When some nodes are not ready, the code calls mutex.wait() and waits for the
> watcher event to call mutex.notify() to wake it up. The problem is, we can't
> guarantee that mutex.notify() will definitely happen after mutex.wait(),
> which will cause client is stuck.
> The solution might be CountDownLatch?
--
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