You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@openjpa.apache.org by "Michael Pradel (JIRA)" <ji...@apache.org> on 2012/07/27 12:03:34 UTC
[jira] [Created] (OPENJPA-2243) Deadlock involving
FormatPreservingProperties
Michael Pradel created OPENJPA-2243:
---------------------------------------
Summary: Deadlock involving FormatPreservingProperties
Key: OPENJPA-2243
URL: https://issues.apache.org/jira/browse/OPENJPA-2243
Project: OpenJPA
Issue Type: Bug
Components: lib
Affects Versions: 2.2.0
Environment: All environments
Reporter: Michael Pradel
FormatPreservingProperties extends Properties, which is a thread-safe class, but it does not preserve the thread safety. This leads to surprising deadlocks if you have a reference of type Properties, because it may turn out to be not thread-safe (despite being documented as such).
Here's a simplified example that shows how we hit this bug:
final Properties p1 = new Properties();
final Properties p2 = createPropsWithDefault(p1);
p2.put(p2, p2);
Thread t1 = new Thread(new Runnable() {
public void run() { p2.remove(p1); }
});
Thread t2 = new Thread(new Runnable() {
public void run() { p2.stringPropertyNames(); }
});
t1.start();
t2.start();
try { t1.join(); t2.join();
} catch (InterruptedException e) { e.printStackTrace(); }
Properties createPropsWithDefault(Properties p) {
// return new Properties(p); // OK
return new FormatPreservingProperties(p); // leads to deadlock
}
If createPropsWithDefault() returns Properties, everything is OK (as it should be, because Properties is thread-safe). However, if it returns FormatPreservingProperties, we occasionally get a deadlock.
Are you aware of this inconsistency? It seems that the safest way of extending Properties is to make methods that override synchronized methods synchronized.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Assigned] (OPENJPA-2243) Deadlock involving
FormatPreservingProperties
Posted by "Albert Lee (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/OPENJPA-2243?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Albert Lee reassigned OPENJPA-2243:
-----------------------------------
Assignee: Albert Lee
> Deadlock involving FormatPreservingProperties
> ---------------------------------------------
>
> Key: OPENJPA-2243
> URL: https://issues.apache.org/jira/browse/OPENJPA-2243
> Project: OpenJPA
> Issue Type: Bug
> Components: lib
> Affects Versions: 2.2.0
> Environment: All environments
> Reporter: Michael Pradel
> Assignee: Albert Lee
> Attachments: OPENJPA-2243.patch
>
>
> FormatPreservingProperties extends Properties, which is a thread-safe class, but it does not preserve the thread safety. This leads to surprising deadlocks if you have a reference of type Properties, because it may turn out to be not thread-safe (despite being documented as such).
> Here's a simplified example that shows how we hit this bug:
> final Properties p1 = new Properties();
> final Properties p2 = createPropsWithDefault(p1);
> p2.put(p2, p2);
>
> Thread t1 = new Thread(new Runnable() {
> public void run() { p2.remove(p1); }
> });
> Thread t2 = new Thread(new Runnable() {
> public void run() { p2.stringPropertyNames(); }
> });
> t1.start();
> t2.start();
> try { t1.join(); t2.join();
> } catch (InterruptedException e) { e.printStackTrace(); }
> Properties createPropsWithDefault(Properties p) {
> // return new Properties(p); // OK
> return new FormatPreservingProperties(p); // leads to deadlock
> }
> If createPropsWithDefault() returns Properties, everything is OK (as it should be, because Properties is thread-safe). However, if it returns FormatPreservingProperties, we occasionally get a deadlock.
> Are you aware of this inconsistency? It seems that the safest way of extending Properties is to make methods that override synchronized methods synchronized.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Updated] (OPENJPA-2243) Deadlock involving
FormatPreservingProperties
Posted by "Albert Lee (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/OPENJPA-2243?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Albert Lee updated OPENJPA-2243:
--------------------------------
Patch Info: Patch Available
> Deadlock involving FormatPreservingProperties
> ---------------------------------------------
>
> Key: OPENJPA-2243
> URL: https://issues.apache.org/jira/browse/OPENJPA-2243
> Project: OpenJPA
> Issue Type: Bug
> Components: lib
> Affects Versions: 2.2.0
> Environment: All environments
> Reporter: Michael Pradel
> Assignee: Albert Lee
> Attachments: OPENJPA-2243.patch
>
>
> FormatPreservingProperties extends Properties, which is a thread-safe class, but it does not preserve the thread safety. This leads to surprising deadlocks if you have a reference of type Properties, because it may turn out to be not thread-safe (despite being documented as such).
> Here's a simplified example that shows how we hit this bug:
> final Properties p1 = new Properties();
> final Properties p2 = createPropsWithDefault(p1);
> p2.put(p2, p2);
>
> Thread t1 = new Thread(new Runnable() {
> public void run() { p2.remove(p1); }
> });
> Thread t2 = new Thread(new Runnable() {
> public void run() { p2.stringPropertyNames(); }
> });
> t1.start();
> t2.start();
> try { t1.join(); t2.join();
> } catch (InterruptedException e) { e.printStackTrace(); }
> Properties createPropsWithDefault(Properties p) {
> // return new Properties(p); // OK
> return new FormatPreservingProperties(p); // leads to deadlock
> }
> If createPropsWithDefault() returns Properties, everything is OK (as it should be, because Properties is thread-safe). However, if it returns FormatPreservingProperties, we occasionally get a deadlock.
> Are you aware of this inconsistency? It seems that the safest way of extending Properties is to make methods that override synchronized methods synchronized.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Updated] (OPENJPA-2243) Deadlock involving
FormatPreservingProperties
Posted by "Albert Lee (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/OPENJPA-2243?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Albert Lee updated OPENJPA-2243:
--------------------------------
Attachment: OPENJPA-2243.patch
> Deadlock involving FormatPreservingProperties
> ---------------------------------------------
>
> Key: OPENJPA-2243
> URL: https://issues.apache.org/jira/browse/OPENJPA-2243
> Project: OpenJPA
> Issue Type: Bug
> Components: lib
> Affects Versions: 2.2.0
> Environment: All environments
> Reporter: Michael Pradel
> Attachments: OPENJPA-2243.patch
>
>
> FormatPreservingProperties extends Properties, which is a thread-safe class, but it does not preserve the thread safety. This leads to surprising deadlocks if you have a reference of type Properties, because it may turn out to be not thread-safe (despite being documented as such).
> Here's a simplified example that shows how we hit this bug:
> final Properties p1 = new Properties();
> final Properties p2 = createPropsWithDefault(p1);
> p2.put(p2, p2);
>
> Thread t1 = new Thread(new Runnable() {
> public void run() { p2.remove(p1); }
> });
> Thread t2 = new Thread(new Runnable() {
> public void run() { p2.stringPropertyNames(); }
> });
> t1.start();
> t2.start();
> try { t1.join(); t2.join();
> } catch (InterruptedException e) { e.printStackTrace(); }
> Properties createPropsWithDefault(Properties p) {
> // return new Properties(p); // OK
> return new FormatPreservingProperties(p); // leads to deadlock
> }
> If createPropsWithDefault() returns Properties, everything is OK (as it should be, because Properties is thread-safe). However, if it returns FormatPreservingProperties, we occasionally get a deadlock.
> Are you aware of this inconsistency? It seems that the safest way of extending Properties is to make methods that override synchronized methods synchronized.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira