<AWT Dev> sun.awt.X11 logs still using String + (waste)

[Laurent Bourgès]

Hi antony,

2 different things:
1/ PlatformLogger was patched (doLog method) to avoid string operations
(message formatting) for disabled logs (patch submiited on JDK8 and JDK7u):
http://mail.openjdk.java.net/pipermail/jdk7u-dev/2012-April/002751.html

2/ I looked 2 hours ago on JDK7u AND JDK8 source codes and both still have:
- log statements WITHOUT log level check : if
(log.isLoggable(PlatformLogger.FINE)) log.fine(...);
- string operations (+) in log calls that could be improved using the
message format syntax (String + args): for example, avoid using
PlatformLogger.fine(String + ...) in favor of using
PlatformLogger.fine(String msg, Object... params)

I reported in my previous mail several cases where the isLoggable() call is
missing and leads to useless String operations but also method calls
(Component.paramString() for example).

Finally, I also provided other possible cases (using grep); maybe there is
a better alternative to find all occurences of String operations in log
calls.

Regards,
Laurent

2013/3/18 Anthony Petrov <anthony.petrov at oracle.com>

> Hi Laurent,
>
> Normally we fix an issue in JDK 8 first, and then back-port the fix to a
> 7u release. You're saying that in JDK 8 the problem isn't reproducible
> anymore. Can you please investigate (using the Mercurial history log) what
> exact fix resolved it in JDK 8?
>
> --
> best regards,
> Anthony
>
> On 03/18/13 15:09, Laurent Bourgès wrote:
>
>> Dear all,
>>
>> I run recently netbeans profiler on my swing application (Aspro2:
>> http://www.jmmc.fr/aspro) under linux x64 platform and I figured out
>> that a lot of char[] instances are coming from String + operator called
>> by sun.awt.X11 code.
>>
>> I looked at PlatformLogger source code but found not way to disable it
>> completely: maybe an empty logger implementation could be interesting to
>> be used during profiling or normal use (not debugging).
>> Apparently JDK8 provides some patchs to avoid String creation when the
>> logger is disabled (level).
>>
>> However, I looked also to the sun.awt code (jdk7u repository) to see the
>> origin of the string allocations:
>> XDecoratedPeer:
>>      public void handleFocusEvent(XEvent xev) {
>> ...
>> *        focusLog.finer("Received focus event on shell: " + xfe);
>> *   }
>>
>>      public boolean requestWindowFocus(long time, boolean timeProvided) {
>> ...
>> *            focusLog.finest("Real native focused window: " +
>> realNativeFocusedWindow +
>> "\nKFM's focused window: " + focusedWindow);
>> *...
>> *        focusLog.fine("Requesting focus to " + (this == toFocus ? "this
>> window" : toFocus));
>> *...
>> }
>>
>> XBaseWindow:
>>      public void xSetBounds(int x, int y, int width, int height) {
>> ...
>> *        insLog.fine("Setting bounds on " + this + " to (" + x + ", " +
>> y + "), " + width + "x" + height);
>> *}
>>
>> XNetProtocol:
>>      boolean doStateProtocol() {
>> ...
>> *        stateLog.finer("**doStateProtocol() returns " + res);
>> *}
>>
>> XSystemTrayPeer:
>>      XSystemTrayPeer(SystemTray target) {
>> ...
>> *        log.fine(" check if system tray is available. selection owner:
>> " + selection_owner);
>> *}
>>      void addTrayIcon(XTrayIconPeer tiPeer) throws AWTException {
>> ...
>> *        log.fine(" send SYSTEM_TRAY_REQUEST_DOCK message to owner: " +
>> selection_owner);
>> *}
>>
>> XFramePeer:
>>      public void handlePropertyNotify(XEvent xev) {
>> ...
>>              stateLog.finer("State is the same: " + state);
>> }
>>
>> However I only give here few cases but certainly others are still
>> present in the source code; maybe findbugs or netbeans warnings could
>> help you finding all of them.
>>
>> I advocate the amount of waste (GC) is not very important but String
>> conversion are also calling several toString() methods that can be
>> costly (event, Frame, window ...)
>>
>> Finally, I ran few grep commands on the sun.awt.X11 code (jdk7u) and you
>> can look at them to see all string + operations related to log statements.
>>
>> PS: I may help fixing the source code but I have no idea how to
>> collaborate (provide a patch ?)
>>
>> Regards,
>> Laurent Bourgès
>>
>
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